Semiconductor device, manufacturing method thereof, display device, and electronic device
The field-effect mobility and reliability of a transistor including an oxide semiconductor film are improved. Provided is a semiconductor device including an oxide semiconductor film. The semiconductor device includes a first insulating film, an oxide semiconductor film over the first insulating film, a second insulating film and a third insulating film over the oxide semiconductor film, and a gate electrode over the second insulating film. The second insulating film comprises a silicon oxynitride film. When excess oxygen is added to the second insulating film by oxygen plasma treatment, oxygen can be efficiently supplied to the oxide semiconductor film.
1. A manufacturing method of a semiconductor device, comprising the steps of:
forming a first oxide semiconductor film over a substrate;
forming a gate insulating layer comprising at least a silicon oxynitride film over the first oxide semiconductor film using a plasma CVD apparatus;
performing oxygen plasma treatment after forming the gate insulating layer using the plasma CVD apparatus;
forming a gate electrode over the gate insulating layer; and
performing heat treatment at a temperature higher than or equal to 150° C. and lower than or equal to 450° C. after forming the gate electrode, thereby decreasing conductivity of the first oxide semiconductor film.
2. The manufacturing method of a semiconductor device, according to claim 1 , wherein the silicon oxynitride film is formed at a substrate temperature lower than or equal to 350° C.
3. The manufacturing method of a semiconductor device, according to claim 1 , wherein the oxygen plasma treatment is performed at a substrate temperature lower than or equal to 350° C.
4. The manufacturing method of a semiconductor device, according to claim 1 , wherein the gate electrode comprises a second oxide semiconductor film.
5. The manufacturing method of a semiconductor device, according to claim 4 , wherein the second oxide semiconductor film comprises indium, gallium, and zinc.
6. The manufacturing method of a semiconductor device, according to claim 1 , further comprising the steps of:
forming a conductive layer on the substrate; and
forming an insulating film over the conductive layer before forming the first oxide semiconductor film.
7. The manufacturing method of a semiconductor device, according to claim 1 , wherein when analyzing the gate insulating layer by thermal desorption spectroscopy, the highest peak of an amount of released gas with a mass-to-charge ratio M/z of 32 is observed at a substrate temperature higher than or equal to 150° C. and lower than or equal to 350° C.
8. The manufacturing method of a semiconductor device, according to claim 1 , wherein the gate electrode is formed using a sputtering apparatus.
9. The manufacturing method of a semiconductor device, according to claim 1 , wherein the first oxide semiconductor film comprises indium, gallium, and zinc.
10. A manufacturing method of a semiconductor device, comprising the steps of:
forming a first oxide semiconductor film over a substrate;
forming a gate insulating layer comprising at least a silicon oxynitride film over the first oxide semiconductor film using a plasma CVD apparatus;
performing oxygen plasma treatment after forming the gate insulating layer using the plasma CVD apparatus;
forming a second oxide semiconductor film on the gate insulating layer in an atmosphere comprising oxygen by sputtering;
forming a gate electrode by etching the second oxide semiconductor film; and
performing heat treatment at a temperature higher than or equal to 150° C. and lower than or equal to 450° C., thereby decreasing conductivity of the first oxide semiconductor film.
11. The manufacturing method of a semiconductor device, according to claim 10 , wherein the silicon oxynitride film is formed at a substrate temperature lower than or equal to 350° C.
12. The manufacturing method of a semiconductor device, according to claim 10 , further comprising the steps of:
forming a conductive layer on the substrate; and
forming an insulating film over the conductive layer before forming the first oxide semiconductor film.
13. The manufacturing method of a semiconductor device, according to claim 10 , wherein when analyzing the gate insulating layer by thermal desorption spectroscopy, the highest peak of an amount of released gas with a mass-to-charge ratio M/z of 32 is observed at a substrate temperature higher than or equal to 150° C. and lower than or equal to 350° C.
14. The manufacturing method of a semiconductor device, according to claim 10 , wherein the first oxide semiconductor film comprises indium, gallium, and zinc.
15. The manufacturing method of a semiconductor device, according to claim 10 , wherein the second oxide semiconductor film comprises indium, gallium, and zinc.
16. A manufacturing method of a semiconductor device, comprising the steps of:
forming a first gate electrode over a substrate;
forming a first gate insulating layer over the first gate electrode;
forming a first oxide semiconductor film over the first gate insulating layer;
forming a second gate insulating layer comprising at least a silicon oxynitride film over the first oxide semiconductor film using a plasma CVD apparatus;
performing oxygen plasma treatment after forming the second gate insulating layer using the plasma CVD apparatus;
forming a second gate electrode over the second gate insulating layer; and
performing heat treatment at a temperature higher than or equal to 150° C. and lower than or equal to 450° C. after forming the second gate electrode.
17. The manufacturing method of a semiconductor device, according to claim 16 , wherein the silicon oxynitride film is formed at a substrate temperature lower than or equal to 350° C.
18. The manufacturing method of a semiconductor device, according to claim 16 , wherein the second gate electrode comprises a second oxide semiconductor film.
19. The manufacturing method of a semiconductor device, according to claim 18 , wherein the second oxide semiconductor film comprises indium, gallium, and zinc.
20. The manufacturing method of a semiconductor device, according to claim 16 ,
wherein the second gate electrode is formed using a sputtering apparatus.
21. The manufacturing method of a semiconductor device, according to claim 16 , wherein when analyzing the second gate insulating layer by thermal desorption spectroscopy, the highest peak of an amount of released gas with a mass-to-charge ratio M/z of 32 is observed at a substrate temperature higher than or equal to 150° C. and lower than or equal to 350° C.
22. The manufacturing method of a semiconductor device, according to claim 16 , wherein the first oxide semiconductor film comprises indium, gallium, and zinc.