Thickness measurement of substrate using color metrology

• Main Author: Benvegnu, Dominic J
• Format: Patent
• Language: English
• Published: 20.06.2023
• Subjects: BASIC ELECTRIC ELEMENTS; CALCULATING; COMPUTING; COUNTING; DRESSING OR CONDITIONING OF ABRADING SURFACES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; GRINDING; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; PERFORMING OPERATIONS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; POLISHING; SEMICONDUCTOR DEVICES; TRANSPORTING

A metrology system for obtaining a measurement representative of a thickness of a layer on a substrate includes a camera positioned to capture a color image of at least a portion of the substrate. A controller is configured to receive the color image from the camera, store a predetermined path in a coordinate space of at least two dimension including a first color channel and a second color channel, store a function that provides a value representative of a thickness as a function of a position on the predetermined path, determine a coordinate of a pixel in the coordinate space from color data in the color image for the pixel, determine a position of a point on the predetermined path that is closest to the coordinate of the pixel, and calculate a value representative of a thickness from the function and the position of the point on the predetermined path.