Semiconductor device

• US 10,236,305 B2
• Filed: 08/15/2017
• Issued: 03/19/2019
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Miyake, Hiroyuki, Shishido, Hideaki, Koyama, Jun
• Primary Examiner(s): Tran, Thien F
• Application Number:
  US15/677,125
• Publication Number:
  US 20180026053A1
• Time in Patent Office: 581 Days
• Field of Search: None
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• 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

A semiconductor device including a capacitor whose charge capacity is increased while improving the aperture ratio is provided. Further, a semiconductor device which consumes less power is provided. A transistor which includes a light-transmitting semiconductor film, a capacitor in which a dielectric film is provided between a pair of electrodes, an insulating film which is provided over the light-transmitting semiconductor film, and a first light-transmitting conductive film which is provided over the insulating film are included. The capacitor includes the first light-transmitting conductive film which serves as one electrode, the insulating film which functions as a dielectric, and a second light-transmitting conductive film which faces the first light-transmitting conductive film with the insulating film positioned therebetween and functions as the other electrode. The second light-transmitting conductive film is formed over the same surface as the light-transmitting semiconductor film of the transistor and is a metal oxide film containing a dopant.

Claims

1. A semiconductor device comprising:

a first conductive film;

a gate insulating film over the first conductive film; and

a first metal oxide film over the gate insulating film;

a second metal oxide film over the gate insulating film;

a second conductive film over the first metal oxide film;

a third conductive film over the first metal oxide film;

an oxide insulating film over the first metal oxide film, the second conductive film and the third conductive film;

a nitride insulating film over the oxide insulating film; and

a pixel electrode over the nitride insulating film,

wherein the first metal oxide film includes a region overlapping the first conductive film,

wherein each of the second conductive film and the third conductive film is electrically connected to the first metal oxide film,

wherein the pixel electrode is electrically connected to the third conductive film,

wherein the pixel electrode includes a region overlapping the second metal oxide film with the nitride insulating film interposed therebetween,

wherein the first metal oxide film includes;

a third metal oxide film; and

a fourth metal oxide film over the third metal oxide film,

wherein each of the third metal oxide film and the fourth metal oxide film contains In, Ga and Zn,

wherein the third metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In≥

Ga, and

wherein the fourth metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In<

Ga.

2. The semiconductor device according to claim 1,

wherein the second metal oxide film is a light-transmitting conductive film, and

wherein the second metal oxide film is one electrode of a capacitor.

3. The semiconductor device according to claim 2,

wherein the light-transmitting conductive film contains a dopant in a higher concentration than the first metal oxide film.

4. The semiconductor device according to claim 2,

wherein the gate insulating film comprises a second nitride insulating film in contact with the light-transmitting conductive film.

5. The semiconductor device according to claim 2,

wherein the gate insulating film comprises a second nitride insulating film and a second oxide insulating film stacked on the second nitride insulating film,

wherein the second nitride insulating film is in contact with the light-transmitting conductive film, and

wherein the second oxide insulating film is in contact with the first metal oxide film.

6. The semiconductor device according to claim 2,

wherein the light-transmitting conductive film contains a higher concentration of hydrogen than the first metal oxide film.

7. The semiconductor device according to claim 2,

wherein the light-transmitting conductive film contains a higher concentration of nitrogen than the first metal oxide film.

8. The semiconductor device according to claim 2,

wherein the light-transmitting conductive film contains a dopant at a concentration greater than 1×

10¹⁹ atoms/cm³ and less than or equal to 1×

10²² atoms/cm³.

9. The semiconductor device according to claim 2, further comprising a capacitor line,

wherein the light-transmitting conductive film is in direct contact with the capacitor line.

10. A display device comprising the semiconductor device according to claim 1.

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

12. A semiconductor device comprising:

a first conductive film;

a gate insulating film over the first conductive film; and

a first metal oxide film over the gate insulating film;

a second metal oxide film over the gate insulating film;

a second conductive film over the first metal oxide film;

a third conductive film over the first metal oxide film;

a fourth conductive film over the second metal oxide film; and

a pixel electrode over the third conductive film,

wherein the first metal oxide film includes a region overlapping the first conductive film,

wherein each of the second conductive film and the third conductive film is electrically connected to the first metal oxide film,

wherein the fourth conductive film is electrically connected to the second metal oxide film,

wherein the pixel electrode is electrically connected to the third conductive film,

wherein the pixel electrode includes a region overlapping the second metal oxide film with a nitride insulating film interposed therebetween,

wherein each of the second conductive film, the third conductive film and the fourth conductive film has a same conductive material,

wherein the first metal oxide film includes;

a third metal oxide film; and

a fourth metal oxide film over the third metal oxide film,

wherein each of the third metal oxide film and the fourth metal oxide film contains In, Ga and Zn,

wherein the third metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In≥

Ga, and

wherein the fourth metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In<

Ga.

