Patent ID: 9324875
Filing Date: 2016-04-26
CPC Classification: H01L

Claim Text:
1. A semiconductor device comprising a transistor, the transistor comprising: a gate electrode; a stacked-layer oxide film comprising a first oxide semiconductor film, a second oxide semiconductor film, and a third oxide semiconductor film; a gate insulating film between the gate electrode and the stacked-layer oxide film; and a source electrode and a drain electrode which are in contact with the stacked-layer oxide film, wherein at least one of the first-third oxide semiconductor films includes a channel formation region, wherein a channel length of the transistor is greater than or equal to 5 nm and less than 60 nm, wherein a thickness of the gate insulating film is larger than a thickness of the one of the first-third oxide semiconductor films including the channel formation region, wherein each of the source electrode and the drain electrode comprises a first conductive layer and a second conductive layer over the first conductive layer, wherein the third oxide semiconductor film is between the source electrode of the first conductive layer and the second conductive layer over the first conductive layer, and is between the drain electrode of the first conductive layer and the second conductive layer, wherein a side surface of the second conductive layer extends beyond a side surface of the first conductive layer in a channel length direction, and wherein the side surface of the second conductive layer is over the channel formation region.