Method of forming multi-domain alignment layer
View Patent ↗A method of forming an alignment layer with a multi-domain is provided. The alignment layer is formed on a substrate. A mask having a transmission part and a shielding part is aligned over the substrate. First and second alignment directions in the alignment layer are formed by irradiating an ion beam onto the substrate at different irradiation angles. Using the aforementioned ion-beam irradiation process eliminates the need for multiple rubbing processes to create the multi-domain alignment layer.
1. A method of forming a multi-domain alignment layer, the method comprising:
forming an alignment layer on a substrate;
aligning a mask having a transmission part and a shielding part over the substrate, the mask having a thickness D; and
forming a first alignment direction in the alignment layer by irradiating an ion beam onto the substrate at an irradiation angle of θ, wherein the thickness D of the mask is determined by the following equation:
D
=
L
4
tan
θ
-
H
,
where H is an interval between the mask and the alignment layer, and L is a pixel size;
rotating the substrate;
aligning and shifting the mask over the substrate; and
forming a second alignment direction in the alignment layer by irradiating the ion beam onto the substrate,
wherein the mask is shifted to a direction parallel to the substrate in consideration of the thickness of the mask and the irradiation angle of the ion beam.
2. The method according to claim 1 , wherein the transmission part of the mask has a width greater than or equal to L/ 2 .
3. The method according to claim 1 , wherein the transmission part of the mask has a width smaller than or equal to 3 L/ 4 .
4. The method according to claim 1 , wherein the irradiation angle of θ has a relationship of tan −1 4D/L≦θ≦π/2 or tan −1 4H/L≦θ≦π/2.
5. The method according to claim 1 , wherein a sum of a width of the transmission part and a width of the shielding part is equal to the pixel size.
6. The method according to claim 1 , wherein a region corresponding to the first alignment direction has a first area and a region corresponding to the second alignment direction has a second area, and the first area is equal to the second area.
7. The method according to claim 1 , wherein the alignment layer comprises at least one of an organic material and an inorganic material.
8. The method according to claim 1 , wherein the mask has a slit pattern.
9. The method according to claim 1 , wherein the first alignment direction is opposite to the second alignment direction.
10. The method according to claim 1 , wherein the forming the second alignment direction is performed by irradiating the ion beam at the irradiation angle of θ in an opposite direction to the first alignment direction.
11. The method according to claim 1 , wherein the forming the second alignment direction is performed by tilting the substrate in an opposite direction to an original alignment direction of the substrate and irradiating the ion beam at the irradiation angle of θ with respect to a parallel direction to the substrate.
12. The method according to claim 1 , wherein the forming the second alignment direction is performed by arranging another mask at a predetermined position.
13. A method of forming a multi-domain alignment layer, the method comprising:
aligning a first mask over an alignment layer on a substrate, the first mask containing a transmission part and a shielding part, and the first mask having a thickness D;
irradiating first different regions of the alignment layer to form first different alignment directions in the first different regions using an ion beam, wherein the thickness D of the first mask is determined by the following equation:
D
=
L
4
tan
θ
-
H
,
where H is an interval between the first mask and the alignment layer, and L is a pixel size;
rotating the substrate;
aligning and shifting a second mask over the alignment layer; and
irradiating second different regions of the alignment layer to form second different alignment directions in the second different regions using the ion beam,
wherein the second mask is shifted to a direction parallel to the substrate in consideration of thickness of the second mask and an irradiation angle of the ion beam.
14. The method according to claim 13 , wherein the first different regions are formed in a unit pixel.
15. The method according to claim 14 , wherein the first different regions are substantially symmetrical in the unit pixel.
16. The method according to claim 13 , wherein the first different regions have substantially same size.
17. The method according to claim 13 , further comprising irradiating the first different regions at different angles relative to normal to the substrate.
18. The method according to claim 17 , wherein the angles are substantially symmetrical to the normal to the alignment layer.
19. The method according to claim 13 , wherein the first alignment directions of the first different regions are opposite to each other.
20. The method according to claim 13 , further comprising adjusting a position of the first mask relative to the substrate between forming a first region of the different regions and forming a second region of the different regions.
21. The method according to claim 20 , further comprising adjusting a lateral position of the first mask relative to the substrate.
22. The method according to claim 21 , further comprising maintaining substantially the same distance between the first mask and the substrate.
23. The method according to claim 20 , further comprising adjusting a distance between the first mask and the substrate.
24. The method according to claim 23 , further comprising maintaining substantially the same lateral position of the first mask relative to the substrate.
25. The method according to claim 13 , wherein the first and second masks have different external dimensions.
26. The method according to claim 13 , wherein the first and second masks have different internal dimensions.
27. The method according to claim 13 , further comprising adjusting a position of the second mask relative to a position of the first mask.
28. The method according to claim 27 , further comprising adjusting a lateral position of the second mask relative to a lateral position of the first mask.
29. The method according to claim 28 , further comprising using substantially the same distance between the second mask and the substrate that was used between the first mask and the substrate.
30. The method according to claim 27 , further comprising using a distance between the second mask and the substrate that is different from a distance that was used between the first mask and the substrate.
31. The method according to claim 30 , further comprising using substantially the same lateral position between the second mask and the substrate that was used between the first mask and the substrate.
32. The method according to claim 13 , further comprising ion beam-irradiating the alignment layer to form the first different regions.
33. The method according to claim 32 , further comprising irradiating the alignment layer using substantially the same ion dosage to form the first different regions.
34. The method according to claim 13 , further comprising forming the first different regions without rubbing the alignment layer.
35. The method according to claim 13 , wherein the transmission part has a width grater than or equal to one half of the pixel size.
36. The method according to claim 13 , wherein the transmission part has a width smaller than or equal to three quarters of the pixel size.
37. The method according to claim 13 , further comprising irradiating the alignment layer at angle of tan −1 4D/L≦θ≦π/2 or tan −1 4H/L≦θ≦π/2.
38. The method according to claim 13 , wherein a sum of a width of the transmission part and a width of the shielding part is equal to the pixel size.
39. The method according to claim 13 , further comprising irradiating an alignment layer comprising at least one of an organic material and an inorganic material.
40. The method according to claim 13 , further comprising using a mask that has a slit pattern.
41. The method according to claim 1 ,
wherein the thickness D of the mask is determined by the following equation:
D
=
L
4
tan
θ
-
H
,
where H is an interval between the mask and the alignment layer, and L is a pixel size.
42. The method according to claim 13 , wherein the ion beam used to irradiate the different regions is maintained substantially at the same direction at an irradiation angle of θ, and the thickness D of the first mask is determined by the following equation:
D
=
L
4
tan
θ
-
H
,
where H is an interval between the first mask and the alignment layer, and L is a pixel size.