Logic circuit and semiconductor device
A logic circuit includes a thin film transistor having a channel formation region formed using an oxide semiconductor, and a capacitor having terminals one of which is brought into a floating state by turning off the thin film transistor. The oxide semiconductor has a hydrogen concentration of 5×10 19 (atoms/cm 3 ) or less and thus substantially serves as an insulator in a state where an electric field is not generated. Therefore, off-state current of a thin film transistor can be reduced, leading to suppressing the leakage of electric charge stored in a capacitor, through the thin film transistor. Accordingly, a malfunction of the logic circuit can be prevented. Further, the excessive amount of current which flows in the logic circuit can be reduced through the reduction of off-state current of the thin film transistor, resulting in low power consumption of the logic circuit.
1. A semiconductor device comprising:
a transistor comprising a first terminal, a second terminal and a gate terminal;
a logic circuit comprising a first output terminal, the first output terminal being electrically connected to the first terminal; and
a capacitor,
wherein the gate terminal is electrically connected to a line,
wherein one terminal of the capacitor is electrically connected to the second terminal and a second output terminal,
wherein a channel formation region of the transistor comprises an oxide semiconductor, and
wherein a carrier density of the oxide semiconductor in the transistor is 5×10 14 /cm 3 or less.
2. The semiconductor device according to claim 1 ,
wherein the logic circuit comprises a second transistor, and
wherein the channel formation region of the second transistor comprises an oxide semiconductor.
3. The semiconductor device according to claim 1 , wherein the other terminal of the capacitor is electrically connected to a low power supply potential line.
4. The semiconductor device according to claim 1 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
5. An electronic device comprising the semiconductor device according to claim 1 .
6. The semiconductor device according to claim 1 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
7. The semiconductor device according to claim 1 , wherein the oxide semiconductor comprises at least one of indium and gallium.
8. The semiconductor device according to claim 1 , wherein at least a part of the oxide semiconductor in the transistor is in an oxygen-excess state.
9. A semiconductor device comprising:
a transistor comprising a first terminal, a second terminal and a gate terminal;
a register comprising a first output terminal, the first output terminal being electrically connected to the first terminal; and
a capacitor,
wherein the gate terminal is electrically connected to a line,
wherein one terminal of the capacitor is electrically connected to the second terminal and a second output terminal,
wherein a channel formation region of the transistor comprises an oxide semiconductor, and
wherein a carrier density of the oxide semiconductor in the transistor is 5×10 14 /cm 3 or less.
10. The semiconductor device according to claim 9 ,
wherein the register comprises a second transistor, and
wherein the channel formation region of the second transistor comprises an oxide semiconductor.
11. The semiconductor device according to claim 9 , wherein the other terminal of the capacitor is electrically connected to a low power supply potential line.
12. The semiconductor device according to claim 9 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
13. An electronic device comprising the semiconductor device according to claim 9 .
14. The semiconductor device according to claim 9 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
15. The semiconductor device according to claim 9 , wherein the oxide semiconductor comprises at least one of indium and gallium.
16. The semiconductor device according to claim 9 , wherein at least a part of the oxide semiconductor in the transistor is in an oxygen-excess state.
17. A semiconductor device comprising:
a first transistor comprising a first terminal which is electrically connected to a high power supply potential line;
a second transistor comprising a gate terminal which is electrically connected to an input terminal, and a first terminal which is electrically connected to a gate terminal and a second terminal of the first transistor;
a third transistor comprising a gate terminal which is electrically connected to a pulse signal line, a first terminal which is electrically connected to a second terminal of the second transistor, and a second terminal which is electrically connected to a low power supply potential line;
a fourth transistor comprising a gate terminal which is electrically connected to the pulse signal line, a first terminal which is electrically connected to the gate terminal and the second terminal of the first transistor and the first terminal of the second transistor, and a second terminal which is electrically connected to an output terminal; and
a capacitor,
wherein one terminal of the capacitor is electrically connected to the second terminal of the fourth transistor and the output terminal, and
wherein a channel formation region of the fourth transistor comprises an oxide semiconductor.
