DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF

• US 20100177269A1
• Filed: 03/24/2010
• Published: 07/15/2010
• Est. Priority Date: 12/28/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KIMURA, Hajime
• Granted Patent: US 8,634,044 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/136231 for reducing the number of lithographic steps
• 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 2202/36 Micro- or nanomaterials

Abstract

In a semi-transmission liquid crystal display device, two resist masks are required to form a reflective electrode and a transparent electrode; therefore, cost is high. A transparent electrode and a reflective electrode which function as a pixel electrode are stacked. A resist pattern which includes a region having a thick film thickness and a region having a thinner film thickness than the aforementioned region is formed over the reflective electrode by using a light exposure mask which includes a semi-transmission portion. The reflective electrode and the transparent electrode are formed by using the resist pattern. Therefore, the reflective electrode and the transparent electrode can be formed by using one resist mask.

Claims

1. A display device comprising:

a transistor formed over a substrate, the transistor including a compound semiconductor;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film;

a transparent electrode formed over the first insulating film; and

a reflective electrode formed over the second insulating film,

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

2. The display device according to claim 1, wherein the compound semiconductor is a-InGaZnO.

3. The display device according to claim 1, wherein the transistor has a bottom gate structure.

4. The display device according to claim 1, wherein the portion of the first insulating film is configured to transmit a light passed through the substrate.

5. The display device according to claim 1, wherein the transparent electrode is formed over the second insulating film.

6. The display device according to claim 1, wherein the reflective electrode is electrically connected to the transparent electrode.

7. The display device according to claim 1, wherein the first insulating film is a silicon oxide film.

8. The display device according to claim 1, wherein the second insulating film comprises acrylic.

9. The display device according to claim 1, wherein the transparent electrode comprises an indium tin oxide.

10. The display device according to claim 1, wherein the reflective electrode comprises Al and Ti.

89. An electronic book comprising a display portion into which the display device according to claim 1 is incorporated.

11. A display device comprising:

a transistor formed over a substrate, the transistor including a compound semiconductor;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film, the second insulating film having a uneven surface;

a transparent electrode formed over the first insulating film; and

a reflective electrode formed over the second insulating film so that the reflective electrode is uneven due to the uneven surface of the second insulating film,

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

12. The display device according to claim 11, wherein the compound semiconductor is a-InGaZnO.

13. The display device according to claim 11, wherein the transistor has a bottom gate structure.

14. The display device according to claim 11, wherein the portion of the first insulating film is configured to transmit a light passed through the substrate.

15. The display device according to claim 11, wherein the transparent electrode is formed over the second insulating film.

16. The display device according to claim 11, wherein the reflective electrode is electrically connected to the transparent electrode.

17. The display device according to claim 11, wherein the first insulating film is a silicon oxide film.

18. The display device according to claim 11, wherein the second insulating film comprises acrylic.

19. The display device according to claim 11, wherein the transparent electrode comprises an indium tin oxide.

20. The display device according to claim 11, wherein the reflective electrode comprises Al and Ti.

90. An electronic book comprising a display portion into which the display device according to claim 11 is incorporated.

21. A display device comprising:

a transistor formed over a first substrate, the transistor including a compound semiconductor;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film;

a transparent electrode formed over the first insulating film;

a reflective electrode formed over the second insulating film;

an opposite electrode formed on a second substrate; and

an third insulating film formed on the opposite electrode,

wherein a liquid crystal layer is provided between the first substrate and the second substrate, and

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

22. The display device according to claim 21, wherein the compound semiconductor is a-InGaZnO.

23. The display device according to claim 21, wherein the transistor has a bottom gate structure.

24. The display device according to claim 21, wherein the portion of the first insulating film is configured to transmit a light passed through the first substrate.

25. The display device according to claim 21, wherein the transparent electrode is formed over the second insulating film.

26. The display device according to claim 21, wherein the reflective electrode is electrically connected to the transparent electrode.

27. The display device according to claim 21, wherein the first insulating film is a silicon oxide film.

28. The display device according to claim 21, wherein the second insulating film comprises acrylic.

29. The display device according to claim 21, wherein the transparent electrode comprises an indium tin oxide.

30. The display device according to claim 21, wherein the reflective electrode comprises Al and Ti.

31. The display device according to claim 21, wherein the third insulating film is overlapped with the reflective electrode.

32. The display device according to claim 21, wherein the third insulating film comprises acrylic.

91. An electronic book comprising a display portion into which the display device according to claim 21 is incorporated.

33. A display device comprising:

a transistor formed over a first substrate, the transistor including a compound semiconductor;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film, the second insulating film having a uneven surface;

a transparent electrode formed over the first insulating film;

a reflective electrode formed over the second insulating film so that the reflective electrode is uneven due to the uneven surface of the second insulating film;

an opposite electrode formed on a second substrate; and

an third insulating film formed on the opposite electrode,

wherein a liquid crystal layer is provided between the first substrate and the second substrate, and

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

34. The display device according to claim 33, wherein the compound semiconductor is a-InGaZnO.

35. The display device according to claim 33, wherein the transistor has a bottom gate structure.

36. The display device according to claim 33, wherein the portion of the first insulating film is configured to transmit a light passed through the first substrate.

37. The display device according to claim 33, wherein the transparent electrode is formed over the second insulating film.

38. The display device according to claim 33, wherein the reflective electrode is electrically connected to the transparent electrode.

39. The display device according to claim 33, wherein the first insulating film is a silicon oxide film.

40. The display device according to claim 33, wherein the second insulating film comprises acrylic.

41. The display device according to claim 33, wherein the transparent electrode comprises an indium tin oxide.

42. The display device according to claim 33, wherein the reflective electrode comprises Al and Ti.

43. The display device according to claim 33, wherein the third insulating film is overlapped with the reflective electrode.

