Liquid crystal display device and semiconductor device

• US 8,338,865 B2
• Filed: 10/08/2010
• Issued: 12/25/2012
• 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): Smith, Zandra
• Assistant Examiner(s): PATTON, PAUL E
• Application Number:
  US12/900,612
• Publication Number:
  US 20110024758A1
• Time in Patent Office: 809 Days
• Field of Search: 349/43, 349/46, 349/47, 349/141, 349/142, 349/FOR.129, 257/59, 257/E33.001
• US Class Current: 257/257
• 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 semiconductor film comprising a channel formation region over the first substrate;

a gate electrode adjacent to the channel formation region with a gate insulating film interposed between the semiconductor film and the gate electrode;

a pixel electrode over the first substrate;

a first insulating film over the pixel electrode;

a second insulating film over the first insulating film;

a common electrode over the second insulating film;

a liquid crystal over the common electrode; and

a second substrate over the liquid crystal,

wherein the common electrode is continuously formed over a plurality of pixels aligned in a source wiring direction.

2. The liquid crystal display device according to claim 1, wherein the first insulating film comprises silicon nitride.

3. The liquid crystal display device according to claim 1, wherein the common electrode comprises ITO.

4. The liquid crystal display device according to claim 1, wherein the channel formation region of the semiconductor film does not overlap the common electrode.

5. The liquid crystal display device according to claim 1, wherein the pixel electrode and the common electrode overlap each other at least partially.

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

wherein the common electrode comprises a first slit and a second slit, and

wherein a long side of the first slit and a long side of the second slit are aligned along different directions.

7. The liquid crystal display device according to claim 1, wherein the pixel electrode does not comprise a slit.

8. The liquid crystal display device according to claim 1, wherein the pixel electrode and the common electrode have transparent characteristic.

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

wherein the liquid crystal display device is configured so that orientation of the liquid crystal is controlled by an electric field generated by a voltage applied between the pixel electrode and the common electrode.

10. The liquid crystal display device according to claim 1, wherein the pixel electrode is in contact with the first substrate.

11. The liquid crystal display device according to claim 1, wherein the gate electrode is located under the gate insulating film.

12. An electronic device comprising the liquid crystal display device according to claim 1.

13. An electronic device comprising an antenna, a battery, and the liquid crystal display device according to claim 1,

wherein the liquid crystal display device is electrically connected to the antenna and the battery.

14. A portable information terminal comprising an operating key and the liquid crystal display device according to claim 1.

15. A liquid crystal display device comprising:

a first substrate;

a semiconductor film comprising a channel formation region over the first substrate;

a gate electrode adjacent to the channel formation region with a gate insulating film interposed between the semiconductor film and the gate electrode;

a pixel electrode over the first substrate;

a conductive film over the pixel electrode;

a first insulating film over the pixel electrode;

a second insulating film over the first insulating film;

a common electrode over the second insulating film;

a liquid crystal over the common electrode; and

a second substrate over the liquid crystal,

wherein the conductive film is electrically connected to the pixel electrode and the conductive film is electrically connected to the semiconductor film,

wherein the common electrode is continuously formed over a plurality of pixels aligned in a source wiring direction.

16. The liquid crystal display device according to claim 15, wherein the conductive film comprises molybdenum.

17. The liquid crystal display device according to claim 15, wherein the first insulating film comprises silicon nitride.

18. The liquid crystal display device according to claim 15, wherein the common electrode comprises ITO.

19. The liquid crystal display device according to claim 15, wherein the channel formation region of the semiconductor film does not overlap the common electrode.

20. The liquid crystal display device according to claim 15, wherein the pixel electrode and the common electrode overlap each other at least partially.

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

wherein the common electrode comprises a first slit and a second slit, and

wherein a long side of the first slit and a long side of the second slit are aligned along different directions.

22. The liquid crystal display device according to claim 15, wherein the pixel electrode does not comprise a slit.

23. The liquid crystal display device according to claim 15, wherein the pixel electrode and the common electrode have transparent characteristic.

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

wherein the liquid crystal display device is configured so that orientation of the liquid crystal is controlled by an electric field generated by a voltage applied between the pixel electrode and the common electrode.

25. The liquid crystal display device according to claim 15, wherein the pixel electrode is in contact with the first substrate.

26. The liquid crystal display device according to claim 15, wherein the gate electrode is located under the gate insulating film.

27. An electronic device comprising the liquid crystal display device according to claim 15.

28. An electronic device comprising an antenna, a battery, and the liquid crystal display device according to claim 15,

wherein the liquid crystal display device is electrically connected to the antenna and the battery.

29. A portable information terminal comprising an operating key and the liquid crystal display device according to claim 15.

