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US 12,663,259 B2Granted
Full wafer thickness map reflectometry
AssigneeGlobalWafers Co., Ltd.
InventorBenno Orschel
Life of this patent
Estimating the term…
Abstract
A method of measuring a thickness of a semiconductor structure includes illuminating the semiconductor structure with the incoherent, uncollimated light from at least one light source, and capturing, using a camera, at least one image of the semiconductor structure illuminated by the light from the light source. The at least one image includes separate first color, second color, and third color images, the first, second, and third colors being different from each other. Thickness maps are produced for at least two layers of the semiconductor structure based on the first color, second color, and third color images and reference first color, second color, and third color images of a reference silicon wafer.
Claims16
A thickness measuring system comprising:
- a camera positioned above a center of a semiconductor structure to capture light reflected by the semiconductor structure;
- at least one light source providing incoherent, uncollimated light;
- and
- a controller including a processor and a memory, the controller operatively coupled to the camera and the at least one light source, the memory including instructions that when executed by the processor cause the controller to:
- illuminate the semiconductor structure with the incoherent, uncollimated light from the at least one light source;
- cause the camera to capture at least one image of the semiconductor structure illuminated by the light from the light source, the at least one image including separate first color, second color, and third color images, the first, second, and third colors being different from each other;
- and
- produce thickness maps for at least two layers of the semiconductor structure based on the first color, second color, and third color images and reference first color, second color, and third color images of a reference silicon wafer, the thickness maps based in part on ratios of light intensity of the first color, second color, and third color images of the semiconductor structure and light intensity of the reference first color, second color, and third color images of the reference silicon wafer, and wherein the instructions cause the controller to produce the thickness maps in part by;
- determining a first semiconductor structure ratio of the light intensity of the first color image of the semiconductor structure to the light intensity of the third color image of the semiconductor structure;
- determining a second semiconductor structure ratio of the light intensity of the second color image of the semiconductor structure to the light intensity of the third color image of the semiconductor structure;
- determining a first reference ratio of the light intensity of the first color image of the reference silicon wafer to the light intensity of the third color image of the reference silicon wafer;
- and
- determining a second reference ratio of the light intensity of the second color image of the reference silicon wafer to the light intensity of the third color image of the reference silicon wafer.
10 more elements
A method of measuring a thickness of a semiconductor structure comprising:
- illuminating the semiconductor structure with the incoherent, uncollimated light from at least one light source;
- capturing, using a camera, at least one image of the semiconductor structure illuminated by the light from the light source, the at least one image including separate first color, second color, and third color images, the first, second, and third colors being different from each other;
- and
- producing thickness maps for at least two layers of the semiconductor structure based on the first color, second color, and third color images and reference first color, second color, and third color images of a reference silicon wafer, wherein producing the thickness maps includes producing the thickness maps based in part on ratios of light intensity of the first color, second color, and third color images of the semiconductor structure and light intensity of the reference first color, second color, and third color images of the reference silicon wafer, and producing the thickness maps includes:
- determining a first semiconductor structure ratio of the light intensity of the first color image of the semiconductor structure to the light intensity of the third color image of the semiconductor structure;
- determining a second semiconductor structure ratio of the light intensity of the second color image of the semiconductor structure to the light intensity of the third color image of the semiconductor structure;
- determining a first reference ratio of the light intensity of the first color image of the reference silicon wafer to the light intensity of the third color image of the reference silicon wafer;
- and
- determining a second reference ratio of the light intensity of the second color image of the reference silicon wafer to the light intensity of the third color image of the reference silicon wafer.
6 more elements
Dependencies are inferred from the claim text.