Semiconductor device and electronic device
To suppress a decrease in on-state current in a semiconductor device including an oxide semiconductor. A semiconductor device includes an insulating film containing silicon, an oxide semiconductor film over the insulating film, a gate insulating film containing silicon over the oxide semiconductor film, a gate electrode which is over the gate insulating film and overlaps with at least the oxide semiconductor film, and a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film. In the semiconductor device, the oxide semiconductor film which overlaps with at least the gate electrode includes a region in which a concentration of silicon distributed from an interface with the insulating film is lower than or equal to 1.1 at. %. In addition, a concentration of silicon contained in a remaining portion of the oxide semiconductor film except the region is lower than the concentration of silicon contained in the region.
1. A semiconductor device comprising:
an insulating film containing silicon and oxygen;
an oxide semiconductor film over the insulating film;
a gate insulating film over the oxide semiconductor film;
a gate electrode which is over the gate insulating film and overlaps with at least the oxide semiconductor film; and
a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film,
wherein the oxide semiconductor film which overlaps with at least the gate electrode includes a region in which a concentration of silicon distributed from an interface between the oxide semiconductor film and the insulating film toward the oxide semiconductor film is lower than or equal to 1.1 at. %.
2. The semiconductor device according to claim 1 ,
wherein the region is present in a range of 5 nm or less in a film thickness direction from the interface with the insulating film, and
wherein a concentration of silicon contained in a remaining portion of the oxide semiconductor film except the region is lower than the concentration of silicon contained in the region.
3. The semiconductor device according to claim 1 ,
wherein a concentration of silicon contained in the region is lower than or equal to 0.1 at. %.
4. The semiconductor device according to claim 1 ,
wherein the insulating film contains carbon, and
wherein a concentration of carbon in the region is lower than or equal to 1.0×10 20 atoms/cm 3 .
5. The semiconductor device according to claim 1 ,
wherein the oxide semiconductor film has crystallinity.
6. The semiconductor device according to claim 1 ,
wherein the oxide semiconductor film includes an amorphous structure.
7. A semiconductor device comprising:
an insulating film containing silicon and oxygen;
an oxide semiconductor film over the insulating film;
a gate insulating film over the oxide semiconductor film;
a gate electrode which is over the gate insulating film and overlaps with at least the oxide semiconductor film; and
a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film,
wherein the oxide semiconductor film which overlaps with at least the gate electrode includes a region in which a concentration of silicon distributed from an interface between the oxide semiconductor film and the insulating film toward the oxide semiconductor film is lower than or equal to 1.1 at. %, and
wherein the oxide semiconductor film comprises at least one of indium and zinc.
8. The semiconductor device according to claim 7 ,
wherein the region is present in a range of 5 nm or less in a film thickness direction from the interface with the insulating film, and
wherein a concentration of silicon contained in a remaining portion of the oxide semiconductor film except the region is lower than the concentration of silicon contained in the region.
9. The semiconductor device according to claim 7 ,
wherein a concentration of silicon contained in the region is lower than or equal to 0.1 at. %.
10. The semiconductor device according to claim 7 ,
wherein the insulating film contains carbon, and
wherein a concentration of carbon in the region is lower than or equal to 1.0×10 20 atoms/cm 3 .
11. The semiconductor device according to claim 7 ,
wherein the oxide semiconductor film has crystallinity.
12. The semiconductor device according to claim 7 ,
wherein the oxide semiconductor film includes an amorphous structure.
13. The semiconductor device according to claim 7 ,
wherein the oxide semiconductor film further comprises tin.
14. An electronic device comprising a semiconductor device:
the semiconductor device comprising:
an insulating film containing silicon and oxygen;
an oxide semiconductor film over the insulating film;
a gate insulating film over the oxide semiconductor film;
a gate electrode which is over the gate insulating film and overlaps with at least the oxide semiconductor film; and
a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film,
wherein the oxide semiconductor film which overlaps with at least the gate electrode includes a region in which a concentration of silicon distributed from an interface between the oxide semiconductor film and the insulating film toward the oxide semiconductor film is lower than or equal to 1.1 at. %.
15. The electronic device according to claim 14 ,
wherein the region is present in a range of 5 nm or less in a film thickness direction from the interface with the insulating film, and
wherein a concentration of silicon contained in a remaining portion of the oxide semiconductor film except the region is lower than the concentration of silicon contained in the region.
16. The electronic device according to claim 14 ,
wherein a concentration of silicon contained in the region is lower than or equal to 0.1 at. %.
17. The electronic device according to claim 14 ,
wherein the insulating film contains carbon, and
wherein a concentration of carbon in the region is lower than or equal to 1.0×10 20 atoms/cm 3 .
18. The electronic device according to claim 14 ,
wherein the oxide semiconductor film has crystallinity.
19. The electronic device according to claim 14 ,
wherein the oxide semiconductor film includes an amorphous structure.