Oxide semiconductor devices, methods of forming oxide semiconductor devices and organic light emitting display devices including oxide semiconductor devices

A method for forming an oxide semiconductor device, the method comprising:

• forming a first insulation layer pattern and second insulation layer pattern on a substrate;
• forming an active layer on the substrate, the first insulation layer pattern, and the second insulation layer pattern;
• forming a source region and a drain region in the active layer, the source region and the drain region comprising the first insulation layer pattern and the second insulation layer pattern, respectively;
• forming a gate insulation layer on the active layer;
• forming a gate electrode on the gate insulation layer;
• forming an insulating interlayer on the gate insulation layer and the gate electrode;
• and
• forming a source electrode and a drain electrode passing through the insulating interlayer and the gate insulation layer, the source electrode and the drain electrode contacting the source region and the drain region, respectively.

An organic light emitting display device, comprising:

• a substrate;
• an oxide semiconductor device disposed on the substrate, the oxide semiconductor device comprising a first insulation layer pattern, a second insulation layer pattern, an active layer comprising a source region comprising the first insulation layer pattern, a drain region comprising the second insulation layer pattern, and a channel region disposed between the source region and the drain region, a source electrode contacting the source region, and a drain electrode contacting the drain region;
• a first electrode electrically connected to the drain electrode;
• a light emitting layer disposed on the first electrode;
• and
• a second electrode disposed on the light emitting layer.