Patent ID: 6988260

Claim:
A method for optimizing fragmentation of integrated circuit boundaries for optical proximity correction (OPC) purposes, comprising steps of: (a) providing a segment of an integrated circuit boundary and a neighborhood of said integrated circuit boundary, said segment having a first end B and a second end E; (b) placing elements (B,0) and (E,0) into a set Ms, an element in said set Ms having a first component representing a point on said segment and a second component representing a numeric value; (c) when a length of said segment is not less than (D min +2·D serif ), placing elements (B serif ,0) and (E serif ,0) into said set Ms, wherein said B serif is a beginning serif point on said segment with a distance between said B and said B serif being equal to said D serif , said E serif is an end serif point on said segment with a distance between said E and said E serif being equal to said D serif , said D serif is a serif size for said segment, and said D min is a minimal allowed distance between any two fragmentation points on said segment; (d) projecting at least one vertex, other than said B and said E, of said integrated circuit boundary and said neighborhood to said segment to form at least one projection point P with a corresponding distance D between said at least one vertex and said segment; (e) when said P lies on said segment, adding an element (P,D) to said set Ms; (f) when an element (P′,D′) of said set Ms is such that a distance between said point P′ and said point B or between said point P′ and said point E is less than said D min , and when said point P′ is neither said point B nor said point E, removing said element (P′,D′) from said set Ms; (g) when said element (B serif ,0) is in said set Ms, when an element (P i , D i ) of said set Ms is such that said point P i lies between said B and said B serif , and when another element (P i ′, D i ′) of said set Ms is such that a distance between said point P i ′ and said B serif is less than said D min , removing said element (B serif ,0) from said set Ms; (h) when said element (E serif ,0) is in said set Ms, when an element (P i ′,D i ′) of said set Ms is such that said point P i ″ lies between said E and said E serif and when another element (P i ′″, D i ′″) of said set Ms is such that a distance between said point P i ′″ and said E serif is less than said D min , removing said element (E serif ,0) from said set Ms; (i) searching for a unworkable element for all elements of said set Ms; and (j) when no unworkable element is found for all elements of said set Ms, defining first components of elements in said set Ms as fragmentation points for said segment.