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

Patent metadata

Field	Value
Publication number	US-10134562-B2
Application number	US-201514969478-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 22, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A multi charged particle beam writing apparatus includes a modulation rate data calculation processing circuitry to calculate, for each pixel being a unit region, a modulation rate of a beam to a pixel concerned and each modulation rate of a beam to at least one pixel at a periphery of the pixel concerned, and a corrected-dose calculation processing circuitry to calculate, for the each pixel, a corrected dose by adding a multiplied value obtained by multiplying the modulation rate of the pixel concerned in a modulation rate map by beam dose to the pixel concerned, and a multiplied value obtained by multiplying the modulation rate of the pixel concerned which becomes one of the at least one pixel at the periphery with respect to another pixel defined for the position of the pixel concerned by a beam dose to the another pixel.

First claim

What is claimed is:

1. A multi charged particle beam writing apparatus comprising:
a modulation rate data calculation processing circuitry configured to calculate, for each pixel being irradiated by a beam of multi charged particle beams, a modulation rate of the beam to the respective pixel and a corresponding modulation rate of the beam to at least one pixel at a periphery of the respective pixel based on a positional deviation amount for each pixel by distributing at least a portion of a dose to the respective pixel to the at least one pixel at the periphery of the respective pixel in accordance with the positional deviation amount of the beam to irradiate the respective pixel;
a modulation rate map generation processing circuitry configured to generate, for each pixel, a modulation rate map which defines the calculated modulation rate of the beam to the respective pixel associated with a position of the respective pixel and defines each calculated modulation rate of the beam to the at least one pixel at the periphery of the respective pixel in association with a corresponding position of the at least one pixel at the periphery of the respective pixel;
a dose calculation processing circuitry configured to calculate, for each pixel, a beam dose to the respective pixel;
a corrected-dose calculation processing circuitry configured to calculate, for each pixel, a corrected dose by adding a first value obtained by multiplying the modulation rate of the beam to the respective pixel defined in the modulation rate map by the beam dose to the respective pixel, and a second value obtained by multiplying the modulation rate of the beam to the respective pixel which is one of the at least one pixel at the periphery with respect to another pixel defined in the modulation rate map by a beam dose to the another pixel; and
a writing mechanism including a stage on which a target object is placed, a charged particle beam source, and a deflector, and configured to write a pattern on the target object with the multi charged particle beams by irradiating each pixel by a beam of the corrected dose corresponding to the respective pixel.

2. The apparatus according to claim 1 , wherein the modulation rate data calculation processing circuitry calculates the modulation rate to irradiate the respective pixel and each modulation rate to irradiate the at least one pixel at the periphery of the respective pixel such that a first beam profile function and a second beam profile function accord with each other, where the first beam profile function uses the modulation rate to irradiate the respective pixel without distributing the dose to a pixel at the periphery of the respective pixel, and the second beam profile function uses the modulation rate to irradiate the respective pixel and each modulation rate to irradiate the at least one pixel at the periphery of the respective pixel such that the dose is divided and distributed to the at least one pixel at the periphery of the respective pixel.

3. The apparatus according to claim 1 , wherein the modulation rate data calculation processing circuitry calculates the modulation rate of the beam to the respective pixel and each modulation rate of the beam to the at least one pixel at the periphery of the respective pixel according to a ratio of an area shifted due to positional deviation of a beam to the respective pixel.

4. The apparatus according to claim 2 , wherein, in a case of calculating the modulation rate to irradiate the respective pixel and each modulation rate to irradiate the at least one pixel at the periphery of the respective pixel in a predetermined pass in multiple writing, the modulation rate data calculation processing circuitry further calculates another modulation rate to be distributed to at least one pixel of the respective pixel and pixels at the periphery of the respective pixel, in another pass different from the predetermined pass.

5. The apparatus according to claim 4 , further comprising:
a positional deviation data acquisition processing circuitry configured to acquire a positional deviation amount for each pixel.

6. The apparatus according to claim 4 , further comprising:
a selection processing circuitry configured to select, for each pixel, another pass in the multiple writing serving as a distribution destination to which a dose for correcting positional deviation is distributed.

7. A multi charged particle beam writing method comprising:
calculating, for each pixel being irradiated by a beam of multi charged particle beams, a modulation rate of the beam to the respective pixel and a corresponding modulation rate of the beam to at least one pixel at a periphery of the respective pixel pixel concerned by modulating a beam dose to the pixel concerned and each beam dose to the based on a positional deviation amount for each pixel by distributing at least a portion of a dose to the respective pixel is distributed to the at least one pixel at the periphery of the respective pixel in accordance with the positional deviation amount of the beam to irradiate the respective pixel;
generating, for each pixel, a modulation rate map which defines the calculated modulation rate of the beam to the respective pixel associated with a position of the respective pixel and defines each calculated modulation rate of the beam to the at least one pixel at the periphery of the respective pixel in association with a corresponding position of the at least one pixel at the periphery of the respective pixel;
calculating, for each pixel, the beam dose to the respective pixel;
calculating, for each pixel, a corrected dose by adding a first value obtained by multiplying the modulation rate of the beam to the respective pixel defined in the modulation rate map by the beam dose to the respective pixel, and a second value obtained by multiplying the modulation rate of the beam to the respective pixel which becomes one of the at least one pixel at the periphery with respect to another pixel defined in the modulation rate map by a beam dose to the another pixel; and
writing a pattern on a target object with the multi charged particle beams by irradiating each pixel by a beam of the corrected dose corresponding to the respective pixel.

8. The method according to claim 7 , wherein the modulation rate to irradiate the respective pixel and each modulation rate to irradiate the at least one pixel at the periphery of the respective pixel are calculated such that a first beam profile function and a second beam profile function accord with each other, where the first beam profile function uses the modulation rate to irradiate the respective pixel without distributing a dose to a pixel at the periphery of the respective pixel, and the second beam profile function uses the modulation rate to irradiate the respective pixel and each modulation rate to irradiate the at least one pixel at the periphery of the respective pixel such that the dose is divided and distributed to the at least one pixel at the periphery of the respective pixel.

9. The method according to claim 7 , wherein the modulation rate of the beam to the respective pixel and each modulation rate of the beam to the at least one pixel at the periphery of the respective pixel are calculated according to a ratio of an area shifted due to positional deviation of the beam to the respective pixel.

10. The method according to claim 8 , wherein, in a case of calculating the modulation rate to irradiate the respective pixel and the modulation rate to irradiate the at least one pixel at the periphery of the respective pixel in a predetermined pass in multiple writing, another modulation rate to be distributed to at least one pixel of the respective pixel and pixels at

Assignees

• Nuflare Technology Inc

Inventors

• Kato Yasuo
• Inoue Hideo
• Matsumoto Hiroshi
• Kawana Ryoh

Classifications

• H01J37/3177

  Multi-beam, e.g. fly's eye, comb probe · CPC title

• H01J37/243 Primary

  Beam current control or regulation circuits (H01J37/241 takes precedence) · CPC title

• H01J37/304

  Controlling tubes by information coming from the objects {or from the beam}, e.g. correction signals · CPC title

• H01J2237/30433

  System calibration · CPC title

• H01J2237/31761

  Patterning strategy · CPC title