摘要 |
An apparatus for measuring the temperature of a substrate in a thermal processing chamber is disclosed. The chamber includes a reflector forming a reflecting cavity with a substrate when the substrate is positioned in the chamber. The apparatus includes a first polarizer positioned to polarize radiation reflected by the reflector, a probe having an input end positioned to receive reflected and non-reflected radiation from the reflecting cavity, a polarizing system optically coupled to an output end of the probe, and a detector apparatus optically coupled to the polarizing system. The polarizing system is configured to generate a first beam and a second beam, and it includes 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. The detector apparatus generates a first intensity signal from the first beam and a second intensity signal from the second beam. The two intensity signals are processed to determine an emissivity-corrected substrate temperature.
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