SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20100065838A1
• Filed: 09/03/2009
• Published: 03/18/2010
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: AKIMOTO, Kengo, YAMAZAKI, Shunpei, UOCHI, Hideki, KOMORI, Shigeki
• Granted Patent: US 9,257,594 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• 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 29/66969 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/0041 characterised by field-effect operation

Abstract

An object is to provide a semiconductor device including a thin film transistor with excellent electrical characteristics and high reliability and a method for manufacturing the semiconductor device with high mass productivity. A main point is to form a low-resistance oxide semiconductor layer as a source or drain region after forming a drain or source electrode layer over a gate insulating layer and to form an oxide semiconductor film thereover as a semiconductor layer. It is preferable that an oxygen-excess oxide semiconductor layer be used as a semiconductor layer and an oxygen-deficient oxide semiconductor layer be used as a source region and a drain region.

Claims

1. A semiconductor device comprising a thin film transistor, the thin film transistor comprising:

a gate electrode layer;

a gate insulating layer over the gate electrode layer;

a source electrode layer and a drain electrode layer over the gate insulating layer;

a source region over the source electrode layer;

a drain region over the drain electrode layer; and

an oxide semiconductor layer over the gate insulating layer, the source electrode layer, the drain electrode layer, the source region, and the drain region,

wherein the oxide semiconductor layer overlaps the gate electrode layer with the gate insulating layer interposed therebetween and has a higher oxygen concentration than the source region and the drain region.

2. The semiconductor device according to claim 1, wherein the oxide semiconductor layer, the source region, and the drain region are oxide semiconductor layers containing indium, gallium, and zinc.

3. The semiconductor device according to claim 1, wherein the semiconductor device is incorporated into one selected from the group consisting of a television set, a digital photo frame, a game machine, and a mobile phone.

4. The semiconductor device according to claim 1, wherein the gate insulating layer comprises a material selected from the group consisting of silicon oxynitride, silicon nitride, aluminum oxide and tantalum oxide.

5. The semiconductor device according to claim 1, wherein the gate insulating layer has a thickness of 50 to 250 nm.

6. The semiconductor device according to claim 1, wherein the oxide semiconductor layer has a thickness of 5 to 200 nm.

7. A semiconductor device comprising a thin film transistor, the thin film transistor comprising:

a gate electrode layer;

a gate insulating layer over the gate electrode layer;

a first source region and a first drain region over the gate insulating layer;

a source electrode layer over the first source region;

a drain electrode layer over the first drain region;

a second source region over the source electrode layer;

a second drain region over the drain electrode layer; and

an oxide semiconductor layer over the gate insulating layer, the first source region, the first drain region, the source electrode layer, the drain electrode layer, the second source region, and the second drain region,

wherein the oxide semiconductor layer overlaps the gate electrode layer with the gate insulating layer interposed therebetween and has a higher oxygen concentration than the first source region, the first drain region, the second source region, and the second drain region.

8. The semiconductor device according to claim 7, wherein the oxide semiconductor layer, the first source region, the first drain region, the second source region, and the second drain region are oxide semiconductor layers containing indium, gallium, and zinc.

9. The semiconductor device according to claim 7, wherein the semiconductor device is incorporated into one selected from the group consisting of a television set, a digital photo frame, a game machine, and a mobile phone.

10. The semiconductor device according to claim 7, wherein the gate insulating layer comprises a material selected from the group consisting of silicon oxynitride, silicon nitride, aluminum oxide and tantalum oxide.

11. The semiconductor device according to claim 7, wherein the gate insulating layer has a thickness of 50 to 250 nm.

12. The semiconductor device according to claim 7, wherein the oxide semiconductor layer has a thickness of 5 to 200 nm.

13. A method for manufacturing a semiconductor device, comprising:

forming a gate electrode layer over a substrate;

forming a gate insulating layer over the gate electrode layer;

forming a source electrode layer and a drain electrode layer over the gate insulating layer;

forming a source region over the source electrode layer;

forming a drain region over the drain electrode layer;

subjecting the gate insulating layer, the source electrode layer, the drain electrode layer, the source region, and the drain region to plasma treatment; and

forming an oxide semiconductor layer without exposure to air over the gate insulating layer, the source electrode layer, the drain electrode layer, the source region, and the drain region after the plasma treatment to overlap the gate electrode layer,

wherein the oxide semiconductor layer has a higher oxygen concentration than the source region and the drain region.

14. The method for manufacturing a semiconductor device according to claim 13, further comprising heating the oxide semiconductor layer, the source region, and the drain region at 200°

C. to 600°

C.

15. The method for manufacturing a semiconductor device according to claim 13, wherein the gate insulating layer, the source electrode layer, the drain electrode layer, the source region, the drain region, and the oxide semiconductor layer are formed by a sputtering method.

16. The method for manufacturing a semiconductor device according to claim 13, wherein the semiconductor device is incorporated into one selected from the group consisting of a television set, a digital photo frame, a game machine, and a mobile phone.

17. The semiconductor device according to claim 13, wherein the gate insulating layer comprises a material selected from the group consisting of silicon oxynitride, silicon nitride, aluminum oxide and tantalum oxide.

18. A method for manufacturing a semiconductor device, comprising:

forming a gate electrode layer over a substrate;

forming a gate insulating layer over the gate electrode layer;

forming a first source region and a first drain region over the gate insulating layer;

forming a source electrode layer over the first source region;

forming a drain electrode layer over the first drain region;

forming a second source region over the source electrode layer;

forming a second drain region over the drain electrode layer;

subjecting the gate insulating layer, the first source region, the first drain region, the source electrode layer, the drain electrode layer, the second source region, and the second drain region to plasma treatment; and

forming an oxide semiconductor layer without exposure to air over the gate insulating layer, the first source region, the first drain region, the source electrode layer, the drain electrode layer, the second source region, and the second drain region after the plasma treatment to overlap the gate electrode layer,

wherein the oxide semiconductor layer has a higher oxygen concentration than the first source region, the first drain region, the second source region, and the second drain region.

19. The method for manufacturing a semiconductor device according to claim 18, further comprising heating the oxide semiconductor layer, the first source region, the first drain region, the second source region, and the second drain region at 200°

C. to 600°

C.

20. The method for manufacturing a semiconductor device according to claim 18, wherein the gate insulating layer, the first source region, the first drain region, the source electrode layer, the drain electrode layer, the second source region, the second drain region, and the oxide semiconductor layer are formed by a sputtering method.

21. The method for manufacturing a semiconductor device according to claim 18, wherein the semiconductor device is incorporated into one selected from the group consisting of a television set, a digital photo frame, a game machine, and a mobile phone.

22. The semiconductor device according to claim 18, wherein the gate insulating layer comprises a material selected from the group consisting of silicon oxynitride, silicon nitride, aluminum oxide and tantalum oxide.