Semiconductor device, display device, input/output device, and electronic device

• US 9,859,444 B2
• Filed: 04/18/2017
• Issued: 01/02/2018
• Est. Priority Date: 03/07/2014
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Suzawa, Hideomi, Jintyou, Masami
• Primary Examiner(s): Kebede, Brook
• Application Number:
  US15/490,433
• Publication Number:
  US 20170222057A1
• Time in Patent Office: 259 Days
• Field of Search: 257 43, 257 57, 257 66, 438149-159
• 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 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/42364 characterised by the insulating layer, e.g. thickness or uniformity H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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: H10K 59/1213 the pixel elements being TFTs

Abstract

A self-aligned transistor including an oxide semiconductor film, which has excellent and stable electrical characteristics, is provided. A semiconductor device is provided with a transistor that includes an oxide semiconductor film, a gate electrode overlapping with part of the oxide semiconductor film, and a gate insulating film between the oxide semiconductor film and the gate electrode. The oxide semiconductor film includes a first region and second regions between which the first region is positioned. The second regions include an impurity element. A side of the gate insulating film has a depressed region. Part of the gate electrode overlaps with parts of the second regions in the oxide semiconductor film.

Claims

1. A semiconductor device comprising:

an oxide semiconductor film;

a gate electrode; and

a gate insulating film between the oxide semiconductor film and the gate electrode,

wherein the gate insulating film has a side region that is more on the inside than at least part of a side of the gate electrode.

2. The semiconductor device according to claim 1,

wherein the oxide semiconductor film comprises a first region, a second region, and a third region,

wherein the first region is between the second region and the third region, and

wherein each of the second region and the third region contains an impurity element.

3. The semiconductor device according to claim 2,

wherein each of the second region and the third region has a region in contact with an insulating film containing hydrogen.

4. The semiconductor device according to claim 3,

wherein the insulating film containing hydrogen further contains nitrogen.

5. The semiconductor device according to claim 3,

wherein the insulating film containing hydrogen is a silicon nitride film.

6. The semiconductor device according to claim 2,

wherein the second region and the third region each have a region with a higher impurity concentration than that in the first region in the oxide semiconductor film.

7. The semiconductor device according to claim 2,

wherein each of the second region and the third region contains, as the impurity element, one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.

8. The semiconductor device according to claim 2,

wherein each of the second region and the third region contains, as the impurity element, hydrogen and one or more of a rare gas, boron, nitrogen, fluorine, aluminum, and phosphorus.

9. The semiconductor device according to claim 2,

wherein the gate electrode contains the same metal element as that in the oxide semiconductor film.

10. The semiconductor device according to claim 9,

wherein the gate electrode comprises a conductive oxide semiconductor film.

11. The semiconductor device according to claim 1,

wherein the gate insulating film comprises a first insulating film and a second insulating film,

wherein the first insulating film is in contact with the oxide semiconductor film,

wherein the first insulating film contains oxygen,

wherein the second insulating film is in contact with the first insulating film and the gate electrode,

wherein the second insulating film contains nitrogen, and

wherein the second insulating film has a side region that is more on the inside than at least part of a side of the gate electrode.

12. The semiconductor device according to claim 2, further comprising an insulating film over the gate electrode,

wherein the gate electrode has regions overlapping with the second region and the third region in the oxide semiconductor film, with part of the gate insulating film sandwiched therebetween.

24. A display device comprising:

the semiconductor device according to claim 1; and

a pixel electrode electrically connected to the semiconductor device.

25. An input/output device comprising:

the semiconductor device according to claim 1; and

an input device electrically connected to the semiconductor device.

26. An electronic device comprising:

the semiconductor device according to claim 1; and

a speaker or an operation key.

13. A semiconductor device comprising:

an oxide semiconductor film;

a gate electrode comprising a first conductive film and a second conductive film over the first conductive film; and

a gate insulating film between the oxide semiconductor film and the gate electrode,

wherein the gate insulating film has a side region that is more on the inside than at least part of a side of the first conductive film.

14. The semiconductor device according to claim 13,

wherein the oxide semiconductor film comprises a first region, a second region, and a third region,

wherein the first region is between the second region and the third region, and

wherein each of the second region and the third region contains an impurity element.

15. The semiconductor device according to claim 14,

wherein each of the second region and the third region has a region in contact with an insulating film containing hydrogen.

16. The semiconductor device according to claim 15,

wherein the insulating film containing hydrogen further contains nitrogen.

17. The semiconductor device according to claim 15,

wherein the insulating film containing hydrogen is a silicon nitride film.

18. The semiconductor device according to claim 14,

wherein the second region and the third region each have a region with a higher impurity concentration than that in the first region in the oxide semiconductor film.

19. The semiconductor device according to claim 14,

wherein each of the second region and the third region contains, as the impurity element, one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.

20. The semiconductor device according to claim 14,

wherein each of the second region and the third region contains, as the impurity element, hydrogen and one or more of a rare gas, boron, nitrogen, fluorine, aluminum, and phosphorus.

21. The semiconductor device according to claim 14,

wherein the gate electrode contains the same metal element as that in the oxide semiconductor film.

22. The semiconductor device according to claim 21,

wherein the gate electrode comprises a conductive oxide semiconductor film.

23. The semiconductor device according to claim 14, further comprising an insulating film over the gate electrode,

wherein the gate electrode has regions overlapping with the second region and the third region in the oxide semiconductor film, with part of the gate insulating film sandwiched therebetween.

27. A display device comprising:

the semiconductor device according to claim 13; and

a pixel electrode electrically connected to the semiconductor device.

28. An input/output device comprising:

the semiconductor device according to claim 13; and

an input device electrically connected to the semiconductor device.

29. An electronic device comprising:

the semiconductor device according to claim 13; and

a speaker or an operation key.