Patent ID: 9472681
Filing Date: 2016-10-18
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a first insulating layer over an insulating surface; a first oxide semiconductor layer over the first insulating layer; a second oxide semiconductor layer over the first oxide semiconductor layer; a third oxide semiconductor layer over the second oxide semiconductor layer; a first mixed layer between the first oxide semiconductor layer and the second oxide semiconductor layer; a second mixed layer between the second oxide semiconductor layer and the third oxide semiconductor layer; a second insulating layer over the third oxide semiconductor layer, and wherein the first oxide semiconductor layer comprises constituent elements of the second oxide semiconductor layer and constituent elements of the third oxide semiconductor layer, wherein the second oxide semiconductor layer comprises constituent elements of the first oxide semiconductor layer and the constituent elements of the third oxide semiconductor layer, wherein the third oxide semiconductor layer comprises the constituent elements of the first oxide semiconductor layer and the constituent elements of the second oxide semiconductor layer, wherein the first mixed layer comprises a composition of the first oxide semiconductor layer and a composition of the second oxide semiconductor layer, and wherein the second mixed layer comprises the composition of the second oxide semiconductor layer and a composition of the third oxide semiconductor layer.