A small magnet assembly is scanned in a retrograde planetary or epicyclic path about the back of a target being plasma sputtered including an orbital rotation about the center axis of the target and a planetary rotation about another axis rotating about the target center axis. The gate wire has gate lines, first and second gate electrodes connected to the gate lines, and gate pads. The product is a layered structure that includes a rigid substrate layer having two substantially planar sides, a resin-saturated sheet layer disposed on each of the substantially flat sides, and a veneer layer disposed on at least one of the sheet layers. The amorphous silicon film is formed to be thicker than the polycrystalline silicon film.