Semiconductor device and method for manufacturing the same

摘要

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.

主权项

1. A semiconductor device comprising:
a first insulating layer over a substrate; an oxide semiconductor layer over the first insulating layer; a second insulating layer over the oxide semiconductor layer; and a third insulating layer formed of silicon oxide over the oxide semiconductor layer, wherein the second insulating layer is formed over the third insulating layer, wherein in the third insulating layer the concentration of a boron element is lower than that in the first and second insulating layers.