| US 7,580,129 B2 | ||
| Method and system for improving accuracy of critical dimension metrology | ||
| Shinn-Sheng Yu, Hsin-Chu (Taiwan); Jacky Huang, Chu-Bei (Taiwan); Chih-Ming Ke, Hsin-Chu (Taiwan); and Tsai-Sheng Gau, Hsin-Chu (Taiwan) | ||
| Assigned to Taiwan Semiconductor Manufacturing Company, Hsin-Chu (Taiwan) | ||
| Filed on Feb. 23, 2007, as Appl. No. 11/678,413. | ||
| Prior Publication US 2008/0204730 A1, Aug. 28, 2008 | ||
| Int. Cl. G01B 11/00 (2006.01) | ||
| U.S. Cl. 356—394 | 20 Claims |
| 1. A method for improving accuracy of optical critical dimension measurement of a substrate, the method comprising:
identifying a process parameter that influences the refractive index (n) and extinction coefficient (k) of a thin film in
the substrate;
identifying the refractive index (n) and extinction coefficient (k) across a plurality of wavelengths as a function of the
process parameter;
adjusting the refractive index (n) and extinction coefficient (k) across the plurality of wavelengths during the regression
modeling of the optical critical dimension measurement through the function via the process parameter; and
completing the optical critical dimension measurement by obtaining an optimal value of the process parameter that minimizes
a deviation between an experimental spectrum and its theoretical prediction.
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