E-beam control data compaction system and method

Abstract

A method of converting circuit design shapes into optimized numerical control (NC) data for controlling an electron beam (e-beam) exposure system. During post processing of a circuit design layout, shapes with angled edges are covered or filled with rectangles and triangular trapezoidal or paralellograms called FILLSHAPES. Whenever a FILLSHAPE is created, it is as close to the preferred size as possible to increase the likelihood of creating duplicate FILLSHAPEs. A proximity correction value which is calculated for an equivalent rectangle is applied to the FILLSHAPE. After proximity correction, groups of identical FILLSHAPES and User-Defined Macros (UDM's) are created. A summary record is generated for each group. A weight factor is calculated for each group and stored in the summary record. The summary records are sorted according to weight factor. A FILLSHAPE Defined Macro FDM) or UDM is stored in the e-beam tool's macro buffer in order of sorted summary record until every Defined Macro (DM) is stored in the macro buffer or the Macro buffer is full. When the design shapes are encoded in the pattern buffer, fill rectangles are encoded as NC data until a FILLSHAPE or Macro is encountered. The macro buffer is checked for a DM corresponding to the encountered FILLSHAPE or Macro.