Skip to Main Content
Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1116/1.3546100
Contact hole patterning has always been one of the most challenging issues in lithography. Conventional optical proximity correction (OPC) approach for contact hole patterning involves dimensional biasing, addition of serifs at corners, and insertion of subresolution enhancement features. However, as dimensions reduce, process window enhancement resulted from conventional OPC approach encounters limitations. In this paper, a new approach for contact hole patterning is investigated. Instead of using a square shape as target of a printed feature, a circular shape is proposed. Using the proposed method improvement in aerial image quality is achieved and the average improvement in the depth of focus is around 11%. In addition, the average normalized image logarithmic slope improvement for different pitches is found to be around 15%.