(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2005/0149901 Al
Tang (43) Pub. Date: Jul. 7,2005
(54) RESOLUTION ENHANCING TECHNOLOGY USING PHASE ASSIGNMENT BRIDGES
(75) Inventor: Chih-Hsien Nail Tang, Taipei (TW)
CHRISTENSEN, O'CONNOR, JOHNSON,
1420 FIFTH AVENUE
SEATTLE, WA 98101-2347 (US) (73) Assignee: Mentor Graphics Corporation
(21) Appl. No.: 11/005,329
(22) Filed: Dec. 6, 2004
Related U.S. Application Data
(63) Continuation of application No. 10/071,858, filed on Feb. 8, 2002, now Pat. No. 6,887,633.
(51) Int. CI.7 G06F 17/50; G03F 9/00
(52) U.S. CI 716/20
In one embodiment, a spacing is determined for each edge of a number of features in a photolithographic design. The edges have at least a partially predictable layout. Based on the spacing and the predictable layout, a bridge structure is generated. Each bridge of the bridge structure connects one of the edges to an edge of a neighboring feature. Then, the features and the bridge structure are provided for a phase assignment. The phase assignment assigns features at opposite ends of each bridge in the bridge structure to opposite phases. In another embodiment, a sub-resolution assist feature (SRAF) is introduced for an edge of a feature and a bridge is generated from the feature to the SRAF. Then, the feature and the SRAF are assigned to opposite phases based on the relationship defined by the bridge.