Patent ID: 8653513

Claim:
A semiconductor device comprising: a semiconductor layer; a source electrode comprising: a first conductive layer; and a second conductive layer in contact with the semiconductor layer; a drain electrode comprising: a third conductive layer; and a fourth conductive layer in contact with the semiconductor layer; a first sidewall insulating layer in contact with the source electrode; a second sidewall insulating layer in contact with the drain electrode; a gate electrode overlapping with the semiconductor layer; and a gate insulating layer between the semiconductor layer and the gate electrode, wherein the second conductive layer has a first region which extends beyond an end portion of the first conductive layer in a channel length direction and which overlaps with part of the gate electrode, wherein the fourth conductive layer has a second region which extends beyond an end portion of the third conductive layer in the channel length direction and which overlaps with part of the gate electrode, wherein the first sidewall insulating layer is provided on the first region, wherein the second sidewall insulating layer is provided on the second region, wherein the first sidewall insulating layer and the second sidewall insulating layer each comprise a nitride insulating layer and an oxide insulating layer, and wherein the nitride insulating layer extends beyond an end portion of the oxide insulating layer.