A method of forming a layer, including forming an insulation layer having an opening on a single crystalline substrate, the opening partially exposing an upper face of the substrate, forming a first seed layer in the opening, converting an upper portion of the first seed layer to a first amorphous layer, converting the first amorphous layer to a second seed layer, forming a second amorphous layer on the second seed layer, and converting the second amorphous layer to a single crystalline layer.