SEMICONDUCTOR DEVICE

• US 20150187952A1
• Filed: 12/23/2014
• Published: 07/02/2015
• Est. Priority Date: 12/27/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Tanaka, Tetsuhiro, Suzawa, Hideomi, Yamane, Yasumasa, Sato, Yuhei, Tezuka, Sachiaki
• Granted Patent: US 9,472,678 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/088 the components being field-effect transistors with insulated gate
• CPC Class Codes: H01L 27/0886 including transistors with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• 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 29/16 including, apart from doping materials or other impurities, only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

To provide a transistor with stable electrical characteristics, a transistor with a low off-state current, a transistor with a high on-state current, a semiconductor device including the transistor, or a durable semiconductor device. The semiconductor device includes a first transistor using silicon, an aluminum oxide film over the first transistor, and a second transistor using an oxide semiconductor over the aluminum oxide film. The oxide semiconductor has a lower hydrogen concentration than silicon.

Claims

1. A semiconductor device comprising:

a first transistor comprising silicon;

an aluminum oxide film over the first transistor; and

a second transistor comprising an oxide semiconductor over the aluminum oxide film,

wherein the oxide semiconductor has a lower hydrogen concentration than the silicon.

2. The semiconductor device according to claim 1, wherein the aluminum oxide film includes a region with a density of lower than 3.2 g/cm³ measured by an X-ray reflectivity method.

3. The semiconductor device according to claim 1, wherein a concentration of hydrogen in the oxide semiconductor is lower than or equal to 1×

10¹⁹ atoms/cm³.

4. The semiconductor device according to claim 1, further comprising an insulator containing excess hydrogen between the first transistor and the aluminum oxide film.

5. The semiconductor device according to claim 1, further comprising an insulator containing excess oxygen between the aluminum oxide film and the second transistor.

6. The semiconductor device according to claim 1, further comprising a conductor between the aluminum oxide film and the second transistor,

wherein the conductor has a stacked-layer structure comprising a layer containing oxide or oxynitride.

7. The semiconductor device according to claim 1, wherein the aluminum oxide film has a function of blocking oxygen and hydrogen.

8. The semiconductor device according to claim 1, further comprising an insulator having a function of blocking oxygen and hydrogen over the second transistor,

wherein the aluminum oxide film and the insulator having the function of blocking oxygen and hydrogen are in contact with each other.

9. A semiconductor device comprising:

a first transistor comprising silicon;

an aluminum oxide film over the first transistor; and

a second transistor over the aluminum oxide film, the second transistor comprising;

a first conductor over the aluminum oxide film;

a first insulator over the first conductor;

a first oxide semiconductor over the first insulator;

a second oxide semiconductor over the first oxide semiconductor;

a second conductor and a third conductor over the second oxide semiconductor;

a third oxide semiconductor over the second conductor and the third conductor;

a second insulator over the third conductor; and

a fourth conductor over the third conductor,

wherein each of the first oxide semiconductor, the second oxide semiconductor, and the third oxide semiconductor has a lower hydrogen concentration than the silicon.

10. The semiconductor device according to claim 9, wherein the aluminum oxide film includes a region with a density of lower than 3.2 g/cm³ measured by an X-ray reflectivity method.

11. The semiconductor device according to claim 9, wherein a concentration of hydrogen in the second oxide semiconductor is lower than or equal to 1×

10¹⁹ atoms/cm³.

12. The semiconductor device according to claim 9, further comprising an insulator containing excess hydrogen between the first transistor and the aluminum oxide film.

13. The semiconductor device according to claim 9, further comprising an insulator containing excess oxygen between the aluminum oxide film and the second transistor.

14. The semiconductor device according to claim 9, wherein the aluminum oxide film has a function of blocking oxygen and hydrogen.

15. The semiconductor device according to claim 9, further comprising an insulator having a function of blocking oxygen and hydrogen over the second transistor,

wherein the aluminum oxide film and the insulator having the function of blocking oxygen and hydrogen are in contact with each other.

16. A semiconductor device comprising:

a first transistor comprising silicon;

an aluminum oxide film over the first transistor; and

a second transistor over the aluminum oxide film, the second transistor comprising;

a first conductor over the aluminum oxide film;

a first insulator over the first conductor, the first insulator having a projection portion;

a first oxide semiconductor over the first insulator, the first oxide semiconductor in contact with a top surface of the projection portion;

a second oxide semiconductor over the first oxide semiconductor;

a second conductor and a third conductor over the second oxide semiconductor;

a third oxide semiconductor over the second conductor and the third conductor;

a second insulator over the third conductor; and

a fourth conductor over the third conductor,

wherein each of the first oxide semiconductor, the second oxide semiconductor, and the third oxide semiconductor has a lower hydrogen concentration than the silicon, and

wherein the third oxide semiconductor is in contact with a side surface of the first oxide semiconductor, a top surface and a side surface of the second oxide semiconductor, and a side surface of the projection portion.

17. The semiconductor device according to claim 16, wherein the aluminum oxide film includes a region with a density of lower than 3.2 g/cm³ measured by an X-ray reflectivity method.

18. The semiconductor device according to claim 16, wherein a concentration of hydrogen in the second oxide semiconductor is lower than or equal to 1×

10¹⁹ atoms/cm³.

19. The semiconductor device according to claim 16, further comprising an insulator containing excess hydrogen between the first transistor and the aluminum oxide film.

20. The semiconductor device according to claim 16, further comprising an insulator containing excess oxygen between the aluminum oxide film and the second transistor.

21. The semiconductor device according to claim 16, wherein the aluminum oxide film has a function of blocking oxygen and hydrogen.

22. The semiconductor device according to claim 16, further comprising an insulator having a function of blocking oxygen and hydrogen over the second transistor,

wherein the aluminum oxide film and the insulator having the function of blocking oxygen and hydrogen are in contact with each other.