Method for manufacturing semiconductor device

• US 8,912,040 B2
• Filed: 01/25/2011
• Issued: 12/16/2014
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Suzawa, Hideomi, Sasagawa, Shinya, Muraoka, Taiga
• Primary Examiner(s): Ghyka, Alexander
• Assistant Examiner(s): MUSTAPHA, ABDULFATTAH B
• Application Number:
  US13/012,987
• Publication Number:
  US 20110117698A1
• Time in Patent Office: 1,421 Days
• Field of Search: 438/46, 438/104, 438/149, 438158-165, 438/355, 438/770, 257/43, 257/E21.301, 257/E21.314, 257/E21.414, 257/E21.485
• US Class Current: 438/104
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G11C 19/28 using semiconductor elements G11C19/14, G11C19/36 take precedence
• CPC Class Codes: H01L 21/465 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/469
• 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• 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 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
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

An object is to establish a processing technique in manufacture of a semiconductor device in which an oxide semiconductor is used. A gate electrode is formed over a substrate, a gate insulating layer is formed over the gate electrode, an oxide semiconductor layer is formed over the gate insulating layer, the oxide semiconductor layer is processed by wet etching to form an island-shaped oxide semiconductor layer, a conductive layer is formed to cover the island-shaped oxide semiconductor layer, the conductive layer is processed by dry etching to form a source electrode, and a drain electrode and part of the island-shaped oxide semiconductor layer is removed by dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.

Claims

1. A method for manufacturing a semiconductor device comprising:

forming a semiconductor layer comprising an oxide semiconductor including indium;

processing the semiconductor layer by wet etching to form an island-shaped semiconductor layer;

forming a conductive layer over and in contact with a top surface of the island-shaped semiconductor layer; and

processing the island-shaped semiconductor layer by dry etching to form a recessed portion in the island-shaped semiconductor layer.

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

wherein an etchant for wet etching is a mixed solution including acetic acid, nitric acid, and phosphoric acid.

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

wherein the dry etching is performed by using a gas selected from the group consisting of boron chloride (BCl₃), silicon chloride (SiCl₄), carbon tetrachloride (CCl₄), carbon tetrafluoride (CF₄), sulfur fluoride (SF₆), nitrogen fluoride (NF₃), trifluoromethane (CHF₃), hydrogen bromide (HBr), and oxygen (O₂), any of these gases to which a rare gas such as helium (He), argon (Ar) is added, or chlorine (Cl₂).

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

after processing the island-shaped semiconductor layer, heating the island-shaped semiconductor layer at 200 to 600°

C.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor, and

wherein a diameter of the crystal grain is 1 to 10 nm.

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

wherein the oxide semiconductor is an In—

Ga—

Zn—

O based oxide semiconductor.

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

wherein the dry etching is performed by using a gas including chlorine and oxygen.

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

wherein a content of the oxygen in the gas including chlorine and oxygen is 15 volume % or more.

33. The method for manufacturing a semiconductor device according to claim 1, further comprising:

performing a radical treatment including oxygen to the recessed portion.

54. The method for manufacturing a semiconductor device according to claim 1, wherein the step of processing the island-shaped semiconductor layer by dry etching is performed after the step of forming the conductive layer.

9. A method for manufacturing a semiconductor device comprising:

forming a gate electrode;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer comprising an oxide semiconductor including indium over the gate insulating layer;

processing the semiconductor layer by wet etching to form an island-shaped semiconductor layer;

forming a conductive layer over the island-shaped semiconductor layer;

processing the conductive layer by first dry etching to form a first conductive layer and a second conductive layer; and

processing the island-shaped semiconductor layer by second dry etching to form a recessed portion in the island-shaped semiconductor layer.

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

wherein an etchant for wet etching is a mixed solution including acetic acid, nitric acid, and phosphoric acid.

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

wherein the first dry etching and the second dry etching are performed by using a gas selected from the group consisting of boron chloride (BCl₃), silicon chloride (SiCl₄), carbon tetrachloride (CCl₄), carbon tetrafluoride (CF₄), sulfur fluoride (SF₆), nitrogen fluoride (NF₃), trifluoromethane (CHF₃), hydrogen bromide (HBr), and oxygen (O₂), any of these gases to which a rare gas such as helium (He), argon (Ar) is added, or chlorine (Cl₂).

