Method for manufacturing single-crystal semiconductor layer, structure comprising single-crystal semiconductor layer, and semiconductor device comprising structure

Thin Film Transistor comprising:

• a single crystalline substrate;
• a single crystalline semiconductor layer having a hexagonal wurtzite structure epitaxially grown from the single crystalline substrate;
• a gate electrode disposed on the single crystalline semiconductor layer;
• a gate insulating film disposed between the single crystalline semiconductor layer and the gate electrode;
• and
• source and drain electrodes electrically connected to both ends of the single crystalline semiconductor layer.

Light Emitting Diode (LED) comprising:

• a substrate;
• a buffer layer in which a lower region adjacent to the substrate has a c-plane preferred orientation and a region located above the lower region has an m-plane preferred orientation;
• a light-emitting structure layer disposed on the buffer layer and including a first-conductive-type semiconductor layer and a second-conductive-type semiconductor layer;
• a first electrode electrically connected to the first-conductive-type semiconductor layer;
• and
• a second electrode electrically connected to the second-conductive-type semiconductor layer.