DISTURBANCE COMPENSATION FOR CHARGED PARTICLE BEAM DEVICES

Abstract

Charged particle beam devices, e.g., for repair tasks, are subject to disturbances. A sensor output of one or more sensors is used to compensate the disturbances, e.g., while executing a manipulation mode for repairing defects on a lithography mask.

Claims

1. A charged particle beam repair device comprising a beam source, a beam deflection unit, a precursor gas source, and a sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage, the charged particle beam repair device comprising: multiple sensors configured to measure multiple disturbances of multiple physical quantities that each affect a beam offset of the beam on the sample stage, and at least one control unit configured to determine, based on a sensor output of the multiple sensors, one or more compensation signals to counteract the beam offset, wherein the at least one control unit is configured to provide, to the beam source, the beam deflection unit, and the precursor gas source control signals to implement an electron-beam-induced manipulation of a sample mounted to the sample stage, wherein the at least one control unit is configured to provide, during the electron-beam-induced manipulation, the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or one or more compensator modules.

2. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to determine a predictive component of the beam offset based on the sensor output of the multiple sensors and to determine the one or more compensation signals based on the predictive component of the beam offset.

3. The charged particle beam repair device of claim 2, wherein the sensor output of at least one of the multiple sensors comprises respective time series data, wherein the at least one control unit is configured to determine the predictive component based on an analysis of the time series data of the sensor output of the at least one of the multiple sensors.

4. The charged particle beam repair device of claim 3, wherein the analysis of the time series data comprises finding fingerprints of one or more predetermined disturbance events in the time series data.

5. The charged particle beam repair device of claim 4, wherein the at least one control unit is configured to selectively activate a calibration phase, wherein, when operating in the calibration phase, the at least one control unit is configured to populate a repository with the fingerprints of the one or more disturbance events based on at least one of identifying respective repetitions of the fingerprints in the time series data or obtaining user input data indicative of a respective one of the one or more disturbance events.

6. The charged particle beam repair device of claim 4, wherein the at least one control unit is configured to selectively activate a calibration phase, wherein, when operating in the calibration phase, the at least one control unit is configured to train a predictive model based on the time series data measured during the calibration phase to find the fingerprints and to thereby enable the predictive model to determine the predictive component.

7. The charged particle beam repair device of claim 1, wherein the at least one control unit is further configured to predict, based on at least one of the sensor output or the one or more compensation signals, an accuracy of an operation of the charged particle beam repair device during a prediction time duration.

8. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to determine the one or more compensation signals based on cross-dependencies between the multiple disturbances.

9. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to determine the one or more compensation signals based on a pre-trained algorithm.

10. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to determine the one or more compensation signals based on pre-parameterized functional dependencies.

11. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to determine the one or more compensation signals using a look-up table linking the sensor output with the one or more compensation signals.

12. The charged particle beam repair device of claim 1, wherein the multiple physical quantities are selected from the group comprising: acoustic vibration; vibration; pressure; humidity; temperature; laminar air flow; turbulent air flow; a differential quantity; a change rate of a physical quantity; a vector quantity; a scalar quantity.

13. The charged particle beam repair device of claim 1, wherein the multiple sensors comprise at least one sensor for measuring a temperature or pressure of a cooling liquid.

14. The charged particle beam repair device of claim 1, wherein at least one of the multiple sensors is arranged inside a vacuum chamber of the charged particle beam repair device.

15. The charged particle beam repair device of claim 1, wherein the multiple sensors comprise at least one sensor for measuring a pressure differential or temperature differential between two or more parts of the charged particle beam repair device.

16. The charged particle beam repair device of claim 1, wherein the multiple disturbances are selected from the group comprising: direct disturbances affecting the beam offset by deflecting the beam; indirect disturbances affecting the beam offset by impacting one or more parts of the charged particle beam repair device.

17. The charged particle beam repair device of claim 1, wherein the beam offset comprises at least one of a placement offset or a focal offset of the beam.

18. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to monitor the sensor output of at least one of the multiple sensors or a further sensor output of at least one further sensor and selectively blank the beam based on said monitoring.

19. The charged particle beam repair device of claim 1, wherein the at least one control unit is configured to provide the one or more compensation signals while the charged particle beam repair device operates in a manipulation mode that comprises repairing or editing semiconductor devices on a wafer mounted to the sample stage.

20. A charged particle beam device comprising a beam source, a beam deflection unit, and a sample stage, the beam deflection unit being configured to deflect a beam originating from the beam source to position the beam on the sample stage, the charged particle beam device comprising: multiple sensors configured to measure multiple disturbances of multiple physical quantities that each affect a beam offset of the beam on the sample stage, and at least one control unit configured to determine, based on a sensor output of the multiple sensors, meta data indicative of one or more compensation operations to counteract the beam offset in image data acquired by the charged particle beam device operating in an imaging mode, and to store the meta data in association with the image data.

21. A method of manipulating a sample mounted to a sample stage of a charged particle beam repair device, the charged particle beam repair device comprising a beam source, a beam deflection unit, a precursor gas source, and the sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage, wherein the method comprises: obtaining a sensor output of multiple sensors of the charged particle beam repair device, the multiple sensors measuring multiple disturbances of multiple physical quantities that each affect a beam offset of the beam on the sample stage, determining, based on the sensor output of the multiple sensors, one or more compensation signals to counteract the beam offset, providing, to the beam source, the beam deflection unit, and the precursor gas source control signals to implement an electron-beam-induced manipulation of the sample, and providing, during the electron beam-induced-manipulation, the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or one or more compensator modules.

22. The method of claim 21, wherein the method is executed by at least one control unit of the charged particle beam repair device, and the charged particle beam repair device comprises: the multiple sensors, and the at least one control unit, which is configured to determine, based on the sensor output of the multiple sensors, the one or more compensation signals to counteract the beam offset, wherein the at least one control unit is configured to provide, to the beam source, the beam deflection unit, and the precursor gas source the control signals to implement the electron-beam-induced manipulation of the sample mounted to the sample stage, wherein the at least one control unit is configured to provide, during the electron-beam-induced manipulation, the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or the one or more compensator modules.

23. A method of post-processing image data acquired by a charged particle beam device that comprises a beam source, a beam deflection unit and a sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage, wherein the method comprises: obtaining a sensor output from multiple sensors of the charged particle beam device, the multiple sensors measuring multiple disturbances of multiple physical quantities that each affect a beam offset of the beam on the sample stage, determining, based on the sensor output of the multiple sensors, meta data indicative of one or more compensation operations to counteract the beam offset in image data acquired by the charged particle beam device operating in an imaging mode, and post-processing the image data based on the meta data and in accordance with the one or more compensation operations.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 schematically illustrates a placement offset of a charged particle beam according to various examples.

[0034] FIG. 2 schematically illustrates compensation of the placement offset of FIG. 1 according to various examples.

[0035] FIG. 3 schematically illustrates compensation of the placement offset of FIG. 1 according to various examples.

[0036] FIG. 4 schematically illustrates a focal offset of a charged particle beam and respective compensation according to various examples.

[0037] FIG. 5 schematically illustrates a focal offset and respective compensation according to various examples.

[0038] FIG. 6 schematically illustrates a charged particle beam device according to various examples.

[0039] FIG. 7 is a flowchart of a method according to various examples.

[0040] FIG. 8 is a flowchart of a method according to various examples.

[0041] FIG. 9 schematically illustrates a time series data of a sensor output and a characteristic fingerprint of a disturbance of a respective physical quantity according to various examples.

[0042] FIG. 10 is a flowchart of a method according to various examples.

[0043] FIG. 11 schematically illustrates an implementation of a charged particle beam device by a repair device according to various examples.

[0044] FIG. 12 schematically illustrates sensor placement with respect to the repair device of FIG. 11 according to various examples.

[0045] FIG. 13 schematically illustrates sensor placement in a repair device according to FIG. 11 according to various examples.

[0046] FIG. 14 schematically illustrates a defect of a lithography mask according to various examples.

[0047] FIG. 15 schematically illustrates a repaired defect of the lithography masks according to various examples.

[0048] FIG. 16 schematically illustrates a charged particle beam device according to various examples.

DETAILED DESCRIPTION

[0049] Some examples of the present disclosure generally provide for a plurality of circuits or other electrical devices. All references to the circuits and other electrical devices and the functionality provided by each are not intended to be limited to encompassing only what is illustrated and described herein. While particular labels may be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the scope of operation for the circuits and the other electrical devices. Such circuits and other electrical devices may be combined with each other and/or separated in any manner based on the particular type of electrical implementation that is desired. It is recognized that any circuit or other electrical device disclosed herein may include any number of microcontrollers, a graphics processor unit (GPU), integrated circuits, memory devices (e.g., FLASH, random access memory (RAM), read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or other suitable variants thereof), and software which co-act with one another to perform operation(s) disclosed herein. In addition, any one or more of the electrical devices may be configured to execute a program code that is embodied in a non-transitory computer readable medium programmed to perform any number of the functions as disclosed.

[0050] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of embodiments is not to be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings, which are taken to be illustrative only.

[0051] The drawings are to be regarded as being schematic representations and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling. A coupling between components may also be established over a wireless connection. Functional blocks may be implemented in hardware, firmware, software, or a combination thereof.

[0052] Hereinafter, techniques associated with particle beam devices are disclosed. Specifically, techniques associated with charged particle beam devices are disclosed. Charged particles that can be used by such devices are electrons and/or ions. In other examples, non-charged particles may be used, e.g., photons. However, hereinafter, techniques will be disclosed in the context of charged particle beam devices, for illustrative purposes.

[0053] Examples of charged particle beam devices include: SEMs; Aberration Corrected SEMs (which typically have a comparatively larger detector aperture so that the depth range of the focus is small); FIB devices; multi-SEMs; cross-beam devices including a SEM and a FIB optics; and SEM or FIB with a precursor gas source, for repair/circuit edit tasks in a manipulation mode (also referred to as repair device; as will be explained in further detail in connection with FIG. 11 below).

