Electro-optical display device

• US 6,778,231 B1
• Filed: 01/19/1999
• Issued: 08/17/2004
• Est. Priority Date: 06/14/1991
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Hiroki, Masaaki, Mase, Akira, Takemura, Yasuhiko, Yamazaki, Shunpei
• Primary Examiner(s): Dudek, James
• Assistant Examiner(s): DUONG, TAI V
• Application Number:
  US09/233,145
• Time in Patent Office: 2,037 Days
• Field of Search: 349/42, 349/43, 349/122, 349/106, 349/138, 349/47, 349/48, 349/143, 257/59, 257/72, 345/92, 348/751, 348/761, 348/766
• US Class Current: 349/43
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G09G 2300/0823 used to establish symmetry in driving, e.g. with polarity inversion
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2330/04 Display protection
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G09G 3/3685 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

A display device including a substrate and at least one thin film transistor formed over the substrate, wherein the thin film transistor includes a semiconductor film. An insulating film including an inorganic material is provided over the thin film transistor. A leveling film including an organic resin is formed over the substrate and covers the thin film transistor. A pixel electrode is formed on the leveling film and is directly connected to the semiconductor film of the thin film transistor through an opening provided in the leveling film, wherein an edge of the organic resin film at a periphery of the opening is round.

Claims

1. A display device comprising:

a substrate having an insulating surface;

at least one thin film transistor formed on said insulating surface, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof;

an interlayer insulating film comprising an inorganic material formed on said thin film transistor;

a first contact hole in said interlayer insulating film;

a wiring formed on said interlayer insulating film and electrically connected to said thin film transistor through said first contact hole formed in said interlayer insulating film;

a leveling film comprising an organic resin to provide a leveled upper surface over said thin film transistor;

a second contact hole through said leveling film and said interlayer insulating film; and

a pixel electrode formed over said leveled upper surface and directly connected to said semiconductor film of said thin film transistor through said second contact hole,

wherein an edge of said leveling film at a periphery of said second contact hole is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

2. A display device according to claim 1 wherein said semiconductor film comprises crystalline silicon.

3. A display device according to claim 1 wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

4. A display device according to claim 1 wherein said organic resin comprises polyimide.

5. A display device according to claim 1 wherein said pixel electrode comprises a transparent conductive film.

6. A display device according to claim 1 wherein said display is a digital gradation display.

7. A display device according to claim 1 wherein said display further comprises a tuner for receiving television radio wave to constitute a television.

8. A display device according to claim 7 wherein said television is a liquid crystal television.

9. A display device according to claim 1 wherein said thin film transistor has at least one gate electrode adjacent to said semiconductor film, said gate electrode comprising a material selected from the group consisting of silicon, molybdenum, tungsten, molybdenum silicide, and tungsten silicide.

10. A display device according to claim 1 wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

11. A display device according to claim 1 wherein said semiconductor film comprises silicon or germanium.

12. A display device comprising:

a substrate having an insulating surface;

at least one thin film transistor formed on said insulating surface, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof;

an interlayer insulating film over said thin film transistor, said interlayer insulating film comprising an inorganic material;

a leveling film comprising an organic resin formed over said interlayer insulating film and said thin film transistor; and

a pixel electrode formed over said leveling film and directly connected to said semiconductor film of said thin film transistor through an opening provided in said leveling film,

wherein an edge of said leveling film at a periphery of said opening is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

13. A display device according to claim 12 wherein said semiconductor film comprises crystalline silicon.

14. A display device according to claim 12 wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

15. A display device according to claim 12 wherein said organic resin comprises polyimide.

16. A display device according to claim 12 wherein said pixel electrode comprises a transparent conductive film.

17. A display device according to claim 12 wherein said display is a digital gradation display.

18. A display device according to claim 12 wherein said display further comprises a tuner for receiving television radio wave to constitute a television.

19. A display device according to claim 18 wherein said television is a liquid crystal television.

20. A display device according to claim 12 wherein said thin film transistor has at least one gate electrode adjacent to said semiconductor film, said gate electrode comprising a material selected from the group consisting of silicon, molybdenum, tungsten, molybdenum silicide, and tungsten silicide.

