Inventors:
Alan C. Janos - Darnstown MD
Andre G. Cardoso - Laurel MD
Daniel B. Richardson - Westminster MD
Assignee:
Axcelis Technologies, Inc. - Beverly MA
International Classification:
G03D 500
US Classification:
396611, 15634525, 156250, 1565592, 156356, 156369, 156118, 156723 R
Abstract:
The present invention is directed to optimization of the optical detection system for the use of optical emission spectroscopy in end-point detection. The optimization specifically addresses the needs of a radiant heated wafer system in a downstream process chamber environment. The present invention 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 to ensure complete end-point, and eliminates light signals from sources other than the wafer.