Multi-tone optical mask, method of manufacturing the same and method of manufacturing thin-film transistor substrate by using the same

1. A multi-tone optical mask comprising:

a substrate;

a light-blocking pattern formed on the substrate;

a first semi-transmitting pattern having a light-transmittance of a first value, and being formed on the substrate;

a second semi-transmitting pattern having a light-transmittance of a second value different from the first value, the second semi-transmitting pattern having a first portion overlapping the first semi-transmitting pattern and a second portion formed on the substrate; and

a first etch-stopping layer covering an entire surface of the substrate including the light-blocking pattern and the first semi-transmitting pattern, wherein the second semi-transmitting pattern is formed on the first etch-stopping layer.

2. The multi-tone optical mask of claim 1 , further comprising a third semi-transmitting pattern having a light-transmittance of a third value different than the first and second light-transmittance values, wherein the third semi-transmitting pattern has a first portion overlapping a portion of the first and second semi-transmitting patterns, a second portion which overlaps only a portion of the first semi-transmitting pattern, a third portion which overlaps only a portion of the second semi-transmitting pattern, and a fourth portion which overlaps only a portion of the substrate.

3. The multi-tone optical mask of claim 2 , wherein the first etch-stopping layer further comprises at least one of a first portion and a third portion, the first portion being formed between the light-blocking pattern and the first semi-transmitting pattern, the third portion being formed between the second semi-transmitting pattern and third semi-transmitting pattern.

4. The multi-tone optical mask of claim 2 , wherein the light-blocking pattern comprises chromium.

5. The multi-tone optical mask of claim 2 , wherein a composition of each of the first, second and third semi-transmitting patterns comprise at least one material selected from the group consisting of chromium oxide, chromium nitride, chromium oxide nitride and molybdenum silicide.

6. The multi-tone optical mask of claim 1 , wherein the substrate includes:

a first area corresponding to the light-blocking pattern having a first light-transmittance;

a second area corresponding to the portion of the first semi-transmitting pattern, which overlaps with the second semi-transmitting pattern, having a second light-transmittance;

a third area corresponding to the portion of the first semi-transmitting pattern formed on the substrate having a third light-transmittance;

a fourth area corresponding to the portion of the second semi-transmitting pattern formed on the substrate having fourth light-transmittance; and

a fifth area corresponding to an exposed portion of the substrate having a fifth light-transmittance.

7. The multi-tone optical mask of claim 1 , further comprising a protecting layer covering the light-blocking pattern, the first semi-transmitting pattern and the second semi-transmitting pattern.

8. The multi-tone optical mask of claim 1 , wherein a portion of the first semi-transmitting pattern overlaps with the light-blocking pattern.

9. The multi-tone optical mask of claim 1 , wherein at least a portion of the first semi-transmitting pattern is disposed on the light-blocking pattern, and a portion of the second semi-transmitting pattern is disposed on the first semi-transmitting pattern.

10. The multi-tone optical mask of claim 9 , wherein a composition of the first semi-transmitting pattern comprises molybdenum silicide, and a composition of the second semi-transmitting pattern comprises at least one material selected from the group consisting of chromium oxide, chromium nitride and chromium oxide nitride.

11. The multi-tone optical mask of claim 10 , further comprising a second etch-stopping layer and a third semi-transmitting pattern formed on the second etch-stopping layer, the second etch-stopping layer covering the light-blocking pattern, the first semi-transmitting pattern and the second semi-transmitting pattern, wherein a composition of the third semi-transmitting pattern comprises at least one material selected from the group consisting of chromium oxide, chromium nitride and chromium oxide nitride.

12. The multi-tone optical mask of claim 1 , wherein at least a portion of the light-blocking pattern is disposed on the first semi-transmitting pattern and/or the second semi-transmitting pattern.

13. A method of manufacturing a multi-tone optical mask, the method comprising:

forming a light-blocking pattern on a substrate;

forming a first semi-transmitting pattern formed on the substrate;

forming a first etch-stopping layer on an entire surface of the substrate including the light-blocking pattern and the first semi-transmitting pattern to cover the entire surface of the substrate; and

forming a second semi-transmitting pattern on the substrate including the first etch-stopping layer, the second semi-transmitting pattern having a first portion which overlaps the first semi-transmitting pattern, and a second portion which overlaps a portion of the substrate.

