Methods of manufacturing an oxide semiconductor thin film transistor

A method of manufacturing an oxide semiconductor thin film transistor, the method comprising:

• forming a gate on a substrate;
• forming a gate insulating layer on the substrate such that the gate insulating layer covers the gate;
• forming a channel layer on the gate insulating layer, the channel layer being formed of an oxide semiconductor;
• forming source and drain electrodes on opposing sides of the channel layer;
• forming a passivation layer that covers the source and drain electrodes and the channel layer;
• injecting a plurality of oxygen-containing ions into the channel layer after forming the passivation layer;
• and
• annealing the oxide semiconductor thin film transistor after forming the passivation layer and injecting the oxygen-containing ions.