ELECTRON BEAM WRITING APPARATUS AND ELECTRON BEAM WRITING METHOD

• US 20150332890A1
• Filed: 02/05/2015
• Published: 11/19/2015
• Est. Priority Date: 05/13/2014
• Status: Active Grant

• Current Assignee: NuFlare Technology, Inc. (Toshiba Corporation)
• Original Assignee: NuFlare Technology, Inc. (Toshiba Corporation)
• Inventors: MATSUI, Hideki
• Granted Patent: US 9,281,161 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01J 2237/30472 Controlling the beam
• CPC Class Codes: H01J 2237/31754 using electron beams
• CPC Class Codes: H01J 2237/31762 Computer and memory organisation
• CPC Class Codes: H01J 2237/31764 Dividing into sub-patterns
• CPC Class Codes: H01J 37/147 Arrangements for directing or deflecting the discharge along a desired path H01J37/045 take precedence; lenses H01J37/10
• CPC Class Codes: H01J 37/3026 Patterning strategy
• CPC Class Codes: H01J 37/3174 Particle-beam lithography, e.g. electron beam lithography

Abstract

An electron beam writing apparatus includes: a first aperture plate that shapes an electron beam emitted from an electron gun assembly; a second aperture plate onto which an electron beam of an aperture plate image passing through the first aperture plate is projected; and a first shaping deflector and a second shaping deflector which are provided between the first aperture plate and the second aperture plate, respectively, deflect an electron beam, control an irradiation position of the aperture plate image on the second aperture plate, and determine a shot shape and a shot size. The first shaping deflector deflects an electron beam such that the aperture plate image is positioned at a determined position in accordance with a shot shape and a shot size. The second shaping deflector deflects an electron beam deflected by the first shaping deflector and controls formation of a desirable shot size.

Claims

1. An electron beam writing apparatus comprising:

an electron gun assembly that emits an electron beam so as to perform pattern writing on a sample;

a first aperture plate that shapes the electron beam;

a second aperture plate onto which the electron beam of an aperture plate image passing through the first aperture plate is projected; and

a first shaping deflector and a second shaping deflector which are provided between the first aperture plate and the second aperture plate, respectively, deflect the electron beam, control an irradiation position of the aperture plate image on the second aperture plate, and determine a shape and a shot size of the electron beam that passes through the second aperture plate,

wherein the first shaping deflector deflects an electron beam such that the aperture plate image is positioned at a determined position in accordance with a shape and a shot size of an electron beam with which the sample is irradiated, and

wherein the second shaping deflector deflects an electron beam deflected by the first shaping deflector and controls formation of a desirable shot size.

2. The apparatus according to claim 1,

wherein, in a case where a size of an electron beam with which the sample is irradiated is equal to or less than a predetermined value, the first shaping deflector deflects the electron beam such that the entire aperture plate image is blocked by the second aperture plate, and

wherein, in a case where a size of an electron beam with which the sample is irradiated is greater than the predetermined value, the first shaping deflector deflects the electron beam such that an area of the aperture plate image that passes through the second aperture plate becomes the largest.

3. The apparatus according to claim 2, further comprising:

a shot data generator that reads a pattern writing data, in which shapes and positions of a plurality of figure patterns, and whether each figure pattern is a pattern of a highly accurate pattern writing or a pattern of a high speed pattern writing are defined, from a storage unit, divides a figure pattern which is defined in the pattern writing data by a maximum shot size that is possibly irradiated by one shot of an electron beam, and generates shot data for each divided shot figure; and

a deflection controller that generates a deflection signal for controlling the first shaping deflector and the second shaping deflector from the shot data,

wherein a maximum shot size that divides a figure pattern which is the pattern of the highly accurate pattern writing is less than a maximum shot size that divides a figure pattern which is the pattern of the high speed pattern writing.

4. The apparatus according to claim 3,

wherein the shot data generator groups the shot data on the basis of a shape of the shot figure and whether a size of the shot figure is equal to or less than the predetermined value and sets an order of the shots.

5. The apparatus according to claim 3,

wherein the maximum shot size that divides the figure pattern which is the pattern of the highly accurate pattern writing is set to be ¼

to ½

of the maximum shot size that divides the figure pattern which is the pattern of the high speed pattern writing.

6. The apparatus according to claim 5,

wherein the maximum shot size that divides the figure pattern which is the pattern of the highly accurate pattern writing is set to be the same as the maximum shot size that divides the figure pattern which is the pattern of the high speed pattern writing.

7. The apparatus according to claim 3,

wherein in the pattern writing data, a figure pattern for forming a semiconductor circuit is set to be a pattern of a highly accurate pattern writing and a figure pattern for forming a bar code or an ID number is set to be a pattern of a high speed pattern writing.