13. The semiconductor device according to claim 12,

wherein the second metal oxide film is a light-transmitting conductive film, and

wherein the second metal oxide film is one electrode of a capacitor.

14. The semiconductor device according to claim 13,

wherein the light-transmitting conductive film contains a dopant in a higher concentration than the first metal oxide film.

15. The semiconductor device according to claim 13,

wherein the gate insulating film comprises a second nitride insulating film in contact with the light-transmitting conductive film.

16. The semiconductor device according to claim 13,

wherein the gate insulating film comprises a second nitride insulating film and a second oxide insulating film stacked on the second nitride insulating film,

wherein the second nitride insulating film is in contact with the light-transmitting conductive film, and

wherein the second oxide insulating film is in contact with the first metal oxide film.

17. The semiconductor device according to claim 13,

wherein the light-transmitting conductive film contains a higher concentration of hydrogen than the first metal oxide film.

18. The semiconductor device according to claim 13,

wherein the light-transmitting conductive film contains a higher concentration of nitrogen than the first metal oxide film.

19. The semiconductor device according to claim 13,

wherein the light-transmitting conductive film contains a dopant at a concentration greater than 1×

10¹⁹ atoms/cm³ and less than or equal to 1×

10²² atoms/cm³.

20. The semiconductor device according to claim 13, further comprising a capacitor line,

wherein the light-transmitting conductive film is in direct contact with the capacitor line.

21. A display device comprising the semiconductor device according to claim 12.

22. An electronic device comprising the semiconductor device according to claim 12.

23. A semiconductor device comprising:

a first conductive film;

a gate insulating film over the first conductive film; and

a first metal oxide film over the gate insulating film;

a second metal oxide film over the gate insulating film;

a second conductive film over the first metal oxide film;

a third conductive film over the first metal oxide film;

a fourth conductive film over the second metal oxide film;

an oxide insulating film over the first metal oxide film, the second conductive film, the third conductive film and the fourth conductive film;

a nitride insulating film over the oxide insulating film; and

a pixel electrode over the nitride insulating film,

wherein the first metal oxide film includes a region overlapping the first conductive film,

wherein each of the second conductive film and the third conductive film is electrically connected to the first metal oxide film,

wherein the fourth conductive film is electrically connected to the second metal oxide film,

wherein the pixel electrode is electrically connected to the third conductive film,

wherein the pixel electrode includes a region overlapping the second metal oxide film with the nitride insulating film interposed therebetween,

wherein each of the second conductive film, the third conductive film and the fourth conductive film has a same conductive material,

wherein the first metal oxide film includes;

a third metal oxide film; and

a fourth metal oxide film over the third metal oxide film,

wherein each of the third metal oxide film and the fourth metal oxide film contains In, Ga and Zn,

wherein the third metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In≥

Ga, and wherein the fourth metal oxide film includes a region where an atomic ratio of In to Ga satisfies a relation In<

Ga.

24. The semiconductor device according to claim 23,

wherein the second metal oxide film is a light-transmitting conductive film, and

wherein the second metal oxide film is one electrode of a capacitor.

25. The semiconductor device according to claim 24,

wherein the light-transmitting conductive film contains a dopant in a higher concentration than the first metal oxide film.

26. The semiconductor device according to claim 24,

wherein the gate insulating film comprises a second nitride insulating film in contact with the light-transmitting conductive film.

27. The semiconductor device according to claim 24,

wherein the gate insulating film comprises a second nitride insulating film and a second oxide insulating film stacked on the second nitride insulating film,

wherein the second nitride insulating film is in contact with the light-transmitting conductive film, and

wherein the second oxide insulating film is in contact with the first metal oxide film.

28. The semiconductor device according to claim 24,

wherein the light-transmitting conductive film contains a higher concentration of hydrogen than the first metal oxide film.

29. The semiconductor device according to claim 24,

wherein the light-transmitting conductive film contains a higher concentration of nitrogen than the first metal oxide film.

30. The semiconductor device according to claim 24,

wherein the light-transmitting conductive film contains a dopant at a concentration greater than 1×

10¹⁹ atoms/cm³ and less than or equal to 1×

10²² atoms/cm³.

31. The semiconductor device according to claim 24, further comprising a capacitor line,

wherein the light-transmitting conductive film is in direct contact with the capacitor line.

32. A display device comprising the semiconductor device according to claim 23.

33. An electronic device comprising the semiconductor device according to claim 23.