Method for manufacturing semiconductor device comprising adding oxygen to buffer film and insulating film
Provided is a method for manufacturing a semiconductor device whose electric characteristics are prevented from being varied and whose reliability is improved. In the method, an insulating film is formed over an oxide semiconductor film, a buffer film is formed over the insulating film, oxygen is added to the buffer film and the insulating film, a conductive film is formed over the buffer film to which oxygen is added, and an impurity element is added to the oxide semiconductor film using the conductive film as a mask. An insulating film containing hydrogen and overlapping with the oxide semiconductor film may be formed after the impurity element is added to the oxide semiconductor film.
1. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating film over an oxide semiconductor film;
forming a metal oxide film over the insulating film;
adding oxygen to the metal oxide film and the insulating film by an ion doping method, an ion implantation method, or plasma treatment after forming the metal oxide film;
forming a conductive film over the metal oxide film to which oxygen is added; and
adding an impurity element to the oxide semiconductor film using the conductive film as a mask.
2. The method for manufacturing the semiconductor device, according to claim 1 , wherein the metal oxide film has an end portion overlapping with the oxide semiconductor film.
3. The method for manufacturing the semiconductor device, according to claim 1 , wherein the conductive film serves as a gate electrode.
4. The method for manufacturing the semiconductor device, according to claim 1 ,
wherein the metal oxide film to which oxygen is added is a semiconductor, and
wherein the metal oxide film to which oxygen is added and the conductive film collectively serve as a gate electrode.
5. The method for manufacturing the semiconductor device, according to claim 1 , wherein the metal oxide film contains one or more of indium, zinc, titanium, tungsten, tantalum, and molybdenum.
6. The method for manufacturing the semiconductor device, according to claim 1 , wherein heat treatment is performed after oxygen is added to the metal oxide film and the insulating film.
7. The method for manufacturing the semiconductor device, according to claim 1 , wherein the impurity element is one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.
8. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating film over an oxide semiconductor film;
forming a metal oxide film over the insulating film;
adding oxygen to the metal oxide film and the insulating film by an ion doping method, an ion implantation method, or plasma treatment after forming the metal oxide film;
forming a conductive film over the metal oxide film to which oxygen is added;
adding an impurity element to the oxide semiconductor film using the conductive film as a mask; and
forming an insulating film containing hydrogen and overlapping with the oxide semiconductor film.
9. The method for manufacturing the semiconductor device, according to claim 8 , wherein the metal oxide film has an end portion overlapping with the oxide semiconductor film.
10. The method for manufacturing the semiconductor device, according to claim 8 , wherein the conductive film serves as a gate electrode.
11. The method for manufacturing the semiconductor device, according to claim 8 ,
wherein the metal oxide film to which oxygen is added is a semiconductor, and
wherein the metal oxide film to which oxygen is added and the conductive film collectively serve as a gate electrode.
12. The method for manufacturing the semiconductor device, according to claim 8 , wherein the metal oxide film contains one or more of indium, zinc, titanium, tungsten, tantalum, and molybdenum.
13. The method for manufacturing the semiconductor device, according to claim 8 , wherein heat treatment is performed after oxygen is added to the metal oxide film and the insulating film.
14. The method for manufacturing the semiconductor device, according to claim 8 , wherein the insulating film containing hydrogen contains nitrogen.
15. The method for manufacturing the semiconductor device, according to claim 8 , wherein the insulating film containing hydrogen is a silicon nitride film.
16. The method for manufacturing the semiconductor device, according to claim 8 , wherein the impurity element is one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.
17. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating film over an oxide semiconductor film;
forming a metal oxide film over the insulating film;
adding oxygen to the metal oxide film and the insulating film by an ion doping method, an ion implantation method, or plasma treatment after forming the metal oxide film;
forming a conductive film over the metal oxide film to which oxygen is added;
etching the insulating film to which oxygen is added and the metal oxide film to which oxygen is added to expose part of the oxide semiconductor film;
adding an impurity element to the oxide semiconductor film using the conductive film as a mask; and
forming an insulating film containing hydrogen and overlapping with the oxide semiconductor film.
18. The method for manufacturing the semiconductor device, according to claim 17 , wherein the metal oxide film has an end portion overlapping with the oxide semiconductor film.
19. The method for manufacturing the semiconductor device, according to claim 17 , wherein the conductive film serves as a gate electrode.
20. The method for manufacturing the semiconductor device, according to claim 17 ,
wherein the metal oxide film to which oxygen is added is a semiconductor, and
wherein the metal oxide film to which oxygen is added and the conductive film collectively serve as a gate electrode.
21. The method for manufacturing the semiconductor device, according to claim 17 , wherein the metal oxide film contains one or more of indium, zinc, titanium, tungsten, tantalum, and molybdenum.
22. The method for manufacturing the semiconductor device, according to claim 17 , wherein heat treatment is performed after oxygen is added to the metal oxide film and the insulating film.
23. The method for manufacturing the semiconductor device, according to claim 17 , wherein the insulating film containing hydrogen contains nitrogen.
24. The method for manufacturing the semiconductor device, according to claim 17 , wherein the insulating film containing hydrogen is a silicon nitride film.
25. The method for manufacturing the semiconductor device, according to claim 17 , wherein the impurity element is one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.
26. The method for manufacturing the semiconductor device, according to claim 1 , wherein the impurity element is added by an ion doping method, an ion implantation method, or a plasma treatment method.
27. The method for manufacturing the semiconductor device, according to claim 8 , wherein the impurity element is added by an ion doping method, an ion implantation method, or a plasma treatment method.
28. The method for manufacturing the semiconductor device, according to claim 17 , wherein the impurity element is added by an ion doping method, an ion implantation method, or a plasma treatment method.
29. A method for manufacturing a semiconductor device, comprising the steps of:
forming an insulating film over an oxide semiconductor film;
forming a metal nitride film over the insulating film;
adding oxygen to the metal nitride film and the insulating film by an ion doping method, an ion implantation method, or plasma treatment after forming the metal nitride film;
forming a conductive film over the metal nitride film to which oxygen is added; and
adding an impurity element to the oxide semiconductor film using the conductive film as a mask.
30. The method for manufacturing the semiconductor device, according to claim 29 , wherein the metal nitride film has an end portion overlapping with the oxide semiconductor film.
31. The method for manufacturing the semiconductor device, according to claim 29 , wherein the conductive film serves as a gate electrode.
32. The method for manufacturing the semiconductor device, according to claim 29 ,
wherein the metal nitride film to which oxygen is added is a semiconductor, and
wherein the metal nitride film to which oxygen is added and the conductive film collectively serve as a gate electrode.
33. The method for manufacturing the semiconductor device, according to claim 29 , wherein the metal nitride film contains one or more of indium, zinc, titanium, tungsten, tantalum, and molybdenum.
34. The method for manufacturing the semiconductor device, according to claim 29 , wherein heat treatment is performed after oxygen is added to the metal nitride film and the insulating film.
35. The method for manufacturing the semiconductor device, according to claim 29 , wherein the impurity element is one or more of a rare gas, hydrogen, boron, nitrogen, fluorine, aluminum, and phosphorus.