Method of manufacturing semiconductor active layer, method of manufacturing thin film transistor using the same and thin film transistor having semiconductor active layer

A method of manufacturing a thin film transistor, the method comprising:

• forming an IGZO active layer on a substrate;
• forming a gate electrode spaced apart from the IGZO active layer by a gate dielectric layer;
• forming a source electrode that contacts a first portion of the IGZO active layer;
• and
• forming a drain electrode that contacts a second portion of the IGZO active layer, wherein forming the IGZO active layer includes:
• depositing ions including In, Ga, and Zn from a first target, and
• depositing ions including In from a second target having a different atomic composition from the first target, the deposition of ions from the second target being controlled to adjust an atomic % of In in the IGZO layer to be about 45 atomic % to about 80 atomic %.

A thin film transistor, comprising:

• a substrate;
• an IGZO active layer on the substrate, the IGZO layer including a channel region, a source region, and a drain region;
• a gate electrode overlapping the channel region and insulated from the active layer by a gate insulator;
• and
• source and drain electrodes contacting the source and drain regions, respectively,
• wherein an atomic % of In in the IGZO active layer is about 45 atomic % to about 80 atomic %.