Multi charged particle beam writing apparatus and multi charged particle beam writing method

A multi charged particle beam writing apparatus comprising:

• an aperture plate in which a plurality of holes are formed and that forms multiple beams in a case where a charged particle beam passes through the plurality of holes;
• a blanking aperture array in which a plurality of blankers are arranged that switch ON-OFF of corresponding respective beams among the multiple beams;
• a stage on which a writing target substrate is placed and that is movable in XY directions;
• an inspection aperture that is provided at the stage and that allows one beam among the multiple beams to pass therethrough;
• a deflector that deflects the multiple beams;
• a current detector that detects a beam current of each of the multiple beams that has passed through the inspection aperture in a case where the multiple beams are scanned on the inspection aperture in the XY directions;
• and
• a control computing machine that generates a beam image based on the detected beam current and detects a defect of the blanking aperture array or the aperture plate based on the beam image,
• wherein the inspection aperture includes a through hole through which the one beam passes, and
• a diameter ϕ1 of the through hole satisfies a following condition:
• S<ϕ1<P−S,
• wherein S is a beam size of the one beam, and P is a beam pitch of the multiple beams on the writing target substrate.