SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110062435A1
• Filed: 09/13/2010
• Published: 03/17/2011
• Est. Priority Date: 09/16/2009
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: GODO, Hiromichi, YAMAZAKI, Shunpei, TSUBUKU, Masashi
• Application Number:
  US12/880,286
• Publication Number:
  US 20110062435A1
• Time in Patent Office: Days
• US Class Current: 257/43
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

It is an object to provide a highly reliable thin film transistor with stable electric characteristics, which includes an oxide semiconductor film. The channel length of the thin film transistor including the oxide semiconductor film is in the range of 1.5 μm to 100 μm inclusive, preferably 3 μm to 10 μm inclusive; when the amount of change in threshold voltage is less than or equal to 3 V, preferably less than or equal to 1.5 V in an operation temperature range of room temperature to 180° C. inclusive or −25° C. to −150° C. inclusive, a semiconductor device with stable electric characteristics can be manufactured. In particular, in a display device which is an embodiment of the semiconductor device, display unevenness due to variation in threshold voltage can be reduced.

Claims

1. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating layer over the gate electrode layer;

an oxide semiconductor layer over the gate insulating layer;

a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and

a protective insulating layer in contact with a part of the oxide semiconductor layer, the source electrode layer, and the drain electrode layer,

wherein an amount of change in threshold voltage is less than or equal to 3 V in a temperature range of room temperature to 180°

C.

2. The semiconductor device according to claim 1, wherein a channel length of the oxide semiconductor layer is greater than or equal to 1.5 μ

m and less than or equal to 100 μ

m.

3. The semiconductor device according to claim 1, wherein a channel length of the oxide semiconductor layer is greater than or equal to 3 μ

m and less than or equal to 100 μ

m.

4. The semiconductor device according to claim 1, wherein the semiconductor device is one selected from the group consisting of an e-book reader, a television set, a digital photo frame, a game machine, a computer and a mobile phone.

5. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating layer over the gate electrode layer;

an oxide semiconductor layer over the gate insulating layer;

a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and

a protective insulating layer in contact with a part of the oxide semiconductor layer, the source electrode layer, and the drain electrode layer,

wherein an amount of change in threshold voltage is less than or equal to 1.5 V in a temperature range of room temperature to 180°

C.

6. The semiconductor device according to claim 5, wherein a channel length of the oxide semiconductor layer is greater than or equal to 1.5 μ

m and less than or equal to 100 μ

m.

7. The semiconductor device according to claim 5, wherein a channel length of the oxide semiconductor layer is greater than or equal to 3 μ

m and less than or equal to 100 μ

m.

8. The semiconductor device according to claim 5, wherein the semiconductor device is one selected from the group consisting of an e-book reader, a television set, a digital photo frame, a game machine, a computer and a mobile phone.

9. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating layer over the gate electrode layer;

an oxide semiconductor layer over the gate insulating layer;

a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and

a protective insulating layer in contact with a part of the oxide semiconductor layer, the source electrode layer, and the drain electrode layer,

wherein an amount of change in threshold voltage is less than or equal to 3 V in a temperature range of −

25°

C. to 150°

C.

10. The semiconductor device according to claim 9, wherein a channel length of the oxide semiconductor layer is greater than or equal to 1.5 μ

m and less than or equal to 100 μ

m.

11. The semiconductor device according to claim 9, wherein a channel length of the oxide semiconductor layer is greater than or equal to 3 μ

m and less than or equal to 100 μ

m.

12. The semiconductor device according to claim 9, wherein the semiconductor device is one selected from the group consisting of an e-book reader, a television set, a digital photo frame, a game machine, a computer and a mobile phone.

13. A semiconductor device comprising:

a gate electrode layer over a substrate having an insulating surface;

a gate insulating layer over the gate electrode layer;

an oxide semiconductor layer over the gate insulating layer;

a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and

a protective insulating layer in contact with a part of the oxide semiconductor layer, the source electrode layer, and the drain electrode layer,

wherein an amount of change in threshold voltage is less than or equal to 1.5 V in a temperature range of −

25°

C. to 150°

C.

14. The semiconductor device according to claim 13, wherein a channel length of the oxide semiconductor layer is greater than or equal to 1.5 μ

m and less than or equal to 100 μ

m.

15. The semiconductor device according to claim 13, wherein a channel length of the oxide semiconductor layer is greater than or equal to 3 μ

m and less than or equal to 100 μ

m.

16. The semiconductor device according to claim 13, wherein the semiconductor device is one selected from the group consisting of an e-book reader, a television set, a digital photo frame, a game machine, a computer and a mobile phone.

17. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode layer over a substrate having an insulating surface;

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer over the gate insulating layer;

performing a first heat treatment after forming the oxide semiconductor layer;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer;

forming a protective insulating layer in contact with a part of the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and

performing a second heat treatment after forming the protective insulating layer,

wherein the second heat treatment is performed at a lower temperature than the first heat treatment.

18. The method for manufacturing a semiconductor device according to claim 17, wherein the first heat treatment is performed at a temperature of greater than or equal to 350°

C. and less than or equal to 750°

C.

19. The method for manufacturing a semiconductor device according to claim 17, wherein the first heat treatment is performed in a nitrogen atmosphere or a rare gas atmosphere.

20. The method for manufacturing a semiconductor device according to claim 17, wherein the second heat treatment is performed at a temperature of greater than or equal to 100°

C. and less than or equal to the temperature of the first heat treatment.

21. The method for manufacturing a semiconductor device according to claim 17, wherein the second heat treatment is performed in air, an oxygen atmosphere, a nitrogen atmosphere, or a rare gas atmosphere.