[0054] Repair tasks pertain to modifying structures on semiconductor masks that are used for lithography. Repair tasks are implemented using an electron beam-induced manipulation of a sample based on interaction of a precursor gas or gases with electron beams. Alternatively or additionally, ions can be used for repair or edit tasks. In some examples, repair tasks are employed for modifying semiconductor devices, e.g., electric circuits on wafers. In detail, charged particlese.g., electrons or ions such as helium or neonare used to modify such structures. For instance, the charged particle beam interacts with a precursor gas or precursor gases that are selectively supplied towards the sample stage. Then, one or more components of the precursor gas or gases is deposited onto the structure. It is also possible in examples to remove material using, e.g., a focused ion beam. A repair task is generally associated with a manipulation mode of a charged particle beam device where the sample/specimen is manipulated. A repair task, as a general rule, includes execution of control of a beam source, beam deflection unit and a precursor gas source using respective control signals to thereby implement an electron beam-induced manipulation of the sample. Examples of the manipulation are: electron-beam induced deposition (EBID) and electron-beam induced etching (EBIE). An example repair task will be explained later on in greater detail in connection with FIG. 14 and FIG. 15.

[0055] Various techniques disclosed herein are based on the finding that with ongoing reduction of typical dimensions of the investigated or modified structures (typically, structures are characterized by a critical dimension that marks the minimum structure size that needs to be handled) the requirements on accuracy for the operation of charged particle beam devices is increased. For instance, typical critical dimensions can be at less than 7 nanometers or even less than 5 nanometers.

[0056] Hereinafter, techniques are disclosed that facilitate operation of charged particle beam devices in inspection mode and/or manipulation mode at a high accuracy, to be able to handle structures having small critical dimensions, e.g., critical dimensions below 7 nanometers or even below 5 nanometers.

[0057] This is achieved by providing one or more compensation signals that compensate a beam offset. Details with respect to such beam offset and an associated compensation are disclosed in connection with the following FIGs.

[0058] FIG. 1 schematically a charged particle beam 91e.g., an electron or ion beam, e.g., of Helium ionsof a charged particle beam device. The charged particle beam 91 is focused, by an optics of a beam deflection unit 112, onto a certain position 85 on a sample stage 113 of the charged particle beam device. However, due to one or more disturbances, a beam offset, here specifically a placement offset 81, occurs, that displaces the charged particle beam 91 towards another position 86 on the sample stage 113. This is a displacement along x-direction. Likewise, a displacement along y-direction would be possible. Further, beyond such placement offset 81, disturbances can also introduce other aberrations that lead to a reduced accuracy.

[0059] As a general rule, an accuracy of charged particle beam devices depends on, both, a resolution of the charged particle beam, as well as a placement of the charged particle beam on the sample stage. Typical resolutions are defined by a beam diameter that is typically in the range of 3 to 5 nanometers or even below (below 1 nm for aberration corrected instruments). On the other hand, the placement of the charged particle beam on the sample stage is typically affected by multiple disturbances of multiple physical quantities that affect the beam offset including the placement offset as described in connection with FIG. 1 above. A further type of beam offset is the focal offset, that will be explained in connection with FIG. 4 and FIG. 5 later on.

[0060] Such placement offset reducing the accuracy of the beam placement is particularly critical for the operation of the charged particle beam device, because the specification requirements imposed on the accuracy of the placement of the charged particle beam on the sample stage are often even higher than the specification requirements imposed on the beam diameter/resolution. One reason for this is that, e.g., in connection with a manipulation mode, certain structures are required to be generated or edited as an accuracy of less than 3 nanometers, optionally less than 2 nanometers or even less than 1 nanometer. Further, while a placement offset while operating in the inspection mode may reduce the overall image quality of the acquired image, a placement offset due to disturbances during manipulation can lead to damage of expensive semiconductor structures or even lithography masks.

[0061] Accordingly, techniques are disclosed that facilitate compensating placement offsets as well as focal offsets by providing one or more compensation signals while the charged particle beam device operates in the manipulation mode.

[0062] According to various examples, a charged particle beam device includes multiple sensors for measuring multiple disturbances of multiple physical quantities. These multiple physical quantities all affect a beam offset of the beam on the sample stage. The charged particle beam device also includes a control unit that is configured to determine, based on a sensor output of the multiple sensors, one or more compensation signals to counteract the beam offset. The control unit is configured to provide the one or more compensation signals to at least one of a beam source of the charged particle beam device, a beam deflection unit of the charged particle beam device, the sample stage or one or more compensator modules.

[0063] As a general rule, the beam offset can include at least one of a placement offset (in FIG. 1 along the X direction or the Y direction, i.e., along the plane of the sample stage 113) or a focal offset (in FIG. 1 along the Z direction; perpendicular to the plane of the sample stage 113) of the beam.

[0064] By considering disturbances originating from multiple physical quantities, a comprehensive compensation of the beam offset is achieved. Specifically, more accurate compensation is achieved if compared to scenarios as known from the prior art according to which only individual physical quantities such as temperature, pressure, vibrations, or acoustic vibrations (i.e., sound waves) are considered in isolation. Cross-correlations between different pairs of physical quantities can be considered, to thereby more accurately perform the compensation of the beam offset. For instance, nonlinear effects due to cross correlations could be considered.

[0065] As a general rule, according to examples various physical quantities for compensation are considered. The multiple physical quantities are selected from the group including: acoustic vibration; vibration; pressure; humidity; laminar air flow; turbulent air flow; a differential quantity; temperature; a change rate (i.e., defining a change rate over time); a differential quantity; a vector quantity (e.g., electric field, magnetic field); or a scalar quantity (e.g., temperature, pressure).

[0066] A differential quantity describes a spatial gradient of a respective quantity, e.g., a temperature gradient or a pressure gradient. Oftentimes such differential quantities can exert stress or strain onto material, thereby causing a disturbance. Further examples include laminar or turbulent air flow.

[0067] Acoustic vibrations include, in some examples, external acoustic vibrations, e.g., stemming from objects moved about in the surrounding of the charged particle beam device. Passive damping systems are known in the prior art that attempt to decouple the charged particle beam device from its surrounding. However, such passive damping cannot usually absorb all acoustic vibrations so that active compensation, as described herein, can be desirable. Acoustic vibrations can have residual components of movable parts within the charged particle beam device. Such internal components can be excited by external acoustic vibrations via mechanical contacts, e.g., via the floor or support lines; or via sound.

[0068] Pressure varies as a function of time in some examples. Pressure variation can occur on a comparatively long time scale if compared to, e.g., acoustical vibrations. Passive compensation is known by pressure stabilization systems; however, such passive compensation has certain limitations in the accuracy. Pressure variation can occur for cooling liquid or ambient air. Ambient air pressure variation varies forces exerted on a vacuum housing of the charged particle beam device, leading to changes in the hardware arrangement.

[0069] Temperature variations are, to some extent, compensated, according to some examples, by passive temperature control, e.g., using stabilizing temperature reservoirs or external air conditioning system. Using active control according to the techniques disclosed herein can more accurately compensate disturbances of even small temperature variations. For instance, temperature variation of a cooling liquid is measured, according to various examples, using an appropriately placed temperature sensor. The temperature of a cooling liquid is measured in further examples. Temperature variation of electronic control devices or measurement devices is measured and compensated for in yet further examples. A temperature differential/gradient between two or more parts of the charged particle beam device is measured according to examples. For instance, temperature gradient between different measurement points in a fluid flow, e.g., a cooling liquid, is measured and the respective disturbance is compensated.

[0070] Another physical quality that can cause disturbances pertains is the electric field. Prior art systems often employ a respective shielding. However, while such shielding may to some extent be effective against external electric fields, internally generated electric fields, e.g., due to current or induced currents or charging of capacitances may not be easily shielded using an external shielding. Charging of unwanted particles inside the column by the charged particle beam can occur. On the other hand, using the techniques described herein, sensors close to the optics are used in some examples, e.g., inside the vacuum chamber of the charged particle beam device, to measure the electrical field and then compensate for such electrical fields. Similar observations also apply to magnetic fields.

[0071] As will be appreciated from the above, some of the disturbancese.g., magnetic or electric fieldhave a direct impact on the charged particle beam, by deflecting the charged particles that propagate along the beam. For instance, an electric field or a magnetic field exerts a force on electrons or charged ions to deflect these particles. These are direct disturbances. Disturbances can also have an indirect impact on to the charged particle beam by impacting one or more parts of the charged particle beam device. For instance, acoustic vibrations cause a positional offset of optics of a beam deflection unit of the charged particle beam device and this positional offset then causes the beam offset of the beam. Electric or magnetic fields change analog supply currents or voltages of the beam source or optics of the beam deflection unit of the charged particle beam device; this then, in turn, affects the placement offset. These are indirect disturbances. According to the techniques disclosed herein, it is possible to compensate for direct disturbances as well as indirect disturbances.

[0072] For instance, placement offsets as illustrated in FIG. 1, or, more generally, beam offsets can occur in an imaging mode of a scanning electron microscope. For instance, movement of magnetic materials such as iron, cobalt, nickel, steel, etc. can change the magnetic field at the site of the charged particle beam. This can be caused by movement in the surrounding of the charged particle beam device, e.g., due to elevators, cranes, doors, lifting trucks, moving persons, cell phones, keys, etc.

[0073] Similar considerations also apply to focused ion beam devices. Using the focused ion beams, it is possible to remove material, in a manipulation mode, from a sample. In case of disturbances affecting the ion beam, the material is removed at unintended regions of the sample. Thus, using the techniques disclosed herein, the ion beam is stabilized on the sample and sample stage, respectively. This helps to avoid damage to the sample and allows for higher accuracy, e.g., in the preparation of transmission electron microscope lamellas or 3D tomographic sample investigation.

[0074] Similarly, for mask repair processes in a manipulation task, structures on the lithography mask are repaired by depositing material using an electron or ion beam induced process; and/or removing material locally from the lithography mask. By using the techniques disclosed herein, any beam offsets of the electron or ion beam with respect to the lithography mask and sample stage, respectively, are reduced so that a higher accuracy in the manipulation task is achieved.

