Abstract: A method for forming a metal wiring of a semiconductor element, which uses an aluminum film as an oxidation prevention film to prevent oxygen from being diffused into copper contained in the metal wiring. An aluminum oxidation prevention film layer is selectively formed on an exposed surface of the copper metal wiring layer using a selective chemical vapor deposition method. The width of the aluminum layer formed is below 100.ANG., and is converted into Al.sub.2 O.sub.3 at heat treating or under an atmosphere, thereby preventing the copper from oxidation. A diffusion prevention film between the substrate and the copper metal wiring layer is further included for preventing the copper from diffusing into the substrate.

Abstract: A defrost assembly for the evaporator of a refrigerator comprises a thin heating plate of thermally conductive material underlying the evaporator. An electric cord is mounted to an underside of the heating plate for heating the heating plate. A thermal insulating board underlies the heating plate. A thermally responsive cut-off terminates flow to the electric cord when the evaporator reaches a prescribed temperature. A rear portion of the heating plate forms a channel for draining-off melted water.