18. The semiconductor device according to claim 17 , wherein channel formation regions of the first to third transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×10 19 atoms/cm 3 or less.
19. The semiconductor device according to claim 17 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
20. An electronic device comprising the semiconductor device according to claim 17 .
21. The semiconductor device according to claim 17 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
22. The semiconductor device according to claim 17 , wherein an off-state current of the fourth transistor is 1×10 −13 [A] or less when a voltage between source and drain of the fourth transistor is 10V.
23. The semiconductor device according to claim 17 , wherein the oxide semiconductor comprises at least one of indium and gallium.
24. The semiconductor device according to claim 17 , wherein a carrier density of the oxide semiconductor in the fourth transistor is 5×10 14 /cm 3 or less.
25. A semiconductor device comprising:
a first transistor comprising a first terminal which is electrically connected to a high power supply potential line;
a second transistor comprising a gate terminal which is electrically connected to a pulse signal line, and a first terminal which is electrically connected to a gate terminal and a second terminal of the first transistor;
a third transistor comprising a gate terminal which is electrically connected to an input terminal, a first terminal which is electrically connected to a second terminal of the second transistor, and a second terminal which is electrically connected to a low power supply potential line;
a fourth transistor comprising a gate terminal which is electrically connected to the pulse signal line, a first terminal which is electrically connected to the second terminal of the second transistor and the first terminal of the third transistor, and a second terminal which is electrically connected to an output terminal; and
a capacitor,
wherein one terminal of the capacitor is electrically connected to the second terminal of the fourth transistor and the output terminal, and
wherein a channel formation region of the fourth transistor comprises an oxide semiconductor.
26. The semiconductor device according to claim 25 , wherein channel formation regions of the first to third transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×10 19 atoms/cm 3 or less.
27. The semiconductor device according to claim 25 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
28. An electronic device comprising the semiconductor device according to claim 25 .
29. The semiconductor device according to claim 25 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
30. The semiconductor device according to claim 25 , wherein an off-state current of the fourth transistor is 1×10 −13 [A] or less when a voltage between source and drain of the fourth transistor is 10V.
31. The semiconductor device according to claim 25 , wherein the oxide semiconductor comprises at least one of indium and gallium.
32. The semiconductor device according to claim 25 , wherein a carrier density of the oxide semiconductor in the fourth transistor is 5×10 14 /cm 3 or less.
33. A semiconductor device comprising:
a first transistor comprising a gate terminal and a first terminal which are electrically connected to a high power supply potential line;
a second transistor comprising a gate terminal which is electrically connected to an input terminal, and a first terminal which is electrically connected to a second terminal of the first transistor;
a third transistor comprising a gate terminal which is electrically connected to a pulse signal line, a first terminal which is electrically connected to a second terminal of the second transistor, and a second terminal which is electrically connected to a low power supply potential line;
a fourth transistor comprising a gate terminal which is electrically connected to the pulse signal line, a first terminal which is electrically connected to the second terminal of the first transistor and the first terminal of the second transistor, and a second terminal which is electrically connected to an output terminal; and
a capacitor,
wherein one terminal of the capacitor is electrically connected to the second terminal of the fourth transistor and the output terminal, and
wherein a channel formation region of the fourth transistor comprises an oxide semiconductor.
34. The semiconductor device according to claim 33 , wherein channel formation regions of the first to third transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×10 19 atoms/cm 3 or less.
35. The semiconductor device according to claim 33 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
36. An electronic device comprising the semiconductor device according to claim 33 .
37. The semiconductor device according to claim 33 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
38. The semiconductor device according to claim 33 , wherein an off-state current of the fourth transistor is 1×10 −13 [A] or less when a voltage between source and drain of the fourth transistor is 10V.
39. The semiconductor device according to claim 33 , wherein the oxide semiconductor comprises at least one of indium and gallium.
40. The semiconductor device according to claim 33 , wherein a carrier density of the oxide semiconductor in the fourth transistor is 5×10 14 /cm 3 or less.
