Patent ID: 6174080
Filing Date: 2001-01-16
Classification: G01J

Abstract:
An apparatus for measuring the temperature of a substrate in a thermal processing chamber, the chamber including a reflector forming a reflecting cavity with a substrate when the substrate is positioned in the chamber, the apparatus comprising:a first polarizer positioned to polarize radiation reflected by the reflector;a probe having an input end positioned to receive radiation from the reflecting cavity, the radiation including reflected radiation emitted by the substrate and reflected by the reflector and non-reflected radiation emitted by the substrate and not reflected by the reflector;a polarizing system optically coupled to an output end of the probe and configured to generate a first beam and a second beam, the polarizing system including a second polarizer oriented such that a ratio of reflected radiation to non-reflected radiation is higher in the first beam than the second beam; anda detector apparatus optically coupled to the polarizing system to generate a first intensity signal from the first beam and a second intensity signal from the second beam.