Optimized optical system design for endpoint detection

摘要

An optimization of the optical detection system 110 for the use of optical emission spectroscopy in end-point detection. The optical detection system 110 addresses the needs of a radiant heated wafer system in a downstream process chamber 22 environment. The optical detection system maximizes signal light from relevant reactions, maximizes signal-to noise and signal-to-background ratios, utilizes very small diagnostics access, collects light from the region of most intense light emission from endpoint processes, collects light from representative parts of an entire wafer with just one diagnostic access port 126 to ensure complete end-point, and eliminates light signals from sources other than the wafer 98.