41. A semiconductor device comprising:
a first transistor comprising a gate terminal and a first terminal which are electrically connected to a high power supply potential line;
a second transistor comprising a gate terminal which is electrically connected to a pulse signal line, and a first terminal which is electrically connected to a second terminal of the first transistor;
a third transistor comprising a gate terminal which is electrically connected to an input terminal, a first terminal which is electrically connected to a second terminal of the second transistor, and a second terminal which is electrically connected to a low power supply potential line;
a fourth transistor comprising a gate terminal which is electrically connected to the pulse signal line, a first terminal which is electrically connected to the second terminal of the second transistor and the first terminal of the third transistor, and a second terminal which is electrically connected to an output terminal; and
a capacitor,
wherein one terminal of the capacitor is electrically connected to the second terminal of the fourth transistor and the output terminal, and
wherein a channel formation region of the fourth transistor comprises an oxide semiconductor.
42. The semiconductor device according to claim 41 , wherein channel formation regions of the first to third transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×10 19 atoms/cm 3 or less.
43. The semiconductor device according to claim 41 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
44. An electronic device comprising the semiconductor device according to claim 41 .
45. The semiconductor device according to claim 41 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
46. The semiconductor device according to claim 41 , wherein an off-state current of the fourth transistor is 1×10 −13 [A] or less when a voltage between source and drain of the fourth transistor is 10V.
47. The semiconductor device according to claim 41 , wherein the oxide semiconductor comprises at least one of indium and gallium.
48. The semiconductor device according to claim 41 , wherein a carrier density of the oxide semiconductor in the fourth transistor is 5×10 14 /cm 3 or less.
49. A semiconductor device comprising:
a transistor comprising a first terminal, a second terminal and a gate terminal;
a logic circuit comprising a first output terminal, the first output terminal being electrically connected to the first terminal; and
a capacitor,
wherein the gate terminal is electrically connected to a line,
wherein one terminal of the capacitor is electrically connected to the second terminal and a second output terminal,
wherein a channel formation region of the transistor comprises an oxide semiconductor, and
wherein an off-state current of the transistor is 1×10 13 [A] or less when a voltage between source and drain of the transistor is 10V.
50. The semiconductor device according to claim 49 ,
wherein the logic circuit comprises a second transistor, and
wherein the channel formation region of the second transistor comprises an oxide semiconductor.
51. The semiconductor device according to claim 49 , wherein the other terminal of the capacitor is electrically connected to a low power supply potential line.
52. The semiconductor device according to claim 49 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
53. An electronic device comprising the semiconductor device according to claim 49 .
54. The semiconductor device according to claim 49 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
55. The semiconductor device according to claim 49 , wherein the oxide semiconductor comprises at least one of indium and gallium.
56. A semiconductor device comprising:
a transistor comprising a first terminal, a second terminal and a gate terminal;
a register comprising a first output terminal, the first output terminal being electrically connected to the first terminal; and
a capacitor,
wherein the gate terminal is electrically connected to a line,
wherein one terminal of the capacitor is electrically connected to the second terminal and a second output terminal,
wherein a channel formation region of the transistor comprises an oxide semiconductor, and
wherein an off-state current of the transistor is 1×10 13 [A] or less when a voltage between source and drain of the transistor is 10V.
57. The semiconductor device according to claim 56 ,
wherein the register comprises a second transistor, and
wherein the channel formation region of the second transistor comprises an oxide semiconductor.
58. The semiconductor device according to claim 56 , wherein the other terminal of the capacitor is electrically connected to a low power supply potential line.
59. The semiconductor device according to claim 56 , wherein the oxide semiconductor comprises an In—Ga—Zn—O-based oxide semiconductor.
60. An electronic device comprising the semiconductor device according to claim 56 .
61. The semiconductor device according to claim 56 , wherein hydrogen concentration of the oxide semiconductor is 5×10 19 atoms/cm 3 or less.
62. The semiconductor device according to claim 56 , wherein the oxide semiconductor comprises at least one of indium and gallium.