SEMICONDUCTOR DEVICE AND DISPLAY DEVICE INCLUDING THE SEMICONDUCTOR DEVICE

• US 20170301699A1
• Filed: 03/28/2017
• Published: 10/19/2017
• Est. Priority Date: 04/13/2016
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, OKAZAKI, Kenichi, KUROSAKI, Daisuke, NAKAZAWA, Yasutaka
• Application Number:
  US15/471,368
• Publication Number:
  US 20170301699A1
• Time in Patent Office: Days
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/78648 arranged on opposing sides of the channel
• 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

Abstract

To improve field-effect mobility and reliability of a transistor including an oxide semiconductor film. A semiconductor device includes an oxide semiconductor film, a gate electrode, an insulating film over the gate electrode, the oxide semiconductor film over the insulating film, and a pair of electrodes over the oxide semiconductor film. The oxide semiconductor film includes a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film. The first oxide semiconductor film and the second oxide semiconductor film, include the same element. The first oxide semiconductor film includes a region having lower crystallinity than the second oxide semiconductor film.

Claims

1. A semiconductor device comprising:

a gate electrode;

an insulating film over the gate electrode;

an oxide semiconductor film over the insulating film; and

a pair of electrodes over the oxide semiconductor film,

wherein the oxide semiconductor film includes a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film,

wherein the first oxide semiconductor film and the second oxide semiconductor film each independently include In, M, and Zn,

wherein the M is Al, Ga, Y, or Sn,

wherein the first oxide semiconductor film includes a region having lower crystallinity than the second oxide semiconductor film,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn is higher than or equal to 1.5 and lower than or equal to 2.5 when an atomic ratio of the In is 4, and

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn is higher than or equal to 2 and lower than or equal to 4 when the atomic ratio of the In is 4.

2. The semiconductor device according to claim 1,

wherein the atomic ratio between the In, the M, and the Zn is In:

M;

Zn=4;

2;

3 or in its neighborhood.

3. A semiconductor device according to claim 1,

wherein the second oxide semiconductor film includes a crystal part, and

wherein the crystal part has a c-axis alignment.

4. A display device comprising:

the semiconductor device according to claim 1; and

a display element.

5. An electronic device comprising:

the display device according to claim 4; and

an operation key or a battery.

6. A semiconductor device comprising:

a gate electrode;

an insulating film over the gate electrode;

an oxide semiconductor film over the insulating film; and

a pair of electrodes over the oxide semiconductor film,

wherein the oxide semiconductor film includes a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film,

wherein the first oxide semiconductor film and the second oxide semiconductor film each independently include In, M, and Zn,

wherein the M is Al, Ga, Y, or Sn,

wherein the first oxide semiconductor film includes a region having lower crystallinity than the second oxide semiconductor film,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn is higher than or equal to 0.5 and lower than or equal to 1.5 when an atomic ratio of the In is 5, and

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn is higher than or equal to 5 and lower than or equal to 7 when the atomic ratio of the In is 5.

7. The semiconductor device according to claim 6,

wherein the atomic ratio between the In, the M, and the Zn is In:

M;

Zn=5;

1;

6 or in its neighborhood.

8. A semiconductor device according to claim 6,

wherein the second oxide semiconductor film includes a crystal part, and

wherein the crystal part has a c-axis alignment.

9. A display device comprising:

the semiconductor device according to claim 6; and

a display element.

10. An electronic device comprising:

the display device according to claim 9; and

an operation key or a battery.

11. A semiconductor device comprising:

a gate electrode;

an insulating film over the gate electrode;

an oxide semiconductor film over the insulating film; and

a pair of electrodes over the oxide semiconductor film,

wherein the oxide semiconductor film includes a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film,

wherein the first oxide semiconductor film and the second oxide semiconductor film include the same element,

wherein an electron affinity of the first oxide semiconductor film is larger than an electron affinity of the second oxide semiconductor film,

wherein a difference between the electron affinity of the first oxide semiconductor film and the electron affinity of the second oxide semiconductor film is more than or equal to 0.15 eV and less than or equal to 2.0 eV, and

wherein the first oxide semiconductor film includes a region having lower crystallinity than the second oxide semiconductor film.

