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Proceedings Paper

End-Point Detection With Laser Interferometry
Author(s): Heinz H. Busta
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Paper Abstract

A laser interferometric method was developed to detect end-of-etching of materials such as doped and undoped polysilicon, Si3N4, Si02 and metals used during different stages of IC and thin film device processing. For metal etching, a detector trace of constant magnitude is obtained until the underlying layers are exposed. At this point, a step change in re-flectivity occurs, signaling the end-point. For the other above mentioned films, a sinu-soidal waveform is obtained which changes its frequency once the film of interest is etched and the underlying layers become exposed. The method is applicable to all of the dry etch-ing processes and will be illustrated in some detail for polysilicon and silicon nitride etching applications using a barrel-type plasma reactor.

Paper Details

Date Published: 30 April 1981
PDF: 6 pages
Proc. SPIE 0276, Optical Characterization Techniques for Semiconductor Technology, (30 April 1981); doi: 10.1117/12.931702
Show Author Affiliations
Heinz H. Busta, Gould Laboratories (United States)

Published in SPIE Proceedings Vol. 0276:
Optical Characterization Techniques for Semiconductor Technology
David E. Aspnes; Roy F. Potter; Samuel S. So, Editor(s)

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