21. A display device according to claim 12 wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

22. A display device according to claim 12 wherein said semiconductor film comprises silicon or germanium.

23. A display device comprising:

a plurality of thin film transistors formed on an insulating surface, each of said thin film transistors comprising at least a semiconductor film;

an interlayer insulating film formed on the thin film transistors, said interlayer insulating film comprising an inorganic material;

first openings formed in the interlayer insulating film on the respective transistors;

a leveling layer formed over said interlayer insulating film to provide a leveled upper surface, wherein said leveling layer comprises an organic resin and is prevented from directly contacting said semiconductor film by said interlayer insulating film;

second openings through said leveling layer and said interlayer insulating film over the respective transistors; and

pixel electrodes formed over said leveled upper surface, each of said pixel electrodes being directly connected to said semiconductor film of the corresponding transistors through the corresponding second openings,

wherein an edge of said leveling layer at a periphery of each of said second openings is rounded,

wherein a surface of each of said pixel electrodes is rounded along the rounded edge of said leveling layer.

24. A display device according to claim 23 wherein said semiconductor film comprises crystalline silicon.

25. A display device according to claim 23 wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

26. A display device according to claim 23 wherein said organic resin comprises polyimide.

27. A display device according to claim 23 wherein said pixel electrode comprises a transparent conductive film.

28. A display device according to claim 23 wherein said display is a digital gradation display.

29. A display device according to claim 23 wherein said display further comprises a tuner for receiving television radio wave to constitute a television.

30. A display device according to claim 29 wherein said television is a liquid crystal television.

31. A display device according to claim 23 wherein said thin film transistor has at least one gate electrode adjacent to said semiconductor film, said gate electrode comprising a material selected from the group consisting of silicon, molybdenum, tungsten, molybdenum silicide, and tungsten silicide.

32. A display device according to claim 23 wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

33. A display device according to claim 23 wherein said semiconductor film comprises silicon or germanium.

34. A display device comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film comprising an inorganic material formed over said gate electrode;

a first contact hole in said insulating film;

a wiring formed on said insulating film and electrically connected to said semiconductor film through said first contact hole formed in said insulating film;

a leveling film comprising an organic resin to provide a leveled upper surface over said insulating film;

a second contact hole through said leveling film and said insulating film; and

a pixel electrode formed over said leveled upper surface and directly connected to said semiconductor film through said second contact hole,

wherein an edge of said leveling film at a periphery of said second contact hole is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

35. A display device according to claim 34, wherein said semiconductor film comprises crystalline silicon.

36. A display device according to claim 34, wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

37. A display device according to claim 34, wherein said organic resin comprises polyimide.

38. A display device according to claim 34, wherein said pixel electrode comprises a transparent conductive film.

39. A display device according to claim 34 wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

40. A display device according to claim 34, wherein said display device is a digital gradation display device.

46. A display device according to claim 34, wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

41. A display device comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film over said gate electrode, said insulating film comprising an inorganic material;

a leveling film comprising an organic resin formed over said insulating film; and

a pixel electrode formed over said leveling film and directly connected to said semiconductor film through an opening provided in said leveling film,

wherein an edge of said leveling film at a periphery of said opening is rounded, wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

42. A display device according to claim 41, wherein said semiconductor film comprises crystalline silicon.

43. A display device according to claim 41, wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

44. A display device according to claim 41, wherein said organic resin comprises polyimide.

45. A display device according to claim 41 wherein said pixel electrode comprises a transparent conductive film.

47. A display device according to claim 41, wherein said display device is a digital gradation display device.

48. A television having a display unit and a tuner for receiving television radio wave, said display unit comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film comprising an inorganic material formed over said gate electrode;

a first contact hole in said insulating film;

a wiring formed on said insulating film and electrically connected to said semiconductor film through said first contact hole formed in said insulating film;

a leveling film comprising an organic resin to provide a leveled upper surface over said gate electrode;

a second contact hole through said leveling film and said insulating film; and

a pixel electrode formed over said leveled upper surface and directly connected to said semiconductor film through said second contact hole,

wherein an edge of said leveling film at a periphery of said second contact hole is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

