PATTERN AREA VALUE CALCULATING METHOD, PROXIMITY EFFECT CORRECTING METHOD, AND CHARGED PARTICLE BEAM WRITING METHOD AND APPARATUS

Abstract

A method for calculating area values of a pattern written by using a charged particle beam, includes virtually dividing a pattern into a plurality of mesh-like first square regions surrounded by first grids defined at intervals of a predetermined size, virtually dividing the pattern into a plurality of mesh-like second square regions surrounded by second grids defined at intervals of the predetermined size, wherein the second grids being positionally deviated from the first grids by a half of the predetermined size, distributing an area value of a sub-pattern in each of the second square regions to a plurality of apexes of each of the second square regions such that a center-of-gravity position of the sub-pattern does not change, wherein the sub-pattern being a part of the pattern, and outputting the distributed area values as area values, for correcting a proximity effect, defined at the center position of each of the first square regions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a main part of a flow chart in a first embodiment;

FIG. 2 is a conceptual diagram showing an example of a main configuration of a writing apparatus according to the first embodiment;

FIG. 3 is a diagram showing a part of a writing pattern divided like a mesh in the first embodiment;

FIG. 4 is a diagram showing an example of a figure divided in figure dividing meshes in the first embodiment;

FIG. 5 is a diagram showing an example of a figure dividing mesh obtained by dividing the figure in the first embodiment;

FIG. 6 is a diagram showing an example of an area value distributed in the first embodiment;

FIG. 7 is a diagram showing another example of the figure dividing mesh obtained by dividing the figure in the first embodiment;

FIG. 8 is a diagram showing another example of the area value distributed in the first embodiment;

FIGS. 9A and 9B are diagrams showing an example the distributed area values and a back scattering energy distribution in the first embodiment;

FIGS. 10A and 10B are diagrams showing an example of an appearance observed when area values of figures in an area mesh are not dispersed and a back scattering energy distribution; and

FIG. 11 is a conceptual diagram for explaining an operation of a conventional variable-shaped electron beam photolithography apparatus.

Claims

1. A method for calculating area values of a pattern written by using a charged particle beam, comprising: virtually dividing a pattern into a plurality of mesh-like first square regions surrounded by first grids defined at intervals of a predetermined size;virtually dividing the pattern into a plurality of mesh-like second square regions surrounded by second grids defined at intervals of the predetermined size, wherein the second grids being positionally deviated from the first grids by a half of the predetermined size;distributing an area value of a sub-pattern in each of the second square regions to a plurality of apexes of each of the second square regions such that a center-of-gravity position of the sub-pattern does not change, wherein the sub-pattern being a part of the pattern; andoutputting the distributed area values as area values, for correcting a proximity effect, defined at the center position of each of the first square regions.

2. The method according to claim 1, wherein when, in distribution of the area value, area value of a sub-pattern in another second square region is distributed to at least one of apexes of a second square region, the distributed area values are cumulatively added to each other with respect to each apex.

3. The method according to claim 1, further comprising: calculating an area value of the sub-pattern in each of the second square regions;calculating a center-of-gravity position of the sub-pattern;calculating a center-of-gravity moment of the sub-pattern in each of the second square regions on the basis of the calculated area value and the calculated center-of-gravity position; andwherein, in distribution of the area value, the calculated area value of the sub-pattern is distributed by using the calculated area value and the calculated center-of-gravity moment.

4. A proximity effect correcting method comprising: virtually dividing a pattern which is written by using a charged particle beam into a plurality of mesh-like square regions surrounded by grids defined at intervals of a predetermined size;distributing a part of area value of a sub-pattern in each of the square regions to a center position of another square region such that a center-of-gravity position of the sub-pattern does not change, wherein the part of area value being defined by the center position of the another square region and the sub-pattern being a part of the pattern; andcalculating an amount of proximity effect correction in each square region by use of an area value of each square region obtained by adding remaining area value which is not distributed to other square region and area value distributed from other square region to output the amount of proximity effect correction.

5. The proximity effect correcting method according to claim 4, further comprising: virtually dividing the pattern into a plurality of mesh-like second square regions surrounded by second grids defined at intervals of the predetermined size, wherein the second grids being positionally deviated from the first grids by a half of the predetermined size; andwherein, when distribution of the part of area value, an area value of a sub-pattern in each of the second square regions is distributed to a plurality of apexes of each of the second square regions such that a center-of-gravity position of the sub-pattern in each of the second square regions does not change.

6. A method for writing a pattern using a charged particle beam, the method comprising: virtually dividing a pattern into a plurality of mesh-like square regions surrounded by grids defined at intervals of a predetermined size;distributing an area value of a sub-pattern in each of the square regions to positions where the distributed area values are defined by a center position of the square region and a center position of other square region, such that a center-of-gravity position of the sub-pattern in each of the square regions does not change;after the area values are distributed, calculating an exposure dose of the charged particle beam corrected with respect to proximity effect by using the area values defined by the center positions of the square regions; andwriting the pattern on a target object at the exposure dose.

7. A charged particle beam writing apparatus for writing a pattern using a charged particle beam, comprising: a dividing unit configured to virtually divide a pattern into a plurality of mesh-like first square regions surrounded by first grids defined at intervals of a predetermined size and a plurality of mesh-like second square regions surrounded by second grids defined at intervals of the predetermined size, wherein the second grids being positionally deviated from the first grids by a half of the predetermined size;a distributing unit configured to distribute an area value of a sub-pattern in each of the second square region to a plurality of apexes of each of the second square regions such that a center-of-gravity position of the sub-pattern in each of the second square region does not change, wherein the sub-pattern being a part of the pattern;a calculating unit configured to calculate an amount of proximity effect correction for correcting proximity effect in each of the first square regions by using area values distributed; anda pattern writing unit configured to write the pattern on a target object at an exposure dose of the charged particle beam corrected with respect to proximity effect by using the amount of proximity effect correction.

8. The charged particle beam writing apparatus according to claim 7, further comprising an area calculating unit configured to calculate an area value of the sub-pattern in each of the second square regions.

9. The charged particle beam writing apparatus according to claim 8, further comprising: a center-of-gravity calculating unit configured to calculate a center-of-gravity position of the sub-pattern.

10. The charged particle beam writing apparatus according to claim 9, further comprising: a moment calculating unit configured to calculate a center-of-gravity moment of the sub-pattern on the basis of the area value calculated and the center-of-gravity position calculated.

11. The charged particle beam writing apparatus according to claim 10, wherein the distributing unit distributes the area value of the sub-pattern by using the area values calculated and the center-of-gravity moment calculated.