Apertures having references edges are situated to define a sample irradiation zone and a shielded zone. The sample irradiation zone includes a portion proximate the shielded zone that is conjugate to a detector. A sample is scanned into the sample irradiation zone from the shielded zone so that the sample can remain unexposed until situated properly with respect to the detector for imaging. Irradiation exposure of the sample is reduced, permitting superior imaging.

A transmission electron microscope includes a control unit that: determines an excitation amount of a second illumination system lens based on an excitation amount of first illumination system lens such that the second illumination system lens satisfies a first optical condition; and determines a control amount of a first deflector and a control amount of a second deflector based on the excitation amount of the second illumination system lens such that the first deflector and the second deflector satisfy a second optical condition. The first optical condition is for a convergence angle of the electron beam to be constant even if the excitation amount of the first illumination system lens has changed, and the second optical condition is for an illuminating position of the electron beam and an illuminating angle of the electron beam to be constant even if the excitation amount of the first illumination system lens has changed.

A charged particle beam system is disclosed, comprising: a charged particle beam generator for generating a beam of charged particles; a charged particle optical column arranged in a vacuum chamber, wherein the charged particle optical column is arranged for projecting the beam of charged particles onto a target, and wherein the charged particle optical column comprises a charged particle optical element for influencing the beam of charged particles; a source for providing a cleaning agent; a conduit connected to the source and arranged for introducing the cleaning agent towards the charged particle optical element; wherein the charged particle optical element comprises: a charged particle transmitting aperture for transmitting and/or influencing the beam of charged particles, and at least one vent hole for providing a flow path between a first side and a second side of the charged particle optical element, wherein the vent hole has a cross section which is larger than a cross section of the charged particle transmitting aperture. Further, a method for preventing or removing contamination in the charged particle transmitting apertures is disclosed, comprising the step of introducing the cleaning agent while the beam generator is active.

A transmission electron microscope includes a control unit that: determines an excitation amount of a second illumination system lens based on an excitation amount of first illumination system lens such that the second illumination system lens satisfies a first optical condition; and determines a control amount of a first deflector and a control amount of a second deflector based on the excitation amount of the second illumination system lens such that the first deflector and the second deflector satisfy a second optical condition. The first optical condition is for a convergence angle of the electron beam to be constant even if the excitation amount of the first illumination system lens has changed, and the second optical condition is for an illuminating position of the electron beam and an illuminating angle of the electron beam to be constant even if the excitation amount of the first illumination system lens has changed.

A multiple particle beam microscope and an associated method can provide a fast autofocus around an adjustable working distance. A system can have one or more fast autofocus correction lenses for adapting, in high-frequency fashion, the focusing, the position, the landing angle and the rotation of individual particle beams upon incidence on a wafer surface during the wafer inspection. Fast autofocusing in the secondary path of the particle beam system can be implemented in analogous fashion. An additional increase in precision can be attained via fast aberration correction mechanism in the form of deflectors and/or stigmators.

A charged particle beam device for imaging and/or inspecting a sample is described. The charged particle beam device includes a beam emitter for emitting a primary charged particle beam; a retarding field device for retarding the primary beam before impinging on the sample, the retarding field device including an objective lens and a proxy electrode; and a first detector for off-axial backscattered particles between the proxy electrode and the objective lens. The charged particle beam device is adapted for guiding the primary beam along an optical axis to the sample for releasing signal particles. The proxy electrode includes one opening allowing a passage of the primary charged particle beam and of the signal particles, wherein the one opening is sized to allow a passage of charged particles backscattered from the sample at angles from 0° to 20° or above relative to the optical axis. Further, a method for imaging and/or inspecting a sample with a charged particle beam device is described.

A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit forms plural and parallel images of one single electron source by deflecting plural beamlets of a parallel primary-electron beam therefrom, and one objective lens focuses the plural deflected beamlets onto a sample surface and forms plural probe spots thereon. A movable condenser lens is used to collimate the primary-electron beam and vary the currents of the plural probe spots, a pre-beamlet-forming means weakens the Coulomb effect of the primary-electron beam, and the source-conversion unit minimizes the sizes of the plural probe spots by minimizing and compensating the off-axis aberrations of the objective lens and condenser lens.

The invention relates to a gas reservoir (3000) for receiving a precursor (3035). The gas reservoir (3000) has a gas-receiving unit (3004) which is arranged in a first receiving unit (3002) of a basic body (3001), and a sliding unit (3007) which is arranged movably in a second receiving unit (3003) of the basic body (3001). The gas-receiving unit (3004) has a movable closure unit (3006) for opening or closing a gas outlet opening (3005) of the gas-receiving unit (3004). In a first position of the sliding unit (3007), both a first opening (3009) of a sliding-unit line device (3008) is fluidically connected to a first basic body opening (3011) and a second opening (3010) of the sliding-unit line device (3008) is fluidically connected to a second basic body opening (3012). In the second position of the sliding unit (3007), both the first opening (3009) is arranged at an inner wall (3015) of the second receiving unit (3003) and the second opening (3010) is arranged at the movable closure unit (3006).

Methods and systems for detecting charged particles from a specimen are provided. One system includes a first repelling mesh configured to repel charged particles from a specimen having an energy lower than a first predetermined energy and a second repelling mesh configured to repel the charged particles that pass through the first repelling mesh and have an energy that is lower than a second predetermined energy. The system also includes a first attracting mesh configured to attract the charged particles that pass through the first repelling mesh, are repelled by the second repelling mesh, and have an energy that is higher than the first predetermined energy and lower than the second predetermined energy. The system further includes a first detector configured to generate output responsive to the charged particles that pass through the first attracting mesh.

The present invention overcomes a trade-off between throughput, SNR, and spatial resolution in a charged particle beam device. Accordingly, a computer 18 sets at least one of a charged particle optical system and a detection system so as to modulate the intensity of signal charged particles or an electromagnetic wave detected by a detector 12 at a prescribed frequency. The charged particle optical system scans a specimen with a charged particle beam. The computer 18 generates an image or a signal profile by associating an irradiation position of the charged particle beam with a DC component of a signal acquired through synchronous detection of a detection signal from the detector at the irradiation position with a reference signal having a prescribed frequency.