12. The method for manufacturing a semiconductor device according to claim 9, further comprising:

after processing the island-shaped semiconductor layer, heating the island-shaped semiconductor layer at 200 to 600°

C.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor, and

wherein a diameter of the crystal grain is 1 to 10 nm.

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

wherein the oxide semiconductor is an In—

Ga—

Zn—

O based oxide semiconductor.

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

wherein the second dry etching is performed by using a gas including chlorine and oxygen.

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

wherein the gate insulating layer includes a silicon oxide.

27. The method for manufacturing a semiconductor device according to claim 9, further comprising:

forming a second semiconductor layer over the semiconductor layer;

wherein the second semiconductor layer is processed together with the semiconductor layer by the wet etching to form the island-shaped semiconductor layer and a second island-shaped semiconductor layer over the island-shaped semiconductor layer;

wherein the conductive layer is formed over the second island-shaped semiconductor layer;

and

wherein the second island-shaped semiconductor layer is processed together with the island-shaped semiconductor layer by the second dry etching to form the recessed portion in the island-shaped semiconductor layer.

29. The method for manufacturing a semiconductor device according to claim 9, further comprising:

performing a radical treatment to the recessed portion under an atmosphere comprising oxygen.

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

wherein a content of the oxygen in the gas including chlorine and oxygen is 15 volume % or more.

18. A method for manufacturing a semiconductor device comprising:

forming a gate electrode;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer comprising an oxide semiconductor including indium over the gate insulating layer;

processing the semiconductor layer by wet etching to form an island-shaped semiconductor layer;

forming a conductive layer over the island-shaped semiconductor layer;

processing the conductive layer by dry etching to form a first conductive layer and a second conductive layer; and

processing the island-shaped semiconductor layer by the dry etching to form a recessed portion in the island-shaped semiconductor layer.

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

wherein an etchant for wet etching is a mixed solution including acetic acid, nitric acid, and phosphoric acid.

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

wherein the dry etching is performed by using a gas selected from the group consisting of boron chloride (BCl₃), silicon chloride (SiCl₄), carbon tetrachloride (CCl₄), carbon tetrafluoride (CF₄), sulfur fluoride (SF₆), nitrogen fluoride (NF₃), trifluoromethane (CHF₃), hydrogen bromide (HBr), and oxygen (O₂), any of these gases to which a rare gas such as helium (He), argon (Ar) is added, or chlorine (Cl₂).

21. The method for manufacturing a semiconductor device according to claim 18, further comprising:

after processing the island-shaped semiconductor layer, heating the island-shaped semiconductor layer at 200 to 600°

C.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor.

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

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor, and

wherein a diameter of the crystal grain is 1 to 10 nm.

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

wherein the oxide semiconductor is an In—

Ga—

Zn—

O based oxide semiconductor.

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

wherein the dry etching is performed by using a gas including chlorine and oxygen.

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

wherein the gate insulating layer includes a silicon oxide.

28. The method for manufacturing a semiconductor device according to claim 18, further comprising:

forming a second semiconductor layer over the semiconductor layer;

wherein the second semiconductor layer is processed together with the semiconductor layer by the wet etching to form a the island-shaped semiconductor layer and a second island-shaped semiconductor layer over the island-shaped semiconductor layer;

wherein the conductive layer is formed over the second island-shaped semiconductor layer;

and

wherein the second island-shaped semiconductor layer is processed together with the island-shaped semiconductor layer by the dry etching to form the recessed portion in the island-shaped semiconductor layer.

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

wherein a content of the oxygen in the gas including chlorine and oxygen is 15 volume % or more.

34. The method for manufacturing a semiconductor device according to claim 18, further comprising:

performing a radical treatment including oxygen to the recessed portion.

35. A method for manufacturing a semiconductor device comprising:

forming a gate electrode;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer comprising an oxide semiconductor including indium over the gate insulating layer;

processing the semiconductor layer by wet etching to form an island-shaped semiconductor layer, wherein the island-shaped semiconductor layer is overlapped with the gate electrode in such a manner that the island-shaped semiconductor layer does not extend beyond any side edge of the gate electrode;

forming a conductive layer over the island-shaped semiconductor layer; and

processing the conductive layer by dry etching to form a first conductive layer and a second conductive layer.

