Photomask using separated exposure technique, method of fabricating photomask, and apparatus for fabricating photomask by using the method

Abstract

A method of fabricating a photomask may include forming a light-shielding layer and a first resist film on a substrate, forming a first resist pattern by exposing first exposed regions of the first resist film to a first exposure source that may have a first energy, forming a first, light shielding pattern by etching the selectively exposed light-shielding layer by using the first resist pattern as an etching mask, removing the first resist pattern, forming a second resist film on the first light-shielding layer, exposing second exposed regions of the second resist film that may have a desired pattern shape to a second exposure source that may have a second energy, forming a second light shielding pattern by etching the selectively exposed first light shielding pattern by using the second resist pattern as an etching mask, and removing the second resist pattern.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:

FIG. 1 illustrates an enlarged schematic plan view of a portion of a photomask for explaining stages in a method of fabricating a photomask according to an embodiment of the present invention;

FIG. 2 illustrates an enlarged schematic plan view of a portion of a photomask for explaining stages of the method of fabricating a photomask according to the embodiment of the present invention in greater detail;

FIGS. 3A and 3B illustrate graphs of the completion results for photomasks fabricated by a method of fabricating a photomask according to an embodiment of the present invention;

FIGS. 4A to 4H illustrate longitudinal sectional views of stages of a method of fabricating a photomask according to an embodiment of the present invention;

FIGS. 5A to 5E illustrate longitudinal sectional schematic views of stages of a method of fabricating a photomask according to another embodiment of the present invention;

FIGS. 6A and 6B illustrate diagrams of an apparatus for fabricating a photomask according to an embodiment of the present invention; and

FIGS. 7A and 7B illustrate flow charts showing stages of a method of fabricating a photomask by using an apparatus for fabricating a photomask according to an embodiment of the present invention.

Claims

1. A method of fabricating a photomask, comprising: preparing a light-shielding layer and a first resist film on a substrate;forming a first resist pattern by exposing first exposed regions of the first resist film adjacent to patterns in a first pattern region to a first exposure source having a first energy, so as to selectively expose the light-shielding layer;forming a first light shielding pattern by etching the selectively exposed light-shielding layer by utilizing the first resist pattern as an etching mask;removing the first resist pattern;forming a second resist film on the first light-shielding layer;forming a second resist pattern by exposing second exposed regions of the second resist film, except for the first exposed regions of the first pattern region, and a second pattern region to a second exposure source having a second energy;forming a second light shielding pattern by etching the selectively exposed first light shielding pattern by utilizing the second resist pattern as a mask for etching; andremoving the second resist pattern.

2. The method as claimed in claim 1, wherein the first pattern region has a pattern density lower than that of the second pattern region.

3. The method as claimed in claim 1, wherein: in the first pattern region, a gap between the patterns is equal to or more than about twice a line width of the pattern; andin the second pattern region, a gap between the patterns is equal to or less than about twice a line width of the pattern.

4. The method as claimed in claim 1, wherein the first exposure source is an electron beam, and the second exposure source is an electron beam or light.

5. The method as claimed in claim 1, wherein the first energy is higher than the second energy.

6. The method as claimed in claim 1, wherein the first energy has an acceleration voltage higher than that of the second energy.

7. The method as claimed in claim 1, wherein the first energy has an acceleration voltage of about 50 KeV, and the second energy has an acceleration voltage of about 10 KeV.

8. A method of fabricating a photomask, comprising: preparing a light-shielding layer and a resist film on a substrate;exposing first exposed regions of the resist film adjacent to patterns in a first pattern region to a first exposure source having a first energy;exposing second exposed regions of the resist film, except for the first exposed regions of the first pattern region, and a second pattern region to a second exposure source having a second energy;forming a resist pattern by developing the resist film to selectively expose the light-shielding layer;forming a light shielding pattern by etching the selectively exposed light-shielding layer by utilizing the resist pattern as a mask for etching; andremoving the resist pattern.

9. The method as claimed in claim 8, wherein the first pattern region has a pattern density lower than that of the second pattern region.

10. The method as claimed in claim 8, wherein: in the first pattern region, a gap between the patterns is equal to or more than about twice a line width of the pattern; andin the second pattern region, a gap between the patterns is equal to or less than about twice a line width of the pattern.

11. The method as claimed in claim 8, wherein the first exposure source is an electron beam, and the second exposure source is an electron beam or light.

12. The method as claimed in claim 8, wherein the first energy is higher than the second energy.

13. The method as claimed in claim 8, wherein the first energy has an acceleration voltage higher than that of the second energy.

14. An apparatus for fabricating a photomask, comprising: a vacuum chamber;a transfer chamber including a transfer arm;an arranging chamber for arranging the photomasks;a first exposure chamber for exposing surfaces of the photomasks to a first exposure source having a first energy; anda second exposure chamber for exposing the surfaces of the photomasks to a second exposure source having a second energy.

15. The apparatus as claimed in claim 14, wherein the first exposure source is an electron beam, and the second exposure source is an electron beam or light.

16. The apparatus as claimed in claim 14, wherein the first exposure source emits higher energy than the second exposure source.

17. The apparatus as claimed in claim 14, wherein the first exposure source emits energy that has an acceleration voltage higher than that of the second energy.

18. A photomask, fabricated by the photomask fabricating method according to claim 1.

19. A photomask, fabricated by the photomask fabricating method according to claim 8.

20. A photomask, fabricated by the apparatus for fabricating a photomask according to claim 14.