US 7,588,868 B2
Method and system for reducing the impact of across-wafer variations on critical dimension measurements
Franz X. Zach, Los Gatos, Calif. (US); Abdurrahman Sezginer, Los Gatos, Calif. (US); and Gokhan Percin, Los Gatos, Calif. (US)
Assigned to Cadence Design Systems, Inc., San Jose, Calif. (US)
Filed on Oct. 22, 2004, as Appl. No. 10/971,350.
Application 10/971350 is a continuation in part of application No. 10/960357, filed on Oct. 06, 2004, abandoned.
Prior Publication US 2006/0073686 A1, Apr. 06, 2006
Int. Cl. G03F 9/00 (2006.01); G03C 5/00 (2006.01)
U.S. Cl. 430—22  [430/30] 42 Claims
 
1. A method for determining a value of a parameter of an optical proximity correction model, the method comprising:
(a) performing a first exposure of a mask onto a wafer, wherein the mask comprises a set of features;
(b) performing a second exposure of the mask onto the wafer, wherein an exposure field of the second exposure partially overlaps an exposure field of the first exposure;
(c) determining a characteristic of the set of features exposed onto the wafer by the first and second exposures; and
(d) determining a value of a parameter of an optical proximity correction model based on the characteristic determined in (c).