Display device and manufacturing method thereof

A method of manufacturing a display device, wherein the display device includes a substrate including a display area and a non-display area, a gate driver disposed on the substrate in the non-display area and including a plurality of stages that generates a gate signal and outputs the gate signal to the display area, a switching transistor and a driving transistor disposed on the substrate in the display area, and a light emitting diode connected to the driving transistor,

• wherein the method includes:
• sequentially forming a first semiconductor material layer and a second semiconductor material layer on the substrate;
• forming a switching semiconductor layer and a driving semiconductor layer by etching the first semiconductor material layer;
• forming a switching channel layer that overlaps at least a portion of the switching semiconductor layer by etching the second semiconductor material layer;
• forming a gate insulating film material layer on the substrate, the switching semiconductor layer, the driving semiconductor layer, and the switching channel layer;
• forming a switching gate electrode that overlaps at least a portion of the switching channel layer and a driving gate electrode that overlaps at least a portion of the driving semiconductor layer on the gate insulating film material layer;
• forming a gate insulating film by etching the gate insulating film material layer using the switching gate electrode and the driving gate electrode as masks;
• forming an interlayer insulating film on the switching semiconductor layer, the driving semiconductor layer, the switching gate electrode, and the driving gate electrode;
• forming a switching source electrode, a switching drain electrode, a driving source electrode, and a driving drain electrode on the interlayer insulating film;
• and
• forming a light emitting diode connected to the driving drain electrode,
• wherein the first semiconductor material layer includes a first oxide semiconductor material, and the second semiconductor material layer include a second oxide semiconductor material,
• wherein the first oxide semiconductor material is different from the second oxide semiconductor material, and
• wherein the second semiconductor material layer includes tin.