ELECTRODE FOR SEMICONDUCTOR ELEMENT

PURPOSE:To capture Au being accelerated and moved thermally or by currents by a substance layer producing an eutectic with Au and alloy Au, and to prevent a diffusion to the semiconductor side of Au more than mentioned above by holding the substance layer between a Ti layer and a Pt layer. CONSTITUTION:An N type InGaAsP layer 2, a P type InP 3 and a P-pole InGaAsP layer 4 as a contact layer are deposited on an N type InP substrate 1 in succession, thus forming a semiconductor element. A Ti layer 5 in 1,000Angstrom thickness, a layer 8 in 200Angstrom thickness using either of indium, germanium, silicon or tin as a substance M producing an eutectic with Au and a Pt layer 6 in 1,000Angstrom thickness are applied in succession by employing resistance heating or electron-beam evaporation as a P-electrode, and an Au layer 7 in 3mum thickness is applied onto the layer 6 through normal electroplating. The whole is thermally treated for 30min at 430 deg.C in an electric furnace in order to take an ohmic contact between the P type InGaAsP layer 4 and the Ti layer 5. Accordingly, element characteristics are not deteriorated, thus obtaining an element for the semiconductor element having high reliability.