[0075] As a general rule, various options are available for counteracting the beam offset according to the disclosed examples. According to examples, different options of counteracting the beam offset are employed for different root causes of the disturbances. For example, different options for counteracting the beam offset are employed for direct and indirect disturbances, as explained above, respectively. For example, a compensation signal is applied to optics of the beam deflection unit, to steer the beam into an opposing direction if compared to the placement offset. For example, a compensation signal is applied to a focusing optics of the beam deflection unit to change the focal length, to counteract a focal offset caused by a respective disturbance. In some examples, the sample stage isalternatively or additionallycontrolled to reposition to counteract a beam offset. In still further examples, dedicated compensation is used for, e.g., external coils for applying magnetic fields or electric field plates for applying electric fields. For instance, compensation of DC magnetic fields or slowly varying magnetic fields is achieved using Helmholtz coil pairs, one coil pair for each spatial direction. Such coil pairs are positioned outside of the housing of the charged particle beam device. Active cooling or heating is used according to a further example. For example, a heating or cooling element is provided in thermal contact with a cooling liquid and active temperature control is possible. In some examples, active damping for suppressing vibrations is controlled. In some examples, pressure is actively controlled. Hereinafter, devices or units that indirectly counteract the beam offseti.e., that do not directly exert a force onto the charged particle beam by applying a magnetic or electric field or that do not shift the sample stage with respect to the charged particle beamare referred to as compensator modules. Such compensator modules are controlled by respective compensation signals.

[0076] Hereinafter, techniques are primarily explained in connection with applying compensation signals to the beam deflection unit and/or the sample stage. Some example options for counteracting the beam offset by such means are explained next.

[0077] FIG. 2 illustrates aspects with respect to counteracting the placement offset 81 of FIG. 1. As illustrated in FIG. 2, an additional beam shift 82 that counteracts the placement offset 81 is achieved by providing a control signal to the beam deflection unit 112. For example, an additional voltage is applied to a respective electronic lens.

[0078] FIG. 3 schematically illustrates counteracting the placement offset 81 of FIG. 1. In the scenario of FIG. 3, a compensation signal is applied to a control motor of the sample stage 113, so as to effect a stage shift 83 that counteracts the placement offset 81.

[0079] Such techniques as illustrated in FIG. 3 may be particularly helpful for closed-loop controlled motorized stages 113. For instance, interferometric stages are known for which a positioning accuracy in the nanometer regime is obtained.

[0080] Above, scenarios of a placement offset that is affected by multiple disturbances have been disclosed. Alternatively or additionally to affecting the placement offset, disturbances can affect a focal offset of the charged particle beam. This is illustrated in FIG. 4.

[0081] In FIG. 4, the unaffected beam 91 in absence of any disturbances is illustrated. Furthermore, two disturbed beams 93, 94 subject to a respective focal offset 71, 72 are illustrated. It is possible to counteract the focal offset 71, 72 by applying an additional defocus to the beam. The beam deflection unit 112 can be controlled accordingly. The defocus 75 to counteract the focal offset 71 is illustrated, as well as the defocus 76 to counteract the focal offset 72 is illustrated. In an alternative scenario, as illustrated in FIG. 5, it is also possible to apply respective vertical stage shifts 77, 78.

[0082] According to various examples, the compensation of a focal offset is applied to aberration-corrected SEMs. Typically, aberration-corrected SEMs have a comparatively large numerical aperture, therefore having a shallow focal depth range. Such aberration-corrected SEMs can be employed for manipulation tasks and it is possible that the thickness of structures to be manipulated is in the same range or even smaller than the focal depth range. In such scenarios, compensation of the focal offset is particularly important to achieve good results of the manipulation task.

[0083] Various techniques are based on the finding that disturbances can occur on different time scales. On the one hand, there can be slowly varying disturbances caused by, e.g., DC magnetic fields, temperature, or pressure changes. Typically, such slowly varying disturbances can be compensated using techniques as disclosed herein, e.g., by applying one or more compensation signals to counteract the beam offset. Here, using a compensation by applying additional voltages to beam opticscf. FIG. 2 or FIG. 4typically provides for a shorter response time if compared to providing compensation based on stage shiftscf. FIG. 3 and FIG. 5. This is because movement of the stage typically requires longer time durations, due to limited movement speed of the motor was. The operation of the charged particle beam device, e.g., an imaging mode or manipulation mode, does not have to be stopped for such compensation, i.e., the compensation can be applied during ongoing operation.

[0084] On the other hand, some disturbances can be varying on a fast time scale, e.g., within seconds or even in the sub-second regime. Examples pertain to physical quantities such as acoustic or seismic vibrations, e.g., due to oscillation of the building foundation. To also compensate for such fast disturbances, techniques will be disclosed hereinafter that enable to determine a predictive component of the beam offset. Alternatively or additionally, information regarding such disturbances is stored in further examples, such information being determined based on the sensor output, e.g., along with imaging data acquired in an imaging mode. In other words, according to examples, based on the sensor output of multiple sensors, meta data is determined that is indicative of one or more compensation operations to counteract the beam offset in image data that is acquired by the charged particle beam device that operates in the imaging mode and then the meta data is stored in association with the image data. Then, acquired image data is digitally post-processed to compensate, after acquisition, for such disturbances based on the meta data.

[0085] In some examples, disturbances are detected that lead to suspending operation of the charged particle beam device. E.g., the charged particle beam can be blanked. The imaging mode or manipulation mode is interrupted, until the disturbance has resolved.

[0086] Such a scenario is, in particular, helpful during manipulation mode; to avoid damage to the manipulated specimen.

[0087] FIG. 6 schematically illustrates a charged particle beam device 100 according to various examples. For example, the charged particle beam device 100 could be a charged particle beam repair device. The charged particle beam device 100 includes a vacuum chamber 110. A beam source 111, a beam deflection unit 112 and a sample stage 113 are arranged inside the vacuum chamber 110. An embedded control unit 119 controls the beam source 111, the beam deflection unit 112, and the sample stage 113. The control unit 119 can also control further parts of the charged particle beam device 100, e.g., a control valve of a precursor gas source (not shown in FIG. 6).

[0088] Also illustrated are two sensors 121, 122 for measuring disturbances of physical quantities that each affect a beam offset of the charged particle beam 90 on the sample stage 113.

[0089] While in the scenario FIG. 6 two sensors 121, 122 are illustrated, as a general rule, only a single sensor is used or more than two sensors are used.

[0090] In some examples, at least one of multiple sensors is arranged inside the vacuum chamber 110. Alternatively or additionally, at least one sensor is arranged outside of the vacuum chamber 110.

[0091] For example, sensors measuring the same physical quantity, e.g., temperature, are located at multiple positions. Thereby, a differential physical quantity is measured, e.g., a temperature or pressure differential.

[0092] By arranging sensors outside of the vacuum chamber, it is possible to measure physical quantities that slowly vary as a function of position, e.g., external electric fields or external magnetic fields. At the same time, an impact on the particle beam by operating the sensor can be avoided. In some examples, a sensor is nonetheless placed closer to the beam path of the beam 90, e.g., for physical quantities that show a strong positional dependency.

[0093] Also illustrated is a control unit 130. In some examples, the control unit 130 is implemented by a computer. The control unit 130 communicates with the embedded control unit 119, as well as the sensors 121, 122. While in FIG. 6 a scenario is illustrated according to which the control unit 130 communicates directly with the sensors 121, 122, such communication in other examples is via the embedded control unit 119.

[0094] In any case, the control unit 130 obtains sensor signals 161, 162 (i.e., sensor output) from the sensors 121, 122. Based on this, the control unit 130 provides one or more compensation signals 165 to one or more parts of the charged particle beam device 100, to counteract the placement offset.

[0095] The control unit 130 includes a processor 132 that is coupled to a memory 133. The processor 132 also communicates via the communication interface 131. The processor loads program code from the memory 133 and executes the program code. Upon executing the program code, the processor 132 performs techniques as disclosed herein with respect to compensating multiple disturbances of multiple physical quantities that each affect a beam offset.

[0096] The control unit 130 also includes a human machine interface (HMI) 134, e.g., a display, a web interface, a mouse, a keyboard, etc. User input is received via the HMI 134 or information is output via the HMI 134. For instance, an indication of a site-specific disturbance event is obtained from the user via the HMI 134. In some examples, a warning is output to the user via the HMI 134.

[0097] While hereinafter scenarios are disclosed which pertain to logic associated with the beam offset compensation residing at the control unit 130, in other examples at least parts of that logic reside at the embedded control unit 119.

[0098] FIG. 7 is a flowchart of a method according to various examples. FIG. 7 illustrates multiple phases of operation of a charged particle beam device such as the charged particle beam device 100 of FIG. 6. The method of FIG. 7 may be executed by the control unit 130 and/or the embedded control unit 119.

[0099] Box 6005 corresponds to a calibration phase. During the calibration phase, one or more transfer functions are set up between sensor outputs of multiple sensors measuring disturbances of multiple physical quantities and compensation signals.

[0100] Such transfer functions, accordingly, link values of multiple physical quantities (represented by the sensor signals 161, 162) to beam offset compensations (represented by the compensation signal 165).

[0101] Box 6010 then corresponds to an operation phase. During the operation phase, the charged particle beam device operates in an imaging mode or a manipulation mode. For instance, as part of the imaging mode, a control unit of the charged particle beam device can provide, to a beam source and a beam deflection unit of the charged particle beam device, control signals to implement imaging of a sample mounted to a sample stage of the charged particle beam device. As part of the manipulation mode, the control unit of the charged particle beam device provides, to the beam source, the beam deflection unit, and a precursor gas source (e.g., including a gas reservoir or tank and a respective nozzle located close to the sample stage; details will be explained in connection with FIG. 11A) control signals to implement an electron-beam-induced manipulation of the sample mounted to the sample stage. Here, the precursor gas supply through the precursor gas source interacts with the electrons of the electron-beam. Material can be deposited or locally etched.

