Semiconductor device and method for manufacturing the same

• US 8,324,027 B2
• Filed: 07/08/2010
• Issued: 12/04/2012
• Est. Priority Date: 07/10/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sakakura, Masayuki
• Primary Examiner(s): Le, Thao P.
• Application Number:
  US12/832,334
• Publication Number:
  US 20110006302A1
• Time in Patent Office: 880 Days
• Field of Search: 438/116, 257/82, 257/E31.099, 257/E31.105
• US Class Current: 438/116
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• 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
• 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 33/42 Transparent materials

Abstract

It is an object to manufacture and provide a highly reliable display device including a thin film transistor with a high aperture ratio which has stable electric characteristics. In a manufacturing method of a semiconductor device having a thin film transistor in which a semiconductor layer including a channel formation region is formed using an oxide semiconductor film, a heat treatment for reducing moisture and the like which are impurities and for improving the purity of the oxide semiconductor film (a heat treatment for dehydration or dehydrogenation) is performed. Further, an aperture ratio is improved by forming a gate electrode layer, a source electrode layer, and a drain electrode layer using conductive films having light transmitting properties.

Claims

1. 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 dehydration or dehydrogenation on the oxide semiconductor layer;

forming a source electrode layer and a drain electrode layer over the dehydrated or dehydrogenated oxide semiconductor layer,

wherein a depression overlapping the gate electrode layer is formed in the oxide semiconductor layer, and

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

2. The method for manufacturing a semiconductor device according to claim 1,

wherein the dehydration or dehydrogenation is performed by a heat treatment in a nitrogen atmosphere or in a rare gas atmosphere.

3. The method for manufacturing a semiconductor device according to claim 1,

wherein the dehydration or dehydrogenation is performed by a heat treatment in an oxygen atmosphere.

4. The method for manufacturing a semiconductor device according to claim 1,

wherein the dehydration or dehydrogenation is performed by a heat treatment under a reduced pressure.

5. The method for manufacturing a semiconductor device according to claim 1,

wherein the conductive film includes a metal oxide.

6. The method for manufacturing a semiconductor device according to claim 5,

wherein the metal oxide is one selected from the group consisting of an In—

Sn—

Zn—

O-based metal oxide, an In—

Al—

Zn—

O-based metal oxide, a Sn—

Ga—

Zn—

O-based metal oxide, an Al—

Ga—

Zn—

O-based metal oxide, a Sn—

Al—

Zn—

O-based metal oxide, an In—

Zn—

O-based metal oxide, a Sn—

Zn—

O-based metal oxide, an Al—

Zn—

O-based metal oxide, an In—

O-based metal oxide, a Sn—

O-based metal oxide, and a Zn—

O-based metal oxide.

23. The method for manufacturing a semiconductor device according to claim 1,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

29. The method for manufacturing a semiconductor device, according to claim 1, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.

7. 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 dehydration or dehydrogenation on the oxide semiconductor layer;

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

forming a protective insulating layer in contact with a part of the dehydrated or dehydrogenated oxide semiconductor layer, over the gate insulating layer, the oxide semiconductor layer, the source electrode layer, and the drain electrode layer; and

forming a pixel electrode layer over the protective insulating layer,

wherein a depression overlapping the gate electrode layer is formed in the oxide semiconductor layer, and

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

8. The method for manufacturing a semiconductor device according to claim 7,

wherein the dehydration or dehydrogenation is performed by a heat treatment in a nitrogen atmosphere or in a rare gas atmosphere.

9. The method for manufacturing a semiconductor device according to claim 7,

wherein the dehydration or dehydrogenation is performed by a heat treatment in an oxygen atmosphere.

10. The method for manufacturing a semiconductor device according to claim 7,

wherein the dehydration or dehydrogenation is performed by a heat treatment under a reduced pressure.

11. The method for manufacturing a semiconductor device according to claim 7,

wherein the conductive film includes a metal oxide.

12. The method for manufacturing a semiconductor device according to claim 11,

wherein the metal oxide is one selected from the group consisting of an In—

Sn—

Zn—

O-based metal oxide, an In—

Al—

Zn—

O-based metal oxide, a Sn—

Ga—

Zn—

O-based metal oxide, an Al—

Ga—

Zn—

O-based metal oxide, a Sn—

Al—

Zn—

O-based metal oxide, an In—

Zn—

O-based metal oxide, a Sn—

Zn—

O-based metal oxide, an Al—

Zn—

O-based metal oxide, an In—

O-based metal oxide, a Sn—

O-based metal oxide, and a Zn—

O-based metal oxide.

