TEMPERATURE MEASUREMENT USING SILICON WAFER REFLECTION INTERFERENCE

摘要

Temperature measurement of a silicon wafer is described using the interference between reflections off surfaces of the wafer. In one example, the invention includes a silicon processing chamber, a wafer holder within the chamber to hold a silicon substrate for processing, and a laser directed to a surface of the substrate. A photodetector receives light from the laser that is reflected off the surface directly and through the substrate and a processor determines a temperature of the silicon substrate based on the received reflected light.