Liquid crystal display device and semiconductor device

• US 9,709,861 B2
• Filed: 02/19/2016
• Issued: 07/18/2017
• Est. Priority Date: 05/16/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime
• Primary Examiner(s): Potter, Roy
• Assistant Examiner(s): PATTON, PAUL E
• Application Number:
  US15/047,844
• Publication Number:
  US 20160246131A1
• Time in Patent Office: 515 Days
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• 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 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136 Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit G02F1/135 takes precedence
• 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 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• 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 2201/121 common or background

Abstract

By increasing an interval between electrodes which drives liquid crystals, a gradient of an electric field applied between the electrodes can be controlled and an optimal electric field can be applied between the electrodes. The invention includes a first electrode formed over a substrate, an insulating film formed over the substrate and the first electrode, a thin film transistor including a semiconductor film in which a source, a channel region, and a drain are formed over the insulating film, a second electrode located over the semiconductor film and the first electrode and including first opening patterns, and liquid crystals provided over the second electrode.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a first conductive film over the first substrate;

a first insulating film over the first conductive film;

a semiconductor film over and in contact with the first insulating film, part of the semiconductor film overlapping with the first conductive film;

a second conductive film and a third conductive film each over and in contact with the semiconductor film;

a second insulating film over the second conductive film and the third conductive film;

a pixel electrode over and in contact with the third conductive film;

a first alignment film over the pixel electrode;

a liquid crystal over the first alignment film;

a second alignment film over the liquid crystal;

a second substrate over the second alignment film;

a fourth conductive film over the first substrate;

a fifth conductive film over and in contact with the fourth conductive film and the first insulating film; and

a sixth conductive film in contact with the fifth conductive film,

wherein the semiconductor film comprises;

a first region overlapping with the first conductive film;

a second region overlapping with the first conductive film; and

a third region between the first region and the second region and not overlapping with the first conductive film, and

wherein each of the pixel electrode and the sixth conductive film comprises indium and zinc.

2. The liquid crystal display device according to claim 1, wherein the sixth conductive film is over and in contact with the first substrate.

3. The liquid crystal display device according to claim 1, comprising a third insulating film over the sixth conductive film, wherein the fourth conductive film is over and in contact with the third insulating film.

4. The liquid crystal display device according to claim 1, comprising a third insulating film over and in contact with the semiconductor film, wherein the second conductive film, the third conductive film, and the fourth conductive film are over and in contact with the third insulating film.

5. The liquid crystal display device according to claim 1, wherein the fourth conductive film, the fifth conductive film, and the sixth conductive film overlap with the liquid crystal.

6. The liquid crystal display device according to claim 1, wherein the sixth conductive film overlaps with the first conductive film.

7. The liquid crystal display device according to claim 1, wherein the second insulating film comprises an organic material.

8. The liquid crystal display device according to claim 1, wherein the sixth conductive film overlaps with the pixel electrode.

9. The liquid crystal display device according to claim 1, wherein the fourth conductive film overlaps with the second conductive film.

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

wherein the semiconductor film comprises a fourth region in contact with the third conductive film, and

wherein the second region is between the third region and the fourth region.

11. The liquid crystal display device according to claim 1, wherein the liquid crystal is driven by an electric field generated by the pixel electrode and the sixth conductive film.

12. A liquid crystal display device comprising:

a first substrate;

a first conductive film over the first substrate;

a first insulating film over the first conductive film;

a semiconductor film over and in contact with the first insulating film, part of the semiconductor film overlapping with the first conductive film;

a second conductive film and a third conductive film each over and in contact with the semiconductor film;

a second insulating film over the second conductive film and the third conductive film;

a pixel electrode over and in contact with the third conductive film;

a first alignment film over the pixel electrode;

a liquid crystal over the first alignment film;

a second alignment film over the liquid crystal; and

a second substrate over the second alignment film,

wherein the semiconductor film comprises;

a first region overlapping with the first conductive film;

a second region overlapping with the first conductive film; and

a third region between the first region and the second region and not overlapping with the first conductive film, and

wherein the pixel electrode comprises indium and zinc.

13. The liquid crystal display device according to claim 12, comprising a third insulating film over and in contact with the semiconductor film, wherein the second conductive film and the third conductive film are over and in contact with the third insulating film.

