Abstract: An optical device includes: a lens including a first lens portion having a first curved surface with a first curvature and a second lens portion having a second curved surface corresponding to the first curved surface; a display device disposed on a first side surface of the lens; a convex lens disposed between the first side surface of the lens and the display device; and a reflector disposed on the first curved surface of the first lens portion of the lens, the reflector configured to reflect light of the display device refracted by the convex lens toward a user's eye.

Abstract: A power semiconductor device includes a semiconductor layer of silicon carbide (SiC), at least one trench that extends in one direction, a gate insulating layer disposed on at least an inner wall of the at least one trench, at least one gate electrode layer disposed on the gate insulating layer, a drift region disposed in the semiconductor layer at least on one side of the at least one gate electrode layer, a well region disposed in the semiconductor layer to be deeper than the at least one gate electrode layer, a source region disposed in the well region, and at least one channel region disposed in the semiconductor layer of one side of the at least one gate electrode layer between the drift region and the source region.

Abstract: The present invention is to provide a method for fabricating a semiconductor device, including the steps of: (a) forming an insulating layer on a semiconductor substrate; (b) selectively removing the insulating layer and then forming an opening and the residual insulating layer on a bottom of the opening; (c) removing the residual insulating layer by wet etching in order to expose the semiconductor substrate; and (d) burying a conductive layer in the opening and then forming a conductive layer pattern connected to the semiconductor substrate.