Method for manufacturing semiconductor device

• US 9,496,375 B2
• Filed: 08/21/2015
• Issued: 11/15/2016
• Est. Priority Date: 02/07/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Isobe, Atsuo, Hosoya, Kunio
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): STEVENSON, ANDRE C
• Application Number:
  US14/831,972
• Publication Number:
  US 20150380529A1
• Time in Patent Office: 452 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/383 using diffusion into or out of a solid from or into a gaseous phase
• CPC Class Codes: H01L 21/425 producing ion implantation
• CPC Class Codes: H01L 21/441 Deposition of conductive or insulating materials for electrodes
• CPC Class Codes: H01L 21/47573 Etching the layer
• 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 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/495 the conductor material next to the insulator being a simple metal, e.g. W, Mo H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• 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: H10B 10/125 the MOSFET being a thin film transistor [TFT]
• CPC Class Codes: H10B 12/05 Making the transistor
• CPC Class Codes: H10B 41/70 the floating gate being an electrode shared by two or more components

Abstract

To improve productivity of a transistor that includes an oxide semiconductor and has good electrical characteristics. In a top-gate transistor including a gate insulating film and a gate electrode over an oxide semiconductor film, a metal film is formed over the oxide semiconductor film, oxygen is added to the metal film to form a metal oxide film, and the metal oxide film is used as a gate insulating film. After an oxide insulating film is formed over the oxide semiconductor film, a metal film may be formed over the oxide insulating film. Oxygen is added to the metal film to form a metal oxide film and added also to the oxide semiconductor film or the oxide insulating film.

Claims

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

forming an oxide semiconductor film over an oxide insulating film;

forming a film over the oxide semiconductor film;

adding oxygen to the film;

forming a gate electrode over the film;

forming an first insulating film comprising an aluminum oxide over the oxide semiconductor film, the film added the oxygen, and the gate electrode;

etching the first insulating film to form a sidewall in contact with side surfaces of the gate electrode and to expose portions of the oxide semiconductor film; and

forming a second insulating film comprising silicon nitride over the gate electrode, the sidewall, and the exposed oxide semiconductor film.

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

wherein the film is metal film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

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

wherein the film is a first oxide insulating film and a metal film over the first oxide insulating film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

4. The method for manufacturing the semiconductor device, according to claim 1, wherein oxygen is added to the oxide semiconductor film when the step of adding oxygen to the film is performed.

5. The method for manufacturing the semiconductor device, according to claim 1, wherein the step of adding oxygen to the film is performed by one of an ion implantation method, an ion doping method, a plasma immersion ion implantation method, and plasma treatment.

6. The method for manufacturing the semiconductor device, according to claim 1, wherein the oxide semiconductor film comprises one or more elements selected from In, Ga, Sn, and Zn.

7. The method for manufacturing the semiconductor device, according to claim 1, further comprising the steps of:

forming a transistor over a semiconductor substrate;

forming a planarization insulating film over the transistor;

forming a first wiring electrically connected to the transistor through an opening in the planarization insulating film;

forming the oxide insulating film over the planarization insulating film and the first wiring; and

electrically connecting the first wiring to the oxide semiconductor film by a second wiring.

8. The method for manufacturing the semiconductor device, according to claim 1, wherein the semiconductor device is a central processing unit, a microprocessor, a random access memory, a converter, a power transistor, a thyristor, an image sensor, an electro-optical device, or a light-emitting display device.

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

forming an oxide semiconductor film over an oxide insulating film;

forming a film over the oxide semiconductor film;

adding oxygen to the film;

forming a gate electrode over the film;

adding dopants to the oxide semiconductor film with use of the gate electrode as a mask to form low-resistance regions in the oxide semiconductor film;

forming an first insulating film comprising an aluminum oxide over the oxide semiconductor film, the film added the oxygen, and the gate electrode;

etching the first insulating film to form a sidewall in contact with side surfaces of the gate electrode and to expose portions of the oxide semiconductor film; and

forming a second insulating film comprising silicon nitride over the gate electrode, the sidewall, and the exposed oxide semiconductor film.

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

wherein the film is metal film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

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

wherein the film is a first oxide insulating film and a metal film over the first oxide insulating film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

12. The method for manufacturing the semiconductor device, according to claim 9, wherein oxygen is added to the oxide semiconductor film when the step of adding oxygen to the film is performed.

13. The method for manufacturing the semiconductor device, according to claim 9, wherein the step of adding oxygen to the film is performed by one of an ion implantation method, an ion doping method, a plasma immersion ion implantation method, and plasma treatment.

14. The method for manufacturing the semiconductor device, according to claim 9, wherein the oxide semiconductor film comprises one or more elements selected from In, Ga, Sn, and Zn.

15. The method for manufacturing the semiconductor device, according to claim 9, further comprising the steps of:

forming a transistor over a semiconductor substrate;

forming a planarization insulating film over the transistor;

forming a first wiring electrically connected to the transistor through an opening in the planarization insulating film;

forming the oxide insulating film over the planarization insulating film and the first wiring; and

electrically connecting the first wiring to the oxide semiconductor film by a second wiring.

16. The method for manufacturing the semiconductor device, according to claim 9, wherein the semiconductor device is a central processing unit, a microprocessor, a random access memory, a converter, a power transistor, a thyristor, an image sensor, an electro-optical device, or a light-emitting display device.

17. The method for manufacturing the semiconductor device, according to claim 9, wherein the dopants are at least one of helium, neon, argon, krypton, and xenon.

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

forming an oxide semiconductor film over an oxide insulating film;

forming a film over the oxide semiconductor film;

adding oxygen to the film;

etching the film to expose portions of the oxide semiconductor film;

forming a gate electrode over the film; and

forming an insulating film over the gate electrode and the exposed oxide semiconductor film,

wherein the insulating film is in contact with the exposed oxide semiconductor film.

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

wherein the film is metal film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

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

wherein the film is a first oxide insulating film and a metal film over the first oxide insulating film, and

wherein a material of the metal film is one of aluminum, gallium, hafnium, and yttrium.

21. The method for manufacturing the semiconductor device, according to claim 18, wherein oxygen is added to the oxide semiconductor film when the step of adding oxygen to the film is performed.

22. The method for manufacturing the semiconductor device, according to claim 18, wherein the step of adding oxygen to the film is performed by one of an ion implantation method, an ion doping method, a plasma immersion ion implantation method, and plasma treatment.

23. The method for manufacturing the semiconductor device, according to claim 18, wherein the oxide semiconductor film comprises one or more elements selected from In, Ga, Sn, and Zn.

24. The method for manufacturing the semiconductor device, according to claim 18, wherein the insulating film comprises silicon nitride.

25. The method for manufacturing the semiconductor device, according to claim 18, wherein the step of etching the film is performed after the step of forming the gate electrode.