Semiconductor device and method of fabricating the same

• US 6,638,781 B1
• Filed: 06/29/2000
• Issued: 10/28/2003
• Est. Priority Date: 07/06/1999
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Goto, Yuugo, Hirakata, Yoshiharu, Yamazaki, Shunpei, Kobayashi, Yuko
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Anya, Igwe U.
• Application Number:
  US09/606,414
• Time in Patent Office: 1,216 Days
• Field of Search: 438/30, 438/155, 438/328, 438/613, 438/705, 438/924, 438/977, 438/980, 257/57, 257/347, 257/66, 257/303, 257/59, 257/72, 257/89, 257/40, 257/433, 257/750, 257/3
• US Class Current: 438/30
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• 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 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 2029/7863 with an LDD consisting of more than one lightly doped zone or having a non-homogeneous dopant distribution, e.g. graded LDD
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/167 further characterised by the doping material H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD
• CPC Class Codes: H01L 29/78669 with inverted-type structure, e.g. with bottom gate
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10S 438/924 : To facilitate selective etching
• CPC Class Codes: Y10S 438/98 : Utilizing process equivalents or options

Abstract

There is provided a high quality liquid crystal panel having a thickness with high accuracy, which is designed, without using a particulate spacer, within a free range in accordance with characteristics of a used liquid crystal and a driving method, and is also provided a method of fabricating the same. The shape of a spacer for keeping a substrate interval constant is made such that it is a columnar shape, a radius R of curvature is 2 μm or less, a height H is 0.5 μm to 10 μm, a diameter is 20 μm or less, and an angle α is 65° to 115°. By doing so, it is possible to prevent the lowering of an opening rate and the lowering of light leakage due to orientation disturbance.

Claims

1. A semiconductor device comprising:

a first substrate;

second substrate; and

a plurality of columnar spacers disposed between said first substrate and said second substrate, each of said columnar spacers having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius R of curvature of said edge is 2 μ

m or less.

2. A semiconductor device according to claim 1, wherein a height H of each of said columnar spacers is 0.5 μ

m to 10 μ

m.

3. A semiconductor device according to claim 1, wherein a height H of each of said columnar spacers is 1.2 μ

m to 5 μ

m.

4. A semiconductor device according to claim 1, wherein a width L1 of each of said columnar spacers is 20 μ

m or less.

5. A semiconductor device according to claim 1, wherein a width L1 of each of said columnar spacers is 7 μ

m or less.

6. A semiconductor device according to claim 1, wherein an angle α

between a tangent plane at a center of a side of each of said columnar spacers and a substrate surface is 65°

to 115°

.

7. A semiconductor device according to claim 1, wherein each of said columnar spacers comprises a flat surface at said upper surface.

8. A semiconductor device according to claim 1, wherein a sectional shape of each of said columnar spacers in a radial direction is one selected from said group consisting of a circle, an ellipse, a triangle, a quadrilateral, and a polygon having sides more than said former.

9. A semiconductor device according to claim 1, wherein each of said columnar spacers comprises an insulating material.

10. A semiconductor device according to claim 1, wherein each of said columnar spacers is formed over a contact portion where a thin film transistor and a pixel electrode are connected to each other.

11. A semiconductor device according to claim 1, wherein said columnar spacers are formed only at a sealing region.

12. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a sealing region and over a region of a driver circuit where an element does not exist.

13. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a sealing region and a pixel portion.

14. A semiconductor device according to claim 1, wherein said columnar spacers are formed over a region of a driver circuit where an element does not exist and at a pixel portion.

15. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a sealing region and a region between a driver circuit and a pixel portion.

16. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a region between a driver circuit and a pixel portion and at said pixel portion.

17. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a sealing region, over a region of a driver circuit where an element does not exist, and at a pixel portion.

18. A semiconductor device according to claim 1, wherein said columnar spacers are formed over a region of a driver circuit where an element does not exist and at a region between said driver circuit and a pixel portion.

19. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a sealing region, over a region of a driver circuit where an element does not exist, at a region between said driver circuit and a pixel portion, and at said pixel portion.

20. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a region between a sealing region and a pixel portion.

21. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a region between a sealing region and a driver circuit.

22. A semiconductor device according to claim 1, wherein said columnar spacers are formed at a region between a sealing region and an end portion of said substrate.

23. A semiconductor device according to claim 1, wherein said columnar spacers are formed at all regions of said substrate.

24. A semiconductor device according to claim 1, wherein said columnar spacers are formed on an alignment film, and a pretilt angle of a liquid crystal is 4°

to 5°

.

25. A semiconductor device according to claim 1, wherein said columnar spacers are covered with an alignment film, and a pretilt angle of a liquid crystal is 6°

to 10°

.

26. A semiconductor device according to claim 1, wherein said semiconductor device is an active matrix type liquid crystal display device.

27. A semiconductor device according to claim 1, wherein said semiconductor device is an EL display device including an electroluminescence element held between said first substrate and said second substrate.

