Exposure mask, method of forming resist pattern and method of forming thin film pattern

Abstract

An exposure mask capable of improving resolution is provided. An exposure mask includes one slit-shaped main transmission region and three pairs of slit-shaped auxiliary transmission regions arranged in order in a direction perpendicular to the longitudinal direction of the main transmission region, each pair of auxiliary transmission regions facing each other with the main transmission region in between. Compared to the case where two or less pairs of auxiliary transmission regions are included, light intensity contrast becomes higher in an end portion in a slit width direction of the main transmission region by exposing and developing a resist film through the use of the exposure mask, so the exposed width of the resist film is narrowed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C are illustrations showing a first structural example of an exposure mask used in a method of forming a thin film pattern according to a first embodiment of the invention;

FIGS. 2A, 2B and 2C are illustrations showing a second structural example of the exposure mask;

FIGS. 3A, 3B and 3C are illustrations showing a third structural example of the exposure mask;

FIGS. 4A, 4B and 4C are illustrations showing a fourth structural example of the exposure mask;

FIGS. 5A, 5B and 5C are illustrations showing a fifth structural example of the exposure mask;

FIGS. 6A, 6B and 6C are illustrations showing a sixth structural example of the exposure mask;

FIGS. 7A, 7B and 7C are illustrations showing a seventh structural example of the exposure mask;

FIGS. 8A, 8B and 8C are illustrations showing an eighth structural example of the exposure mask;

FIGS. 9A, 9B and 9C are sectional views for describing a method of forming a thin film pattern using the exposure mask of the fifth structural example shown in FIGS. 5A, 5B and 5C;

FIGS. 10A, 10B and 10C are sectional views for describing a method of forming a thin film pattern using the exposure mask of the sixth structural example shown in FIGS. 6A, 6B and 6C;

FIGS. 11A, 11B and 11C are illustrations showing a modification of the structure of the exposure mask;

FIGS. 12A, 12B and 12C are illustrations showing a structural example of an exposure mask used in a method of forming a thin film pattern according to a second embodiment of the invention;

FIGS. 13A and 13B are sectional views of a thin film magnetic head manufactured by a method of manufacturing a thin film magnetic head based on a method of forming a thin film pattern;

FIG. 14 is a plan view of a main part of the thin film magnetic head shown in FIGS. 13A and 13B;

FIG. 15 is a plan view of a first structural example of an exposure mask used in the method of manufacturing a thin film magnetic head;

FIG. 16 is a plan view of a second structural example of the exposure mask; and

FIG. 17 is a plan view of a third structural example of the exposure mask.

Claims

1. An exposure mask comprising: a slit-shaped main transmission region; andthree or more pairs of slit-shaped auxiliary transmission regions arranged in order in a direction perpendicular to the longitudinal direction of the main transmission region, each pair of auxiliary transmission regions facing each other with the main transmission region in between.

2. The exposure mask according to claim 1, wherein the main transmission region and the auxiliary transmission regions allow exposure light to pass through in the same phase.

3. The exposure mask according to claim 1, wherein a phase of exposure light passing through a region of the main transmission ergion and the auxiliary transmission regions is opposite to that of exposure light passing through an adjacent region.

4. The exposure mask according to claim 1, wherein spacings between the main transmission region and one pair of the auxiliary transmission regions closest to the main transmission region are equal to spacings between the auxiliary transmission regions.

5. The exposure mask according to claim 1, wherein spacings between the main transmission region and one pair of the auxiliary transmission regions closest to the main transmission region are larger than spacings between the auxiliary transmission regions.

6. The exposure mask according to claim 5, wherein spacings between the auxiliary transmission regions are equal to each other.

7. The exposure mask according to claim 1, wherein a relationship of S1□T×0.095□00.22 μm is satisfied, where spacings between the main transmission region and one pair of the auxiliary transmission regions closest to the main transmission region are S1 (μm), respectively, and the thickness of a resist film exposed to exposure light is T (μm).

8. The exposure mask according to claim 1, wherein the slit widths of the auxiliary transmission regions are equal to the slit width of the main transmission region.

9. The exposure mask according to claim 1, wherein the slit widths of the auxiliary transmission regions are smaller than the slit width of the main transmission region.

10. The exposure mask according to claim 1, wherein the slit lengths of the auxiliary transmission regions are equal to the slit length of the main transmission region.

11. The exposure mask according to claim 1, wherein the slit lengths of the auxiliary transmission regions are larger than the slit length of the main transmission region.

12. The exposure mask according to claim 1, wherein the slit lengths of the auxiliary transmission regions gradually increase with distance from the main transmission region.

13. An exposure mask comprising: a main transmission region; andthree or more circular auxiliary transmission regions arranged in order around the main transmission region.

14. An exposure mask comprising: a main transmission region including a uniform width region extending with a uniform width and a widening region having a width gradually increasing from the uniform width of the uniform width region; andthree or more pairs of slit-shaped auxiliary transmission regions arranged in order in a direction perpendicular to the longitudinal direction of the main transmission region, each pair of auxiliary transmission regions facing each other with the uniform width region in between.

15. The exposure mask according to claim 14, wherein the slit lengths of the auxiliary transmission regions are equal to the length of the uniform width region in the main transmission region.

16. The exposure mask according to claim 14, wherein the slit lengths of the auxiliary transmission regions gradually increases along the outer edge of the widening region in the main transmission region with distance from the uniform width region in the main transmission region.

17. The exposure mask according to claim 14, wherein the slit lengths of the auxiliary transmission regions are larger than the length of the uniform width region in the main transmission region, and are bended along the outer edge of the widening region in the main transmission region according to an increase in the width of the widening region.

18. The exposure mask according to claim 17, wherein the slit lengths of the auxiliary transmission regions are equal to each other.

19. A method of forming a resist pattern comprising: a first step of forming a resist film;a second step of selectively exposing the resist film through the use of an exposure mask according to claim 1; anda third step of developing the exposed resist film.

20. The method of forming a resist pattern according to claim 19, wherein in the first step, the thickness of the resist film is 0.5 μm or over.

21. The method of forming a resist pattern according to claim 19, wherein in the second step, oblique illumination is used.

22. The method of forming a resist pattern according to claim 19, wherein in the second step, normal illumination is used, and a ratio σ(□NA1/NA2) between the numerical aperture NA1 of a illumination system and the numerical aperture NA2 of an optical system is 0.3 or less.

23. A method of forming a thin film pattern comprising: a first step of forming a resist pattern by a method of forming a resist pattern according to claim 19; anda second step of forming a thin film pattern through the use of the resist pattern.

24. The method of forming a thin film pattern according to claim 23, wherein in the first step, a positive resist is used, and in the second step, a plating film is selectively grown through the use of the resist pattern as a frame.

25. The method of forming a thin film pattern according to claim 24, wherein in the second step, a pole layer of a thin film magnetic head is formed as the thin film pattern.