[0102] During the operation phase, compensation of multiple disturbances of multiple physical quantities is employed; the multiple physical quantities each affect a beam offset of the beam of the charged particle beam device with respect to the sample stage. For example, the control unit employs the transfer function obtained from box 6005 to determine, based on a sensor output of the multiple sensors, the one or more compensation signals to contact any beam offset and then provide the one or more compensation signals to one or more parts of the charged particle beam device.

[0103] Also illustrated in FIG. 7 is an optional post-processing phase, associated with box 6015. Here, meta data that is acquired based on the sensor output of multiple sensors is used to apply one or more compensation operations to counteract a beam offset by postprocessing respective image data. In some examples, such compensation operations include applying an imaging shift, e.g., displacing pixels of image is included in the image data by a certain image offset. Also, rotation operations or skew operations are used in further examples. In some examples, complex image artifacts are compensated. Examples of image artifacts include artificially reoccurring contrast. To compensate this, the compensation operations can be implemented using, e.g., a neural network that obtains configuration information in the form of the meta data.

[0104] As illustrated in FIG. 7 by the dashed line, it is possible to re-execute the calibration mode of box 6005 from time to time. Thereby, certain disturbance events that are site-specific, i.e., depend on the specific deployment side of the charged particle beam device, are captured. This will be explained in further detail later-on.

[0105] Next, details with respect to the calibration phase of box 6005 are disclosed in connection with FIG. 8.

[0106] FIG. 8 is a flowchart of a method according to various examples. FIG. 8 illustrates details with respect to the calibration phase of box 6005.

[0107] Initially, at box 6105, one or more disturbances are applied; this is done by modifying one or more physical quantities. Some examples are: apply a certain disturbing electrical or magnetic field (e.g., using a Helmholtz coil setup surrounding the charged particle beam device), vary the surrounding temperature (e.g., in a temperature-stabilized environment), vary the surrounding pressure, etc. where the one or more disturbances are actively applied, the respective magnitude of the disturbance is known.

[0108] As will be appreciated from the above, a tailored disturbance event is thus triggered, for calibration purposes.

[0109] As a general rule, such active application of a certain disturbance is optional. In other scenarios, at box 6110 naturally-occurring disturbances are measured, e.g., site-specific disturbances. In other words, in some scenarios, a disturbance event is actively triggered at box 6105; while in other scenarios, environmental disturbance events are monitored and characterized at box 6110.

[0110] Then, at box 6115, it is possible to measure the beam offset.

[0111] This beam offset can either result from a respective tailored disturbance that is actively applied at box 6105; the beam offset can alternatively result from a natively occurring disturbance, e.g., from environmental disturbance events. For example, a placement offset and/or a focal offset of the beam is measured. This can be achieved using, e.g., a test pattern sample and using a respective inspection task. For instance, an image of the test pattern acquired by the charged particle device operating in the imaging mode while the disturbance is present is compared with a ground truth knowledge regarding the test pattern. From deviations between the image appearance of the test pattern and the ground truth regarding the test pattern, a conclusion on the beam offset is drawn. For instance, image shifts could be determined between a true position of certain features of the test pattern and a position at which those features are depicted in the image. For instance, an image blur could be quantified to determine the focal offset.

[0112] Then, at box 6120, a transfer function between the disturbance and the beam offset is determined. This transfer function is then stored for later use during the compensation mode (cf. FIG. 7: box 6010).

[0113] Next, various examples of determining the transfer function at box 6120 will be discussed.

[0114] In one example, the one or more compensation signals are determined using a look-up table that links the sensor output with one or more compensation signals. In other words, for multiple strengths of the disturbances, e.g., multiple values of the respective physical quantities, an associated beam offset and the required compensation signals to compensate therefore are determined. Respective value pairs are then stored in the look-up table. Linear interpolation is optionally used during the operation phase to increase the accuracy.

[0115] The look-up table can be device-specific, i.e., different charged particle beam devices can have different look-up tables. Site-specific disturbances can be used to populate such device-specific look-up tables. The look-up table could also be stored in the cloud, and thus be retrieved via the Internet. This allows to centrally maintain and manage disturbance compensation for multiple charged particle beam devices.

[0116] An example look-up table is provided by TAB. 1 below:

TABLE-US-00001 TABLE 1 example lookup table that links a temperature disturbance with offset voltage to be applied at beam optics of a beam deflection unit of the charged particle device. TEMPERATURE DISTURBANCE OFFSET VOLTAGE +0.2 K +0.3 V +0.4 K +0.58 V +0.6 K +0.88 V

[0117] Such lookup table has the advantage that it is not required to model dependencies between the sensor output and the compensation signal using predetermined functions. Nonlinear dependencies are directly captured. On the other hand, such lookup table can have a significant size. This can lead to latency in the lookup of the appropriate compensation signal, which can be a problem, in particular, for quickly varying disturbances.

[0118] In another example, the one or more compensation signals are determined using a (pre-parameterized) functional dependency. Such functional dependency is illustrated for a linear case.

[0119] For instance, for a scalar physical quantity, e.g., temperature, such linear functional dependency may be defined as follows:

[00001]$\left(\begin{array}{c}{P}_x\\ P_y\\ P_z\end{array}\right)=\left(\begin{array}{c}{T}_x^c\\ T_y^c\\ T_z^c\end{array}\right)T,$

here T denotes the temperature disturbance (e.g., defined with respect to a reference temperature) and is obtained from the sensor output, P.sub.x denotes the x component of the compensation of the placement offset, P.sub.y denotes the y component of the compensation of the placement offset, and P.sub.z denotes the compensation of the focal offset. The linear functional dependencies are then given by the parameters T.sub.x.sup.c, T.sub.y.sup.c, T.sub.z.sup.c. These are determined during the calibration (pre-parameterization). The placement offset defines the one or more compensation signals.

[0120] For instance, for a vector physical quantity, e.g., electrical field, such linear functional dependency is defined as follows:

[00002]$\left(\begin{array}{c}{P}_x\\ P_y\\ P_z\end{array}\right)=E^c\left(\begin{array}{c}{E}_x\\ E_y\\ E_z\end{array}\right),$

where E.sup.c is a 33 matrix wherein the matrix elements are determined during the calibration. E.sub.x, E.sub.y, E.sub.z denote the components of the disturbing electric field. In the scenario above, a given physical quantitye.g., temperature, electric field, and so forthhas an impact on the beam offset. Impacts of different physical quantities onto the beam offset can superimpose. In some scenarios, it is possible to consider the different physical quantities independent of each other, i.e., neglect mixing effect between the impacts onto the beam offset of different physical quantities.

[0121] In some scenarios, cross-dependencies between multiple disturbances that are associated with different physical quantities are considered.

[0122] For instance, an example would be a cross-dependency between temperature and pressure, as explained below:

[00003]$\left(\begin{array}{c}{P}_x\\ P_y\\ P_z\end{array}\right)=X^c\left(\begin{array}{c}T\\ p\end{array}\right),$

where the 23 matrix X.sup.c has non-zero off-diagonal elements defining the cross-dependencies between pressure disturbance and temperature disturbance.

[0123] Above, linear functional dependencies have been disclosed, but it would be likewise possible to include non-linear terms, e.g., quadratic terms, cubic terms, etc.

[0124] Beyond such functional dependencies as exemplified above, in another example, the one or more compensation signals are determined using a model. For example, the compensation of the positioning and focal offset is determined using a trained neural network or another machine learning algorithm or generally a pre-trained algorithm. The trained neural network receives, as input, a vector including the sensor output of the multiple sensors, e.g., temperature, pressure, multiple components of the electrical field, multiple components of the magnetic field, etc. Then, the neural network outputs the one or more compensation signals or the beam offset from which the one or more compensation signals are determined. Such neural network is trained using ground truth labels acquired during the calibration mode, i.e., the measured beam offset of box 6115 in combination with input vectors as determined at box 6105 or at box 6110.

[0125] This is an example of a data-driven model. In other examples, also an analytical model may be employed. To give an example, a change in pressure has been shown to lead to a twist of the beam optics column. This results in a displacement of the focal point on a circle tilted with respect to the surface of the sample stage, i.e., the displacement has x and y and z components. A focal offset either in +z-direction or in z-direction can occur. An analytical model is determined according to example, the analytical model determining torque exerted on the optics column based on the pressure gradient. Such analytical model has the benefit of reduced lead time in the parameterization, e.g., if compared to a lengthy calibration of a transfer function. Such model can be extended, in some examples, to also cover placement offsets based to other disturbances such as magnetic field.

[0126] Above, scenarios of instantaneous compensation of disturbances have been disclosed. Such techniques generally work well for slowly-varying disturbances, e.g., in the kHz regime or below. For fast-varying disturbances, an even higher accuracy can be achieved by considering time-resolved properties of the disturbances. This is explained in further detail below.

[0127] According to various examples, a predictive component of the beam offset is determined based on the sensor output of the multiple sensors and determine the one or more compensation signals based on the predictive component of the beam offset. In other words, the disturbances are anticipated for a certain look-ahead time duration.

[0128] Such techniques are based on the finding that certain disturbance events are repetitive. Specifically, site-specific disturbance events can re-occur over the course of time. For instance, stray magnetic fields can be caused by movement of an office chair between two desks in the laboratory or deployment site of the charged particle beam device. For instance, vibrations can be caused by a train entering or leaving a train station nearby or a delivery truck arriving at or leaving from a loading dock. In another example, stray magnetic fields can be caused by operation of equipment in a wafer fab, e.g., opening or closing of a load lock, depressurization of a vacuum chamber, or temperature changes as a function of daytime/sun height, etc. These are only some examples of typical repetitive disturbance events that are site-specific.

[0129] To make such predictions, in some examples, the sensor output of at least one of the multiple sensors includes respective time series data. In other words, sensor readings over a certain observation duration (e.g., along with respective timestamps) are considered. Then, the predictive component is determined based on an analysis of the time series data.

[0130] There are various options for performing such analysis of the time series data. In one option, fingerprints of one or more predetermined disturbance events are found in the time series data. These fingerprints include characteristic time dependencies of the sensor output of the respective at least one sensor. The fingerprints pertain to characteristic time-domain patterns. This is illustrated in connection with FIG. 9.

