Patent ID: 9391213
Filing Date: 2016-07-12
CPC Classification: G02F,H01L

Claim Text:
1. A bottom gate thin film transistor using a first oxide semiconductor as a channel layer, the transistor comprising: a substrate, a gate electrode which is formed on the substrate, a gate insulating film which is formed on the gate electrode, a first oxide semiconductor layer as a channel layer which is formed on the gate insulating film, a channel protection layer which is formed on the first oxide semiconductor layer as the channel layer; a first laminated film which includes a source electrode and a second oxide semiconductor layer formed to extend from the first oxide semiconductor layer to one upper end part of the channel protection layer in a source region; a second laminated film which includes a drain electrode and a second oxide semiconductor layer formed to extend from the first oxide semiconductor layer to other upper end part of the channel protection layer in a drain region; and a passivation film which is formed to cover the source electrode, the channel protection film, and the drain electrode, and wherein the first and second oxide semiconductor layers include indium and oxygen, and a content ratio of oxygen to indium (O/In) of the second oxide semiconductor layer is equal to or larger than that of the first oxide semiconductor layer, and a film thickness of the second oxide semiconductor layer is thicker than that of the first oxide semiconductor layer below the channel protection layer.