Disclosed is a metrology sensor apparatus and associated method. The metrology sensor apparatus comprises an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state and an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark. The metrology mark comprises a main structure and changes, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to the polarization state of the second portion of the scattered radiation. The metrology sensor apparatus further comprises an optical filtering system which filters out the second portion of the scattered radiation based on its polarization state.

System and method for monitoring of performance of a mirror array of a digital scanner with a use of a lateral shearing interferometer (operated in either static or a phase-shifting condition) to either simply identify problematic pixels for further troubleshooting or measure the exact magnitude of the mirror's deformation.

A method of controlling a feedback system with a data matching module of an extreme ultraviolet (EUV) radiation source is disclosed. The method includes obtaining a slit integrated energy (SLIE) sensor data and diffractive optical elements (DOE) data. The method performs a data match, by the data matching module, of a time difference of the SLIE sensor data and the DOE data to identify a mismatched set of the SLIE sensor data and the DOE data. The method also determines whether the time difference of the SLIE sensor data and the DOE data of the mismatched set is within an acceptable range. Based on the determination, the method automatically validates a configurable data of the mismatched set such that the SLIE sensor data of the mismatched set is valid for a reflectivity calculation.

Disclosed is method of optimizing bandwidth of measurement illumination for a measurement application, and an associated metrology apparatus. The method comprises performing a reference measurement with reference measurement illumination having a reference bandwidth and performing one or more optimization measurements, each of said one or more optimization measurements being performed with measurement illumination having a varied candidate bandwidth. The one or more optimization measurements are compared with the reference measurement; and an optimal bandwidth for the measurement application is selected based on the comparison.

The present disclosure provides an apparatus and a method for detecting an optimal focal plane of a lithographic projection objective lens, the apparatus comprising: an illumination means, a beam splitting means, a lens array, a mask plate, a reflecting device, a photoelectric detector and a controller. The illumination means may generate a collimated beam, which is transmitted through the beam splitting means, focused by the lens array to the mask plate for spatial-filtering, and then delivered to the lithographic projection objective lens. The reflecting device reflects a focused beam passing through the lithographic projection objective lens to generate a reflected beam. The photoelectric detector detects an intensity of the reflected beam from the reflecting device after being spatial-filtered via the mask plate and generates a beam intensity signal. The controller connects a workpiece table and the photoelectric detector and is configured to control a movement of the workpiece table and/or collect the beam intensity signal generated by the photoelectric detector. By utilizing the movement of the reflecting device along a direction of the optical axis of the lithographic projection objective lens, the present disclosure is capable of detecting the position of the optimal focal plane of the lithographic projection objective lens according to a change in an intensity of reflected beam under each field of view.

An exposure apparatus includes a projection optical system configured to project a pattern of a mask onto a substrate, a substrate stage configured to hold and move the substrate, and a controller configured to control exposure of the substrate held by the substrate stage, wherein the controller obtains an amount of deviation of an image of the pattern projected onto the substrate with respect to the pattern of the mask based on telecentricity information, which is information on telecentricity for respective image heights of the projection optical system, and height information, which is information on the height of a surface of the substrate, and corrects deviation of the image based on the obtained amount of deviation to expose the substrate.

The invention relates to a method and a device for characterizing a mask for microlithography. In a method according to the invention, structures of a mask intended for use in a lithography process in a microlithographic projection exposure apparatus are illuminated by an illumination optical unit, wherein the mask is imaged onto a detector unit by an imaging optical unit, wherein image data recorded by the detector unit are evaluated in an evaluation unit. In this case, for emulating an illumination setting predefined for the lithography process in the microlithographic projection exposure apparatus, the imaging of the mask onto the detector unit is carried out in a plurality of individual imagings which differ from one another with regard to the illumination setting set in the illumination optical unit or the polarization-influencing effect set in the imaging optical unit.

Disclosed is an illumination source apparatus comprising a high harmonic generation medium, a pump radiation source and a spatial filter. The pump radiation source emits a beam of pump radiation having a profile comprising no pump radiation in a central region of the beam and excites the high harmonic generation medium so as to generate high harmonic radiation. The pump radiation and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation. The spatial filter is located beyond a focal plane of the beam of pump radiation, and blocks the pump radiation. Also disclosed is a method of generating high harmonic measurement radiation optimized for filtration of pump radiation therefrom.

The disclosure provides a method and an apparatus for modifying imaging properties of a microlithographic optical system. In a method according to the disclosure, the imaging properties are modified by way of control signals coupled into the optical system by way of at least one interface. The values of the control signals that are in each case coupled in during the controlling for a desired modification of the imaging properties are ascertained on the basis of a model. The model is created by virtue of performing, in a learning phase in which the modification of the imaging properties that is in each case attained for different values of the control signals is ascertained, a successive individual adaptation of the model to the optical system. The learning phase is performed without prior specification of explicit information relating to internal mechanisms of action within the optical system.

An eccentricity measuring method includes a forming step of dividing reflected light from a first surface and a second surface of a test lens by a plurality of optical elements and of forming a first spot group and a second spot group, and an eccentricity calculating step of calculating an eccentricity amount of the first surface relative to the second surface based on the first spot group and the second spot group.