Semiconductor device, and electronic apparatus

• US 20030015703A1
• Filed: 05/23/2002
• Published: 01/23/2003
• Est. Priority Date: 05/24/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Osada, Mai
• Granted Patent: US 6,906,344 B2
• Time in Patent Office: Days
• US Class Current: 257/66
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 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: 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 29/6675 Amorphous silicon or polysilicon transistors
• 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 29/78636 with supplementary region or layer for improving the flatness of the device
• CPC Class Codes: H01L 29/78645 with multiple gate
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel

Abstract

An object of the present invention is to provide a technique for improving characteristics of a TFT and realizing the structure of the TFT optimal for driving conditions of a pixel section and a driving circuit, using a smaller number of photo masks. A semiconductor device has a semiconductor film, a first electrode, and a first insulating film sandwiched between the semiconductor film and the first electrode, and further has a second electrode, and a second insulating film sandwiched between the semiconductor film and the second electrode. The first electrode and the second electrode overlap with each other across a channel-formed region which the semiconductor film has. A constant voltage is applied to the first electrode at any time.

Claims

1. A semiconductor device comprising:

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and plural second electrodes in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the channel-formed regions,

one of two impurity regions out of the plural impurity regions is connected to the first interconnection and the other is connected to the second interconnection,

the first electrode overlaps with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions,

the second electrodes are electrically connected to each other; and

each of the second electrodes overlaps with each of the channel-formed regions.

2. A device according to claim 1,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

3. A device according to claim 1,

wherein the first insulating film is flattened by chemical-mechanical polishing.

4. A device according to claim 3, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

5. A device according to claim 3, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

6. A device according to claim 3, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

7. A device according to claim 3, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

8. A device according to claim 1, wherein the semiconductor device is a microprocessor.

9. A device according to claim 1, wherein the semiconductor device is incorporated into an electronic apparatus.

10. A device according to claim 1, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

11. A semiconductor device comprising:

a first interconnection;

a second interconnection;

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and a second electrode in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the respective channel-formed regions;

one of two impurity regions out of the plural impurity regions is connected to the first interconnection and the other is connected to the second interconnection; and

the first electrode and the second electrode overlap with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions.

12. A device according to claim 11,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

13. A device according to claim 11,

wherein the first insulating film is flattened by chemical-mechanical polishing.

14. A device according to claim 13, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

15. A device according to claim 13, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

16. A device according to claim 13, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

17. A device according to claim 13, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

18. A device according to claim 11, wherein the semiconductor device is a microprocessor.

19. A device according to claim 11, wherein the semiconductor device is incorporated into an electronic apparatus.

20. A device according to claim 11, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

21. A semiconductor device comprising:

a first interconnection;

a second interconnection;

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and plural second electrodes in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions, plural first impurity regions each in contact with corresponding one of the channel-formed regions, and plural second impurity regions each in contact with corresponding one of the first impurity regions;

one of two second impurity regions out of the second impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode overlaps with all the second impurity regions except the above-mentioned two second impurity regions, with all the channel-formed regions, and with all the first impurity regions except the first impurity regions in contact with the above-mentioned two second impurity regions;

the second electrodes are electrically connected to each other; and

each of the second electrodes overlaps with corresponding one of the channel-formed regions.

22. A device according to claim 21, wherein the first impurity regions have a lower impurity concentration than the second impurity regions.

23. A device according to claim 21,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

24. A device according to claim 21,

wherein the first insulating film is flattened by chemical-mechanical polishing.

25. A device according to claim 24, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

26. A device according to claim 24, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

27. A device according to claim 24, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

28. A device according to claim 24, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

29. A device according to claim 21, wherein the semiconductor device is a microprocessor.

30. A device according to claim 21, wherein the semiconductor device is incorporated into an electronic apparatus.

31. A device according to claim 21, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

32. A semiconductor device comprising:

a first interconnection;

a second interconnection;

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and a second electrode in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions, plural first impurity regions each in contact with corresponding one of the channel-formed regions, and plural second impurity regions each in contact with corresponding one of the first impurity regions;

one of two second impurity regions out of the second impurity regions is connected to the first interconnection and the other is connected to the second interconnection; and

the first electrode and the second electrode overlap with all the second impurity regions except the above-mentioned two second impurity regions, with all the channel-formed regions, and with all the first impurity regions except the first impurity regions in contact with the above-mentioned two second impurity regions.

