Organic light emitting diode display having thin film transistor substrate using oxide semiconductor

A method for manufacturing an organic light emitting diode (OLED) display can include forming a gate electrode on a substrate, forming a semiconductor layer by depositing a gate insulating layer and an oxide semiconductor material and patterning the oxide semiconductor material, forming an etch stopper on a central portion of the semiconductor layer, conducting a plasma treatment using the etch stopper as a mask to conductorize portions of the semiconductor layer exposed by the etch stopper for defining a channel area, a source area and a drain area, and forming a source electrode contacting portions of the conductorized source area and a drain electrode contacting portions of the conductorized drain area.