14. The method of claim 13 , further comprising forming a third semi-transmitting pattern having a first portion which overlaps a portion of the first and second semi-transmitting patterns, a second portion which overlaps only a portion of the first semi-transmitting pattern, a third portion which overlaps only a portion of the second semi-transmitting pattern, and a fourth portion which only overlaps a portion of the substrate.

15. The method of claim 14 , wherein the first etch-stopping layer further comprises at least one of a first portion and a third portion, the first portion being formed between the light-blocking pattern and the first semi-transmitting pattern, the third portion being formed between the second semi-transmitting pattern and third semi-transmitting pattern.

16. The method of claim 14 , wherein the light-blocking pattern, the first semi-transmitting pattern, the second semi-transmitting pattern and the third semi-transmitting pattern are sequentially formed on the substrate.

17. The method of claim 14 , further comprising sequentially depositing a light-blocking layer, a first semi-transmitting layer, a second semi-transmitting layer and a third semi-transmitting layer on the substrate, wherein the third semi-transmitting pattern, the second semi-transmitting pattern, the first semi-transmitting pattern and the light-blocking pattern are sequentially formed.

18. The method of claim 14 , wherein the multi-tone optical mask has;

a first area corresponding to a portion of the light-blocking pattern having a first light-transmittance;

a second area corresponding to an exposed portion of the substrate to have a second light-transmittance; and

at least three areas of a third area corresponding to a portion of the first semi-transmitting pattern, which overlaps the second semi-transmitting pattern, a fourth area corresponding to a portion of the first semi-transmitting pattern, which overlaps the second and third semi-transmitting patterns, a fifth area corresponding to a portion of the first semi-transmitting pattern, which overlaps the third semi-transmitting pattern, a sixth area corresponding to a remaining portion of the first semi-transmitting pattern except for the first, third, fourth and fifth areas, a seventh area corresponding to a portion of the second semi-transmitting pattern, which overlaps the third semi-transmitting pattern, an eighth area corresponding to a remaining portion of the second semi-transmitting pattern except for the first, third, fourth and seventh areas and a ninth area corresponding to a remaining portion of the third semi-transmitting pattern except for the first, fourth, fifth and seventh areas.

19. The method of claim 13 , further comprising forming a protecting layer covering the light-blocking pattern, the first semi-transmitting pattern and the second semi-transmitting pattern.

20. The method of claim 13 , wherein a portion of the first semi-transmitting pattern overlaps with the light-blocking pattern.

21. The method of claim 13 , wherein at least a portion of the first semi-transmitting pattern is disposed on the light-blocking pattern, and a portion of the second semi-transmitting pattern is disposed on the first semi-transmitting pattern.

22. The method of claim 21 , wherein a composition of the first semi-transmitting pattern comprises molybdenum silicide, and a composition of the second semi-transmitting pattern comprises at least one material selected from the group consisting of chromium oxide, chromium nitride and chromium oxide nitride.

23. The method of claim 22 , further comprising:

forming a second etch-stopping layer covering the light-blocking pattern, the first semi-transmitting pattern and the second semi-transmitting pattern; and

forming a third semi-transmitting pattern disposed on the second etch-stopping layer, wherein a composition of the third semi-transmitting pattern comprises at least one material selected from the group consisting of chromium oxide, chromium nitride and chromium oxide nitride.

24. The method of claim 13 , wherein at least a portion of the light-blocking pattern is disposed on the first semi-transmitting pattern and/or the second semi-transmitting pattern.

25. The method of claim 24 , wherein the first semi-transmitting pattern, the light-blocking pattern and the second semi-transmitting pattern are sequentially formed on the substrate.

26. The method of claim 24 , wherein the first semi-transmitting pattern, the second semi-transmitting pattern and the light-blocking pattern are sequentially formed on the substrate.

27. The method of claim 24 , further comprising:

sequentially depositing a first semi-transmitting layer and a light-blocking layer;

sequentially etching the light-blocking layer and the first semi-transmitting layer;

depositing a second semi-transmitting layer covering the light-blocking pattern and the first semi-transmitting pattern; and

etching the second semi-transmitting layer.