Optimizing light path uniformity in inspection systems
AssigneeInfineon Technologies AG
InventorsWilliam Roberts, Gerhard Kunkel, Patrick Lomtscher, Karl Schumacher
Life of this patent
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Abstract
An inspection system includes an illumination source configured to illuminate a blazed phase grating sample, image collection pathways and an imaging system configured to capture an image of a sample point of the blazed phase grating sample, and a controller configured to adjust the illumination source in response to an analysis of the image of the sample point to determine illumination uniformity of the inspection system.
Claims17
An inspection system comprising:
- an illumination source configured to illuminate a blazed phase grating sample comprising relief gratings at a plurality of angles and relief depths, each relief grating angle adapted to direct light through a different azimuth of a pupil of the inspection system;
- image collection pathways and an imaging system configured to capture an image of a sample point of the blazed phase grating sample;
- and
- a controller configured to adjust the illumination source in response to an analysis of the image of the sample point to determine illumination uniformity of the inspection system, the analysis being based on a comparison of maximum image intensities for each azimuth.
An inspection system comprising:
- means for providing a blazed phase grating sample configured to reflect light through a plurality of azimuths of a pupil of an inspection system;
- means for obtaining an image of a sample point of the blazed phase grating sample in the inspection system;
- means for analyzing the image to determine illumination uniformity of the inspection system;
- and
- means for adjusting the inspection system based on the analysis to optimize the illumination uniformity of the inspection system;
- wherein the means for analyzing the image comprises:
- means for determining a maximum image intensity for each azimuth;
- means for comparing the maximum image intensities;
- and
- means for generating feedback based on the comparison for adjusting the inspection system.
A method for optimizing the illumination uniformity of an inspection system, the method comprising:
- providing a blazed phase grating sample configured to reflect light through a plurality of azimuths of a pupil of an inspection system;
- obtaining an image of a sample point of the blazed phase grating sample in the inspection system;
- analyzing the image to determine illumination uniformity of the inspection system;
- and
- adjusting the inspection system based on the analysis to optimize the illumination uniformity of the inspection system;
- wherein analyzing the image comprises:
- determining a maximum image intensity for each azimuth;
- comparing the maximum image intensities;
- and
- generating feedback based on the comparison for adjusting the inspection system.
A method for optimizing the light path uniformity of an inspection system, the method comprising:
- providing a blazed phase grating sample comprising relief gratings at a plurality of angles and relief depths, each relief grating angle adapted to direct light though a different azimuth of a pupil of the inspection system;
- obtaining an image of the sample in an inspection system;
- analyzing the image to determine a maximum image intensity for each azimuth;
- comparing the maximum image intensities for each azimuth;
- providing feedback to the inspection tool based on the comparison;
- and
- adjusting an illumination element of the inspection system based on the feedback.
Dependencies are inferred from the claim text.