Liquid crystal display device and method for manufacturing the same

• US 7,795,616 B2
• Filed: 11/05/2004
• Issued: 09/14/2010
• Est. Priority Date: 11/14/2003
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kuwabara, Hideaki, Maekawa, Shinji, Fujii, Gen, Yamazaki, Shunpei
• Primary Examiner(s): Pham; Thanh V
• Assistant Examiner(s): Tran; Tony
• Application Number:
  US10/576,420
• Publication Number:
  US 20070069210A1
• Time in Patent Office: 2,139 Days
• Field of Search: 257/57, 257/59, 257/66, 257/72
• US Class Current: 257/57
• CPC Class Codes: G02F 1/13415 Drop filling process
• CPC Class Codes: G02F 1/13458 Terminal pads
• 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 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• CPC Class Codes: H01L 27/1292 using liquid deposition, e.g. printing

Abstract

As a substrate gets larger, time of manufacture is increased due to the repetition of film formations and etchings; waste disposal costs of etchant and the like are increased; and material efficiency is significantly reduced. A base film for improving adhesion between a substrate and a material layer formed by a droplet discharge method is formed in the invention. Further, a manufacturing method of a liquid crystal display device according to the invention includes at least one step for forming the following patterns required for manufacturing a liquid crystal display device without using a photomask: a pattern of a material layer typified by a wiring (or an electrode) pattern, an insulating layer pattern; or a mask pattern for forming another pattern.

Claims

1. A liquid crystal display device comprising:

a substrate;

a base film comprising a photocatalyst formed over the substrate;

a thin film transistor formed over the base film;

a projection comprising a conductive material formed over at least one of a drain electrode and a source electrode of the thin film transistor;

an interlayer insulating film formed over the thin film transistor; and

a pixel electrode connected to the projection,

wherein the interlayer insulating film is interposed between the base film and the pixel electrode,

wherein the projection has a stacked structure including a plurality of conductors and

wherein each of the plurality of conductors is in direct contact with the interlayer insulating film.

2. The liquid crystal display device according to claim 1,

wherein the projection has a tapered shape.

3. The liquid crystal display device according to claim 1,

wherein a part of a surface of the base film has a hydrophilic property.

4. The liquid crystal display device according to claim 1,

wherein the base film contains one selected from the group consisting of titanium oxide, strontium titanate, cadmium selenide, potassium tantalate, cadmium sulfide, zirconium oxide, niobium oxide, zinc oxide, iron oxide, tungsten oxide.

5. The liquid crystal display device according to claim 1, wherein the base film is doped with a transition metal.

6. The liquid crystal display device according to claim 1,

wherein at least one of a gate electrode of the thin film transistor contains one selected from the group consisting of gold, silver, copper, platinum, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc, titanium and aluminum.

7. The liquid crystal display device according to claim 1,

wherein at least one of the drain electrode, the source electrode, and the projection contains one selected from the group consisting of gold, silver, copper, tungsten, and aluminum.

8. The liquid crystal display device according to claim 1,

wherein the liquid crystal display device is selected from the group consisting of a display device, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, an audio reproducing device, a laptop computer, a game machine, a portable information terminal and an image reproducing device.

9. The liquid crystal display device according to claim 1,

wherein the plurality of conductors are formed from the same material.

10. A liquid crystal display device comprising:

a pixel portion comprising;

a base film comprising a photocatalyst formed over a substrate;

a thin film transistor formed over the base film;

a first projection comprising a conductive material formed over at least one of a drain electrode and a source electrode of the thin film transistor;

an interlayer insulating film formed over the thin film transistor; and

a pixel electrode connected to the first projection;

a terminal portion comprising;

the base film comprising the photocatalyst formed over the substrate;

a first wiring formed over the base film;

a first insulating film formed over the first wiring;

a second wiring formed over the first insulating film;

a second projection comprising a conductive material formed over the second wiring;

a second insulating film formed over the second wiring; and

a terminal electrode connected to the second projection,

wherein the interlayer insulating film is interposed between the base film and the pixel electrode,

wherein each of the first projection and the second projection has a stacked structure, said first projection including a plurality of first conductors and said second projection including a plurality of second conductors; and

wherein each of the plurality of first conductors is in direct contact with the interlayer insulating film and each of the plurality of second conductors is in direct contact with the second insulating film.

11. The liquid crystal display device according to claim 10,

wherein each of the first projection and the second projection has a tapered shape.

12. The liquid crystal display device according to claim 10,

wherein a part of a surface of the base film has a hydrophilic property.

13. The liquid crystal display device according to claim 10,

wherein the base film contains one selected from the group consisting of titanium oxide, strontium titanate, cadmium selenide, potassium tantalate, cadmium sulfide, zirconium oxide, niobium oxide, zinc oxide, iron oxide, tungsten oxide.

14. The liquid crystal display device according to claim 10,

wherein the base film is doped with a transition metal.

15. The liquid crystal display device according to claim 10,

wherein at least one of a gate electrode of the thin film transistor and the first wiring contains one selected from the group consisting of gold, silver, copper, platinum, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc, titanium, and aluminum.

16. The liquid crystal display device according to claim 10,

wherein at least one of the drain electrode, the source electrode, the second wiring, the first projection and the second projection contains one selected from the group consisting of gold, silver, copper, tungsten, and aluminum.

17. The liquid crystal display device according to claim 10,

wherein a conductor is formed over the first wiring, and wherein the conductor is connected to the first wiring and the second wiring.

18. The liquid crystal display device according to claim 17,

wherein the conductor contains one selected from the group consisting of gold, silver, copper, tungsten, and aluminum.

19. The liquid crystal display device according to claim 10,

wherein the liquid crystal display device is selected from the group consisting of a display device, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, an audio reproducing device, a laptop computer, a game machine, a portable information terminal and an Image reproducing device.

20. The liquid crystal display device according to claim 10,

wherein the plurality of first conductors are formed from the same material.