Organic light emitting diode display device and method of manufacturing an organic light emitting diode display device

A method of manufacturing OLED display device, the method comprising:

• providing a substrate having a display region including a plurality of sub-pixel regions, the substrate having a peripheral region located at a side of the display region;
• forming a first preliminary oxide semiconductor layer on the substrate;
• forming a first oxide semiconductor pattern including Sn in the peripheral region on the substrate after the first preliminary oxide semiconductor layer is patterned using a first etchant;
• forming a second preliminary oxide semiconductor layer on the substrate and the first oxide semiconductor pattern;
• forming a second oxide semiconductor pattern in the sub-pixel regions each after the second preliminary oxide semiconductor layer is patterned using a second etchant;
• and
• forming a sub-pixel structure on the second oxide semiconductor pattern.