Method and system for design of enhanced edge slope patterns for charged particle beam lithography

摘要

A method and system for fracturing or mask data preparation are presented in which overlapping shots are generated to increase dosage in selected portions of a pattern, thus improving the fidelity and/or the critical dimension variation of the transferred pattern. In various embodiments, the improvements may affect the ends of paths or lines, or square or nearly-square patterns. Simulation is used to determine the pattern that will be produced on the surface.

主权项

1. A method for fracturing or mask data preparation or proximity effect correction comprising the steps of:
calculating a line end pattern that will be produced on a resist-coated surface and calculating the edge slope of the line end pattern from an original set of shots for a shaped beam charged particle beam writer; modifying the original set of shots to improve the edge slope of the calculated line end pattern by increasing a dosage delivered to the surface near the line end, such that the surface dosage near the line end is higher than a normal dosage, wherein the modification comprises at least one of the group consisting of 1) determining an additional shot which overlaps a shot in the set of shots; 2) varying the overlap of two or more shots in the set of shots; 3) varying the size of a shot which overlaps another shot; and 4) varying the dosage of a shot in the set of shots with respect to the dosage of another overlapping shot in the set of shots, wherein the resist comprises a resist threshold, and wherein the edge slope comprises the slope of the surface dosage, at the resist threshold, with respect to a linear dimension perpendicular to the perimeter of the pattern; and inputting a library of precalculated glyphs, wherein the step of determining determines shots from one or more glyphs, and wherein the glyph precalculation constitutes at least a part of the pattern calculation.