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

A multi-charged particle beam writing apparatus comprising:

• a beam forming mechanism configured to form multi-charged particle beams;
• a dose calculation circuit configured to calculate a dose at each position on a target object;
• an additional dose allocation circuit configured to allocate an additional dose to a position inside a writing target pattern in order to change a first dose distribution by an excessive dose, generated on the target object by applying, in the multi-charged particle beams, an excessive dose defective beam whose irradiation dose is excessive because a beam dose cannot be controlled to a position where a dose for cancelling out the excessive dose is insufficient in a range of the excessive dose being spread, to a second dose distribution whose center is located inside the writing target pattern and for which beam irradiation canceling out the excessive dose and being in a range of the first dose distribution exists;
• a correction circuit configured to perform correction by subtracting an increased dose amount, generated at the center of the second dose distribution because of the additional dose being allocated, from a dose with which one of the center of the second dose distribution and a vicinity of the center of the second dose distribution is irradiated;
• and
• a writing mechanism configured to write a pattern on the target object, using the multi-charged particle beams including the excessive dose defective beam.