Electron beam apparatus and positional displacement correcting method of electron beam

1. An electron beam apparatus comprising:

charge amount distribution operation processing circuitry that operates to calculate a charge amount distribution of an irradiation region in a case that a substrate is irradiated with an electron beam using a combined function combining a first exponential function having an inflection point and at least one of a first-order proportional function and a second exponential function that converges and depending on a pattern area density;

positional displacement operation processing circuitry that operates to calculate a positional displacement of an irradiation pattern formed due to irradiation of the electron beam using the charge amount distribution obtained;

correction processing circuitry that corrects an irradiation position using the positional displacement; and

an electron beam column including an emission source that emits the electron beam and a deflector that deflects the electron beam to irradiate a corrected irradiation position with the electron beam,

wherein the inflection point is a local maximum point or a local minimum point, and coefficients of the combined function are set such that the local maximum point has a positive charge amount or the local minimum point has a negative charge amount.

2. An electron beam apparatus comprising:

charge amount distribution operation processing circuitry that operates to calculate a charge amount distribution of an irradiation region in a case that a substrate is irradiated with an electron beam using a combined function combining a first exponential function having a local maximum point or a local minimum point and at least one of a first-order proportional function and a second exponential function that converges at infinity and having at least a pattern area density as a variable;

positional displacement operation processing circuitry that operates to calculate a positional displacement of an irradiation pattern formed due to irradiation of the electron beam using the charge amount distribution obtained;

correction processing circuitry that corrects an irradiation position using the positional displacement; and

an electron beam column including an emission source that emits the electron beam and a deflector that deflects the electron beam to irradiate a corrected irradiation position with the electron beam,

wherein coefficients of the combined function are set such that the local maximum point has a positive charge amount or the local minimum point has a negative charge amount.

3. The apparatus according to claim 2 , wherein in a case that the combined function uses the second exponential function, coefficients of the combined function are set such that a charge amount converges to a negative charge amount in a maximum pattern area density.

4. The apparatus according to claim 2 , wherein coefficients of the combined function are set such that the local maximum point is positioned within a range in which the pattern area density is 3 to 7%.

5. A positional displacement correcting method of an electron beam comprising:

operating to calculate a charge amount distribution of an irradiation region in a case that a substrate is irradiated with an electron beam using a combined function combining a first exponential function having a local maximum point or a local minimum point and at least one of a first-order proportional function and a second exponential function that converges at infinity and having at least a pattern area density as a variable;

operating to calculate a positional displacement of an irradiation pattern formed due to irradiation of the electron beam using the charge amount distribution obtained;

correcting an irradiation position using the positional displacement; and

irradiating a corrected irradiation position with the electron beam,

wherein coefficients of the combined function are set such that the local maximum point has a positive charge amount or the local minimum point has a negative charge amount.

6. An electron beam apparatus comprising:

an exposure intensity operator that operates to calculate an exposure intensity distribution in a case that a substrate is irradiated with an electron beam;

positional displacement operation processing circuitry that operates to calculate a positional displacement of an irradiation pattern based on the exposure intensity distribution using a neural network model using, as an input/output conversion function, a combined function combining a first exponential function having a local maximum point or a local minimum point and at least one of a first-order proportional function and a second exponential function that converges at infinity and having at least a pattern area density as a variable;

correction processing circuitry that corrects an irradiation position using the positional displacement; and

an electron beam column including an emission source that emits the electron beam and a deflector that deflects the electron beam to irradiate a corrected irradiation position with the electron beam.

7. The apparatus according to claim 6 , wherein in a case that the combined function uses the second exponential function and the first exponential function has a positive local maximum point, coefficients of the combined function are set such that the second exponential function converges to a negative value.

8. The apparatus according to claim 6 , wherein in a case that the combined function uses the second exponential function and the first exponential function has a negative local minimum point, coefficients of the combined function are set such that the second exponential function converges to a negative value.

9. A positional displacement correcting method of an electron beam comprising:

operating to calculate an exposure intensity distribution in a case that a substrate is irradiated with an electron beam;

operating to calculate a positional displacement of an irradiation pattern based on the exposure intensity distribution using a neural network model using, as an input/output conversion function, a combined function combining a first exponential function having a local maximum point or a local minimum point and at least one of a first-order proportional function and a second exponential function that converges at infinity and having at least a pattern area density as a variable;

correcting an irradiation position using the positional displacement; and

irradiating a corrected irradiation position with the electron beam.