33. A device according to claim 32, wherein the first impurity regions have a lower impurity concentration than the second impurity regions.

34. A device according to claim 32,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

35. A device according to claim 32,

wherein the first insulating film is flattened by chemical-mechanical polishing.

36. A device according to claim 35, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

37. A device according to claim 35, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

38. A device according to claim 35, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

39. A device according to claim 35, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

40. A device according to claim 32, wherein the semiconductor device is a microprocessor.

41. A device according to claim 32, wherein the semiconductor device is incorporated into an electronic apparatus.

42. A device according to claim 32, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

43. A semiconductor device comprising:

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and second electrodes in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the channel-formed regions;

one of two impurity regions out of the plural impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode overlaps with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions;

the second electrodes are electrically connected to each other;

each of the second electrodes overlaps with corresponding one of the channel-formed regions; and

the first electrode is electrically connected to the second electrodes.

44. A device according to claim 43,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

45. A device according to claim 43,

wherein the first insulating film is flattened by chemical-mechanical polishing.

46. A device according to claim 45, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

47. A device according to claim 45, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

48. A device according to claim 45, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

49. A device according to claim 45, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

50. A device according to claim 43, wherein the semiconductor device is a microprocessor.

51. A device according to claim 43, wherein the semiconductor device is incorporated into an electronic apparatus.

52. A device according to claim 43, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

53. A semiconductor device comprising:

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and a second electrode in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the channel-formed regions;

one of two impurity regions out of the plural impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode and the second electrode overlap with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions; and

the first electrode is electrically connected to the second electrode.

54. A device according to claim 53,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

55. A device according to claim 53,

wherein the first insulating film is flattened by chemical-mechanical polishing.

56. A device according to claim 55, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

57. A device according to claim 55, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

58. A device according to claim 55, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

59. A device according to claim 55, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

60. A device according to claim 53, wherein the semiconductor device is a microprocessor.

61. A device according to claim 53, wherein the semiconductor device is incorporated into an electronic apparatus.

62. A device according to claim 53, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

63. A semiconductor device comprising:

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and plural second electrodes in contact with the second insulating film; and

wherein the semiconductor film comprises plural channel-formed regions, plural first impurity regions each in contact with corresponding one of the channel-formed regions, and plural second impurity regions each in contact with corresponding one of the first impurity regions;

one of two second impurity regions out of the plural second impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode overlaps with all the second impurity regions except the above-mentioned two second impurity regions, with all the channel-formed regions, and with all the first impurity regions except the first impurity regions in contact with the above-mentioned two second impurity regions;

the second electrodes are electrically connected to each other;

each of the second electrodes overlaps with corresponding one of the channel-formed regions; and

the first electrode is electrically connected to the second electrodes.

64. A device according to claim 63, wherein the first impurity regions have a lower impurity concentration than the second impurity regions.

65. A device according to claim 63,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

66. A device according to claim 63,

wherein the first insulating film is flattened by chemical-mechanical polishing.

67. A device according to claim 66, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

68. A device according to claim 66, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

69. A device according to claim 66, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

70. A device according to claim 66, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d 1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

71. A device according to claim 63, wherein the semiconductor device is a microprocessor.

72. A device according to claim 63, wherein the semiconductor device is incorporated into an electronic apparatus.

73. A device according to claim 63, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

74. A semiconductor device comprising:

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and a second electrode in contact with the second insulating film,

wherein the semiconductor film comprises plural channel-formed regions, plural first impurity regions each in contact with corresponding one of the channel-formed regions, and plural second impurity regions each in contact with corresponding one of the first impurity regions;

one of two second impurity regions out of the plural second impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode and the second electrode overlap with all the second impurity regions except the above-mentioned two second impurity regions, with all the channel-formed regions, and with all the first impurity regions except the first impurity regions in contact with the above-mentioned two second impurity regions; and

the first electrode is electrically connected to the second electrode.

