LOGIC CIRCUIT AND SEMICONDUCTOR DEVICE

• US 20130200370A1
• Filed: 03/18/2013
• Published: 08/08/2013
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, KOYAMA, Jun, TSUBUKU, Masashi, NODA, Kosei
• Granted Patent: US 10,211,344 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633
• CPC Class Codes: H01L 27/0207 Geometrical layout of the components, e.g. computer aided design; custom LSI, semi-custom LSI, standard cell technique
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• 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

Abstract

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 5×10¹⁹ (atoms/cm³) 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, leadind 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.

Claims

1. A semiconductor device comprising:

a thin film 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, and

wherein a channel formation region of the thin film transistor comprises an oxide semiconductor.

2. The semiconductor device according to claim 1,

wherein the logic circuit comprises a second thin film transistor, and

wherein the channel formation region of the second thin film 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×

10¹⁹ atoms/cm³ or less.

7. The semiconductor device according to claim 1, wherein an off-state current of the thin film transistor is 1×

10¹³ [A] or less when a voltage between source and drain of the thin film transistor is 10V.

8. The semiconductor device according to claim 1, wherein the oxide semiconductor comprises at least one of indium and gallium.

9. The semiconductor device according to claim 1, wherein a carrier density of the oxide semiconductor in the thin film transistor is 5×

10¹⁴/cm³ or less.

10. The semiconductor device according to claim 1, wherein at least a part of the oxide semiconductor in the thin film transistor is in an oxygen-excess state.

11. A semiconductor device comprising:

a thin film 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, and

wherein a channel formation region of the thin film transistor comprises an oxide semiconductor.

12. The semiconductor device according to claim 11,

wherein the register comprises a second thin film transistor, and

wherein the channel formation region of the second thin film transistor comprises an oxide semiconductor.

13. The semiconductor device according to claim 11, wherein the other terminal of the capacitor is electrically connected to a low power supply potential line.

14. The semiconductor device according to claim 11, wherein the oxide semiconductor comprises an In—

Ga—

Zn—

O-based oxide semiconductor.

15. An electronic device comprising the semiconductor device according to claim 11.

16. The semiconductor device according to claim 11, wherein hydrogen concentration of the oxide semiconductor is 5×

10¹⁹ atoms/cm³ or less.

17. The semiconductor device according to claim 11, wherein an off-state current of the thin film transistor is 1×

10¹³ [A] or less when a voltage between source and drain of the thin film transistor is 10V.

18. The semiconductor device according to claim 11, wherein the oxide semiconductor comprises at least one of indium and gallium.

19. The semiconductor device according to claim 11, wherein a carrier density of the oxide semiconductor in the thin film transistor is 5×

10¹⁴/cm³ or less.

20. The semiconductor device according to claim 11, wherein at least a part of the oxide semiconductor in the thin film transistor is in an oxygen-excess state.

21. A semiconductor device comprising:

a first thin film transistor comprising a first terminal which is electrically connected to a high power supply potential line;

a second thin film 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 thin film transistor;

a third thin film 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 thin film transistor, and a second terminal which is electrically connected to a low power supply potential line;

a fourth thin film 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 thin film transistor and the first terminal of the second thin film 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 thin film transistor and the output terminal, and

wherein a channel formation region of the fourth thin film transistor comprises an oxide semiconductor.

22. The semiconductor device according to claim 21, wherein channel formation regions of the first to third thin film transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

23. The semiconductor device according to claim 21, wherein the oxide semiconductor comprises an In—

Ga—

Zn—

O-based oxide semiconductor.

24. An electronic device comprising the semiconductor device according to claim 21.

25. The semiconductor device according to claim 21, wherein hydrogen concentration of the oxide semiconductor is 5×

10¹⁹ atoms/cm³ or less.

26. The semiconductor device according to claim 21, wherein an off-state current of the fourth thin film transistor is 1×

10¹³ [A] or less when a voltage between source and drain of the fourth thin film transistor is 10V.

27. The semiconductor device according to claim 21, wherein the oxide semiconductor comprises at least one of indium and gallium.

28. The semiconductor device according to claim 21, wherein a carrier density of the oxide semiconductor in the fourth thin film transistor is 5×

10¹⁴/cm³ or less.