36. The method for manufacturing a semiconductor device according to claim 35,

wherein an etchant for wet etching is a mixed solution including acetic acid, nitric acid, and phosphoric acid.

37. The method for manufacturing a semiconductor device according to claim 35,

wherein the dry etching is performed by using a gas selected from the group consisting of boron chloride (BCl₃), silicon chloride (SiCl₄), carbon tetrachloride (CCl₄), carbon tetrafluoride (CF₄), sulfur fluoride (SF₆), nitrogen fluoride (NF₃), trifluoromethane (CHF₃), hydrogen bromide (HBr), and oxygen (O₂), any of these gases to which a rare gas such as helium (He), argon (Ar) is added, or chlorine (Cl₂).

38. The method for manufacturing a semiconductor device according to claim 35, further comprising:

after processing the island-shaped semiconductor layer, heating the island-shaped semiconductor layer at 200 to 600°

C.

39. The method for manufacturing a semiconductor device according to claim 35,

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor.

40. The method for manufacturing a semiconductor device according to claim 35,

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor, and

wherein a diameter of the crystal grain is 1 to 10 nm.

41. The method for manufacturing a semiconductor device according to claim 35,

wherein the oxide semiconductor is an In—

Ga—

Zn—

O based oxide semiconductor.

42. The method for manufacturing a semiconductor device according to claim 35,

wherein the dry etching is performed by using a gas including chlorine and oxygen.

43. The method for manufacturing a semiconductor device, according to claim 35,

wherein the gate insulating layer includes a silicon oxide.

44. A method for manufacturing a semiconductor device comprising:

forming a gate electrode;

forming a gate insulating layer comprising a first oxide insulator over the gate electrode;

forming a semiconductor layer comprising an oxide semiconductor including indium over the gate insulating layer;

processing the semiconductor layer by wet etching to form an island-shaped semiconductor layer, wherein the island-shaped semiconductor layer is overlapped with the gate electrode in such a manner that the island-shaped semiconductor layer does not extend beyond any side edge of the gate electrode;

forming a conductive layer over the island-shaped semiconductor layer;

processing the conductive layer by dry etching to form a first conductive layer and a second conductive layer;

forming a first insulating layer comprising a second oxide insulator over the semiconductor layer, the first conductive layer and the second conductive layer;

forming a second insulating layer comprising a third oxide insulator over the first insulating layer;

forming a third insulating layer comprising an organic insulator over the second insulating layer; and

forming a pixel electrode over the third insulating layer so as to be electrically connected to one of the first conductive layer and the second conductive layer.

45. The method for manufacturing a semiconductor device according to claim 44,

wherein an etchant for wet etching is a mixed solution including acetic acid, nitric acid, and phosphoric acid.

46. The method for manufacturing a semiconductor device according to claim 44,

wherein the dry etching is performed by using a gas selected from the group consisting of boron chloride (BCl₃), silicon chloride (SiCl₄), carbon tetrachloride (CCl₄), carbon tetrafluoride (CF₄), sulfur fluoride (SF₆), nitrogen fluoride (NF₃), trifluoromethane (CHF₃), hydrogen bromide (HBr), and oxygen (O₂), any of these gases to which a rare gas such as helium (He), argon (Ar) is added, or chlorine (Cl₂).

47. The method for manufacturing a semiconductor device according to claim 44, further comprising:

after processing the island-shaped semiconductor layer, heating the island-shaped semiconductor layer at 200 to 600°

C.

48. The method for manufacturing a semiconductor device according to claim 44,

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor.

49. The method for manufacturing a semiconductor device according to claim 44,

wherein the island-shaped semiconductor layer comprises a crystal grain of the oxide semiconductor, and

wherein a diameter of the crystal grain is 1 to 10 nm.

50. The method for manufacturing a semiconductor device according to claim 44,

wherein the oxide semiconductor is an In—

Ga—

Zn—

O based oxide semiconductor.

51. The method for manufacturing a semiconductor device according to claim 44,

wherein the dry etching is performed by using a gas including chlorine and oxygen.

52. The method for manufacturing a semiconductor device according to claim 44,

wherein the first oxide insulator is a silicon oxide,

wherein the second oxide insulator is a silicon oxide, and

wherein the third oxide insulator is a silicon nitride.

53. The method for manufacturing a semiconductor device according to claim 52, wherein the first insulating layer and the second insulating layer are in contact with each other.