30. A liquid crystal display device comprising:

a first substrate;

a semiconductor film comprising a channel formation region over the first substrate;

a gate electrode adjacent to the channel formation region with a gate insulating film interposed between the semiconductor film and the gate electrode;

a pixel electrode over the first substrate;

a first insulating film over the pixel electrode;

a second insulating film over the first insulating film;

a common electrode over the second insulating film;

a liquid crystal over the common electrode; and

a second substrate over the liquid crystal,

wherein the common electrode is continuously formed over a plurality of pixels aligned M a source wiring direction,

wherein the channel formation region of the semiconductor film does not overlap the pixel electrode.

31. The liquid crystal display device according to claim 30, wherein the first insulating film comprises silicon nitride.

32. The liquid crystal display device according to claim 30, wherein the common electrode comprises ITO.

33. The liquid crystal display device according to claim 30, wherein the channel formation region of the semiconductor film does not overlap the common electrode.

34. The liquid crystal display device according to claim 30, wherein the pixel electrode and the common electrode overlap each other at least partially.

35. The liquid crystal display device according to claim 30,

wherein the common electrode comprises a first slit and a second slit, and

wherein a long side of the first slit and a long side of the second slit are aligned along different directions.

36. The liquid crystal display device according to claim 30, wherein the pixel electrode does not comprise a slit.

37. The liquid crystal display device according to claim 30, wherein the pixel electrode and the common electrode have transparent characteristic.

38. The liquid crystal display device according to claim 30,

wherein the liquid crystal display device is configured so that orientation of the liquid crystal is controlled by an electric field generated by a voltage applied between the pixel electrode and the common electrode.

39. The liquid crystal display device according to claim 30, wherein the pixel electrode is in contact with the first substrate.

40. The liquid crystal display device according to claim 30, wherein the gate electrode is located under the gate insulating film.

41. An electronic device comprising the liquid crystal display device according to claim 30.

42. An electronic device comprising an antenna, a battery, and the liquid crystal display device according to claim 30,

wherein the liquid crystal display device is electrically connected to the antenna and the battery.

43. A portable information terminal comprising an operating key and the liquid crystal display device according to claim 30.

44. A liquid crystal display device comprising:

a first substrate;

a gate electrode over the first substrate;

a first insulating film over the gate electrode;

a semiconductor film comprising a channel formation region wherein the semiconductor film is provided over the gate electrode with the first insulating film interposed therebetween;

a source wiring over the semiconductor film;

a second insulating film over the source wiring;

a pixel electrode over the first substrate;

a third insulating film over the pixel electrode;

a common electrode over the third insulating film;

a fourth insulating film over the common electrode;

a liquid crystal over the fourth insulating film; and

a second substrate over the liquid crystal; and

an auxiliary wiring over the first substrate, wherein the auxiliary wiring is extended so as to intersect with the source wiring,

wherein the common electrode is in contact with the auxiliary wiring through an opening provided in the first insulating film and the second insulating film,

wherein the gate electrode and the auxiliary wiring are provided on a same surface,

wherein the common electrode is continuously formed over a plurality of pixels aligned in a source wiring direction.

45. The liquid crystal display device according to claim 44, wherein the third insulating film comprises silicon nitride.

46. The liquid crystal display device according to claim 44, wherein the common electrode comprises ITO.

47. The liquid crystal display device according to claim 44, wherein the channel formation region of the semiconductor film does not overlap the common electrode.

48. The liquid crystal display device according to claim 44, wherein the pixel electrode and the common electrode overlap each other at least partially.

49. The liquid crystal display device according to claim 44,

wherein the common electrode comprises a first slit and a second slit, and

wherein a long side of the first slit and a long side of the second slit are aligned along different directions.

50. The liquid crystal display device according to claim 44, wherein the pixel electrode does not comprise a slit.

51. The liquid crystal display device according to claim 44, wherein the pixel electrode and the common electrode have transparent characteristic.

52. The liquid crystal display device according to claim 44,

wherein the liquid crystal display device is configured so that orientation of the liquid crystal is controlled by an electric field generated by a voltage applied between the pixel electrode and the common electrode.

53. The liquid crystal display device according to claim 44, wherein the pixel electrode is in contact with the first substrate.

54. The liquid crystal display device according to claim 44, wherein the gate electrode is located under the first insulating film.

55. An electronic device comprising the liquid crystal display device according to claim 44.

56. An electronic device comprising an antenna, a battery, and the liquid crystal display device according to claim 44,

wherein the liquid crystal display device is electrically connected to the antenna and the battery.

57. A portable information terminal comprising an operating key and the liquid crystal display device according to claim 44.

58. The liquid crystal display device according to claim 44, wherein the gate electrode and the auxiliary wiring are provided on the third insulating film.

59. The liquid crystal display device according to claim 44, wherein the semiconductor film is electrically connected to the pixel electrode through a conductive film.

60. The liquid crystal display device according to claim 44, wherein the pixel electrode comprises indium and tin.

61. The liquid crystal display device according to claim 44, wherein the gate electrode is provided over the pixel electrode with the third insulating film interposed therebetween.