Transistor panel having a good insulation property and a manufacturing method thereof

A display device, comprising:

• a semiconductor layer comprising a channel region, a source region and a drain region, wherein the channel region including an oxide including a first metal, the source region and the drain region including the first metal, and the channel region is disposed between the source and drain regions;
• an insulation layer disposed on the channel region;
• an upper electrode disposed on the insulation layer;
• an interlayer insulation layer disposed on the upper electrode, the source region, and the drain region;
• a barrier layer including a first portion and a second portion, wherein the first portion of the barrier layer is disposed between the interlayer insulation layer and each of source and drain regions, wherein the first portion of the barrier layer contacts the source region and the drain region, and wherein the second portion of the barrier layer is disposed between the upper electrode and the insulation layer;
• a drain electrode disposed on the interlayer insulation layer and electrically connected to the drain region;
• an emission layer disposed on the drain electrode;
• and
• a common electrode on the emission layer.