| US 7,301,634 B2 | ||
| Apparatus and methods for detecting overlay errors using scatterometry | ||
| Walter D. Mieher, Los Gatos, Calif. (US); Ady Levy, Sunnyvale, Calif. (US); Boris Golovanesky, Haifa (Israel); Michael Friedmann, Mountain View, Calif. (US); Ian Smith, Los Gatos, Calif. (US); Michael E. Adel, Zichron Ya'akov (Israel); Christopher F. Bevis, Los Gatos, Calif. (US); John Fielden, Los Altos, Calif. (US); Noah Bareket, Saratoga, Calif. (US); Anatoly Fabrikant, Fremont, Calif. (US); Mark Ghinovker, Migdal Ha'Emek (Israel); Piotr Zalicki, Sunnyvale, Calif. (US); and Dan Wack, Los Altos, Calif. (US) | ||
| Assigned to KLA-Tencor Technologies Corporation, Milpitas, Calif. (US) | ||
| Filed on Feb. 23, 2004, as Appl. No. 10/785,821. | ||
| Application 10/785821 is a continuation in part of application No. 10/729838, filed on Dec. 05, 2003. | ||
| Claims priority of provisional application 60/504093, filed on Sep. 19, 2003. | ||
| Claims priority of provisional application 60/498524, filed on Aug. 27, 2003. | ||
| Claims priority of provisional application 60/449496, filed on Feb. 22, 2003. | ||
| Prior Publication US 2004/0233444 A1, Nov. 25, 2004 | ||
| Int. Cl. G01B 11/00 (2006.01) | ||
| U.S. Cl. 356—401 | 33 Claims |
| 1. A method of determining an overlay error between two layers of a multiple layer sample, the method comprising:
for a plurality of periodic targets that each have a first structure formed from a first layer and a second structure formed
from a second layer of the sample, employing an interferometer to modulate substantially a plurality of wavelengths of a broadband
source and then acquiring one or more images of the periodic targets, wherein there are predefined offsets between the first
and second structures; and
determining and storing an overlay error between the first and second structures by analyzing the one or more acquired images
from the periodic targets using a scatterometry overlay technique based on the predefined offsets.
|