SEM-contour-based OPC model calibration through the process window

Jim Vasek; Ovadya Menedeva; Dan Levitzky; Ofer Lindman; Youval Nemadi; George E. Bailey; John L. Sturtevant

doi:10.1117/12.712232

12 April 2007 SEM-contour-based OPC model calibration through the process window

Jim Vasek, Ovadya Menedeva, Dan Levitzky, Ofer Lindman, Youval Nemadi, George E. Bailey, John L. Sturtevant

Proceedings Volume 6518, Metrology, Inspection, and Process Control for Microlithography XXI; 65180D (2007) https://doi.org/10.1117/12.712232
Event: SPIE Advanced Lithography, 2007, San Jose, California, United States

Abstract

As design rules shrink, there is an unavoidable increase in the complexity of OPC/RET schemes required to enable design printability. These complex OPC/RET schemes have been facilitating unprecedented yield at k₁ factors previously deemed "unmanufacturable", but they increase the mask complexity and production cost, and can introduce yield-detracting errors. The most common errors are found in OPC design itself, and in the resulting patterning robustness across the process window. Two factors in the OPC design process that contribute to these errors are a) that 2D structures used in the design are not sufficiently well-represented in the OPC model calibration test pattern suite, and b) that the OPC model calibration is done only at the nominal process settings and not across the entire focus-exposure window. This work compares two alternative methods for calibrating OPC models. The first method uses a traditional industry flow for making CD measurements on standard calibration target structures. The second method uses 2D contour profiles extracted automatically by the CD-SEM over varying focus and exposure conditions. OPC models were developed for aggressive quadrupole illumination conditions (k₁=0.35) used in 65nm- and 45nm-node logic gate patterning. Model accuracy improvement using 2D contours for calibration through the process window is demonstrated. Additionally this work addresses the issues of automating the contour extraction and calibration process, reducing the data collection burden with improved calibration cycle time.

Citation Download Citation

Jim Vasek, Ovadya Menedeva, Dan Levitzky, Ofer Lindman, Youval Nemadi, George E. Bailey, and John L. Sturtevant "SEM-contour-based OPC model calibration through the process window", Proc. SPIE 6518, Metrology, Inspection, and Process Control for Microlithography XXI, 65180D (12 April 2007); https://doi.org/10.1117/12.712232

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available