24. The method for manufacturing a semiconductor device according to claim 7,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

30. The method for manufacturing a semiconductor device, according to claim 7, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.

13. 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;

heating the oxide semiconductor layer in a nitrogen atmosphere or in a rare gas atmosphere so that carrier concentration is increased;

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

wherein a depression overlapping the gate electrode layer is formed in the oxide semiconductor layer, and

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

14. The method for manufacturing a semiconductor device according to claim 13,

wherein the conductive film includes a metal oxide.

15. The method for manufacturing a semiconductor device according to claim 14,

wherein the metal oxide is one selected from the group consisting of an In—

Sn—

Zn—

O-based metal oxide, an In—

Al—

Zn—

O-based metal oxide, a Sn—

Ga—

Zn—

O-based metal oxide, an Al—

Ga—

Zn—

O-based metal oxide, a Sn—

Al—

Zn—

O-based metal oxide, an In—

Zn—

O-based metal oxide, a Sn—

Zn—

O-based metal oxide, an Al—

Zn—

O-based metal oxide, an In—

O-based metal oxide, a Sn—

O-based metal oxide, and a Zn—

O-based metal oxide.

25. The method for manufacturing a semiconductor device according to claim 13,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

31. The method for manufacturing a semiconductor device, according to claim 13, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.

16. 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;

heating the oxide semiconductor layer under a reduced pressure so that carrier concentration is increased;

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

wherein a depression overlapping the gate electrode layer is formed in the oxide semiconductor layer, and

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

17. The method for manufacturing a semiconductor device according to claim 16,

wherein the conductive film includes a metal oxide.

18. The method for manufacturing a semiconductor device according to claim 17,

wherein the metal oxide is one selected from the group consisting of an In—

Sn—

Zn—

O-based metal oxide, an In—

Al—

Zn—

O-based metal oxide, a Sn—

Ga—

Zn—

O-based metal oxide, an Al—

Ga—

Zn—

O-based metal oxide, a Sn—

Al—

Zn—

O-based metal oxide, an In—

Zn—

O-based metal oxide, a Sn—

Zn—

O-based metal oxide, an Al—

Zn—

O-based metal oxide, an In—

O-based metal oxide, a Sn—

O-based metal oxide, and a Zn—

O-based metal oxide.

26. The method for manufacturing a semiconductor device according to claim 16,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

32. The method for manufacturing a semiconductor device, according to claim 16, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.

19. 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;

heating the oxide semiconductor layer in an oxygen atmosphere so that the oxide semiconductor layer is placed into a state where oxygen is in excess;

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

wherein a depression overlapping the gate electrode layer is formed in the oxide semiconductor layer, and

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

20. The method for manufacturing a semiconductor device according to claim 19,

wherein the conductive film includes a metal oxide.

21. The method for manufacturing a semiconductor device according to claim 20,

wherein the metal oxide is one selected from the group consisting of an In—

Sn—

Zn—

O-based metal oxide, an In—

Al—

Zn—

O-based metal oxide, a Sn—

Ga—

Zn—

O-based metal oxide, an Al—

Ga—

Zn—

O-based metal oxide, a Sn—

Al—

Zn—

O-based metal oxide, an In—

Zn—

O-based metal oxide, a Sn—

Zn—

O-based metal oxide, an Al—

Zn—

O-based metal oxide, an In—

O-based metal oxide, a Sn—

O-based metal oxide, and a Zn—

O-based metal oxide.

27. The method for manufacturing a semiconductor device according to claim 19,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

33. The method for manufacturing a semiconductor device, according to claim 19, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.

22. 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 dehydration or dehydrogenation on the oxide semiconductor layer;

forming a protective layer overlapping the gate electrode, on and in contact with the oxide semiconductor layer;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer and the protective layer,

wherein the gate electrode layer, the source electrode layer, and the drain electrode layer are each a conductive film having a light transmitting property.

28. The method for manufacturing a semiconductor device according to claim 22,

wherein, when seen in cross-section along the source electrode layer and the drain electrode layer, the gate electrode layer has a larger width than the oxide semiconductor layer.

34. The method for manufacturing a semiconductor device, according to claim 22, wherein the semiconductor device is one of a liquid crystal display device and an electrophoretic display device.