Patent ID: 8729507

Claim:
A multi charged particle beam writing method comprising: calculating first shot positions of multiple beams, each of the first shot positions including a distortion amount of an irradiating corresponding beam, in a case of irradiating each beam of multiple beams of a charged particle beam on a target object, based on control grid intervals having been set in length and width in advance; calculating first condition positions based on a pre-set condition, each of the first condition positions being arranged in a corresponding first region of a plurality of first regions respectively surrounded by closest second shot positions of 2×2 in length and width of the first shot positions, using the first shot positions including the distortion amount of the corresponding beam; calculating, for each of a plurality of second regions respectively surrounded by a plurality of closest second condition positions of the first condition positions, an area density of a figure pattern to be written in overlapping with a second region concerned in the plurality of second regions, by using the first condition positions; calculating an irradiation amount or an irradiation time of each beam whose corresponding first shot position of the first shot positions is in a corresponding second region of the plurality of second regions, based on an area density of a second region concerned; and writing a pattern on a target object by irradiating a beam of the irradiation amount or the irradiation time calculated.