12. The semiconductor device according to claim 11,

wherein the first oxide semiconductor film and the second oxide semiconductor film each independently include In, M, and Zn, and

wherein the M is Al, Ga, Y, or Sn.

13. A semiconductor device according to claim 11,

wherein the second oxide semiconductor film includes a crystal part, and

wherein the crystal part has a c-axis alignment.

14. A display device comprising:

the semiconductor device according to claim 11; and

a display element.

15. An electronic device comprising:

the display device according to claim 14; and

an operation key or a battery.

16. A semiconductor device comprising:

a gate electrode;

an insulating film over the gate electrode;

an oxide semiconductor film over the insulating film; and

a pair of electrodes over the oxide semiconductor film,

wherein the oxide semiconductor film includes a first oxide semiconductor film and a second oxide semiconductor film over the first oxide semiconductor film,

wherein the first oxide semiconductor film and the second oxide semiconductor film each independently include In, M, and Zn,

wherein the M is Al, Ga, Y, or Sn,

wherein an atomic ratio of the In to the Zn in the first oxide semiconductor film is higher than an atomic ratio of the In to the Zn in the second oxide semiconductor film, and

wherein the first oxide semiconductor film includes a region having lower crystallinity than the second oxide semiconductor film.

17. The semiconductor device according to claim 16,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn in the first oxide semiconductor film is higher than or equal to 1.5 and lower than or equal to 2.5 when an atomic ratio of the In is 4,

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn in the first oxide semiconductor film is higher than or equal to 2 and lower than or equal to 4 when the atomic ratio of the In is 4,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn in the second oxide semiconductor film is higher than or equal to 0.5 and lower than or equal to 1.5 when an atomic ratio of the In is 1, and

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn in the second oxide semiconductor film is higher than or equal to 0.1 and lower than or equal to 2 when the atomic ratio of the In is 1.

18. The semiconductor device according to claim 17,

wherein the atomic ratio between the In, the M, and the Zn in the first oxide semiconductor film is In:

M;

Zn=4;

2;

3 or in its neighborhood, and

wherein the atomic ratio between the In, the M, and the Zn in the second oxide semiconductor film is In;

M;

Zn=1;

1;

1 or in its neighborhood.

19. The semiconductor device according to claim 16,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn in the first oxide semiconductor film is higher than or equal to 1.5 and lower than or equal to 2.5 when an atomic ratio of the In is 4,

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn in the first oxide semiconductor film is higher than or equal to 2 and lower than or equal to 4 when the atomic ratio of the In is 4,

wherein an atomic ratio of the M to a total sum of the In, the M, and the Zn in the second oxide semiconductor film is higher than or equal to 0.5 and lower than or equal to 1.5 when an atomic ratio of the In is 5, and

wherein an atomic ratio of the Zn to the total sum of the In, the M, and the Zn in the second oxide semiconductor film is higher than or equal to 5 and lower than or equal to 7 when the atomic ratio of the In is 5.

20. The semiconductor device according to claim 19,

wherein the atomic ratio between the In, the M, and the Zn in the first oxide semiconductor film is In:

M;

Zn=4;

2;

3 or in its neighborhood, and

wherein the atomic ratio between the In, the M, and the Zn in the second oxide semiconductor film is In;

M;

Zn=5;

1;

6 or in its neighborhood.

21. The semiconductor device according to claim 16,

wherein the first oxide semiconductor film includes a composite oxide semiconductor including a first region and a second region,

wherein the first region includes a plurality of first clusters,

wherein the plurality of first clusters includes one or both of the In and the Zn as its main component,

wherein the second region includes a plurality of second clusters,

wherein the plurality of second clusters includes one or more selected from the In, the M, and the Zn as its main component,

wherein the M is Al, Ga, Y, or Sn,

wherein the plurality of first clusters is connected to each other, and

wherein the plurality of second clusters is connected to each other.

22. A semiconductor device according to claim 16,

wherein the second oxide semiconductor film includes a crystal part, and

wherein the crystal part has a c-axis alignment.

23. A display device comprising:

the semiconductor device according to claim 16; and

a display element.

24. An electronic device comprising:

the display device according to claim 23; and

an operation key or a battery.