[0131] FIG. 9 illustratesas an illustrative examplea disturbance of the x-component of the electrical field that affects the beam offset of the charged particle beam, over the course of time. The time series data 310 of the x-component of the electrical field is obtained from a respective electrical field sensor.

[0132] Illustrated is a disturbance event 311 that is caused, as one example, by arrival of a bus at the bus station nearby the deployment site of the charged particle beam device. A respective disturbance duration 313 is also illustrated. For instance, the disturbance duration 313 could be in the range of seconds or minutes.

[0133] The disturbance event 311 has a characteristic fingerprint 312 (here: large upswing then small downswing) that is detected in the time series data of the electric field sensor. Once this fingerprint 312 has been found, a prediction on the future behavior of the disturbance can be made, i.e., a predictive component of the beam offset can be determined (under the assumption of a repetitive nature of the disturbance). The behavior of the disturbance during the remaining disturbance duration 313 can be predicted.

[0134] When operating in the calibration phase of box 6005 (cf. FIG. 7), a repository is populated, according to some examples, with fingerprints of multiple disturbance events. To find such fingerprints, various options are conceivable. In one option, repetitions of the fingerprints are identified. For instance, during the calibration mode, the sensor output of the respective at least one sensor is monitored over an extended duration, e.g., hours or days or even weeks and then find repetitions of the fingerprints. In a further option, user input data is obtained that is indicative of a respective one of the one or more disturbance events. For instance, referring to FIG. 9, a user labels/annotates the time series data to identify the disturbance duration 313. The user may do so with domain knowledge, e.g., in the discussed example the user may be aware of the arrival of the bus at the bus station. Another option includes training a predictive model based on the timeseries data that is measured during the calibration mode to find the fingerprints. Then, the predictive model, e.g., a recurrent neural network such as a long-short-term memory (LSTM) neural network, is enabled to determine the predictive component of the beam offset. This enables to react to disturbance events having a signal component with a high bandwidth. In other words, disturbance events with fast time dynamics, e.g., in the sub-millisecond regime or even in the microsecond regime can be compensated for. This is because once the fingerprint has been detected a compensation signal can be pro-actively played out.

[0135] FIG. 10 is a flowchart of an example method. FIG. 10 schematically illustrates operation in the operation phase of box 6010 of FIG. 7.

[0136] At box 6205, multiple sensors of the charged particle beam device measure multiple disturbances of multiple physical quantities that each effect a beam offset, e.g., a placement offset and/or a focal offset, of the charged particle beam on a sample stage. A respective sensor output including multiple sensor signals provided by the multiple sensors is provided. The sensor output is indicative of the values of the physical quantities. I.e., the sensor output is associated with the disturbances. The disturbances can be super-imposed or can correlate with each other.

[0137] As a general rule, different placements for the multiple sensors are conceivable. Example placements will be discussed later on in connection with FIG. 12 in FIG. 13.

[0138] Next, at box 6210, one or more compensation signals are determined to counteract such beam offset. This is based on the sensor output of the multiple sensors. More specifically, the disturbances are estimated from the sensor output and the disturbances are translated into the one or more compensation signals.

[0139] Above, examples have been disclosed that facilitate determining such compensation signals, e.g., using a transfer function that may be implemented by a lookup table, a modele.g., a data-driven model using machine learning or an analytical model, a functional dependency, a machine-learning algorithm, etc.

[0140] It is also possible to determine a predictive component of the beam offset, to thereby reduce a latency and applying the compensation signal and provide more accurate compensation.

[0141] In some scenarios, alternatively or additionally to determining compensation signals to actively compensate the beam offset during the operation of the charged particle beam device, e.g., in the imaging mode or the manipulation mode, meta data that is indicative of one or more compensation operations is determined, to counteract the beam offset in imaging data. This enables post-processing of the imaging data (cf. FIG. 7: box 6015). Here, compensation of the beam offset is achieved when digitally postprocessing imaging data that is acquired using the charged particle beam device; alternatively or additionally to compensation of at least a part of the beam offset during the operation.

[0142] A trust level of respective image data can be determined. A log file can be generated to store the disturbances or specifically the one or more compensation signals.

[0143] At box 6211 is optionally possible to predict, based on the sensor output and/or the one or more compensation signals determined at box 6210, an accuracy of an operation of the charged particle beam device during a prediction time duration. This can equate to predicting the level of disturbances. For example, a recurrent neural network or an LSTM is used for making such prediction. Again, such prediction can be based on characteristic fingerprints of repetitive disturbance events, as discussed in connection with FIG. 9. Different to what has been explained in connection with FIG. 9, such prediction of the level of accuracy may not directly impact the compensation signals. Sometimes, the prediction may not be accurate enough to determine a predictive component of one or more compensation signals. In such a scenario, it is still possible to predict the accuracy. In some examples, such accuracy is output via an HMI to the user. The user may then decide whether to abort or not a port the operation. In other examples, the prediction of the accuracy is used in the context of box 6215.

[0144] Sometimes, a scenario occurs according to which the disturbance exceeds or is predicted to exceed (cf. box 6211) a certain predetermined threshold. If a disturbance exceeds a predetermined threshold, it is assumed that such disturbance cannot be compensated.

[0145] Accordingly, at box 6215, it is checked whether one or more pre-determined events are detected in the sensor output of the multiple sensors. In some examples, such one or more predetermined events are associated with at least one of the of multiple disturbances exceeding a certain predetermined threshold; this corresponds to the sensor output crossing a respective threshold. In further examples, it is checked whether the one or more compensation signals exceed a certain threshold. An alternative example of such one or more predetermined events is detection of an anomaly in the sensor output. In some examples, an anomaly detector algorithm is used: Examples include cluster-based anomaly detection or autoencoder neural networks. Such anomaly detector algorithms can be trained in an unsupervised manner.

[0146] If one or more predetermined events are not detected at box 6215, then box 6205 is re-executed, i.e., the disturbance is measured again and compensation signals are further applied. On the other hand, if an excess disturbances detected at box 6215, the beam is blanked at box 6220. For instance, the inspection or manipulation mode is aborted. Alternatively or additionally, a warning message is output via an HMI. The respective sensor outputs that led to execution of box 6220 are logged in some examples. A safe mode is entered that may be manually exited by a user, according to some examples.

[0147] Beam blanking can be executed at comparatively low latency, to avoid damage. For instance, typically determining one or more compensation signals will require significant time, e.g., to perform a look-up operation or calculate the compensation signal. Accordingly, beam blanking is, in some examples, executed at a lower latency than such determining of one or more compensation signals.

[0148] As a general rule, the decision making at box 6215 is based on other sensor signals than the sensor signals that are considered by the logic of box 6210 according to some examples. For instance, it has been found that the following physical quantities are particularly suited for detecting an excess disturbance at box 6215: acoustic vibration; vibration; environmental pressure; environmental pressure change. On the other hand, the following physical quantities have been found to be particularly suited for determining one or more compensation signals to counteract the beam offset: magnetic field; environmental temperature; environmental pressure; environmental pressure change.

[0149] FIG. 11 schematically illustrates an example implementation of a charged particle beam device such as the charged particle beam device 100 discussed above. The scenario of FIG. 11 pertains to a charged particle beam repair device (or simply repair device). FIG. 11 shows a schematic sectional view through some important components of one example of a repair device 11120 which can be used to identify and repair a defect 11160 of a photolithographic mask. A sample 11405 can be arranged in the form of a photolithographic mask 11110, for example, on the sample stage 11402 (corresponding to the sample stage 113). The photomask can have one or a plurality of defects 11160 in the form of excess material (dark defects) and/or missing material (clear defects). The defect of the photolithographic mask is not reproduced in FIG. 11. The defect or generally defects of excess or missing material can be scanned and thus analyzed with the aid of a charged particle beam. Furthermore, defects can be corrected by use of particle beam-induced processing process. For this purpose, the repair device 11120 comprises a scanning electron microscope (SEM, Scanning Electron Microscope) 11410. Moreover, defects of excess material can be repaired by use of a measuring tip of a scanning probe microscope 11480. Therefore, the repair device 11120 comprises one or a plurality of scanning probe microscopes 11480 typically in the form of an atomic force microscope (AFM, Atomic Force Microscope) 11480.

[0150] In the SEM 11410 in FIG. 11, an electron gun implementing a beam source 11412 generates an electron beam 11415, which the imaging elements (implementing a beam deflection unit) arranged in the electron column 11417, said imaging elements not being illustrated in FIG. 11, direct/deflect as a focused electron beam 11415 onto the sample 11405 at the location 11422, which sample-as already explained-can comprise a photolithography mask. The sample 11405 is arranged on a sample stage 11402. A sample stage 11402 is also known as a stage in the art. As symbolized by the arrows in FIG. 11, a positioning unit 11407 can move the sample stage 11402 about six axes relative to the column 11417 of the SEM 11410. The movement of the sample stage 11402 by the positioning unit 11407 can be effected with the aid of micromanipulators, for example, which are not shown in FIG. 11.

[0151] At the processing location 11422, the particle beam 11415 impinges on the sample 11405. Thus, the positioning unit 11407, by virtue of the displacement of the sample stage 11402 perpendicularly to the beam axis of the electron beam 11415, makes it possible firstly to analyze defects of the photomask by generating an image of the defect (inspection task). For this purpose, the imaging elements of the column 11417 of the SEM 11410 can scan the electron beam 11415 over the sample 11405. By use of the tilting and/or rotation of the sixth-axis sample stage 11402, the latter makes it possible to examine one or a plurality of defects from different angles or perspectives. The respective position of the various axes of the sample stage 11402 can be measured by interferometry (not reproduced in FIG. 11). The positioning unit 11407 is controlled by signals of a control unit 11425. The control unit 11425 can be part of a computer system 11430 of the repair device 11120. The control unit 11425 implements, in some examples, the control unit 119 or the control unit 130 (cf. FIG. 6).

