FORMING METHOD FOR OHMIC ELECTRODE TO SURFACE OF P TYPE 4-6 GROUP COMPOUND SEMICONDUCTOR

PURPOSE:To form a good ohmic electrode on the surface of a P type IV-VI group compound semiconductor by energizing a gold tantalum plating solution with the semiconductor and a gold electrode, thereby depositing gold-tantalum alloy on the surface of the semiconductor. CONSTITUTION:A gold thallium plating solution added with Tl(SO4)2 to a gold plating solution containing mainly K(Au(CJ)2) is energized with a P type IV-VI group compound semiconductor and gold electrode of PBTe sereis, PbSnTe series and PbTeSe series as a cathode and an anode in the state arranged with the semiconductor and the gold, and the surface is thus slightly etched, thereby obtaining the surface formed with no oxide. With the cathode and the anode connected reversely, gold-tantalum alloy is deposited on the surface, and the P type IV-VI group compounds are thereafter removed from the solution. In this manner, good ohmic electrode can be formed on the surface of the semiconductor with the extremely simple steps.