ELECTRODE STRUCTURE OF SEMICONDUCTOR ELEMENT

PURPOSE:To prevent an electrode from being corroded by Cl ions or Na ions at high humidity and by a diffusion operation at high temperature and to enhance relaibility of the electrode by a method wherein an Ni metal layer is formed on an Al electrode on an Si substrate, an Au metal layer is formed additionally and the thickness of all the metal layers is set to 5mum or lower. CONSTITUTION:A circuit is formed on a semiconductor element 1 by using an SiO2 oxide film 3, an Al interconnection 2 and the like; parts excluding a pad part to be connected to the outside are covered with a passivation 4 used to protect the circuit. An Ni metal layer 5 is formed on Al exposed at the pad part by a vacuum thin-film technique such as a sputtering method; an Au metal layer 6 is formed on it by the same technique or by an electroless plating operation; the total thickness of an electrode is set to 5mum or lower. When the thickness is excessive, Ni is precipitated outside the electrode, probability of a short circuit between electrodes becomes high, their formation time becomes long and the cost is increased. A wire-bonded Au wire can prevent the drop in strength by a diffusion operation at a high temperature of 150 deg.C and can prevent the electrode from being corroded at high humidity.