44. The display device according to claim 33, wherein the third insulating film comprises acrylic.

92. An electronic book comprising a display portion into which the display device according to claim 33 is incorporated.

45. A display device comprising:

a transistor formed over a substrate, the transistor including InGaZnO;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film;

a transparent electrode formed over the first insulating film; and

a reflective electrode formed over the second insulating film,

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

46. The display device according to claim 45, wherein InGaZnO is a-InGaZnO.

47. The display device according to claim 45, wherein the transistor has a bottom gate structure.

48. The display device according to claim 45, wherein the portion of the first insulating film is configured to transmit a light passed through the substrate.

49. The display device according to claim 45, wherein the transparent electrode is formed over the second insulating film.

50. The display device according to claim 45, wherein the reflective electrode is electrically connected to the transparent electrode.

51. The display device according to claim 45, wherein the first insulating film is a silicon oxide film.

52. The display device according to claim 45, wherein the second insulating film comprises acrylic.

53. The display device according to claim 45, wherein the transparent electrode comprises an indium tin oxide.

54. The display device according to claim 45, wherein the reflective electrode comprises Al and Ti.

93. An electronic book comprising a display portion into which the display device according to claim 45 is incorporated.

55. A display device comprising:

a transistor formed over a substrate, the transistor including InGaZnO;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film, the second insulating film having a uneven surface;

a transparent electrode formed over the first insulating film; and

a reflective electrode formed over the second insulating film so that the reflective electrode is uneven due to the uneven surface of the second insulating film,

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

56. The display device according to claim 55, wherein InGaZnO is a-InGaZnO.

57. The display device according to claim 55, wherein the transistor has a bottom gate structure.

58. The display device according to claim 55, wherein the portion of the first insulating film is configured to transmit a light passed through the substrate.

59. The display device according to claim 55, wherein the transparent electrode is formed over the second insulating film.

60. The display device according to claim 55, wherein the reflective electrode is electrically connected to the transparent electrode.

61. The display device according to claim 55, wherein the first insulating film is a silicon oxide film.

62. The display device according to claim 55, wherein the second insulating film comprises acrylic.

63. The display device according to claim 55, wherein the transparent electrode comprises an indium tin oxide.

64. The display device according to claim 55, wherein the reflective electrode comprises Al and Ti.

94. An electronic book comprising a display portion into which the display device according to claim 55 is incorporated.

65. A display device comprising:

a transistor formed over a first substrate, the transistor including InGaZnO;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film;

a transparent electrode formed over the first insulating film;

a reflective electrode formed over the second insulating film;

an opposite electrode formed on a second substrate; and

an third insulating film formed on the opposite electrode,

wherein a liquid crystal layer is provided between the first substrate and the second substrate, and

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

66. The display device according to claim 65, wherein InGaZnO is a-InGaZnO.

67. The display device according to claim 65, wherein the transistor has a bottom gate structure.

68. The display device according to claim 65, wherein the portion of the first insulating film is configured to transmit a light passed through the first substrate.

69. The display device according to claim 65, wherein the transparent electrode is formed over the second insulating film.

70. The display device according to claim 65, wherein the reflective electrode is electrically connected to the transparent electrode.

71. The display device according to claim 65, wherein the first insulating film is a silicon oxide film.

72. The display device according to claim 65, wherein the second insulating film comprises acrylic.

73. The display device according to claim 65, wherein the transparent electrode comprises an indium tin oxide.

74. The display device according to claim 65, wherein the reflective electrode comprises Al and Ti.

75. The display device according to claim 65, wherein the third insulating film is overlapped with the reflective electrode.

76. The display device according to claim 65, wherein the third insulating film comprises acrylic.

95. An electronic book comprising a display portion into which the display device according to claim 65 is incorporated.

77. A display device comprising:

a transistor formed over a first substrate, the transistor including InGaZnO;

a first insulating film formed over the transistor;

a second insulating film formed over the first insulating film, the second insulating film having a uneven surface;

a transparent electrode formed over the first insulating film;

a reflective electrode formed over the second insulating film so that the reflective electrode is uneven due to the uneven surface of the second insulating film;

an opposite electrode formed on a second substrate; and

an third insulating film formed on the opposite electrode,

wherein a liquid crystal layer is provided between the first substrate and the second substrate, and

wherein a portion of the first insulating film is overlapped with the transparent electrode and is not overlapped with the reflective electrode.

78. The display device according to claim 77, wherein InGaZnO is a-InGaZnO.

79. The display device according to claim 77, wherein the transistor has a bottom gate structure.

80. The display device according to claim 77, wherein the portion of the first insulating film is configured to transmit a light passed through the first substrate.

81. The display device according to claim 77, wherein the transparent electrode is formed over the second insulating film.

82. The display device according to claim 77, wherein the reflective electrode is electrically connected to the transparent electrode.

83. The display device according to claim 77, wherein the first insulating film is a silicon oxide film.

84. The display device according to claim 77, wherein the second insulating film comprises acrylic.

85. The display device according to claim 77, wherein the transparent electrode comprises an indium tin oxide.

86. The display device according to claim 77, wherein the reflective electrode comprises Al and Ti.

87. The display device according to claim 77, wherein the third insulating film is overlapped with the reflective electrode.

88. The display device according to claim 77, wherein the third insulating film comprises acrylic.

96. An electronic book comprising a display portion into which the display device according to claim 77 is incorporated.