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US 11,899,380 B2Granted
Apparatus for and method of sensing alignment marks
AssigneeASML Holding N.V.
InventorsKrishanu Shome, Igor Matheus Petronella Aarts, Junwon Lee
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Abstract
An apparatus for and method of sensing alignment marks in which a self-referencing interferometer based sensor outputs standing images of the alignment marks and camera device is used to capture the images as output by the sensor and a detector is used to obtain phase information about the alignment marks from the images as output by the sensor.
Claims18
An apparatus for sensing an alignment mark on a substrate, the apparatus comprising:
- a sensor comprising a self-referencing interferometer having a field of view at the substrate larger than the alignment mark and configured to receive light diffracted by the alignment mark and adapted to generate an output comprising at least one standing output image of the alignment mark as the alignment mark is scanned;
- a detector adapted to detect a phase signal in the output;
- a camera adapted to capture an image of the output;
- an optical device configured to receive the output and adapted to convey the output to the detector and the camera;
- and
- a processor configured to receive data from the camera and adapted to perform image manipulation on the data, wherein the image manipulation comprises setting a digital aperture that is one of an arbitrary shape, modulated, or apodized.
3 more elements
A method, implemented by a metrology apparatus, for sensing an alignment mark on a substrate, the method comprising:
- receiving, at a sensor comprising a self-referencing interferometer having a field of view at the substrate larger than the alignment mark, light diffracted by the alignment mark;
- generating an output comprising at least one standing output image of the alignment mark as the alignment mark is scanned;
- detecting, at a detector, a phase signal in the output;
- capturing, at a camera, an image of the output;
- receiving, at an optical device, the output;
- conveying the output to the detector and the camera;
- receiving, at a processor, data from the camera;
- and
- performing image manipulation on the data, the image manipulation comprising setting a digital aperture that is one of an arbitrary shape, modulated, or apodized.
6 more elements
Dependencies are inferred from the claim text.