As the industry progresses toward smaller patterning nodes with tighter CD error budgets and narrower process windows, the ability to control pattern quality becomes a critical, yield-limiting factor. In addition, as the feature size of design layouts continues to decrease at 32nm and below, optical proximity correction (OPC) technology becomes more complex and more difficult. From a lithographic point of view, it is the most important that the patterns are printed as designed. However, unfavorable localized CD variation can be induced by the lithography process, which will cause catastrophic patterning failures (i.e. ripple effects, and severe necking or bridging phenomenon) through process variation. It is becoming even more severe with strong off-axis illumination conditions and other resolution enhancement techniques (RETs). Traditionally, it can be reduced by optimizing the rule based edge fragmentation in the OPC setup, but this fragmentation optimization is very dependent upon the engineer's skill. Most fragmentation is based on a set of simple rules, but those rules may not always be robust in every possible design shape. In this paper, a model based approach for solving these imaging distortions has been tested as opposed to a previous rule based one. The model based approach is automatic correction techniques for reducing complexity of the OPC recipe. This comes in the form of automatically adjusting fragments lengths along with feedback values at every OPC iterations for a better convergence. The stability and coverage for this model based approach has been tested throughout various layout cases.

Date Published: 3 March 2010
PDF: 10 pages
Proc. SPIE 7640, Optical Microlithography XXIII, 76401F (3 March 2010); doi: 10.1117/12.848447

Published in SPIE Proceedings Vol. 7640:
Optical Microlithography XXIII
Mircea V. Dusa; Will Conley, Editor(s)