Patent ID: 6573515
Filing Date: 2003-06-03
Classification: B82Y,H01J

Abstract:
In a method for performing charged-particle-beam (CPB) projection-exposure including the steps of dividing a pattern, to be projection-exposed onto a sensitive substrate, into multiple exposure units each defining a respective portion of the pattern; sequentially illuminating the exposure units with a charged-particle (CP) illumination beam to form a respective CP patterned beam; and projecting the patterned beam onto a sensitive substrate to form images of the exposure units at respective locations on the substrate at which the images of the exposure units are stitched together to form an image of the pattern on the substrate, a method for projection-exposing an exposure unit requiring more than one exposure shot, comprising:(a) with respect to any exposure unit defining a feature requiring two separate exposure shots to fully transfer the feature to the substrate, dividing each of such exposure units into first and second complementary exposure units each defining respective feature portions; (b) defining boundaries around each first complementary exposure unit, and boundaries around each second complementary exposure unit, wherein the boundaries around the first complementary exposure units do not cross over the respective feature portions defined by the first complementary exposure units, and the boundaries around the second complementary exposure units do not cross over the respective feature portions defined by the second complementary exposure units, thereby causing the boundaries around the second complementary exposure units to be shifted relative to the boundaries around the first complementary exposure units; and (c) projection-exposing the first complementary exposure units and the second complementary exposure units onto respective locations on the substrate such that, when projection-exposing a second complementary exposure unit on an image of a respective first complementary exposure unit, the boundaries around the second complementary exposure unit are shifted relative to the boundaries around the respective first complementary exposure unit.