Proximity effect correction in e-beam lithography is expected to be an essential step in the fabrication of high-density fine-feature circuits in the future. In the past, successful proximity correction by a shape modification approach with a single dose for the entire circuit pattern has been demonstrated. This approach has a few advantages over dose modification, including the fact that it is compatible with future multiple-beam or projection-based systems. As we continue to reduce the minimum feature size, accuracy of correction becomes more critical. In order to improve correction accuracy of the shape-only modification, a hybrid approach allowing region-wise dose control has been proposed. In this paper, a practical fast scheme for determining spatial dose distribution for the hybrid correction scheme is presented. (C) 2001 Elsevier Science B.V. All rights reserved.
