A non-uniform SEM contour sampling technique for OPC model calibration

T. Shibahara; M. Oikawa; H. Shindo; H. Sugahara; Y. Hojyo

doi:10.1117/12.913957

5 April 2012 A non-uniform SEM contour sampling technique for OPC model calibration

T. Shibahara, M. Oikawa, H. Shindo, H. Sugahara, Y. Hojyo

Proceedings Volume 8324, Metrology, Inspection, and Process Control for Microlithography XXVI; 83242Q (2012) https://doi.org/10.1117/12.913957
Event: SPIE Advanced Lithography, 2012, San Jose, California, United States

Abstract

OPC model calibration techniques that use SEM contours are a major reason for the modern day improved fitting efficiency in complex mask design compared to conventional CD-based calibration. However, contour-based calibration has a high computational cost and requires a lot of memory. To overcome this problem, in conventional contour-based calibration, the SEM contour is sampled uniformly at intervals of several nanometers. However, such sparse uniform sampling significantly increases deviations from real CD values, which are measured by CD-SEM. We also have to consider the shape errors of 2D patterns. In general, the calibration of 2D patterns requires higher frequency sampling of the SEM contour than 1D patterns do. To achieve accurate calibration results, and while considering the varied shapes of calibration patterns, it is necessary to set precise sampling intervals of the SEM contour. In response to these problems, we have developed a SEM contour sampling technique in which contours are sampled at a non-uniform rate with arbitrary mask shapes within the allowable sampling error. Experimental results showed that the sampling error rate was decreased to sub-nm when we reduced the number of contour points.

Citation Download Citation

T. Shibahara, M. Oikawa, H. Shindo, H. Sugahara, and Y. Hojyo "A non-uniform SEM contour sampling technique for OPC model calibration", Proc. SPIE 8324, Metrology, Inspection, and Process Control for Microlithography XXVI, 83242Q (5 April 2012); https://doi.org/10.1117/12.913957

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