Method for fabricating photoresist pattern, color filter and display device

Patent metadata

Field	Value
Publication number	US-9971187-B2
Application number	US-201615307295-A
Country	US
Kind code	B2
Filing date	Mar 2, 2016
Priority date	Sep 24, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

The disclosure provides in some embodiments a method for fabricating a photoresist pattern, a color filter and a method for fabricating the same, and a display device. The method for fabricating a photoresist pattern includes coating negative photoresist on a base substrate to form a first photoresist layer, coating positive photoresist on the first photoresist layer to form a second photoresist layer, conducting a first exposure process on first regions of the second photoresist layer, conducting a first developing process to remove the positive photoresist within the first regions of the second photoresist layer and the negative photoresist within second regions of the first photoresist layer, so as to obtain a first photoresist pattern and a second photoresist pattern, conducting a second exposure process on the first photoresist pattern and the second photoresist pattern, and conducting a second developing process to remove the first photoresist pattern.

First claim

What is claimed is:

1. A method for fabricating a photoresist pattern comprising:
coating negative photoresist on a base substrate to form a first photoresist layer;
coating positive photoresist on the first photoresist layer to form a second photoresist layer;
conducting a first exposure process on first regions of the second photoresist layer;
conducting a first developing process to remove the positive photoresist within the first regions of the second photoresist layer and form a first photoresist pattern of the second photoresist layer, and remove the negative photoresist within second regions of the first photoresist layer to form a second photoresist pattern of the first photoresist layer, wherein a line width of the first photoresist pattern is larger than that of the second photoresist pattern, and a projection of each of the first regions on the base substrate is located within that of a corresponding one of the second regions on the base substrate;
conducting a second exposure process on the first photoresist pattern and the second photoresist pattern; and
conducting a second developing process to remove the first photoresist pattern but to retain the second photoresist pattern.

2. The method according to claim 1 , wherein
the first exposure process is conducted on the second photoresist layer using a mask that is provided with light transmitting regions and light shielding regions, the light transmitting regions corresponding to the first regions of the second photoresist layer; and
the first developing process is conducted using developer to remove the positive photoresist within the first regions of the second photoresist layer as well as the negative photoresist beneath the positive photoresist to be removed and at its perimeter, so as to obtain the first photoresist pattern and the second photoresist pattern.

3. The method according to claim 2 , wherein the mask is provided with a predetermined line width of 8 μm, while a line width of the second photoresist pattern is 4 μm.

4. A method for fabricating a color filter comprising the method for fabricating a photoresist pattern according to claim 3 .

5. The method according to claim 2 , wherein the conducting the first developing process using the developer comprises:
conducting the first developing process in accordance with a predetermined temperature or concentration of the developer.

6. A method for fabricating a color filter comprising the method for fabricating a photoresist pattern according to claim 5 .

7. The method according to claim 2 , wherein the developer includes at least one of low-concentration inorganic alkaline and low-concentration organic alkaline.

8. The method according to claim 7 , wherein the inorganic alkaline includes at least one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, and potassium bicarbonate;
wherein the organic alkaline includes at least one of amine compounds, alkali metal salts, and alkyl lithium compounds; and
wherein the amine compounds is chosen from a group of tetramethylammonium hydroxide (TMAOH), sodium methoxide, and potassium ethoxide.

9. A method for fabricating a color filter, comprising the method for fabricating a photoresist pattern according to claim 2 .

10. The method according to claim 1 , wherein the conducting the first developing process on the first regions of the second photoresist layer comprises:
conducting the first developing process on the first regions of the second photoresist layer in accordance with a predetermined developing time period.

11. A method for fabricating a color filter comprising the method for fabricating a photoresist pattern according to claim 10 .

12. The method according to claim 1 , wherein the negative photoresist is black negative photoresist; and
a photo-sensitivity range of the black negative photoresist and that of the positive photoresist partially overlap or do not overlap.

13. A method for fabricating a color filter comprising the method for fabricating a photoresist pattern according to claim 12 .

14. The method according to claim 1 , further comprising:
conducting a vacuum dry process and a soft bake process on the base substrate provided with the first photoresist layer, subsequent to forming the first photoresist layer; and
conducting another vacuum dry process and another soft bake process on the base substrate provided with the first photoresist layer and the second photoresist layer, subsequent to forming the second photoresist layer.

15. The method according to claim 1 , wherein conducting the second exposure process comprises:
conducting the second exposure process both on the first photoresist pattern from the upper side of the base substrate and on the second photoresist pattern from the lower side of the base substrate; and
wherein conducting the second developing process comprises:
conducting the second developing process using developer to remove the first photoresist pattern but to retain the second photoresist pattern.

16. The method according to claim 1 , further comprising:
curing the base substrate provided with the second photoresist pattern.

17. The method according to claim 16 , wherein the curing process is conducted in a situation where temperature is within a range of 160°˜230°.

18. A color filter comprising the photoresist pattern formed by using the method according to claim 1 .

19. A display device, comprising the color filter according to claim 18 .

20. A method for fabricating a color filter, comprising the method for fabricating a photoresist pattern according to claim 1 .

Assignees

• Boe Technology Group Co Ltd
• Chengdu Boe Optoelect Tech Co
• Chengdu Boe Optoelectronics Technolgy Co Ltd

Inventors

• Long Qingde
• Kang Yulong
• Liang Yuan
• Zhang Zhiyong
• Fan Liwei

Classifications

• G03F7/2024

  of the already developed image · CPC title

• G02B5/201

  in the form of arrays · CPC title

• G02F1/133516

  Methods for their manufacture, e.g. printing, electro-deposition or photolithography · CPC title

• G03F7/0007

  Filters, e.g. additive colour filters; Components for display devices · CPC title

• G03F7/095

  having more than one photosensitive layer (G03F7/075 takes precedence) · CPC title