SEMICONDUCTOR DEVICE

• US 20110278564A1
• Filed: 05/05/2011
• Published: 11/17/2011
• Est. Priority Date: 05/14/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yoneda, Seiichi
• Granted Patent: US 8,664,658 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 21/823807 with a particular manufacturing method of the channel structures, e.g. channel implants, halo or pocket implants, or channel materials
• CPC Class Codes: H01L 21/8258 the substrate being a semiconductor, using a combination of technologies covered by H01L21/8206, H01L21/8213 , H01L21/822, H01L21/8252, H01L21/8254 or H01L21/8256
• CPC Class Codes: H01L 27/0605 integrated circuits made of compound material, e.g. AIIIBV
• 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 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1229 with different crystal properties within a device or between different devices
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs

Abstract

An n-channel transistor or a p-channel transistor provided with a second gate electrode for controlling a threshold voltage in addition to a normal gate electrode is used for a complementary logic circuit. In addition, an insulated gate field-effect transistor with an extremely low off-state current is used as a switching element to control the potential of the second gate electrode. A channel formation region of the transistor which functions as a switching element includes a semiconductor material whose band gap is wider than that of a silicon semiconductor and whose intrinsic carrier density is lower than that of silicon.

Claims

1. A semiconductor device comprising:

an n-channel transistor;

a p-channel transistor; and

a transistor containing, in a channel formation region, a semiconductor material whose band gap is wider than that of silicon and whose intrinsic carrier density is lower than that of silicon,

wherein the n-channel transistor and the p-channel transistor are connected to each other in series,

wherein a logical value of a signal supplied to a first gate electrode included in the n-channel transistor accords with a logical value of a signal supplied to a first gate electrode included in the p-channel transistor,

wherein the n-channel transistor or the p-channel transistor includes a second gate electrode which faces the first gate electrode with a channel formation region provided between the first gate electrode and the second gate electrode, and

wherein supply of a potential to the second gate electrode is controlled by the transistor.

2. The semiconductor device according to claim 1, wherein the semiconductor material is an oxide semiconductor.

3. The semiconductor device according to claim 2, wherein the oxide semiconductor is an In—

Ga—

Zn—

O-based oxide semiconductor.

4. The semiconductor device according to claim 1, wherein a hydrogen concentration in the channel formation region is less than or equal to 5×

10¹⁹ atoms/cm³.

5. The semiconductor device according to claim 1, wherein a value obtained by dividing an off-state current by a channel width of the transistor is lower than or equal to 100 zA/μ

m.

6. The semiconductor device according to claim 1,

wherein the n-channel transistor and the p-channel transistor are connected between a first node to which a first potential is supplied and a second node to which a second potential is supplied, and

wherein the first potential is higher than the second potential.

7. A semiconductor device comprising:

an n-channel transistor;

a p-channel transistor; and

a transistor containing, in a channel formation region, a semiconductor material whose band gap is wider than that of silicon and whose intrinsic carrier density is lower than that of silicon,

wherein the n-channel transistor and the p-channel transistor are connected to each other in series,

wherein a logical value of a signal supplied to a first gate electrode included in the n-channel transistor accords with a logical value of a signal supplied to a first gate electrode included in the p-channel transistor,

wherein the n-channel transistor or the p-channel transistor includes a second gate electrode which faces the first gate electrode with a channel formation region provided between the first gate electrode and the second gate electrode,

wherein supply of a potential to the second gate electrode is controlled by the transistor, and

wherein silicon or germanium is used for the channel formation region of the n-channel transistor and the p-channel transistor.

8. The semiconductor device according to claim 7, wherein the semiconductor material is an oxide semiconductor.

9. The semiconductor device according to claim 8, wherein the oxide semiconductor is an In—

Ga—

Zn—

O-based oxide semiconductor.

10. The semiconductor device according to claim 7, wherein a hydrogen concentration in the channel formation region is less than or equal to 5×

10¹⁹ atoms/cm³.

