Patent ID: 9570625
Date: 2017-02-14
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a first oxide layer over an insulating surface; an oxide semiconductor layer over the first oxide layer; a second oxide layer over the oxide semiconductor layer; an insulating layer surrounding a side surface of the oxide semiconductor layer; a source electrode comprising a first source electrode and a second source electrode over the first source electrode; a drain electrode comprising a first drain electrode and a second drain electrode over the first drain electrode, a gate electrode overlapping with the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode, wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor layer, wherein each of an end portion of the source electrode and an end portion of the drain electrode is interposed between the oxide semiconductor layer and the second oxide layer, wherein the first source electrode and the first drain electrode are in direct contact with the oxide semiconductor layer and the insulating layer, wherein the second source electrode and the second drain electrode are in direct contact with the oxide semiconductor layer, wherein a side surface of the second source electrode is in direct contact with the second oxide layer, wherein a side surface of the second drain electrode is in direct contact with the second oxide layer, and wherein the second oxide layer comprises indium or zinc.