[0152] The repair device 11120 can furthermore comprise one or more sensors that make it possible to characterize both a current state of the SEM 410 and the process environment in which the SEM 11410 is used (for instance a vacuum environment). For instance, vibration, temperature, pressure, respective differentials or change rates (over time) could be measured.

[0153] The electron beam 11415 can furthermore be used for inducing a particle beam-induced processing process for correcting identified defects for example in the context of an electron beam-induced etching process EBIE (Electron Beam Induced Etching) for removing dark defects and/or an electron beam-induced deposition process EBID (Electron Beam Induced Deposition) for correcting clear defects. In addition, in the repair device 11120 in FIG. 11, the electron beam 11415 can be used for analyzing a repaired location of a photomask.

[0154] The electrons backscattered from the electron beam 11415 by the sample 11405 and the secondary electrons produced by the electron beam 11415 in the sample 11405 are registered by the detector 11420. If the sample 11405 comprises the photomask, the detector 11420 identifies secondary electrons emitted during the scanning of absorbent strips arranged on the photomask for lithography purposes. The detector 11420 that is arranged in the electron column 11417 is referred to as an in lens detector. The detector 11420 can be installed in the column 11417 in various embodiments. The detector 11420 can also be used for detecting the electrons backscattered from one or a plurality of defects 11160 of the mask 11110. The detector 11420 is controlled by a control unit 11425 of a computer system 11430 of the device 120. For instance, the computer system 11430 can implement the control unit 130. It would be possible that the embedded control unit 119 is implemented by the control unit 11425.

[0155] The repair device 11120 can include a second detector 11445. The second detector 11445 is designed to detect electromagnetic radiation, particularly in the x-ray range. As a result, the second detector 11445 makes it possible to analyze the material composition of the sample, e.g., the photolithography mask, i.e., the substrate thereof, the absorbent strips, and/or one or a plurality of defects. The detector 11445 is likewise controlled by the control unit 11425.

[0156] The control unit 11425 of the computer system 430 (it could also be separate from the computer system 430) can set the parameters of the electron beam 11415 for inducing a deposition process for removing clear defects and/or an EBIE process for etching dark defects.

[0157] Furthermore, the computer system 11430 has an evaluation unit 11435. The evaluation unit 11435 receives the measurement data of the detector(s) 11420, 11445. The evaluation unit 11435 can generate from the measurement data, for example from secondary electron contrast data, images in a greyscale representation or a greyscale value representation, which are represented on a monitor 11432. In addition, the computer system 11430 comprises an interface 11437, via which the computer system 11430 can transmit to further processing devices. Furthermore, the computer system 11430 of the repair device 11120 can receive one or a plurality of processed or evaluated images and/or one or a plurality of superimposed images from the evaluation device.

[0158] As already explained above, the electron beam 11415 of the modified SEM 11410 can be used for inducing an electron beam-induced processing process/manipulation. As likewise already explained above, defects of the sample 11405 can be corrected by use of an electron beam-induced manipulation. In order to carry out these processes, the exemplary scanning electron microscope 11410 of the repair device 11120 in FIG. 11 has three different supply containers 11450, 11460 and 11470.

[0159] The first supply container 11450 stores a first precursor gas in the form of a deposition gas, for example a metal carbonyl, for instance chromium hexacarbonyl (Cr(CO).sub.6), or a carbon-containing precursor gas, such as pyrene, for instance. With the aid of the precursor gas stored in the first supply container 11450, material can be deposited on the sample 11405 or the mask in a local chemical reaction, with the electron beam 11415 of the SEM 11410 acting as an energy supplier in order to split the precursor gas stored in the first supply container 11450 preferably into chromium atoms and carbon monoxide molecules at the location at which the material is intended to be deposited, i.e. at a location of a clear defect. This means that an EBID process for correcting defects of the photomask is carried out by the combined provision of an electron beam 11415 and a precursor gas. The modified SEM 11410 in combination with the first supply container 11450 or the deposition gas stored therein forms a repair device 11120.

[0160] In the repair device 11120 illustrated in FIG. 11, the second supply container 11460 stores a precursor gas in the form of an etching gas, which makes it possible to perform a local electron beam induced etching (EBIE) process. Defects of excess material or dark defects can be removed from the photolithographic mask 11110 (or another sample, e.g., a semiconductor wafer) with the aid of an electron beam-induced etching process. A precursor gas in the form of an etching gas can comprise for example xenon difluoride (XeF.sub.2), chlorine (Cl.sub.2), oxygen (O.sub.2), ozone (O.sub.3), water vapour (H.sub.2O), hydrogen peroxide (H.sub.2O.sub.2), dinitrogen monoxide (N.sub.2O), nitrogen monoxide (NO), nitrogen dioxide (NO.sub.2), nitric acid (HNO.sub.3), ammonia (NH.sub.3) or sulfur hexafluoride (SF6) or a combination thereof. Consequently, the modified SEM 11410 in combination with the second supply container 11460 or the precursor gas stored therein forms a repair device 11120.

[0161] An additive gas can be stored in the third supply container 11470, said additive gas, where necessary, being able to be added to the etching gas kept available in the second supply container 11460 or to the deposition gas stored in the first supply container 11450. Alternatively, the third supply container 11470 can store a precursor gas in the form of a second deposition gas or a second etching gas.

[0162] In the scanning electron microscope 11410 illustrated in FIG. 11, each of the supply containers 11450, 11460 and 11470 has its own control valve 11452, 11462 and 11472 in order to monitor or control the amount of the corresponding gas that is provided per unit time, i.e., the gas volumetric flow at the location 11422 of the incidence of the electron beam 11415 on the sample 11405. The control valves 11452, 11462 and 11472 are controlled and monitored by the control unit 11425. By this means, it is possible to set the partial pressure conditions of the gas or gases provided at the processing location 11422 for carrying out an EBID and/or EBIE process in a wide range, during operation (cf. FIG. 7: box 6010).

[0163] Furthermore, in the exemplary SEM 11410 in FIG. 11, each supply container 11450, 11460 and 11470 has its own gas feedline system 11454, 11464 and 11474, which ends with a nozzle 11456, 11466 and 11476 in the vicinity of the point of incidence, i.e., the processing location 11422 of the electron beam 11415 on the sample 11405.

[0164] The supply containers 11450, 11460 and 11470 can have their own temperature setting element and/or control element, which allows both cooling and heating of the corresponding supply containers 11450, 11460 and 11470. This makes it possible to store and in particular provide the precursor gases of the deposition gas and/or the etching gas at the respectively optimum temperature (not shown in FIG. 11). The control unit 11425 can control the temperature setting elements and the temperature control elements of the supply containers 11450, 11460 and 11470. During the EBID and the EBIE processing processes, the temperature setting elements of the supply containers 11450, 11460 and 11470 can furthermore be used to set the vapour pressure of the process gas(es) stored therein by way of the selection of an appropriate temperature.

[0165] The device 11400 can comprise more than one supply container 11450 in order to store precursor gases of two or more deposition gases. Furthermore, the device 400 can comprise more than one supply container 11460 for storing precursor gases of two or more etching gases.

[0166] The scanning electron microscope 11410 illustrated in FIG. 11 can be operated under ambient conditions or in a vacuum chamber 11442. Implementing the EBID and EBIE processes necessitates a negative pressure in the vacuum chamber 11442 relative to the ambient pressure. For this purpose, the SEM 11410 in FIG. 11 comprises a pump system 11444 for generating and for maintaining a negative pressure required in the vacuum chamber 11442. With closed control valves 11452, 11462 and 11472, a residual gas pressure of <10.sup.4 Pa is achieved in the vacuum chamber 11442. The pump system 11444 can comprise separate pump systems (not shown in FIG. 11) for the upper part of the vacuum chamber 11442 for providing the electron beam 11415 of the SEM 11410 and for the lower part or the reaction chamber 11448. A pressure sensor may be provided to monitor the pressure inside and outside of the vacuum chamber 11442. A pressure differential may be monitored.

[0167] The SEM 11410 presented in the repair device 11120 in FIG. 11 has a single electron beam 11415. However, it is also possible for the SEM 11410 to have a source of a second particle beam. The second particle beam can comprise a photon beam and/or an ion beam (not shown in FIG. 11). Furthermore, the SEM 11410 can have two or more electron beams 11415 in order to be able to carry out in parallel two or more particle beam-induced processing processes or two or more analysis processes of two or more defects.

[0168] Additionally, the exemplary repair device 11120 illustrated in FIG. 11 comprises a scanning probe microscope 11480 which, in the repair device 11120, is embodied in the form of a scanning force microscope (SFM) 11480 or an atomic force microscope (AFM) 11480. The scanning probe microscope 11480 can be used for scanning one or a plurality of defects 11160 of the sample 11405 or of the photomask 11110. Moreover, the scanning probe microscope 11480 can be used for repairing the defects of excess material. For this purpose, the scanning probe microscope 11480 can comprise a first measuring tip for analyzing the sample 11405 and a second measuring tip for processing one or a plurality of defects.

[0169] Only the measuring head 11485 of the scanning probe microscope 11480 is illustrated in the repair device 11120 in FIG. 11. In the example in FIG. 11, the measuring head 11485 comprises a holding device 11487. The measuring head 11485 is secured to the frame of the repair device 11120 by use of the holding device 11487 (not shown in FIG. 11). A piezo-actuator 11490 which enables a movement of the free end of the piezo-actuator in three spatial directions (not illustrated in FIG. 11) is attached to the holding device 11487 of the measuring head 11485. A probe 11492 comprising a cantilever 11494 or lever arm 11494 and a measuring tip 11495 is secured to the free end of the piezo-actuator 11490. The free end of the cantilever 11494 of the probe 11492 has the measuring tip 11495.

[0170] Next, in connection with FIG. 12 and FIG. 13, options for positioning sensors 800 that can be used to measure disturbances of physical quantities that each affect a beam offset of the beam 11415 of the repair device 11120 will be disclosed. The repair device 11120 is only schematically illustrated, at a higher level of abstraction if compared to FIG. 11 in FIG. 12 and FIG. 13. FIG. 12 and FIG. 13, beyond what is disclosed in FIG. 11, also discloses a beam blanker 11801 that can be used to blank the beam 11415, as well as an aperture 11802 and electric coils 11803 and 11804 for deflecting the beam (i.e., forming optics of the beam deflection unit 112).

