Semiconductor device having oxide semiconductor layer
View Patent ↗It is an object to manufacture a highly reliable semiconductor device including a thin film transistor whose electric characteristics are stable. An insulating layer which covers an oxide semiconductor layer of the thin film transistor contains a boron element or an aluminum element. The insulating layer containing a boron element or an aluminum element is formed by a sputtering method using a silicon target or a silicon oxide target containing a boron element or an aluminum element. Alternatively, an insulating layer containing an antimony (Sb) element or a phosphorus (P) element instead of a boron element covers the oxide semiconductor layer of the thin film transistor.
1. A semiconductor device comprising:
a first insulating layer over a substrate;
an oxide semiconductor layer over the first insulating layer; and
a second insulating layer over the oxide semiconductor layer,
wherein the first insulating layer and the second insulating layer each contain a boron element or an aluminum element at greater than or equal to 1×10 18 cm −3 and less than or equal to 1×10 22 cm −3 .
2. The semiconductor device according to claim 1 , wherein the second insulating layer is in contact with the oxide semiconductor layer.
3. The semiconductor device according to claim 1 , further comprising a third insulating layer formed of silicon oxide between the second insulating layer and the oxide semiconductor layer,
wherein the third insulating layer does not contain a boron element, an aluminum element, a phosphorus element, or an antimony element.
4. The semiconductor device according to claim 1 , wherein the first insulating layer and the second insulating layer are each formed of silicon oxide.
5. A semiconductor device comprising:
a first insulating layer over a substrate;
an oxide semiconductor layer over the first insulating layer; and
a second insulating layer over the oxide semiconductor layer,
wherein the first insulating layer and the second insulating layer each contain a phosphorus element or an antimony element at greater than or equal to 1×10 19 cm −3 and less than or equal to 3×10 21 cm 31 3 .
6. The semiconductor device according to claim 5 , wherein the second insulating layer is in contact with the oxide semiconductor layer.
7. The semiconductor device according to claim 5 , further comprising a third insulating layer formed of silicon oxide between the second insulating layer and the oxide semiconductor layer,
wherein the third insulating layer does not contain a boron element, an aluminum element, a phosphorus element, or an antimony element.
8. The semiconductor device according to claim 5 , wherein the first insulating layer and the second insulating layer are each formed of silicon oxide.
9. A semiconductor device comprising:
a first insulating layer over a substrate;
an oxide semiconductor layer on and in contact with the first insulating layer; and
a second insulating layer on and in contact with the oxide semiconductor layer,
wherein the first insulating layer and the second insulating layer each contain a boron element or an aluminum element at greater than or equal to 1×10 18 cm −3 and less than or equal to 1×10 22 cm −3 .
10. The semiconductor device according to claim 9 , wherein the second insulating layer is in contact with the oxide semiconductor layer.
11. The semiconductor device according to claim 9 , further comprising a third insulating layer formed of silicon oxide between the second insulating layer and the oxide semiconductor layer,
wherein the third insulating layer does not contain a boron element, an aluminum element, a phosphorus element, or an antimony element.
12. The semiconductor device according to claim 9 , wherein the first insulating layer and the second insulating layer are each formed of silicon oxide.