Semiconductor device and method for manufacturing the same
It is an object to provide a semiconductor device including a thin film transistor with favorable electric properties and high reliability, and a method for manufacturing the semiconductor device with high productivity. In an inverted staggered (bottom gate) thin film transistor, an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer, and a buffer layer formed using a metal oxide layer is provided between the semiconductor layer and a source and drain electrode layers. The metal oxide layer is intentionally provided as the buffer layer between the semiconductor layer and the source and drain electrode layers, whereby ohmic contact is obtained.
1. A semiconductor device comprising:
a driver circuit comprising:
a driver IC;
a first transistor comprising a channel formation region comprising an oxide semiconductor including indium, wherein one of a source terminal and a drain terminal of the first transistor is electrically connected to a first terminal of the driver IC;
a second transistor comprising a channel formation region comprising an oxide semiconductor including indium, wherein one of a source terminal and a drain terminal of the second transistor is electrically connected to the first terminal of the driver IC;
a third transistor comprising a channel formation region comprising an oxide semiconductor including indium, wherein one of a source terminal and a drain terminal of the third transistor is electrically connected to a second terminal of the driver IC;
a fourth transistor comprising a channel formation region comprising an oxide semiconductor including indium, wherein one of a source terminal and a drain terminal of the fourth transistor is electrically connected to the second terminal of the driver IC;
a first wiring electrically connected to a gate of the first transistor and a gate of the third transistor; and
a second wiring electrically connected to a gate of the second transistor and a gate of the fourth transistor,
wherein the one of the source terminal and the drain terminal of the first transistor comprises titanium, and
wherein the first transistor comprises a layer comprising titanium oxide between the channel formation region of the first transistor and the one of the source terminal and the drain terminal of the first transistor.
2. A semiconductor device comprising:
a first insulating film comprising silicon and halogen;
an oxide semiconductor film in contact with the first insulating film, the oxide semiconductor film including a channel forming region; and
a gate electrode adjacent to the oxide semiconductor film.
3. The semiconductor device according to claim 2 ,
wherein a concentration of the halogen is from 1×10 15 atoms/cm 3 to 1×10 20 atoms/cm 3 inclusive at the concentration peak.
4. The semiconductor device according to claim 2 , further comprising a second insulating film under and in contact with the first insulating film.
5. The semiconductor device according to claim 4 ,
wherein the first insulating film is a silicon nitride film, and
wherein the second insulating film is silicon oxide film.
6. The semiconductor device according to claim 2 ,
wherein the oxide semiconductor film is located over the gate electrode with the first insulating film therebetween.
7. The semiconductor device according to claim 2 , wherein the oxide semiconductor film comprises indium.
8. The semiconductor device according to claim 2 , wherein the oxide semiconductor film comprises indium, gallium, and zinc.
9. The semiconductor device according to claim 2 , wherein the first insulating film is located below the oxide semiconductor film.
10. The semiconductor device according to claim 2 , further comprising:
a source electrode electrically connected to the oxide semiconductor film; and
a drain electrode electrically connected to the oxide semiconductor film,
wherein each of the source electrode and the drain electrode comprises copper.
11. The semiconductor device according to claim 4 , wherein the concentration is a concentration measured by secondary ion mass spectrometry.
12. A semiconductor device comprising:
a gate electrode;
an insulating film over the gate electrode, the insulating film comprising silicon and halogen;
an oxide semiconductor film over and in contact with the insulating film, the oxide semiconductor film including a channel forming region,
wherein the insulating film comprises:
a first insulating film comprising silicon nitride; and
a second insulating film over the first insulating film, the second insulating film comprises silicon oxide.
13. The semiconductor device according to claim 12 ,
wherein a concentration of the halogen is from 1×10 15 atoms/cm 3 to 1×10 20 atoms/cm 3 inclusive at the concentration peak.
14. The semiconductor device according to claim 12 , wherein the oxide semiconductor film comprises indium.
15. The semiconductor device according to claim 12 , wherein the oxide semiconductor film comprises indium, gallium, and zinc.
16. The semiconductor device according to claim 12 , further comprising:
a source electrode electrically connected to the oxide semiconductor film; and
a drain electrode electrically connected to the oxide semiconductor film,
wherein each of the source electrode and the drain electrode comprises copper.
17. The semiconductor device according to claim 13 , wherein the concentration is a concentration measured by secondary ion mass spectrometry.