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

A multi charged particle beam writing apparatus comprising:

• a stage configured to mount a target object thereon and be movable continuously;
• an emission unit configured to emit a charged particle beam;
• an aperture member, in which a plurality of openings are formed, configured to form multiple beams by letting a region including a whole of the plurality of openings be irradiated with the charged particle beam and letting parts of the charged particle beam respectively pass through a corresponding opening of the plurality of openings;
• a plurality of deflectors configured to respectively perform blanking deflection of a corresponding beam in the multiple beams having passed through the plurality of openings of the aperture member;
• a blanking aperture member configured to block each beam that has been deflected to be in an off state by the plurality of deflectors;
• and
• a current detector, movably arranged, configured to move in order to block all beams that are in an on state in the multiple beams so that the all beams do not reach the target object, and to detect a current value of the all beams in the on state.

A multi charged particle beam writing method comprising:

• measuring a current value of a beam group per region of a plurality of regions which are obtained by dividing a multi-beam formation region, for a plurality of beam groups, wherein multiple beams, which respectively have passed through a corresponding opening of a plurality of openings of an aperture member where the plurality of openings are provided to form the multiple beams by being irradiated with a charged particle beam, are separated into the plurality of beam groups, each being per region of the plurality of regions which are obtained by dividing the multi-beam formation region;
• generating a current distribution of the current value of the beam group of the each region;
• and
• judging whether a difference between a current distribution generated last time and the current distribution generated this time is within a tolerance range,
• wherein, in a case the difference between the current distribution generated last time and the current distribution generated this time is out of the tolerance range, writing is stopped, and in a case the difference between the current distribution generated last time and the current distribution generated this time is within the tolerance range, a pattern is written on a target object by using the multiple beams.