New Method to Enhance Overlay Tool Performance

Published

May 1, 2003

Author(s)

Ravikiran Attota, Richard M. Silver, Michael T. Stocker, Egon Marx, Jay S. Jun, M P. Davidson, Robert D. Larrabee

Abstract

New methods to enhance and improve algorithm performance and data analysis are being developed at NIST for overlay measurement applications. Both experimental data and improved theoretical optical scattering models have been used for the study. We have identified error sources that arise from (I) the optical cross talk between neighboring lines on an overlay target (ii) the selection of the window size used in the auto-correlation and (iii) the portion of the intensity profile that is used in the overlay calculation (defined as a truncated profile). Further, we suggest methods to optimally minimize these error sources. We also present a relationship between tool-induced shift (TIS) and the asymmetry in the intensity profile.

Proceedings Title

Proceedings of SPIE on Metrology, Inspection, and Process Control for Microlithography XVII, Daniel J. Herr, Editor May 2003

Volume

5038

Issue

Pt. 1

Conference Dates

February 1, 2003

Conference Location

Santa Clara, CA, USA

Conference Title

Overlay and Registration Metrology II

Pub Type

Conferences

Keywords

optical interaction, optimization, overlay metrology, TIS, truncation

Citation

Attota, R. , Silver, R. , Stocker, M. , Marx, E. , Jun, J. , Davidson, M. and Larrabee, R. (2003), New Method to Enhance Overlay Tool Performance, Proceedings of SPIE on Metrology, Inspection, and Process Control for Microlithography XVII, Daniel J. Herr, Editor May 2003, Santa Clara, CA, USA (Accessed October 27, 2025)