Patent ID: 8143678

Claim:
A thin film transistor, comprising: a gate insulating layer; a gate electrode formed on a first side of the gate insulating layer; a channel layer formed of a ZnO based material on a second side of the gate insulating layer; a source electrode that contacts a first portion of the channel layer; and a drain electrode that contacts a second portion of the channel layer; wherein the channel layer has a double-layer structure, including an uppermost layer and a lower layer, the lower layer being disposed between the uppermost layer and the gate insulating layer, wherein a thickness of the uppermost layer is greater than or equal to 10 nm and less than or equal to 100 nm, wherein the uppermost layer is doped with a carrier acceptor and the lower layer is not doped with the carrier acceptor, and the uppermost layer has a lower carrier concentration than the lower layer, so that an electrical resistance of the uppermost layer is higher than the electrical resistance of the lower layer, wherein the carrier acceptor comprises Cu, and wherein a Cu content of the uppermost layer is 29-44 atomic %.