Method of manufacturing a mask

1. A method of manufacturing a mask, comprising the steps of:

patterning a mask substrate to form initial ribs and initial slits interposed between the initial ribs, a width of each initial slit being determined by a distance between upper edge portions of the immediately adjacent initial ribs which said each initial slit is interposed between; and

respectively converting the initial ribs and the initial slits to final ribs and final slits by removing the upper edge portions of the initial ribs.

2. The method of claim 1 , wherein each of the forming of the initial ribs and the initial slits and the converting of the initial ribs and the initial slits to the final ribs and the final slits comprises at least one photolithography process.

3. The method of claim 2 , wherein the forming of the initial ribs and the initial slits comprises:

forming a first pattern on a top surface of the mask substrate;

forming a second pattern on a bottom surface of the mask substrate so as to face the first pattern;

etching the top and bottom surfaces of the mask substrate by using the first and second patterns as etching masks to form first recesses in the top surface of the mask substrate and second recesses in the bottom surface of the mask substrate;

forming a third pattern to cover the first pattern and the first recesses; and

forming the initial ribs and the initial slits by etching the mask substrate with the first, second and third patterns as etching masks.

4. The method of claim 3 , wherein a width of an opening of the first pattern, which exposes one of the initial slits, is less than a width of the final slit that is converted from said one of the initial slits.

5. The method of claim 3 , wherein the converting of the initial ribs and the initial slits to the final ribs and the final slits comprises:

forming a bottom pattern to cover the second pattern and portions of sidewalls of the initial ribs and to expose the upper edge portions of the initial ribs; and

etching the upper edge portions of the initial ribs by using the first, second and third patterns and the bottom pattern as etching masks.

6. The method of claim 3 , wherein the converting of the initial ribs and the initial slits to the final ribs and the final slits comprises:

removing the first through third patterns;

forming a bottom pattern to cover bottom surfaces and sidewalls of the initial ribs;

forming an upper pattern to cover portions of top surfaces of the initial ribs and to expose the upper edge portions of the initial ribs; and

etching the upper edge portions of the initial ribs by using the upper and bottom patterns as etching masks.

7. The method of claim 3 , wherein the etching of the mask substrate by using the first, second and third patterns as etching masks is performed in an isotropic etching manner by using a wet etching process.

8. The method of claim 1 , wherein the mask is one of a deposition mask used for a deposition process and a photo mask used for a photolithography process.

9. The method of claim 1 , wherein each of the final ribs has a mirror-symmetric trapezoidal section having a top width which is greater than a bottom width thereof; and

wherein each of the final ribs comprises a linear sidewall extending downward from an edge of a top surface of said each of final ribs along a vertical direction, and a curved sidewall extending from an edge of the linear sidewall to an edge of a bottom surface of said each of final ribs in a concave manner with respect to a center plane of said each of the final ribs.

10. A method of manufacturing a mask, comprising the steps of:

forming an initial rib by using a first photolithography process, the initial rib including opposite upper edge portions with respect to a center plane of the initial rib, each of the opposite upper edge portions having a thickness decreasing in a direction away from the center plane of the initial rib; and

removing the opposite upper edge portions of the initial rib by using a second photolithography process so as to form a final rib and a slit defined by the final rib, a top width of the final rib being less than a top width of the initial rib,

the final rib comprising a linear sidewall extending downward from an edge of a top surface of the final rib along a vertical direction, and a curved sidewall extending from an edge of the linear sidewall to an edge of a bottom surface thereof in a concave manner with respect to a center plane of the final rib.

11. The method of claim 10 , wherein the step of forming the initial rib comprises:

forming a first pattern on a top surface of a mask substrate;

forming a second pattern on a bottom surface of the mask substrate;

etching the top surface of the mask substrate by using the first pattern as an etching mask to form a first recess having a depth smaller than a vertical length of the linear sidewall of the final rib, and etching the bottom surface of the mask substrate by using the second pattern as an etching mask to form a second recess having a depth smaller than a height of the curved sidewall of the final rib;

forming a third pattern to cover the first pattern and the first recess; and

etching the mask substrate by using the first, second and third patterns as etching masks to form an extended curvilinear sidewall of the initial rib, a curvilinear length of the extended curvilinear sidewall of the initial rib being greater than a curvilinear length of the curved sidewall of the final rib.

12. The method of claim 11 , wherein the forming of the final rib comprises:

forming a bottom pattern to cover the second pattern and portions of the extended curvilinear sidewall of the initial rib and to expose the opposite edge portions of the initial rib; and

etching the opposite edge portions of the initial rib by using the bottom photoresist pattern as an etching mask to form the final rib having the linear sidewall and the curved sidewall.

13. The method of claim 11 , wherein the forming of the final rib comprises:

removing the first, second and third patterns;

forming a bottom pattern to cover a bottom surface and the extended curvilinear sidewall of the initial rib;

forming an upper pattern on a top surface of the initial rib and to expose the opposite edge portions of the initial rib; and

etching the upper edge portions of the initial rib by using the upper and bottom patterns as etching masks to form the final rib having the linear sidewall and the curved sidewall.

14. The method of claim 13 , wherein the mask is one of a deposition mask used for a deposition process of one of a flat panel display and a semiconductor device, and a photo mask used for a photolithography process of one of a flat panel display and a semiconductor device.

15. The method of claim 14 , wherein the forming of the extended curvilinear sidewall of the initial rib is performed in an isotropic etching manner by using a wet etching process.

16. The method of claim 12 , wherein the mask is one of a deposition mask used for a deposition process of one of a flat panel display and a semiconductor device, and a photo mask used for a photolithography process of one of a flat panel display and a semiconductor device.

17. The method of claim 16 , wherein the forming of the extended curvilinear sidewall of the initial rib is performed in an isotropic etching manner by using a wet etching process.