Amorphous oxide semiconductor thin film transistor fabrication method

A thin film transistor (TFT) device comprising:

• a substrate including a surface;
• an oxide semiconductor layer disposed over the substrate surface, a channel region of the oxide semiconductor layer being between a source region and a drain region of the oxide semiconductor layer, the source region and the drain region of the oxide semiconductor layer being a heavily doped n-type oxide semiconductor;
• a gate dielectric on the channel region of the oxide semiconductor layer;
• a gate metal on the gate dielectric, wherein the gate metal defines the channel region of the oxide semiconductor layer;
• source means for removing oxygen from the oxide semiconductor layer on the source region of the oxide semiconductor layer, wherein the source removing means defines the source region;
• drain means for removing oxygen from the oxide semiconductor layer on the drain region of the oxide semiconductor layer, wherein the drain removing means defines the drain region of the oxide semiconductor layer;
• a passivation dielectric on the gate metal and on the source removing means and the drain removing means;
• a first metal contact extending through the source removing means and contacting the source region of the oxide semiconductor layer;
• and
• a second metal contact extending through the drain removing means and contacting the drain region of the oxide semiconductor layer.