49. A television according to claim 48, wherein said semiconductor film comprises crystalline silicon.

50. A television according to claim 48, wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

51. A television according to claim 48, wherein said organic resin comprises polyimide.

52. A television according to claim 48, wherein said pixel electrode comprises a transparent conductive film.

53. A television according to claim 48, wherein said television is a liquid crystal television.

54. A television according to claim 48, wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

55. A television according to claim 48, wherein said display unit is a digital gradation display device.

56. A television having a display unit and a tuner for receiving television radio wave, said display unit comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film over said gate electrode, said insulating film comprising an inorganic material;

a leveling film comprising an organic resin formed over said insulating film; and

a pixel electrode formed over said leveling film and directly connected to said semiconductor film through an opening provided in said leveling film,

wherein an edge of said organic resin film at a periphery of said opening is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

57. A television according to claim 56, wherein said semiconductor film comprises crystalline silicon.

58. A television according to claim 56, wherein said thin film transistor further comprises a gate electrode located over said semiconductor film with a gate insulating film interposed therebetween.

59. A television according to claim 56, wherein said organic resin comprises polyimide.

60. A television according to claim 56, wherein said pixel electrode comprises a transparent conductive film.

61. A television according to claim 56, wherein said television is a liquid crystal television.

62. A television according to claim 56, wherein a liquid crystal material is formed between said substrate and an opposite substrate, said liquid crystal material selected from the group consisting of a twisted nematic liquid crystal, super twisted nematic liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, dispersion liquid crystal, and polymer liquid crystal.

63. A television according to claim 56 wherein said display unit is a digital gradation display device.

64. A display device comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film over said gate electrode, said insulating film comprising an inorganic material;

a leveling film comprising an organic resin formed over said insulating film; and

a pixel electrode formed over said leveling film and electrically connected to said semiconductor film through an opening provided in said leveling film,

wherein an edge of said leveling film at a periphery of said opening is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

65. A display device according to claim 64 wherein said organic resin comprises polyimide.

66. A display device according to claim 64 wherein said pixel electrode comprises a transparent conductive film.

67. A display device according to claim 64 wherein said display is a digital gradation display.

68. A display device comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film comprising an inorganic material formed over said gate electrode;

a first contact hole in said insulating film;

a wiring formed on said insulating film and electrically connected to said semiconductor film through said first contact hole formed in said insulating film;

a leveling film comprising an organic resin to provide a leveled upper surface over said insulating film;

a second contact hole through said leveling film; and

a pixel electrode formed over said leveled upper surface and electrically connected to said semiconductor film through said second contact hole,

wherein an edge of said leveling film at a periphery of said second contact hole is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

69. A display device according to claim 68 wherein said organic resin comprises polyimide.

70. A display device according to claim 68 wherein said pixel electrode comprises a transparent conductive film.

71. A display device according to claim 68 wherein said display is a digital gradation display.

72. A television having a display unit and a tuner for receiving television radio wave, said display unit comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film over said gate electrode, said insulating film comprising an inorganic material;

a leveling film comprising an organic resin formed over said insulating film; and

a pixel electrode formed over said leveling film and electrically connected to said semiconductor film through an opening provided in said leveling film,

wherein an edge of said organic resin film at a periphery of said opening is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

73. A television according to claim 72 wherein said organic resin comprises polyimide.

74. A television according to claim 72 wherein said pixel electrode comprises a transparent conductive film.

75. A television according to claim 72 wherein said television is a liquid crystal television.

76. A television having a display unit and a tuner for receiving television radio wave, said display unit comprising:

at least one thin film transistor formed over a substrate, said thin film transistor having a semiconductor film comprising silicon as an active layer thereof and a gate electrode adjacent to said semiconductor film with a gate insulating film interposed therebetween;

an insulating film comprising an inorganic material formed over said gate electrode;

a first contact hole in said insulating film;

a wiring formed on said insulating film and electrically connected to said semiconductor film through said first contact hole formed in said insulating film;

a leveling film comprising an organic resin to provide a leveled upper surface over said gate electrode;

a second contact hole through said leveling film; and

a pixel electrode formed over said leveled upper surface and electrically connected to said semiconductor film through said second contact hole,

wherein an edge of said leveling film at a periphery of said second contact hole is rounded,

wherein a surface of said pixel electrode is rounded along the rounded edge of said leveling film.

77. A television according to claim 76 wherein said organic resin comprises polyimide.

78. A television according to claim 76 wherein said pixel electrode comprises a transparent conductive film.

79. A television according to claim 76 wherein said television is a liquid crystal television.