US 12,230,472 B1
Effective temperature calculation method for multi-charged particle beam writing region, multi-charged particle beam writing apparatus, multi-charged particle beam writing method, and recording medium recording program
Shingo Mori, Yokohama (JP)
Assigned to NuFlare Technology, Inc., Yokohama (JP)
Filed by NuFlare Technology, Inc., Yokohama (JP)
Filed on Jul. 15, 2024, as Appl. No. 18/772,999.
Application 18/772,999 is a continuation of application No. PCT/JP2023/037658, filed on Oct. 18, 2023.
Int. Cl. H01J 37/317 (2006.01); H01J 37/304 (2006.01)
CPC H01J 37/3177 (2013.01) [H01J 37/304 (2013.01); H01J 2237/24507 (2013.01); H01J 2237/24585 (2013.01); H01J 2237/31769 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An effective temperature calculation method for multi-charged particle beam writing region, the effective temperature calculation method comprising:
a step of calculating, based on writing data, a dose amount of each of a plurality of pixels into which a writing region of a sample is divided, the sample being placed on a stage which moves during pattern writing;
a step of calculating an effective temperature of a mesh region of interest as a temperature calculation target by accumulating a temperature rise amount given to the mesh region of interest by a plurality of unit heat source regions around the mesh region of interest in a time domain in which a beam array region of a multi-charged particle beam passes through the mesh region of interest;
in the step of calculating the effective temperature,
at a plurality of observation times which are irradiation end times of a tracking cycle in the time domain in which the beam array region passes through the mesh region of interest, for each of the plurality of unit heat source regions around the mesh region of interest, a temperature rise amount given to the mesh region of interest is determined based on a total irradiation time of the unit heat source region, times since start of irradiation to the unit heat source region to the observation times, and a distance from the unit heat source region to the mesh region of interest, the temperature rise amount is accumulated, and accumulated values corresponding to the plurality of observation times are averaged to calculate an effective temperature of the mesh region of the interest, and
time integration of temperature is performed using a time structure in which irradiation of the multi-charged particle beam is pulse-like beam irradiation with a period of the tracking cycle.