1. A semiconductor device comprising: a semiconductor substrate having a surface; a gate insulating film formed on the surface of the semiconductor substrate; a gate electrode formed on the gate insulating film, the gate electrode including a polycrystalline silicon layer as a lowermost layer and a conductive layer as an uppermost layer, the conductive layer having an antireflection function; an insulating layer covering the gate electrode, the insulating layer having openings of different depth exposing part of the conductive layer of the gate electrode and part of the substrate surface; and a higher level wiring layer including portions respectively connected to the part of the conductive layer and the part of the substrate surface via the openings.