Liquid crystal display device

• US 9,348,189 B2
• Filed: 03/05/2013
• Issued: 05/24/2016
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ishitani, Tetsuji, Kubota, Daisuke
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US13/785,233
• Publication Number:
  US 20130176516A1
• Time in Patent Office: 1,176 Days
• Field of Search: 349/46, 349/106, 349/141
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• 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

Abstract

A liquid crystal display device is provided, which includes a thin film transistor including an oxide semiconductor layer, a first electrode layer, a second electrode layer having an opening, a light-transmitting chromatic-color resin layer between the thin film transistor and the second electrode layer, and a liquid crystal layer. One of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the thin film transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer. The light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the oxide semiconductor layer of the thin film transistor.

Claims

1. A liquid crystal display device comprising:

a transistor comprising;

a gate electrode;

a gate insulating layer over the gate electrode;

an oxide semiconductor layer comprising a channel formation region over the gate insulating layer; and

a source electrode and a drain electrode which are in contact with the oxide semiconductor layer;

a first electrode layer;

a second electrode layer having an opening; and

a liquid crystal layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer, and

wherein the oxide semiconductor layer comprises a depression portion between the source electrode and the drain electrode.

2. The liquid crystal display device according to claim 1, wherein the oxide semiconductor layer comprises indium, gallium, zinc and oxygen.

3. The liquid crystal display device according to claim 1, wherein the oxide semiconductor layer comprises at least one of iron and nickel.

4. The liquid crystal display device according to claim 1, further comprising a light-transmitting chromatic-color resin layer between the transistor and the second electrode layer,

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

5. The liquid crystal display device according to claim 1, further comprising a light-blocking layer,

wherein the light-blocking layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

6. The liquid crystal display device according to claim 1, wherein the first electrode layer is in a flat-plate shape, and

wherein the second electrode layer has a comb-like shape.

7. A liquid crystal display device comprising:

a transistor comprising;

a gate electrode;

a gate insulating layer over the gate electrode;

an oxide semiconductor layer comprising a channel formation region over the gate insulating layer; and

a source electrode and a drain electrode which are in contact with the oxide semiconductor layer;

an insulating film over the transistor;

a first electrode layer;

a second electrode layer having an opening; and

a liquid crystal layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer,

wherein the oxide semiconductor layer comprises a depression portion between the source electrode and the drain electrode,

wherein the oxide semiconductor layer is in contact with the gate insulating layer and the insulating film, and

wherein the channel formation region of the transistor is not overlapped with the first electrode layer and the second electrode layer.

8. The liquid crystal display device according to claim 7, wherein the oxide semiconductor layer comprises indium, gallium, zinc and oxygen.

9. The liquid crystal display device according to claim 7, wherein the oxide semiconductor layer comprises at least one of iron and nickel.

10. The liquid crystal display device according to claim 7, further comprising a light-transmitting chromatic-color resin layer between the transistor and the second electrode layer,

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

11. The liquid crystal display device according to claim 7, further comprising a light-blocking layer,

wherein the light-blocking layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

12. The liquid crystal display device according to claim 7, wherein the first electrode layer is in a flat-plate shape, and

wherein the second electrode layer has a comb-like shape.

13. A liquid crystal display device comprising:

a transistor comprising;

a gate electrode;

a gate insulating layer over the gate electrode;

a first oxide semiconductor layer comprising a channel formation region over the gate insulating layer;

a second oxide semiconductor layer over the first oxide semiconductor layer; and

a source electrode and a drain electrode which are in contact with the second oxide semiconductor layer;

a first electrode layer;

a second electrode layer having an opening; and

a liquid crystal layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer,

wherein the first oxide semiconductor layer comprises a depression portion between the source electrode and the drain electrode,

wherein the second oxide semiconductor layer comprises nanocrystals, and

wherein a diameter of each of the nanocrystals is greater than or equal to 1 nm and less than or equal to 10 nm.

14. The liquid crystal display device according to claim 13, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises indium, gallium, zinc and oxygen.

15. The liquid crystal display device according to claim 13, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises at least one of iron and nickel.

16. The liquid crystal display device according to claim 13, further comprising a light-transmitting chromatic-color resin layer between the transistor and the second electrode layer,

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer, the first oxide semiconductor layer, and the second oxide semiconductor layer.

17. The liquid crystal display device according to claim 13, further comprising a light-blocking layer,

wherein the light-blocking layer is overlapped with the pixel electrode layer, the first oxide semiconductor layer, and the second oxide semiconductor layer.

18. The liquid crystal display device according to claim 13, wherein the nanocrystals are included in an amorphous structure of the second oxide semiconductor layer.

19. The liquid crystal display device according to claim 13, wherein the first electrode layer is in a flat-plate shape, and

wherein the second electrode layer has a comb-like shape.

20. A liquid crystal display device comprising:

a transistor comprising;

a gate electrode;

a gate insulating layer;

an oxide semiconductor layer comprising a channel formation region, wherein the oxide semiconductor layer, the gate insulating layer and the gate electrode overlap each other; and

a source electrode and a drain electrode which are in contact with the oxide semiconductor layer;

a first electrode layer;

a second electrode layer having an opening; and

a liquid crystal layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer, and

wherein the oxide semiconductor layer comprises a depression portion between the source electrode and the drain electrode.

21. The liquid crystal display device according to claim 20, wherein the oxide semiconductor layer comprises indium, gallium, zinc and oxygen.

22. The liquid crystal display device according to claim 20, wherein the oxide semiconductor layer comprises at least one of iron and nickel.

23. The liquid crystal display device according to claim 20, further comprising a light-transmitting chromatic-color resin layer between the transistor and the second electrode layer,

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

24. The liquid crystal display device according to claim 20, further comprising a light-blocking layer,

wherein the light-blocking layer is overlapped with the pixel electrode layer and the oxide semiconductor layer.

25. The liquid crystal display device according to claim 20, wherein the first electrode layer is in a flat-plate shape, and

wherein the second electrode layer has a comb-like shape.

26. A liquid crystal display device comprising:

a transistor comprising;

a gate electrode;

a gate insulating layer;

a semiconductor layer comprising a channel formation region, wherein the semiconductor layer, the gate insulating layer and the gate electrode overlap each other; and

a source electrode and a drain electrode which are in contact with the semiconductor layer;

a first electrode layer;

a second electrode layer having an opening; and

a liquid crystal layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer, and

wherein the semiconductor layer comprises a depression portion between the source electrode and the drain electrode.

27. The liquid crystal display device according to claim 26,

wherein the semiconductor layer comprises an oxide semiconductor, and

wherein the oxide semiconductor comprises indium, gallium, zinc and oxygen.

28. The liquid crystal display device according to claim 26, further comprising a light-transmitting chromatic-color resin layer between the transistor and the second electrode layer,

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the semiconductor layer.

29. The liquid crystal display device according to claim 26, further comprising a light-blocking layer,

wherein the light-blocking layer is overlapped with the pixel electrode layer and the semiconductor layer.

30. The liquid crystal display device according to claim 26, wherein the first electrode layer is in a flat-plate shape, and

wherein the second electrode layer has a comb-like shape.