Non-contact temperature measurement by double-wavelength shift of Brewster's angle

摘要

Embodiments disclosed herein relate to a thermal processing chamber having a substrate monitoring system. In one embodiment, a temperature monitoring system is disclosed herein. The temperature monitoring system includes a window and a housing defining an interior volume. The temperature monitoring system further includes two or more light sources, a camera, and a polarizer. Two or more light sources are placed in the inner volume, under the window. Among the two or more light sources, a first light source has a first wavelength. Among the two or more light sources, the second light source has a second wavelength. The camera is placed opposite two or more light sources. The camera is configured to capture a plurality of frames of two or more light beams from two or more light sources. The polarizer is placed in the optical path of two or more light beams.