29. A semiconductor device comprising:

a first thin film transistor comprising a first terminal which is electrically connected to a high power supply potential line;

a second thin film 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 thin film transistor;

a third thin film 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 thin film transistor, and a second terminal which is electrically connected to a low power supply potential line;

a fourth thin film 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 thin film transistor and the first terminal of the third thin film 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 thin film transistor and the output terminal, and

wherein a channel formation region of the fourth thin film transistor comprises an oxide semiconductor.

30. The semiconductor device according to claim 29, wherein channel formation regions of the first to third thin film transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

31. The semiconductor device according to claim 29, wherein the oxide semiconductor comprises an In—

Ga—

Zn—

O-based oxide semiconductor.

32. An electronic device comprising the semiconductor device according to claim 29.

33. The semiconductor device according to claim 29, wherein hydrogen concentration of the oxide semiconductor is 5×

10¹⁹ atoms/cm³ or less.

34. The semiconductor device according to claim 29, wherein an off-state current of the fourth thin film transistor is 1×

10¹³ [A] or less when a voltage between source and drain of the fourth thin film transistor is 10V.

35. The semiconductor device according to claim 29, wherein the oxide semiconductor comprises at least one of indium and gallium.

36. The semiconductor device according to claim 29, wherein a carrier density of the oxide semiconductor in the fourth thin film transistor is 5×

10¹⁴/cm³ or less.

37. A semiconductor device comprising:

a first thin film transistor comprising a gate terminal and a first terminal which are electrically connected to a high power supply potential line;

a second thin film 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 thin film transistor;

a third thin film 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 thin film transistor, and a second terminal which is electrically connected to a low power supply potential line;

a fourth thin film 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 thin film transistor and the first terminal of the second thin film 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 thin film transistor and the output terminal, and

wherein a channel formation region of the fourth thin film transistor comprises an oxide semiconductor.

38. The semiconductor device according to claim 37, wherein channel formation regions of the first to third thin film transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

39. The semiconductor device according to claim 37, wherein the oxide semiconductor comprises an In—

Ga—

Zn—

O-based oxide semiconductor.

40. An electronic device comprising the semiconductor device according to claim 37.

41. The semiconductor device according to claim 37, wherein hydrogen concentration of the oxide semiconductor is 5×

10¹⁹ atoms/cm³ or less.

42. The semiconductor device according to claim 37, wherein an off-state current of the fourth thin film transistor is 1×

10¹³ [A] or less when a voltage between source and drain of the fourth thin film transistor is 10V.

43. The semiconductor device according to claim 37, wherein the oxide semiconductor comprises at least one of indium and gallium.

44. The semiconductor device according to claim 37, wherein a carrier density of the oxide semiconductor in the fourth thin film transistor is 5×

10¹⁴/cm³ or less.

45. A semiconductor device comprising:

a first thin film transistor comprising a gate terminal and a first terminal which are electrically connected to a high power supply potential line;

a second thin film 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 thin film transistor;

a third thin film 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 thin film transistor, and a second terminal which is electrically connected to a low power supply potential line;

a fourth thin film 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 thin film transistor and the first terminal of the third thin film 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 thin film transistor and the output terminal, and

wherein a channel formation region of the fourth thin film transistor comprises an oxide semiconductor.

46. The semiconductor device according to claim 45, wherein channel formation regions of the first to third thin film transistors each comprises an oxide semiconductor with a hydrogen concentration of 5×

10¹⁹ atoms/cm³ or less.

47. The semiconductor device according to claim 45, wherein the oxide semiconductor comprises an In—

Ga—

Zn—

O-based oxide semiconductor.

48. An electronic device comprising the semiconductor device according to claim 45.

49. The semiconductor device according to claim 45, wherein hydrogen concentration of the oxide semiconductor is 5×

10¹⁹ atoms/cm³ or less.

50. The semiconductor device according to claim 45, wherein an off-state current of the fourth thin film transistor is 1×

10<sup>−

13</sup> [A] or less when a voltage between source and drain of the fourth thin film transistor is 10V.

51. The semiconductor device according to claim 45, wherein the oxide semiconductor comprises at least one of indium and gallium.

52. The semiconductor device according to claim 45, wherein a carrier density of the oxide semiconductor in the fourth thin film transistor is 5×

10¹⁴/cm³ or less.