28. A semiconductor device according to claim 1, wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

29. A method of fabricating a semiconductor device comprising the steps of:

forming a thin film transistor over a substrate;

forming a leveling film to cover said thin film transistor;

forming an opening in said leveling film to reach to said thin film transistor and forming a pixel electrode;

forming an alignment film on said pixel electrode;

performing a rubbing processing on said alignment film; and

forming a columnar spacer comprising an insulating film over a contact portion where said thin film transistor is connected to said pixel electrode after forming said alignment film,

wherein said columnar spacers have at least an upper surface, a side surface, and an edge between said upper surface and said side surface, and

wherein a radius R of curvature of said edge is 2 μ

m or less.

30. A method of fabricating a semiconductor device according to claim 29, wherein said step of forming said columnar spacer comprising said insulating film includes a step of forming said insulating film and a step of patterning said insulating film so that said columnar spacer is formed.

31. A method of fabricating a semiconductor device according to claim 29, wherein said semiconductor device is an active matrix liquid crystal display device.

32. A method of fabricating a semiconductor device according to claim 29, wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

33. A method of fabricating a semiconductor device comprising the steps of:

forming a thin film transistor over a substrate;

forming a leveling film to cover said thin film transistor;

forming an opening in said leveling film to reach to said thin film transistor and forming a pixel electrode;

forming a columnar spacer comprising an insulating film over a contact portion where said thin film transistor is connected to said pixel electrode;

forming an alignment to cover said pixel electrode and said columnar spacer; and

performing a rubbing processing on said alignment film,

wherein said columnar spacers have at least an upper surface, a side surface, and an edge between said upper surface and said side surface, and

wherein a radius R of curvature of said edge is 2 μ

m or less.

34. A method of fabricating a semiconductor device according to claim 33, wherein said step of forming said columnar spacer comprising said insulating film includes a step of forming said insulating film and a step of patterning said insulating film so that said columnar spacer is formed.

35. A method of fabricating a semiconductor device according to claim 33, wherein said semiconductor device is an active matrix liquid crystal display device.

36. A method of fabricating a semiconductor device according to claim 33, wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

37. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, and a height of said columnar spacer is 10 μ

m or less.

38. A semiconductor device according to claim 37 wherein said columnar spacer has a flat surface at said upper surface.

39. A semiconductor device according to claim 37 wherein said columnar spacer comprises an insulating material.

40. A semiconductor device according to claim 37 wherein said semiconductor device is an active matrix type liquid crystal display device.

41. A semiconductor device according to claim 37 wherein said semiconductor device is an EL display device.

42. A semiconductor device according to claim 37 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

43. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, and a width of said columnar spacer is 20 μ

m or less.

44. A semiconductor device according to claim 43 wherein said columnar spacer has a flat surface at said upper surface.

45. A semiconductor device according to claim 43 wherein said columnar spacer comprises an insulating material.

46. A semiconductor device according to claim 43 wherein said semiconductor device is an active matrix type liquid crystal display device.

47. A semiconductor device according to claim 43 wherein said semiconductor device is an EL display device.

48. A semiconductor device according to claim 43 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

49. A semiconductor device comprising:

first substrate;

second substrate; and

columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, and an angle between a tangent at a center of a side columnar spacer and a substraate surface is 65°

to 115°

.

50. A semiconductor device according to claim 49 wherein said columnar spacer has a flat surface at said upper surface.

51. A semiconductor device according to claim 49 wherein said columnar spacer comprises an insulating material.

52. A semiconductor device according to claim 49 wherein said semiconductor device is an active matrix type liquid crystal display device.

53. A semiconductor device according to claim 49 wherein said semiconductor device is an EL display device.

54. A semiconductor device according to claim 49 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

55. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, a height of said columnar spacer is 10 μ

m or less, and a width of said columnar spacer is 20 μ

m or less.

56. A semiconductor device according to claim 55 wherein said columnar spacer has a flat surface at said upper surface.

57. A semiconductor device according to claim 55 wherein said columnar spacer comprises an insulating material.

58. A semiconductor device according to claim 55 wherein said semiconductor device is an active matrix type liquid crystal display device.

59. A semiconductor device according to claim 55 wherein said semiconductor device is an EL display device.

60. A semiconductor device according to claim 56 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

61. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, a height of said columnar spacer is 10 μ

m or less, and an angle between a tangent plane at a center of a side of said columnar spacer and a substrate surface is 65°

to 115°

.

62. A semiconductor device according to claim 61 wherein said columnar spacer has a flat surface at said upper surface.

63. A semiconductor device according to claim 61 wherein said columnar spacer comprises an insulating material.

64. A semiconductor device according to claim 61 wherein said semiconductor device is an active matrix type liquid crystal display device.

