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Proceedings Paper • Open Access

Lithography overlay controller formulation
Author(s): Christopher A. Bode; Anthony J. Toprac; Richard D. Edwards; Thomas F. Edgar

Paper Abstract

Lithography overlay refers to the measurement of the alignment of successive patterns within the manufacture of semiconductor devices. Control of overlay has become of great importance in semiconductor manufacturing, as the tolerance for overlay error is continually shrinking in order to manufacture next-generation semiconductor products. Run-to-run control has become an attractive solution to many control problems within the industry, including overlay. The term run-to-run control refers to any automated procedure whereby recipe settings are updated between successive process runs in order to keep the process under control. The following discussion will present the formulation of such a controller by examining control of overlay. A brief introduction of overlay will be given, highlighting the control challenge overlay presents. A data management methodology that groups like processes together in order to improve controllability, referred to as control threads, will then be presented. Finally, a discussion of linear model predictive control will show its utility in feedback run-to-run control.

Paper Details

Date Published: 23 August 2000
PDF: 10 pages
Proc. SPIE 4182, Process Control and Diagnostics, (23 August 2000); doi: 10.1117/12.410061
Show Author Affiliations
Christopher A. Bode, Advanced Micro Devices, Inc. (United States)
Anthony J. Toprac, Advanced Micro Devices, Inc. (United States)
Richard D. Edwards, Advanced Micro Devices, Inc. (United States)
Thomas F. Edgar, Univ. of Texas at Austin (United States)

Published in SPIE Proceedings Vol. 4182:
Process Control and Diagnostics
Michael L. Miller; Kaihan A. Ashtiani, Editor(s)

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