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Two-Color Etch Monitoring Technique

IP.com Disclosure Number: IPCOM000066002D
Original Publication Date: 1979-Jan-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Chappelow, RE [+details]

Abstract

If an etching layer is illuminated by monochromatic, coherent light, the reflected light suffers periodic variations in intensity due to wellknown thin-film interference effects. If the sample is illuminated with two distinct frequencies of light, so that an interference function is obtained for each of the two frequency values, it is possible to determine the thickness of the etching layer and the material etch rate in real time.