Charged particle beam writing apparatus, charged particle beam writing method, and a non-transitory computer-readable storage medium

A charged particle beam writing method that writes a pattern on a substrate on a stage by causing a deflector to deflect a charged particle beam, the charged particle beam writing method comprising:

• virtually dividing a writing region of the substrate in a mesh-like manner and calculating a pattern density distribution indicating an arrangement ratio of the pattern for each mesh region;
• calculating a dose distribution indicating a dose for each mesh region using the pattern density distribution;
• calculating an exposure amount distribution of the charged particle beam, to which the substrate is exposed, using the pattern density distribution and the dose distribution;
• calculating a plurality of fogging charged particle amount distributions by convoluting each of a plurality of distribution functions for fogging charged particles with the exposure amount distribution, the plurality of distribution functions having different distribution centers and radius of influence of a fogging effect from each other;
• calculating a charge amount distribution due to direct charge using the pattern density distribution, the dose distribution, and the exposure amount distribution, and calculating a plurality of charge amount distributions due to fogging charge using the plurality of fogging charged particle amount distributions;
• calculating a position shift amount of a writing position based on the charge amount distribution due to direct charge and the plurality of charge amount distributions due to fogging charge;
• correcting an exposure position using the position shift amount;
• and
• exposing the corrected exposure position to a charged particle beam.

A non-transitory computer-readable storage medium with an executable program stored thereon, wherein the program causes a computer to execute:

• processing in which a writing region of a substrate on which a pattern is to be written by causing a deflector to deflect a charged particle beam is virtually divided in a mesh-like manner and a pattern density distribution indicating an arrangement ratio of the pattern is calculated for each mesh region;
• processing in which a dose distribution indicating a dose for each mesh region is calculated using the pattern density distribution;
• processing in which an exposure amount distribution of the charged particle beam, to which the substrate is exposed, is calculated using the pattern density distribution and the dose distribution;
• processing in which a plurality of fogging charged particle amount distributions are calculated by convoluting each of a plurality of distribution functions for fogging charged particles with the exposure amount distribution, the plurality of distribution functions having different distribution centers and radius of influence of a fogging effect from each other;
• processing in which a charge amount distribution due to direct charge is calculated using the pattern density distribution, the dose distribution, and the exposure amount distribution, and a plurality of charge amount distributions due to fogging charge are calculated using the plurality of fogging charged particle amount distributions;
• processing in which a position shift amount of a writing position is calculated that is based on the charge amount distribution due to direct charge and the plurality of charge amount distributions due to fogging charge;
• processing in which an exposure position is corrected using the position shift amount;
• and
• processing in which the corrected exposure position is exposed to a charged particle beam.