8. The apparatus according to claim 1, further comprising:

a shot data generator that reads a pattern writing data, in which shapes and positions of a plurality of figure patterns, and whether each figure pattern is a pattern of a highly accurate pattern writing, a pattern of a normal pattern writing, or a pattern of a high speed pattern writing are defined, from a storage unit, divides a figure pattern which is defined in the pattern writing data by the maximum shot size that is possibly irradiated by one shot of an electron beam, and generates shot data for each divided shot figure; and

a deflection controller that generates a deflection signal for controlling the first shaping deflector and the second shaping deflector from the shot data,

wherein a maximum shot size that divides the figure pattern which is the pattern of the normal pattern writing is less than the maximum shot size that divides a figure pattern which is the pattern of the high speed pattern writing and greater than the maximum shot size that divides a figure pattern which is the pattern of the highly accurate pattern writing.

9. The apparatus according to claim 1,

wherein an opening of an octagonal shape which includes a hexagonal-shape portion and a rectangular-shape portion that is in contact with the hexagonal-shape portion is provided in the second aperture plate,

wherein a vertex portion of the rectangular-shape portion is irradiated with an electron beam and a shape of the electron beam becomes a rectangle, and

wherein a side portion of the hexagonal-shape portion is irradiated with an electron beam and a shape of the electron beam becomes an isosceles right triangle.

10. An electron beam writing method comprising:

emitting an electron beam from an electron gun assembly;

shaping the electron beam that passes through a first aperture plate using a second aperture plate that is provided below the first aperture plate, and a first shaping deflector and a second shaping deflector which are provided between the first aperture plate and the second aperture plate; and

irradiating a sample with the electron beam that passes through the second aperture plate,

wherein the first shaping deflector controls a deflection amount of an electron beam on the basis of a shape of an electron beam with which the sample is irradiated and whether a size of the electron beam with which the sample is irradiated is equal to or less than a predetermined value, and

wherein the second shaping deflector controls a deflection amount of an electron beam on the basis of a size of the electron beam with which the sample is irradiated.

11. The method according to claim 10,

wherein, in a case where a size of an electron beam with which the sample is irradiated is equal to or less than the predetermined value, the first shaping deflector controls a deflection amount such that the entire electron beam that passes through the first aperture plate is blocked by the second aperture plate, and

wherein, in a case where a size of an electron beam with which the sample is irradiated is greater than the predetermined value, the first shaping deflector controls a deflection amount such that an area of an electron beam that passes through the second aperture plate becomes the largest.

12. The method according to claim 11, further comprising:

reading a pattern writing data, in which shapes and positions of a plurality of figure patterns and whether each figure pattern is a pattern of a highly accurate pattern writing or a pattern of a high speed pattern writing are defined, from a storage unit;

dividing a figure pattern which is defined in the pattern writing data by a maximum shot size that is possibly irradiated by one shot of an electron beam, and generating shot data for each divided shot figure; and

generating a deflection signal for controlling the first shaping deflector and the second shaping deflector from the shot data,

wherein a maximum shot size that divides the figure pattern which is the pattern of the highly accurate pattern writing is less than a maximum shot size that divides a figure pattern which is the pattern of the high speed pattern writing.

13. The method according to claim 12,

wherein the shot data is grouped on the basis of a shape of the shot figure and whether a size of the shot figure is equal to or less than the predetermined value and an order of the shots is set.

14. The method according to claim 12,

wherein the maximum shot size that divides the figure pattern which is the pattern of the highly accurate pattern writing is set to be ¼

to ½

of the maximum shot size that divides the figure pattern which is the pattern of the high speed pattern writing.

15. The method according to claim 14,

wherein the maximum shot size that divides the figure pattern which is the pattern of the highly accurate pattern writing is set to be the same as the maximum shot size that divides the figure pattern which is the pattern of the high speed pattern writing.

16. The method according to claim 12,

wherein, in the pattern writing data, a figure pattern for forming a semiconductor circuit is set to be a pattern of a highly accurate pattern writing and a figure pattern for forming a bar code or an ID number is set to be a pattern of a high speed pattern writing.

17. The method according to claim 10, further comprising:

reading a pattern writing data, in which shapes and positions of a plurality of figure patterns, and whether each figure pattern is a pattern of a highly accurate pattern writing, a pattern of a normal pattern writing, or a pattern of a high speed pattern writing are defined, from a storage unit;

dividing a figure pattern which is defined in the pattern writing data by the maximum shot size that is possibly irradiated by one shot of an electron beam, and generating shot data for each divided shot figure; and

generating a deflection signal for controlling the first shaping deflector and the second shaping deflector from the shot data,

wherein a maximum shot size that divides the figure pattern which is the pattern of the normal pattern writing is less than the maximum shot size that divides a figure pattern which is the pattern of the high speed pattern writing and is greater than the maximum shot size that divides a figure pattern which is the pattern of the highly accurate pattern writing.