11. The semiconductor device according to claim 7, wherein a value obtained by dividing an off-state current by a channel width of the transistor is lower than or equal to 100 zA/μ

m.

12. The semiconductor device according to claim 7,

wherein the n-channel transistor and the p-channel transistor are connected between a first node to which a first potential is supplied and a second node to which a second potential is supplied, and

wherein the first potential is higher than the second potential.

13. A semiconductor device comprising:

an n-channel transistor;

a p-channel transistor; and

a transistor containing, in a channel formation region, a semiconductor material whose band gap is wider than that of silicon and whose intrinsic carrier density is lower than that of silicon,

wherein the n-channel transistor and the p-channel transistor are connected to each other in series,

wherein a logical value of a signal supplied to a first gate electrode included in the n-channel transistor accords with a logical value of a signal supplied to a first gate electrode included in the p-channel transistor, and

wherein a substrate potential of the n-channel transistor or the p-channel transistor is controlled by the transistor.

14. The semiconductor device according to claim 13, wherein the semiconductor material is an oxide semiconductor.

15. The semiconductor device according to claim 14, wherein the oxide semiconductor is an In—

Ga—

Zn—

O-based oxide semiconductor.

16. The semiconductor device according to claim 13, wherein a hydrogen concentration in the channel formation region is less than or equal to 5×

10¹⁹ atoms/cm³.

17. The semiconductor device according to claim 13, wherein a value obtained by dividing an off-state current by a channel width of the transistor is lower than or equal to 100 zA/μ

m.

18. The semiconductor device according to claim 13,

wherein the n-channel transistor and the p-channel transistor are connected between a first node to which a first potential is supplied and a second node to which a second potential is supplied, and

wherein the first potential is higher than the second potential.

19. A semiconductor device comprising:

an n-channel transistor;

a p-channel transistor; and

a transistor containing, in a channel formation region, a semiconductor material whose band gap is wider than that of silicon and whose intrinsic carrier density is lower than that of silicon,

wherein the n-channel transistor and the p-channel transistor are connected to each other in series,

wherein a logical value of a signal supplied to a first gate electrode included in the n-channel transistor accords with a logical value of a signal supplied to a first gate electrode included in the p-channel transistor,

wherein a substrate potential of the n-channel transistor or the p-channel transistor is controlled by the transistor, and

wherein silicon or germanium is used for the channel formation region of the n-channel transistor and the p-channel transistor.

20. The semiconductor device according to claim 19, wherein the semiconductor material is an oxide semiconductor.

21. The semiconductor device according to claim 20, wherein the oxide semiconductor is an In—

Ga—

Zn—

O-based oxide semiconductor.

22. The semiconductor device according to claim 19, wherein a hydrogen concentration in the channel formation region is less than or equal to 5×

10¹⁹ atoms/cm³.

23. The semiconductor device according to claim 19, wherein a value obtained by dividing an off-state current by a channel width of the transistor is lower than or equal to 100 zA/μ

m.

24. The semiconductor device according to claim 19,

wherein the n-channel transistor and the p-channel transistor are connected between a first node to which a first potential is supplied and a second node to which a second potential is supplied, and

wherein the first potential is higher than the second potential.

25. A semiconductor device comprising:

an n-channel transistor;

a p-channel transistor; and

a transistor containing, in a channel formation region, a semiconductor material whose band gap is wider than that of silicon and whose intrinsic carrier density is lower than that of silicon,

wherein the n-channel transistor and the p-channel transistor are connected to each other in series,

wherein a logical value of a signal supplied to a first gate electrode included in the n-channel transistor accords with a logical value of a signal supplied to a first gate electrode included in the p-channel transistor, and

wherein a threshold voltage of the n-channel transistor or the p-channel transistor is controlled by setting a potential supplied to a second gate electrode or a substrate potential of the n-channel transistor or the p-channel transistor.

26. The semiconductor device according to claim 25, wherein the semiconductor material is an oxide semiconductor.