US 12,488,959 B2
Coverage calculating method, charged particle beam writing method, coverage calculating device, charged particle beam writing apparatus, and computer-readable storage medium
Kenichi Yasui, Kawasaki (JP); and Yasuo Kato, Yokohama (JP)
Assigned to NuFlare Technology, Inc., Yokohama (JP)
Filed by NuFlare Technology, Inc., Yokohama (JP)
Filed on Apr. 13, 2023, as Appl. No. 18/299,749.
Claims priority of application No. 2022-079606 (JP), filed on May 13, 2022.
Prior Publication US 2023/0369015 A1, Nov. 16, 2023
Int. Cl. H01J 37/317 (2006.01); H01J 37/04 (2006.01); H01J 37/302 (2006.01)
CPC H01J 37/3177 (2013.01) [H01J 37/045 (2013.01); H01J 37/3026 (2013.01); H01J 2237/31762 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A coverage calculating method for calculating a coverage of a pattern in each of pixel regions obtained by dividing a writing region onto which the pattern is to be written by irradiation with a charged particle beam, the pixel regions each having a predetermined size, the coverage calculating method comprising:
generating a plurality of first pixel regions by virtually dividing the writing region, the first pixel regions each having a first size;
calculating a coverage of a pattern in the first pixel region;
generating a plurality of second pixel regions by virtually dividing the first pixel region, the second pixel regions corresponding to the pixel region and each having a second size smaller than the first size;
selecting a second pixel region approximating a pattern shape in the first pixel region; and
calculating a coverage in the selected second pixel region based on the coverage of the pattern in the first pixel region, the number of the second pixel regions in the first pixel region, and the number of selected second pixel regions.