Translator Disclaimer
Paper
17 May 2005 Robust linear regression for modeling systematic spatial wafer variation
Author Affiliations +
Abstract
We describe a new method of estimating the systematic spatial variation across wafers. Current methods for this task share some common deficiencies. For example, few of these techniques are able to decompose the systematic variation into components that can be assigned to different types of tools. Most of these methods are also sensitive to outliers and require that the outliers be manually removed before the model can be estimated. Almost none of the previous methods can account for high-frequency effects caused by reticle non-uniformity. Our method is based on a linear regression model with various components to account for the systematic variation that occurs in practice. Polynomial components model the smooth variation caused by tools that cannot process the wafer uniformly. Reticle components model the variation that occurs due to non-uniformities in the microlithography and etch tools. To generate distinct patterns, we apply QR orthogonalization to the systematic patterns prior to regression. To limit the effects of outliers, we employ robust regression. We demonstrate the performance of our technique with an example on data collected from production wafers.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
James McNames, Byungsool Moon, Bruce Whitefield, and David Abercrombie "Robust linear regression for modeling systematic spatial wafer variation", Proc. SPIE 5755, Data Analysis and Modeling for Process Control II, (17 May 2005); https://doi.org/10.1117/12.600198
PROCEEDINGS
12 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

Pattern uniformity control in integrated structures
Proceedings of SPIE (March 27 2017)
Mask topography effects in low k1 lithography
Proceedings of SPIE (July 05 2000)
Multi layer model vs. single layer model for N and...
Proceedings of SPIE (September 24 2010)
Reticle process effects on OPC models
Proceedings of SPIE (July 30 2002)

Back to Top