The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 2006
Filed:
Feb. 05, 2004
Vishnu G. Kamat, Cupertino, CA (US);
Armen Kroyan, San Francisco, CA (US);
Vishnu G. Kamat, Cupertino, CA (US);
Armen Kroyan, San Francisco, CA (US);
Synopsys, Inc., Mountain View, CA (US);
Abstract
Using phase shifting on a mask can advantageously improve printed feature resolution on a wafer, thereby allowing greater feature density on an integrated circuit. Phase shifting can create an intensity imbalance between 0 degree and 180 degree phase shifters on the mask. An improved method of designing an alternating PSM to minimize this intensity imbalance is provided. Sub-resolution features, called 'blockers', can be incorporated in the alternating PSM design. Specifically, blockers can be formed in the 0 degree phase shifters. In this configuration, the intensity associated with the 0 degree phase shifters approximates the intensity associated with the corresponding 180 degree phase shifters. Intensity balancing using blockers retains image contrast, thereby ensuring printed feature quality.