Patent ID: 9385238
Filing Date: 2016-07-05
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising: a first insulating layer over a substrate; a first buffer layer over the first insulating layer; an oxide semiconductor layer over and in contact with the first buffer layer, the oxide semiconductor layer including a channel region; a second buffer layer in contact with side surfaces of the oxide semiconductor layer, wherein the side surfaces of the oxide semiconductor layer are opposed to each other in a channel length direction; a gate insulating film over the second buffer layer; a gate electrode over the gate insulating film; a second insulating layer over the gate electrode, the second insulating layer comprising a first opening and a second opening; a source electrode over the second insulating layer, the source electrode electrically connected to the oxide semiconductor layer through the first opening; and a drain electrode over the second insulating layer, the drain electrode electrically connected to the oxide semiconductor layer through the second opening, wherein the second buffer layer is in direct contact with a top surface of the oxide semiconductor layer and a top surface of the first buffer layer, wherein each of the first buffer layer and the second buffer layer comprises an oxide of one or more elements selected from a group comprising aluminum, gallium, zirconium, hafnium, and a rare earth element, and wherein the second buffer layer is a single layer.