65. A semiconductor device according to claim 61 wherein said semiconductor device is an EL display device.

66. A semiconductor device according to claim 61 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

67. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, a width of said columnar spacer is 20 μ

m or less, and an angle between a tangent plane at a center of a side of said columnar spacer and a substrate surface is 65°

to 115°

.

68. A semiconductor device according to claim 67 wherein said columnar spacer has a flat surface at said upper surface.

69. A semiconductor device according to claim 67 wherein said columnar spacer comprises an insulating material.

70. A semiconductor device according to claim 67 wherein said semiconductor device is an active matrix type liquid crystal display device.

71. A semiconductor device according to claim 67 wherein said semiconductor device is an EL display device.

72. A semiconductor device according to claim 67 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

73. A semiconductor device comprising:

a first substrate;

a second substrate; and

a columnar spacer disposed between said first substrate and said second substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate, and

wherein a radius of curvature of said edge is 2 μ

m or less, a height of said columnar spacer is 10 μ

m or less, a width of said columnar spacer is 20 μ

m or less, and an angle between a tangent plane at a center of a side of said columnar spacer and a substrate surface is 65°

to 115°

.

74. A semiconductor device according to claim 73 wherein said columnar spacer has a flat surface at said upper surface.

75. A semiconductor device according to claim 73 wherein said columnar spacer comprises an insulating material.

76. A semiconductor device according to claim 73 wherein said semiconductor device is an active matrix type liquid crystal display device.

77. A semiconductor device according to claim 73 wherein said semiconductor device is an EL display device.

78. A semiconductor device according to claim 73 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

79. A semiconductor device comprising:

a thin film transistor over a first substrate;

a pixel electrode electrically connected to said thin film transistor;

a columnar spacer over said first substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate; and

a light-shielding film provided over said second substrate,

wherein said columnar spacer is located below said light-shielding film, and

wherein a radius R of curvature of said edge is 2 μ

m or less.

80. A semiconductor device according to claim 79 wherein said columnar spacer has a flat surface at said upper surface.

81. A semiconductor device according to claim 79 wherein said columnar spacer comprises an insulating material.

82. A semiconductor device according to claim 79 wherein said semiconductor device is an active matrix type liquid crystal display device.

83. A semiconductor device according to claim 79 wherein said semiconductor device is an EL display device.

84. A semiconductor device according to claim 79 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

85. A semiconductor device comprising:

a thin film transistor over a-first substrate;

a pixel electrode electrically connected to said thin film transistor in a contact hole;

a columnar spacer on said contact hole, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate; and

a light-shielding film provided over said second substrate,

wherein said columnar spacer is located below said light-shielding film, and

wherein a radius R of curvature of said edge is 2 μ

m or less.

86. A semiconductor device according to claim 85 wherein said columnar spacer has a flat surface at said upper surface.

87. A semiconductor device according to claim 85 wherein said columnar spacer comprises an insulating material.

88. A semiconductor device according to claim 85 wherein said semiconductor device is an active matrix type liquid crystal display device.

89. A semiconductor device according to claim 85 wherein said semiconductor device is an EL display device.

90. A semiconductor device according to claim 85 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

91. A semiconductor device comprising:

a thin film transistor over a first substrate;

a pixel electrode electrically connected to said thin film transistor;

a columnar spacer over said first substrate, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate and a radius R of curvature of said edge is 2 μ

m or less; and

a light-shielding film provided over said second substrate,

wherein said columnar spacer is overlapped with said light-shielding film.

92. A semiconductor device according to claim 91 wherein said columnar spacer has a flat surface at said upper surface.

93. A semiconductor device according to claim 91 wherein said columnar spacer comprises an insulating material.

94. A semiconductor device according to claim 91 wherein said semiconductor device is an active matrix type liquid crystal display device.

95. A semiconductor device according to claim 91 wherein said semiconductor device is an EL display device.

96. A semiconductor device according to claim 91 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.

97. A semiconductor device comprising:

a thin film transistor over a first substrate;

a pixel electrode electrically connected to said thin film transistor in a contact hole;

a columnar spacer on said contact hole, said columnar spacer having at least an upper surface, a side surface, and an edge between said upper surface and said side surface, wherein said upper surface faces a surface of said second substrate and a radius R of curvature of said edge is 2 μ

m or less; and

a light-shielding film provided over said second substrate, wherein said columnar spacer is overlapped with said light-shielding film.

98. A semiconductor device according to claim 97 wherein said columnar spacer has a flat surface at said upper surface.

99. A semiconductor device according to claim 97 wherein said columnar spacer comprises an insulating material.

100. A semiconductor device according to claim 97 wherein said semiconductor device is an active matrix type liquid crystal display device.

101. A semiconductor device according to claim 97 wherein said semiconductor device is an EL display device.

102. A semiconductor device according to claim 97 wherein said semiconductor device is at least one selected from the group consisting of a video camera, a digital camera, a projector, a goggle type display, a car navigation system, a personal computer, and a portable information terminal.