[0171] In the scenario of FIG. 12, the sensors 800 are arranged outside of the vacuum chamber 11442 of the repair device 11120. In the scenario FIG. 13, the sensors 800 are arranged inside the vacuum chamber 11442 of the repair device 11120. Combinations are possible, i.e., some of the sensors can be arranged inside the vacuum chamber while other sensors can be arranged outside of the vacuum chamber.

[0172] FIGS. 14 and 15 illustrate a mask repair operation at the high precision achievable with the repair device 11120 of the preceding FIGs. In a first step illustrated at FIG. 14, a mask defect 1471.1 in an absorber line 1453 on a substrate layer 1451 of the mask is determined with high precision. Using the inspection mode, a precise determination of the extension of the defect 1471.1 is determined, including at least a slope angle 1473.1 of the defect 1471.1. The position, a deviation to a target range 1475 of the edge position and the extensions of the defect can be determined with an accuracy below 1 nm, preferably even below 0.5 nm. The missing volume of material to be deposited in a repair operation can be determined with high accuracy. In the repair step (manipulation mode), utilizing for example low energy electron beam assisted deposition of material from precursor gases provided by the gas supply apparatus, the defect 1471.1 is filled with for example chromium, forming the repaired defect 1477. This is illustrated in FIG. 15. The performance of the repair operation is then verified by the apparatus in inspection mode. A resulting edge position of the line 1453 and a slope angle 1473.2 of the line edge can be obtained with high accuracy. Thereby it is maintained that a repair operation is performed very well within the specification requirement for masks, including the strong requirements for EUV masks with edge positions below 0.5 nm or even less. The steps of repair and verification can also be performed iteratively. Such manipulation is not limited to missing material in a mask layer but can also be applied in analogy to the removal of excess material in mask layer. Further, the manipulation is not limited to mask repair, but also to circuit edit operations at processed wafers. In both examples, layer material is removed by electron beam induced etching or deposited by electron beam induced deposition, and an end-pointing of the processing with high precision is required.

[0173] FIG. 16 schematically illustrates an example implementation of a charged particle beam device such as the charged particle beam device 100 discussed above.

[0174] The charged particle device 161001 in FIG. 16 is a low-energy corrected electron microscope with reduced aberrations, as described in German patent application, DE 10 2019 214 936, filed on Sep. 27, 2019, which is hereby incorporated by reference. Generally, a low-energy corrected electron microscope is comprising correction means chromatic aberration (CC), spherical aberration (CS), and optionally also field curvature (FC). A low-energy corrected single beam charged particle microscope 161001 comprises a beamlet generator 161301 for generating a single primary charged particle beamlet 161003, an object irradiation unit 161100 for illuminating an image subfield on a surface of a sample 11110 (e.g., a lithography mask or a semiconductor wafer including semiconductor structures) arranged in an object plane 16101, thereby generating during use a secondary electron beamlet 161009 emitting from a focus point 161605 of the primary beamlet 161003 within the image subfield. The subfield has typically a lateral extension of at least 5 m, preferably 8 m, 12 m or more. The object irradiation unit 161100 further comprises first to third electrostatic or magnetic lenses 161403, 161405 and 161407 and an objective lens 161102. The charged particle microscope 161001 further comprises a detection unit 161200 for acquisition during use a digital image of the image subfield of the surface of the sample. The detection unit 161200 comprises an electron sensor 161207 and optional electrostatic or electromagnetic deflection elements 161205. The charged particle microscope 161001 further comprises an electro-magnetic beam splitting system 161400 for guiding the primary beamlet 161003 along the primary beam-path (solid line 161013) and guiding the secondary beamlet 161009 along the secondary beam-path (dashed line, 161011). The secondary beamlet 161009, collected by objective lens 161102, is propagating opposite to the primary beamlet 161003 und therefore separated from the primary beamlet 161003 by the magnetic beam splitting system 161400. The charged particle microscope 161001 further comprises a long stroke raster scanner 161110. The raster scanner 161110 (forming a beam deflection unit) comprises at least a first set of deflection electrodes 161111. The charged particle microscope 161001 further comprises a control unit 16800 (implementing the control unit 119 or the control unit 130). The charged particle microscope 161001 further comprises at least a first corrector 161601 for correction the primary charged particle beamlet 161003. The charged particle system 161001 further comprises a correction system 161052 with a second optical axis 161050 at an angle to the optical axis 16105. The beam splitter system 161400 guides the primary beamlet in direction of the second optical axis 161050 into a correction system 161052. The correction system comprises an electrostatic mirror 161414, which reflects the primary beamlet back to the beam splitter system 161400. In an example, a second corrector 161602 is arranged in the correction system 161052, with correction electrodes 161612. With a low-energy corrected single beam charged particle microscope 161001, electron imaging with kinetic energies below 400 eV, preferable below 300 eV, even more preferably below 200 eV, or even more preferably below 150 eV, is enabled and a high resolution below 2 nm, preferably below 1.5 nm, even more preferably below 1 nm is achieved by utilizing primary electrons of low landing energy and the correction means of the low-energy electron microscope.

[0175] The charged particle beams are again arranged in a vacuum chamber (not shown in FIG. 16). The sensors can be arranged inside and/or outside of the vacuum chamber, as previously discussed in connection with FIGS. 14 and 15.

[0176] Summarizing, techniques have been disclosed that facilitate compensation of multiple disturbances caused by multiple physical quantities, the disturbances affecting a beam offset of a beam of a charged particle beam device. Such compensation is executed during an imaging mode or a manipulation mode, e.g., for mask repair or circuit added. Such compensation, in particular, is possible in case the disturbances/the beam offset is within a certain predetermined range. Else, if the disturbances cannot be compensated, the imaging mode or the manipulation mode is stopped according to examples, e.g., by blanking the beam and/or by closing precursor gas supply valves. A warning is output according to examples. Once the disturbances have resolved, the operation is restarted at the point of the process at which the stopping has occurred. Using the techniques disclosed herein, an increased quality for imaging tasks or manipulation tasks is achieved. The risk for damaging expensive lithography masks or semiconductor devices subject to a manipulation can be reduced.

[0177] Furthermore, techniques have been disclosed that facilitate using a sensor output of multiple sensors for a prediction of the future behavior of the charged particle beam device. For instance, the sensor output can be stored in a data repository and multiple time series can be correlated with each other. Correlations can be found and repetitive fingerprints can be identified. This can be used to make predictions for the future behavior of the charged particle beam device. Predictive maintenance information can be obtained, e.g., by acquiring the acoustic frequency spectrum and/or acoustic noise pressure using microphones the, e.g., continuous increasing noise level at certain frequencies in the sound spectrum can be detected, which can be indicative of failure of one or more parts of the charged particle beam device such as the pump.

[0178] The sensor output, in various examples, is analyzed using machine learning algorithms such as deep neural networks. Training can be reiterated from time to time, based on training data that is acquired during a calibration mode. Thus, the accuracy can be continuously increased. Furthermore, site-specific training based on site-specific calibration becomes possible.

[0179] Summarizing, at least the following examplesas defined by the following clauseshave been disclosed.

[0180] Clause 1. A charged particle beam device, comprising a beam source, a beam deflection unit, and a sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage, the charged particle beam device including: [0181] one or more sensors configured to measure one or more disturbances of one or more physical quantities that each affect a beam offset of the beam on the sample stage, [0182] at least one control unit configured to determine, based on a sensor output of the one or more sensors, one or more compensation signals to counteract the beam offset, wherein the at least one control unit is configured to provide the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or one or more compensator modules.

[0183] Clause 2. The charged particle beam device of clause 1,

wherein the at least one control unit is configured to determine a predictive component of the beam offset based on the sensor output of the one or more sensors and to determine the one or more compensation signals based on the predictive component of the beam offset.

[0184] Clause 3. The charged particle beam device of clause 2,

wherein the sensor output of at least one of the one or more sensors includes respective time series data,
wherein the at least one control unit is configured to determine the predictive component based on an analysis of the time series data of the sensor output of the at least one of the one or more sensors.

[0185] Clause 4. The charged particle beam device of clause 3,

wherein the analysis of the time series data comprises finding fingerprints of one or more predetermined disturbance events in the time series data, and/or applying a recurrent neural network such as a Long Short Term Memory Network.

[0186] Clause 5. The charged particle beam device of clause 4,

wherein the at least one control unit is configured to selectively activate a calibration phase,
wherein, when operating in the calibration phase, the at least one control unit is configured to populate a repository with the fingerprints of the one or more disturbance events, e.g., based on at least one of identifying respective repetitions of the fingerprints in the time series data or obtaining user input data that is indicative of a respective one of the one or more disturbance events.

[0187] Clause 6. The charged particle beam device of clause 4 or 5,

wherein the at least one control unit is configured to selectively activate a calibration phase,
wherein, when operating in the calibration phase, the at least one control unit is configured to train a predictive model based on the time series data measured during the calibration phase to find the fingerprints and to thereby enable the predictive model to determine the predictive component.

[0188] Clause 7. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is further configured to predict, based on at least one of the sensor output or the one or more compensation signals, an accuracy of operation of the charged particle beam device during a prediction time duration.

[0189] Clause 8. The charged particle beam device of clause 7,

wherein the at least one control unit is further configured to selectively abort operation of the charged particle beam device depending on the accuracy of operation, e.g., by blanking the beam.

[0190] Clause 9. The charged particle beam device of any one of the preceding clauses, wherein the one or more disturbances comprise multiple disturbances,

wherein the at least one control unit is configured to determine the one or more compensation signals based on cross-dependencies between the multiple disturbances.

[0191] Clause 10. The charged particle beam device of clause 9,

wherein the at least one control unit is configured to determine the one or more compensation signals based on a cross dependency between temperature-induced disturbances and pressure-induced disturbances.

[0192] Clause 11. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to determine the one or more compensation signals based on a pre-trained algorithm.

