A method of forming an ohmic contact layer including forming an insulation layer pattern on a substrate, the insulation pattern layer having an opening selectively exposing a silicon bearing layer, forming a metal layer on the exposed silicon bearing layer using an electrode-less plating process, and forming a metal silicide layer from the silicon bearing layer and the metal layer using a silicidation process. Also, a method of forming metal wiring in a semiconductor device using the foregoing method of forming an ohmic contact layer.