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US 12,754,482 B2Granted
Field mirrors for imaging field compression driven photon efficiency and imaging wavefront improvement
AssigneeKLA Corporation
InventorAlon Rosenthal
Life of this patent
Estimating the term…
Abstract
Collected light may be split into fields using grazing incidence mirrors to avoid illuminating gaps between the active areas for readout electronics. The grazing incidence mirrors may reduce lost field space in the integrating direction by splitting the imaging field in that direction to allow the readout electronics to be outside of the field. The fields may be split so there is space for readout circuits but no associated light on the readout circuits. The size of the illumination may then be decreased and/or the number and/or size of sensors increased to improve the photon collection efficiency. The better photon collection efficiency may reduce shot noise and/or improves tool throughput.
Claims24
An inspection system comprising:
- one or more grazing incidence mirrors, wherein the one or more grazing incidence mirrors are configured to split a collected light into at least two fields, wherein the at least two fields include one or more reflected fields, wherein the one or more grazing incidence mirrors are disposed in a path of the one or more reflected fields such that the one or more reflected fields reflect from the one or more grazing incidence mirrors;
- and
- a detector, wherein the detector is configured to generate one or more images from the at least two fields, wherein the detector includes a plurality of time-delay-integration sensors, wherein the plurality of time-delay-integration sensors include a plurality of active areas and a plurality of readout circuits, wherein the plurality of active areas are arranged in an array of columns and rows, wherein the at least two fields are configured to land on separate of the columns of the plurality of active areas, wherein at least a portion of the detector between the columns of the plurality of active areas does not receive the collected light, wherein the plurality of readout circuits are configured to readout charges from the plurality of active areas as lines of the one or more images.
An inspection system comprising:
- a source sub-system configured to emit illumination, wherein the illumination is vacuum ultraviolet light;
- illumination optics configured to direct the illumination to a sample, wherein the illumination is configured to reflect from the sample as collected light;
- a stage, wherein the stage is configured to support the sample;
- imaging optics configured to direct the collected light to one or more grazing incidence mirrors, wherein the imaging optics magnify the collected light;
- the one or more grazing incidence mirrors, wherein the one or more grazing incidence mirrors are configured to split the collected light into at least two fields, wherein the at least two fields include one or more reflected fields, wherein the one or more grazing incidence mirrors are disposed in a path of the one or more reflected fields such that the one or more reflected fields reflect from the one or more grazing incidence mirrors;
- a detector, wherein the detector is configured to generate one or more images from the at least two fields, wherein the detector includes a plurality of time-delay-integration sensors, wherein the plurality of time-delay-integration sensors include a plurality of active areas and a plurality of readout circuits, wherein the plurality of active areas are arranged in an array of columns and rows, wherein the at least two fields are configured to land on separate of the columns of the plurality of active areas, wherein at least a portion of the detector between the columns of the plurality of active areas does not receive the collected light, wherein the plurality of readout circuits are configured to readout charges from the plurality of active areas as lines of the one or more images;
- and
- a controller configured to receive the one or more images and detect one or more defects based on the one or more images.
5 more elements
A method comprising:
- splitting a collected light into at least two fields, wherein the collected light is split into the at least two fields using one or more grazing incidence mirrors, wherein the at least two fields include one or more reflected fields, wherein the one or more grazing incidence mirrors are disposed in a path of the one or more reflected fields such that the one or more reflected fields reflect from the one or more grazing incidence mirrors;
- and
- generating one or more images from the at least two fields, wherein the one or more images are generated using a detector, wherein the detector includes a plurality of time-delay-integration sensors, wherein the plurality of time-delay-integration sensors include a plurality of active areas and a plurality of readout circuits, wherein the plurality of active areas are arranged in an array of columns and rows, wherein the at least two fields are configured to land on separate of the columns of the plurality of active areas, wherein at least a portion of the detector between the columns of the plurality of active areas does not receive the collected light, wherein the plurality of readout circuits are configured to readout charges from the plurality of active areas as lines of the one or more images.
Dependencies are inferred from the claim text.