Semiconductor device and electronic device

• US 9,349,757 B2
• Filed: 10/20/2015
• Issued: 05/24/2016
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kimura, Hajime, Umezaki, Atsushi, Yamazaki, Shunpei
• Primary Examiner(s): Blum, David S
• Application Number:
  US14/887,517
• Publication Number:
  US 20160043106A1
• Time in Patent Office: 217 Days
• Field of Search: 257/438
• US Class Current: 1/1
• 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 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13345 Network or three-dimensional gels
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: H01L 21/823412 with a particular manufacturing method of the channel structures, e.g. channel implants, halo or pocket implants, or channel materials
• 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 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 29/247 Amorphous materials
• CPC Class Codes: H01L 29/786 : Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• CPC Class Codes: H01L 29/78606 : with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• CPC Class Codes: H01L 29/78693 : the semiconducting oxide being amorphous
• 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

Abstract

An object is to improve the drive capability of a semiconductor device. The semiconductor device includes a first transistor and a second transistor. A first terminal of the first transistor is electrically connected to a first wiring. A second terminal of the first transistor is electrically connected to a second wiring. A gate of the second transistor is electrically connected to a third wiring. A first terminal of the second transistor is electrically connected to the third wiring. A second terminal of the second transistor is electrically connected to a gate of the first transistor. A channel region is formed using an oxide semiconductor layer in each of the first transistor and the second transistor. The off-state current of each of the first transistor and the second transistor per channel width of 1 μm is 1 aA or less.

Claims

1. A semiconductor device comprising:

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor; and

a sixth transistor,

wherein a first terminal of the first transistor is directly connected to a first wiring,

wherein a gate of the first transistor is directly connected to a first terminal of the second transistor,

wherein a second terminal of the second transistor is directly connected to the first wiring,

wherein a gate of the second transistor is directly connected to the first wiring,

wherein a first terminal of the third transistor is directly connected to a second terminal of the first transistor,

wherein a second terminal of the third transistor is directly connected to a second wiring,

wherein a gate of the third transistor is directly connected to a gate of the fourth transistor,

wherein a first terminal of the fourth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the fourth transistor is directly connected to the second wiring,

wherein a first terminal of the fifth transistor is directly connected to the second terminal of the first transistor,

wherein a second terminal of the fifth transistor is directly connected to the second wiring,

wherein a first terminal of the sixth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the sixth transistor is directly connected to the second wiring, and

wherein a channel width of the third transistor is larger than a channel width of the fourth transistor.

2. The semiconductor device according to claim 1,

wherein the second terminal of the first transistor is directly connected to a third wiring.

3. The semiconductor device according to claim 1,

wherein a gate of the third transistor is directly connected to a fourth wiring.

4. The semiconductor device according to claim 1,

wherein a gate of the fifth transistor is directly connected to a fifth wiring.

5. The semiconductor device according to claim 1,

wherein each of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor comprises an oxide semiconductor layer comprising a channel formation region.

6. An electronic device comprising the semiconductor device according to claim 1.

7. A display device comprising:

a pixel portion formed over a substrate; and

a gate driver circuit formed over the substrate, the gate driver circuit comprising;

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor; and

a sixth transistor,

wherein a first terminal of the first transistor is directly connected to a first wiring,

wherein a gate of the first transistor is directly connected to a first terminal of the second transistor,

wherein a second terminal of the second transistor is directly connected to the first wiring,

wherein a gate of the second transistor is directly connected to the first wiring,

wherein a first terminal of the third transistor is directly connected to a second terminal of the first transistor,

wherein a second terminal of the third transistor is directly connected to a second wiring,

wherein a gate of the third transistor is directly connected to a gate of the fourth transistor,

wherein a first terminal of the fourth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the fourth transistor is directly connected to the second wiring,

wherein a first terminal of the fifth transistor is directly connected to the second terminal of the first transistor,

wherein a second terminal of the fifth transistor is directly connected to the second wiring,

wherein a first terminal of the sixth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the sixth transistor is directly connected to the second wiring, and

wherein a channel width of the third transistor is larger than a channel width of the fourth transistor.

8. The display device according to claim 7,

wherein the second terminal of the first transistor is directly connected to a third wiring.

9. The display device according to claim 7,

wherein a gate of the third transistor is directly connected to a fourth wiring.

10. The display device according to claim 7,

wherein a gate of the fifth transistor is directly connected to a fifth wiring.

11. The display device according to claim 7,

wherein each of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor comprises an oxide semiconductor layer comprising a channel formation region.

12. An electronic device comprising the display device according to claim 7.

13. A display device comprising:

a pixel portion formed over a substrate;

a first gate driver circuit formed over the substrate, the first gate driver circuit configured to output a gate signal to a wiring; and

a second gate driver circuit formed over the substrate, the second gate driver circuit configured to output the gate signal to the wiring,

wherein each of the first gate driver circuit and the second gate driver circuit comprising;

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor; and

a sixth transistor,

wherein a first terminal of the first transistor is directly connected to a first wiring,

wherein a gate of the first transistor is directly connected to a first terminal of the second transistor,

wherein a second terminal of the second transistor is directly connected to the first wiring,

wherein a gate of the second transistor is directly connected to the first wiring,

wherein a first terminal of the third transistor is directly connected to a second terminal of the first transistor,

wherein a second terminal of the third transistor is directly connected to a second wiring,

wherein a gate of the third transistor is directly connected to a gate of the fourth transistor,

wherein a first terminal of the fourth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the fourth transistor is directly connected to the second wiring,

wherein a first terminal of the fifth transistor is directly connected to the second terminal of the first transistor,

wherein a second terminal of the fifth transistor is directly connected to the second wiring,

wherein a first terminal of the sixth transistor is directly connected to the gate of the first transistor,

wherein a second terminal of the sixth transistor is directly connected to the second wiring, and

wherein a channel width of the third transistor is larger than a channel width of the fourth transistor.

14. The display device according to claim 13,

wherein the second terminal of the first transistor is directly connected to a third wiring.

15. The display device according to claim 13,

wherein a gate of the third transistor is directly connected to a fourth wiring.

16. The display device according to claim 13,

wherein a gate of the fifth transistor is directly connected to a fifth wiring.

17. The display device according to claim 13,

wherein each of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor comprises an oxide semiconductor layer comprising a channel formation region.

18. An electronic device comprising the display device according to claim 13.