Share Email Print

Proceedings Paper

How focus budgets are spent: limitations of advanced i-line lithography
Author(s): Andreas Grassmann; Rebecca D. Mih; Andreas Kluwe
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

In order to decide if a given process window is sufficient for volume production without suffering from a significant yield loss, a clear understanding of the process capability is required. Therefore we performed a statistical analysis of all potential contributions for process variations and drifts and evaluated their magnitude for state-of-the-art equipment and processes. Since lithography related fails are not uniformly distributed across the wafer we developed a model to simulate the focus errors across the exposure field and across the wafer. We also developed a yield model, which gives a realistic yield loss number for a given process window. By using these models we show areas of potential improvement, which allow support of processes with significantly less focus latitude. We also investigated field size dependence of focus control and compared the step and repeat and step and scan systems, showing a significant advantage for step and scan systems. All of these findings are not specific to the exposure wavelength, so that they can be easily applied to Deep UV lithography.

Paper Details

Date Published: 7 June 1996
PDF: 12 pages
Proc. SPIE 2726, Optical Microlithography IX, (7 June 1996); doi: 10.1117/12.240912
Show Author Affiliations
Andreas Grassmann, Siemens Components Inc. (Germany)
Rebecca D. Mih, IBM Microelectronics Div. (United States)
Andreas Kluwe, Siemens Components Inc. (Germany)

Published in SPIE Proceedings Vol. 2726:
Optical Microlithography IX
Gene E. Fuller, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?