14. The liquid crystal display device according to claim 12, wherein the second insulating film comprises an organic material.

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

wherein the semiconductor film comprises a fourth region in contact with the third conductive film, and

wherein the second region is between the third region and the fourth region.

16. A liquid crystal display device comprising:

a first substrate;

a first conductive film over the first substrate;

a first insulating film over the first conductive film;

a semiconductor film over and in contact with the first insulating film, part of the semiconductor film overlapping with the first conductive film;

a second conductive film and a third conductive film each over and in contact with the semiconductor film;

a second insulating film over the second conductive film and the third conductive film;

a pixel electrode over and in contact with the third conductive film;

a first alignment film over the pixel electrode;

a liquid crystal over the first alignment film;

a second alignment film over the liquid crystal;

a second substrate over the second alignment film;

a fourth conductive film over the first substrate;

a fifth conductive film over and in contact with the fourth conductive film and the first insulating film; and

a sixth conductive film in contact with the fifth conductive film,

wherein the semiconductor film comprises indium, gallium, zinc, and oxygen,

wherein the semiconductor film comprises;

a first region overlapping with the first conductive film;

a second region overlapping with the first conductive film; and

a third region between the first region and the second region and not overlapping with the first conductive film, and

wherein each of the pixel electrode and the sixth conductive film comprises indium and zinc.

17. The liquid crystal display device according to claim 16, wherein the sixth conductive film is over and in contact with the first substrate.

18. The liquid crystal display device according to claim 16, comprising a third insulating film over the sixth conductive film, wherein the fourth conductive film is over and in contact with the third insulating film.

19. The liquid crystal display device according to claim 16, comprising a third insulating film over and in contact with the semiconductor film, wherein the second conductive film, the third conductive film, and the fourth conductive film are over and in contact with the third insulating film.

20. The liquid crystal display device according to claim 16, wherein the fourth conductive film, the fifth conductive film, and the sixth conductive film overlap with the liquid crystal.

21. The liquid crystal display device according to claim 16, wherein the sixth conductive film overlaps with the first conductive film.

22. The liquid crystal display device according to claim 16, wherein the second insulating film comprises an organic material.

23. The liquid crystal display device according to claim 16, wherein the sixth conductive film overlaps with the pixel electrode.

24. The liquid crystal display device according to claim 16, wherein the fourth conductive film overlaps with the second conductive film.

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

wherein the semiconductor film comprises a fourth region in contact with the third conductive film, and

wherein the second region is between the third region and the fourth region.

26. The liquid crystal display device according to claim 16, wherein the liquid crystal is driven by an electric field generated by the pixel electrode and the sixth conductive film.

27. The liquid crystal display device according to claim 16, wherein the semiconductor film comprises a-InGaZnO.

28. A liquid crystal display device comprising:

a first substrate;

a first conductive film over the first substrate;

a first insulating film over the first conductive film;

a semiconductor film over and in contact with the first insulating film, part of the semiconductor film overlapping with the first conductive film;

a second conductive film and a third conductive film each over and in contact with the semiconductor film;

a second insulating film over the second conductive film and the third conductive film;

a pixel electrode over and in contact with the third conductive film;

a first alignment film over the pixel electrode;

a liquid crystal over the first alignment film;

a second alignment film over the liquid crystal; and

a second substrate over the second alignment film,

wherein the semiconductor film comprises indium, gallium, zinc, and oxygen,

wherein the semiconductor film comprises;

a first region overlapping with the first conductive film;

a second region overlapping with the first conductive film; and

a third region between the first region and the second region and not overlapping with the first conductive film, and

wherein the pixel electrode comprises indium and zinc.

29. The liquid crystal display device according to claim 28, comprising a third insulating film over and in contact with the semiconductor film, wherein the second conductive film and the third conductive film are over and in contact with the third insulating film.

30. The liquid crystal display device according to claim 28, wherein the second insulating film comprises an organic material.

31. The liquid crystal display device according to claim 28,

wherein the semiconductor film comprises a fourth region in contact with the third conductive film, and

wherein the second region is between the third region and the fourth region.

32. The liquid crystal display device according to claim 28, wherein the semiconductor film comprises a-InGaZnO.