Semiconductor device and manufacturing method thereof
View Patent ↗A semiconductor device having excellent electric characteristics and a method for manufacturing the semiconductor device are provided. A method for manufacturing a semiconductor device includes the steps of: forming a gate electrode; forming a gate insulating film to cover the gate electrode; forming an oxide semiconductor film over the gate insulating film; forming a hydrogen permeable film over the oxide semiconductor film; forming a hydrogen capture film over the hydrogen permeable film; performing heat treatment to release hydrogen from the oxide semiconductor film; forming a source electrode and a drain electrode to be in contact with a part of the oxide semiconductor film; and removing an exposed portion of the hydrogen capture film to form a channel protective film formed of the hydrogen permeable film. A semiconductor device manufactured by the above method is also provided.
1. A semiconductor device comprising:
a gate electrode;
a gate insulating film over the gate electrode;
an oxide semiconductor film over the gate insulating film;
a channel protective film having a hydrogen permeable property over the oxide semiconductor film;
a film having a hydrogen capture property in contact with a part of the channel protective film, a part of the oxide semiconductor film, and a part of the gate insulating film; and
a source electrode and a drain electrode over and in direct contact with an upper surface of the film having a hydrogen capture property.
2. The semiconductor device according to claim 1 , wherein the channel protective film contains an oxide.
3. The semiconductor device according to claim 1 ,
wherein a metal element included in the film having a hydrogen capture property as a main component and a metal element included in the oxide semiconductor film as a main component are the same, and
wherein the channel protective film does not include the metal element as a main component.
4. The semiconductor device according to claim 1 ,
wherein the channel protective film comprises a silicon oxide film or a silicon oxynitride film, and
wherein the film having a hydrogen capture property comprises an oxynitride film containing indium.
5. The semiconductor device according to claim 4 ,
wherein the oxide semiconductor film is an In—Ga—Zn—O film, and
wherein the oxynitride film containing indium is an In—Ga—Zn—O—N film.
6. The semiconductor device according to claim 4 , wherein a thickness of the silicon oxide film or the silicon oxynitride film is less than or equal to 5 nm.
7. A semiconductor device comprising:
a gate electrode;
a gate insulating film over the gate electrode;
an oxide semiconductor film over the gate insulating film;
a first film comprising silicon oxide or silicon oxynitride over the oxide semiconductor film;
a second oxynitride film comprising indium and one or more element selected from the group consisting of gallium, zinc, tin, aluminum, tungsten, molybdenum, titanium, tantalum, and silicon in contact with a part of the first film, a part of the oxide semiconductor film, and a part of the gate insulating film; and
a source electrode and a drain electrode over and in direct contact with an upper surface of the second oxynitride film.
8. The semiconductor device according to claim 7 ,
wherein a metal element included in the second oxynitride film as a main component and a metal element included in the oxide semiconductor film as a main component are the same, and
wherein the first film does not include the metal element as a main component.
9. The semiconductor device according to claim 7 ,
wherein the oxide semiconductor film is an In—Ga—Zn—O film, and
wherein the second oxynitride film is an In—Ga—Zn—O—N film.
10. The semiconductor device according to claim 7 , wherein a thickness of the first film is less than or equal to 5 nm.
11. The semiconductor device according to claim 1 , wherein a nitrogen concentration in the film having a hydrogen capture property is higher than or equal to 7 atomic % and lower than or equal to 20 atomic %.
12. The semiconductor device according to claim 7 , wherein a nitrogen concentration in the second oxynitride film is higher than or equal to 7 atomic % and lower than or equal to 20 atomic %.
13. The semiconductor device according to claim 1 , wherein the oxide semiconductor film is a c-axis aligned crystalline oxide semiconductor film.
14. The semiconductor device according to claim 7 , wherein the oxide semiconductor film is a c-axis aligned crystalline oxide semiconductor film.