Partitioning method for E-beam lithography
AssigneeInternational Business Machines Corporation
InventorsAbraham Z. Meiri, Dov Ramm, Uzi Shvadron
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Abstract
A method of partitioning design shapes, in an E-beam lithography system, into subshapes such that a constant dose may be applied to an E-beam sensitive resist within each subshape. Within each subshape the constant dose corresponds to an approximation to an indicator function, indicative of the degree of the proximity effect, such as the effective exposure of the resist from backscattered electrons or the required dose. The error of the approximation is equal to a predetermined value for each subshape, and can depend upon the position of the subshape within the shape and the influence of errors in the applied dose at that position on the position, on development, of the edge of the shape.
Claims8
Method of partitioning, in an E-beam lithography system, a design pattern, comprising at least one design shape, into a plurality of subshapes to each of which a respective constant E-beam dose is applied, the method comprising the steps of:
- (a) determining, at a plurality of points on the design, an indicator field indicative of the magnitude of the proximity effect;
- (b) determining boundaries of the subshapes;
- (c) assigning a constant indicator value to each subshape;
- (d) assigning the respective constant E-beam dose to each subshape based on the value of the constant indicator value, and
- wherein the boundary determination and the constant indicator value assignment being such that, within each subshape, the constant indicator value represents an approximation to the indicator field, the error of the approximation being substantially equal to a predetermined value.
Dependencies are inferred from the claim text.