[0193] Clause 12. The charged particle beam device of clause 11,

wherein the pre-trained algorithm comprises a deep neural network such as a convolutional neural network.

[0194] Clause 13. The charged particle beam device of clause 11,

wherein the pre-trained algorithm comprises a machine learning algorithm.

[0195] Clause 14. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to determine the one or more compensation signals based on pre-parameterized functional dependencies.

[0196] Clause 15. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to determine the one or more compensation signals using a lookup table linking the sensor output with the one or more compensation signals.

[0197] Clause 16. The charged particle beam device of clause 15,

wherein the lookup table is retrieved from a device-specific repository associated with the charged particle beam device.

[0198] Clause 17. The charged particle beam device of clause 15,

wherein the lookup table is retrieved from a cloud storage repository associated with multiple charged particle beam devices.

[0199] Clause 18. The charged particle beam device of any one of the preceding clauses, wherein the multiple physical quantities are selected from the group comprising: acoustic vibration; vibration; pressure; humidity; temperature; laminar air flow; turbulent air flow; a differential quantity; a change rate of a physical quantity; a vector quantity; a scalar quantity.

[0200] Clause 19. The charged particle beam device of any one of the preceding clauses, wherein the one or more sensors comprise at least one sensor for measuring a temperature or pressure of a cooling liquid.

[0201] Clause 20. The charged particle beam device of any one of the preceding clauses, wherein at least one of the one or more sensors is arranged inside a vacuum chamber of the charged particle beam repair device.

[0202] Clause 21, the charged particle beam device of any one of the preceding clauses, wherein at least one of the one or more sensors is arranged outside of a vacuum chamber of the charged particle beam repair device.

[0203] Clause 22. The charged particle beam device of any one of the preceding clauses, wherein the one or more sensors comprise at least one sensor for measuring a pressure differential or temperature differential between two or more parts of the charged particle beam repair device.

[0204] Clause 23. The charged particle beam device of any one of the preceding clauses, wherein the one or more disturbances are selected from the group comprising: direct disturbances affecting the beam offset by deflecting the beam; indirect disturbances affecting the beam offset by impacting one or more parts of the charged particle beam device.

[0205] Clause 24. The charged particle beam device of any one of the preceding clauses, wherein the beam offset comprises at least one of a placement offset or a focal offset of the beam.

[0206] Clause 25. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to monitor the sensor output of a least one of the one or more sensors or a further sensor output of at least one further sensor and selectively blank the beam based on said monitoring.

[0207] Clause 26. The charged particle beam device of clause 25,

wherein the at least one control unit is configured to selectively blank the beam at lower latency if comparted to said determining the one or more compensation signals.

[0208] Clause 27. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to provide the one or more compensation signals by the charged particle beam device operates in the manipulation mode such as an electron beam induced etching or deposition mode, the manipulation mode comprising repairing or editing semiconductor devices on a wafer mounted to the sample stage.

[0209] Clause 28. The charged particle beam device of any one of the preceding clauses, wherein the charged particle beam device is a charged particle beam repair device.

[0210] Clause 29. The charged particle beam device of any one of the preceding clauses, wherein the charged particles are electrons or ions such as Helium or Neon ions.

[0211] Clause 30. The charged particle beam device of any one of the preceding clauses, wherein the charged particle beam device is a combined focused ion beam and an electron microscope cross-beam device.

[0212] Clause 31. The charged particle beam device of any one of the preceding clauses, wherein the charged particle beam device is a charged particle beam repair device, wherein the charged particle beam repair device further comprises a precursor gas source,

wherein the at least one control unit is configured to provide, to the beam source, the beam deflection unit, and the precursor gas source, control signals to implement an electron-beam-induced manipulation of a sample mounted to the sample stage, wherein the at least one control unit is configured to provide the one or more compensation signals during the electron-beam-induced manipulation.

[0213] Clause 32. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit is configured to provide the one or more compensation signals while the charged particle beam device operates in an imaging mode that comprises imaging structures of the sample mounted to the sample stage.

[0214] Clause 33. The charged particle beam device of any one of the preceding clauses, wherein the at least one control unit determines the one or more compensation signals in accordance with a linear or a nonlinear dependency of the one or more compensation signals on the sensor output.

[0215] Clause 34. The charged particle beam device of any one of the preceding clauses, wherein the one or more disturbances comprise multiple disturbances,

wherein the one or more physical quantities comprise multiple physical quantities.

[0216] Clause 35. The charged particle beam device of any one of the preceding clauses, wherein the one or more compensator modules are selected from the group comprising: external, i.e., outside of a vacuum chamber or housing of the charged particle beam device, coils for applying magnetic fields; external electric field plates for applying electric fields; Helmholtz coil pairs; an active cooling or heating element; an active damping element; a pressure-control element such as a pump.

[0217] Clause 36. A charged particle beam device comprising a beam source, a beam deflection unit, and a sample stage, the beam deflection unit being configured to deflect a beam originating from the beam source to position the beam on the sample stage, the charged particle beam device comprising: [0218] one or more sensors configured to measure one or more disturbances of one or more physical quantities that each affect a beam offset of the beam on the sample stage, and [0219] at least one control unit configured to determine, based on the sensor output of the one or more sensors, metadata that is indicative of one or more compensation operations to counteract the beam offset in image data acquired by the charged particle beam device operating in an imaging mode, and to store the metadata in association with the image data.

[0220] Clause 37. The charged particle beam device of clause 36,

wherein the one or more compensation operations are selected from the group comprising: imaging shift; rotation; skew; contrast enhancement; blur reduction.

[0221] Clause 38. A method, comprising: [0222] monitoring physical quantities that cause disturbances onto a beam of a charged particle beam device, [0223] based on said monitoring, compensating the disturbances.

[0224] Clause 39. The method of clause 38,

wherein said compensating of the disturbances comprises applying a voltage or current to an electronic optics of a beam deflection unit of the charged particle beam device, to move the beam in an opposite direction of a beam offset caused by the disturbances.

[0225] Clause 40. The method of clause 38 or 39,

wherein said compensating or reducing of the disturbances comprises moving a sample stage of the charged particle beam device in a direction of a beam offset caused by the disturbances.

[0226] Clause 41. The method of any one of clauses 38 to 40,

wherein the time latency between said monitoring and said compensating or reducing is less than 50 milliseconds, optionally less than 500 milliseconds, further optionally less than 5 seconds.

[0227] Clause 42. The method of any one of clauses 38 to 41,

wherein said compensating or reducing is executed while the charged particle beam device operates in a manipulation mode that comprises an electron-beam-induced etching or deposition of material from or onto a wafer mask.

[0228] Clause 43. The method of any one of clauses 38 to 42, further comprising: [0229] based on said monitoring, selectively aborting operation of the charged particle beam device.

[0230] Clause 44. The method of clause 43,

wherein said selectively aborting operation of the charged particle beam device comprises blanking the beam.

[0231] Clause 45. The method of clause 43 or 44, further comprising: [0232] based on said monitoring, selecting between executing said compensating of the disturbances and executing said aborting operation.

[0233] Clause 46. A method of manipulating or imaging a sample mounted to a sample stage of a charged particle beam device, the charged particle beam device comprising a beam source, a beam deflection unit, and the sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage,

wherein the method comprises: [0234] obtaining a sensor output of one or more sensors of the charged particle beam device, the one or more sensors measuring one or more disturbances of one or more physical quantities that each affect a beam offset of the beam on the sample stage, [0235] determining, based on the sensor output of the one or more sensors, one or more compensation signals to counteract the beam offset, [0236] providing the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or one or more compensator modules.

[0237] Clause 47. The method of clause 46, wherein the method is executed by the control unit of the charged particle beam device of clause 1.

[0238] Clause 48. A method of post-processing image data that is acquired by a charged particle beam device that comprises a beam source, a beam deflection unit, and a sample stage, the beam deflection unit being configured to deflect a beam of charged particles originating from the beam source to position the beam on the sample stage, wherein the method comprises: [0239] obtaining a sensor output from one or more sensors of the charged particle beam device, the one or more sensors measuring one or more disturbances of one or more physical quantities that each affect a beam offset of the beam on a sample stage, [0240] determining, based on the sensor output of the one or more sensors, metadata that is indicative of one or more compensation operations to counteract the beam offset in image data acquired by the charged particle beam device operating in an imaging mode, and [0241] post-processing the image data based on the metadata and in accordance with the one or more compensation operations.

[0242] Clause 49. The method of clause 48, wherein the method is at least partially executed by the control unit of the charged particle beam device of clause 36.

[0243] Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.

[0244] For illustration, above various examples have been disclosed in the context of a charged particle beam repair device that executes a repair task using an electron-beam-induced manipulation of a sample, i.e., EBID and/or EBIE. As a general rule, repair tasks could also be employed using physical action using ions, i.e., FIB etching. Furthermore, the techniques disclosed herein are not limited to a charged particle beam repair devices, but can also used for compensating disturbances during a circuit edit operation at a semiconductor wafer, or during an inspection or measurement task during operation in the imaging mode of a respective imaging charged particle beam device.

[0245] For illustration, above various examples have been disclosed in the context of a charged particle beam device employing charged particles such as electrons or ions. Similarly, techniques disclosed herein may be applied to non-charged particle beam devices, e.g., for photon-based microscopes. Here, disturbances can be caused by physical quantities such as seismic variation, acoustics, pressure changes, changes of wind speed, changes of humidity, temperature, etc. Respective beam devices could be, e.g., lasers, x-ray investigation tools, etc. A compensation can be achieved by shifting the sample stage to counteract the beam offset, as has been explained in connection with FIG. 1-FIG. 5.

[0246] Furthermore, techniques of active compensation of a beam offset due to disturbances of physical quantities have been disclosed. Such techniques can be applied with passive shielding. For instance, acoustic vibrations, thermal drift, laminar or turbulent airflow can be reduced by encapsulating the beam related parts of the charged particle beam device in a housing. Noise absorbent material can be attached to the housing. Passive or active vibration damping systems can be used to support the housing on the floor.