Method for manufacturing semiconductor device
View Patent ↗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.
1. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide semiconductor film over an oxide insulating film;
forming a metal film covering the oxide semiconductor film;
forming a metal oxide film by adding oxygen to the metal film;
forming a gate electrode over the metal oxide film; and
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed,
wherein the dopants are one or more of helium, neon, argon, krypton, and xenon, and
wherein the dopants are contained in the low-resistance regions at a concentration of greater than or equal to 5×10 18 atoms/cm 3 and smaller than or equal to 1×10 22 atoms/cm 3 .
2. The method for manufacturing a semiconductor device, according to claim 1 , further comprising the steps of:
forming sidewall insulating films in contact with side surfaces of the gate electrode;
etching the metal oxide film not overlapping with the gate electrode and the sidewall insulating films; and
forming a pair of electrodes in contact with parts of the oxide semiconductor film and the sidewall insulating films which are exposed by the etching.
3. The method for manufacturing a semiconductor device, according to claim 1 , wherein oxygen is added to the metal film and added also to the oxide semiconductor film.
4. The method for manufacturing a semiconductor device, according to claim 1 , further comprising the steps of:
forming an oxide insulating film over the oxide semiconductor film; and
forming the metal film over the oxide insulating film,
wherein oxygen is added to the metal film and added also to the oxide insulating film over the oxide semiconductor film.
5. The method for manufacturing a semiconductor device, according to claim 1 ,
wherein the metal film is an aluminum film, a hafnium film, or an yttrium film, and
wherein the metal oxide film is an oxide film or an oxynitride film corresponding to the metal film.
6. The method for manufacturing a semiconductor device, according to claim 1 , further comprising the steps of:
forming sidewall insulating films in contact with side surfaces of the gate electrode;
etching the metal oxide film not overlapping with the gate electrode and the sidewall insulating films;
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed; and
forming the sidewall insulating films over the oxide semiconductor film including the low-resistance regions,
wherein the dopants are one or more of boron, nitrogen, phosphorus, and arsenic.
7. The method for manufacturing a semiconductor device, according to claim 1 , wherein the oxide semiconductor film comprises one or more elements selected from the group of In, Ga, Sn, and Zn.
8. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide semiconductor film over a first oxide insulating film;
forming a second oxide insulating film over the oxide semiconductor film;
forming a gate electrode over the second oxide insulating film;
forming a metal film covering the gate electrode;
forming a metal oxide film by adding oxygen to the metal film, and
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed,
wherein the dopants are one or more of boron, nitrogen, phosphorus, and arsenic, and
wherein the dopants are contained in the low-resistance regions at a concentration of greater than or equal to 5×10 18 atoms/cm 3 and smaller than or equal to 1×10 22 atoms/cm 3 .
9. The method for manufacturing a semiconductor device, according to claim 8 , further comprising the steps of:
forming a third oxide insulating film over the gate electrode after a pair of electrodes is formed; and
forming the metal film covering the third oxide insulating film,
wherein oxygen is added to the metal film and added also to the third oxide insulating film.
10. The method for manufacturing a semiconductor device, according to claim 8 ,
wherein the metal film is an aluminum film, a hafnium film, or an yttrium film, and
wherein the metal oxide film is an oxide film or an oxynitride film corresponding to the metal film.
11. The method for manufacturing a semiconductor device, according to claim 8 , further comprising the steps of:
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed; and
wherein the dopants are one or more of helium, neon, argon, krypton, and xenon.
12. The method for manufacturing a semiconductor device, according to claim 8 , wherein the oxide semiconductor film comprises one or more elements selected from the group of In, Ga, Sn, and Zn.
13. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide semiconductor film over an oxide insulating film;
forming a metal film covering the oxide semiconductor film;
forming a metal oxide film by adding oxygen to the metal film;
forming a gate electrode over the metal oxide film; and
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed,
wherein the dopants are one or more of boron, nitrogen, phosphorus, and arsenic, and
wherein the dopants are contained in the low-resistance regions at a concentration of greater than or equal to 5×10 18 atoms/cm 3 and smaller than or equal to 1×10 22 atoms/cm 3 .
14. The method for manufacturing a semiconductor device, according to claim 13 , further comprising the steps of:
forming sidewall insulating films in contact with side surfaces of the gate electrode;
etching the metal oxide film not overlapping with the gate electrode and the sidewall insulating films; and
forming a pair of electrodes in contact with parts of the oxide semiconductor film and the sidewall insulating films which are exposed by the etching.
15. The method for manufacturing a semiconductor device, according to claim 13 , wherein oxygen is added to the metal film and added also to the oxide semiconductor film.
16. The method for manufacturing a semiconductor device, according to claim 13 , further comprising the steps of:
forming an oxide insulating film over the oxide semiconductor film; and
forming the metal film over the oxide insulating film,
wherein oxygen is added to the metal film and added also to the oxide insulating film over the oxide semiconductor film.
17. The method for manufacturing a semiconductor device, according to claim 13 ,
wherein the metal film is an aluminum film, a hafnium film, or an yttrium film, and
wherein the metal oxide film is an oxide film or an oxynitride film corresponding to the metal film.
18. The method for manufacturing a semiconductor device, according to claim 13 , wherein the oxide semiconductor film comprises one or more elements selected from the group of In, Ga, Sn, and Zn.
19. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide semiconductor film over a first oxide insulating film;
forming a second oxide insulating film over the oxide semiconductor film;
forming a gate electrode over the second oxide insulating film;
forming a metal film covering the gate electrode;
forming a metal oxide film by adding oxygen to the metal film, and
forming low-resistance regions in the oxide semiconductor film by adding dopants to the oxide semiconductor film with use of the gate electrode as a mask after the gate electrode is formed,
wherein the dopants are one or more of helium, neon, argon, krypton, and xenon, and
wherein the dopants are contained in the low-resistance regions at a concentration of greater than or equal to 5×10 18 atoms/cm 3 and smaller than or equal to 1×10 22 atoms/cm 3 .
20. The method for manufacturing a semiconductor device, according to claim 19 , further comprising the steps of:
forming a third oxide insulating film over the gate electrode after a pair of electrodes is formed; and
forming the metal film covering the third oxide insulating film,
wherein oxygen is added to the metal film and added also to the third oxide insulating film.
21. The method for manufacturing a semiconductor device, according to claim 19 ,
wherein the metal film is an aluminum film, a hafnium film, or an yttrium film, and
wherein the metal oxide film is an oxide film or an oxynitride film corresponding to the metal film.
22. The method for manufacturing a semiconductor device, according to claim 19 , wherein the oxide semiconductor film comprises one or more elements selected from the group of In, Ga, Sn, and Zn.