75. A device according to claim 74, wherein the first impurity regions have a lower impurity concentration than the second impurity regions.

76. A device according to claim 74,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

77. A device according to claim 74,

wherein the first insulating film is flattened by chemical-mechanical polishing.

78. A device according to claim 77, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

79. A device according to claim 77, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

80. A device according to claim 77, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

81. A device according to claim 77, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

82. A device according to claim 74, wherein the semiconductor device is a microprocessor.

83. A device according to claim 74, wherein the semiconductor device is incorporated into an electronic apparatus.

84. A device according to claim 74, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

85. A semiconductor device comprising:

plural pixels;

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and plural second electrodes in contact with the second insulating film,

wherein each of said pixels contains said first interconnection and said second interconnection and said thin film transistor,

the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the channel-formed regions;

one of two impurity regions out of the impurity regions is connected to the first interconnection and the other is connected to the second interconnection;

the first electrode overlaps with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions;

the second electrodes are electrically connected to each other; and

each of the second electrodes overlaps with corresponding one of the channel-formed regions.

86. A device according to claim 85,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

87. A device according to claim 85,

wherein the first insulating film is flattened by chemical-mechanical polishing.

88. A device according to claim 87, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

89. A device according to claim 87, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

90. A device according to claim 87, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

91. A device according to claim 87, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

92. A device according to claim 85, wherein the semiconductor device is a microprocessor.

93. A device according to claim 85, wherein the semiconductor device is incorporated into an electronic apparatus.

94. A device according to claim 85, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.

95. A semiconductor device comprising:

plural pixels;

a first interconnection;

a second interconnection; and

a thin film transistor comprising a first electrode, a first insulating film in contact with the first electrode, a semiconductor film in contact with the first insulating film, a second insulating film in contact with the semiconductor film, and a second electrode in contact with the second insulating film,

wherein each of said pixels contains the first interconnection and the second interconnection and the thin film transistor,

the semiconductor film comprises plural channel-formed regions and plural impurity regions each in contact with corresponding one of the channel-formed regions;

one of two impurity regions out of the impurity regions is connected to the first interconnection and the other is connected to the second interconnection; and

the first electrode and the second electrode overlap with all the impurity regions except the above-mentioned two impurity regions and with all the channel-formed regions.

96. A device according to claim 95,

wherein the dielectric constant of the first insulating film is substantially equal to that of the second insulating film, and

the film thickness of the first insulating film in an area where it overlaps with the first electrode is substantially equal to that of the second insulating film in an area where it overlaps with the second electrodes.

97. A device according to claim 95,

wherein the first insulating film is flattened by chemical-mechanical polishing.

98. A device according to claim 97, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 5 nm or less.

99. A device according to claim 97, wherein irregularities formed in the surface of the flattened first insulating film has an elevation difference of 1 nm or less.

100. A device according to claim 97, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrode(s) is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.1 and |d1−

d2|/d2≦

0.1

101. A device according to claim 97, wherein when the film thickness of the flattened first insulating film in an area where the channel-formed regions overlap with the first electrode is represented by d1 and the film thickness of the second insulating film in an area where the channel-formed regions overlap with the second electrodes is represented by d2, the film thicknesses d1 and d2 satisfy the following:

|d1−

d2|/d1≦

0.05 and |d1−

d2|/d2≦

0.05.

102. A device according to claim 95, wherein the semiconductor device is a microprocessor.

103. A device according to claim 95, wherein the semiconductor device is incorporated into an electronic apparatus.

104. A device according to claim 95, wherein the semiconductor device is incorporated into one selected from the group consisting of a display device, a digital still camera, a notebook-type personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera or a portable telephone.