MANUFACTURING METHOD OF DISPLAY DEVICE

• US 20150221684A1
• Filed: 01/27/2015
• Published: 08/06/2015
• Est. Priority Date: 01/31/2014
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: KANDA, Noriyoshi
• Granted Patent: US 9,508,761 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13685 Top gates
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: H01L 21/76804 by forming tapered via holes
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate

Abstract

Since a film, which is the upper layer of an interlayer insulating film and has a fast etching rate, does not have dense film quality, moisture is entered from the end portion of a substrate, and it is likely that display unevenness and the like occur. A manufacturing method of a display device includes the steps of: forming a first contact hole on the first interlayer film; forming a second interlayer film on the first interlayer film and in the first contact hole, the second interlayer film having a lower layer film and an upper layer film having an etching rate faster than an etching rate of the lower layer film; forming a second contact hole on the second interlayer film; and removing at least a part of the upper layer film.

Claims

1. A manufacturing method of a display device comprising the steps of:

(a) preparing a substrate having an electrode of a thin film transistor;

(b) forming a first interlayer film on the electrode;

(c) forming a first contact hole on the first interlayer film;

(d) forming a second interlayer film on the first interlayer film and in the first contact hole, the second interlayer film having a first film and a second film provided above the first film, the second film having an etching rate faster than an etching rate of the first film;

(e) forming a second contact hole on the second interlayer film in the first contact hole;

(f) removing at least a part of the second film, and

(g) forming a transparent conductive film on the second interlayer film and in the second contact hole.

2. The manufacturing method of a display device according to claim 1,

wherein the step (e) includes the steps of:

(e1) patterning a photoresist, and

(e2) dry etching the second interlayer film using the patterned photoresist as a mask.

3. The manufacturing method of a display device according to claim 2,

wherein the step (f) includes the steps of:

(f1) ashing the photoresist, and

(f2) dry etching the second film.

4. The manufacturing method of a display device according to claim 3,

wherein the step (f) includes the step of:

(f3) removing the photoresist.

5. The manufacturing method of a display device according to claim 2,

wherein the step (f) includes the steps of:

(f1) ashing the photoresist, and

(f2) wet etching the second film.

6. The manufacturing method of a display device according to claim 5,

wherein the step (f) includes the step of:

(f3) removing the photoresist.

7. The manufacturing method of a display device according to claim 2,

wherein the step (f) includes the steps of:

(f1) ashing the photoresist, and

(f2) removing the photoresist.

8. The manufacturing method of a display device according to claim 7,

wherein the step (f) includes the step of:

(f3) wet etching the second film.

9. The manufacturing method of a display device according to claim 7,

wherein the step (f) includes the step of:

(f3) dry etching the second film.

10. The manufacturing method of a display device according to claim 1, wherein the first interlayer film is an organic film.

11. The manufacturing method of a display device according to claim 10, wherein the organic film is formed of a photosensitive resin.

12. The manufacturing method of a display device according to claim 1, wherein the second interlayer film is a silicon nitride film (SiN).

13. The manufacturing method of a display device according to claim 12, wherein the silicon nitride film is formed by plasma CVD.

14. The manufacturing method of a display device according to claim 13, wherein film forming conditions for the first film and the second film of the silicon nitride film are changed.

15. The manufacturing method of a display device according to claim 14, wherein in the step of forming the first film and the second film of the silicon nitride film, a gas flow ratio of monosilane (SiH₄) to ammonia (NH₃), which are material gases, is changed in forming the films by plasma CVD.

16. The manufacturing method of a display device according to claim 1, further comprising the step of:

(h) patterning the transparent conductive film to form a pixel electrode.

17. The manufacturing method of a display device according to claim 16, further comprising the step of:

(i) forming an alignment film on the pixel electrode.

18. The manufacturing method of a display device according to claim 1, wherein the electrode of thin film transistor is a drain electrode.

19. The manufacturing method of a display device according to claim 1, wherein a semiconductor layer of the thin film transistor is formed of polysilicon.

20. The manufacturing method of a display device according to claim 1, wherein a semiconductor layer of the thin film transistor is formed of amorphous silicon.