METHOD FOR FORMING ELECTRODE OF SEMICONDUCTOR ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide electroless nickel plating and gold plating methods on an aluminum electrode for forming a highly reliable electrode. SOLUTION: Zinc is deposited 14 on the aluminum electrode 12 with zincate treating liquid containing sodium hydroxide and zinc oxide. Then, sodium hypophosphite being a reducing agent is dissolved in pure water. Pure water is added while it is adjusted to pH 9.0-12.0 with sodium hydroxide solution and it is immersed into solution 15 which is set to be 1000 mL in total. Then, nickel plating is executed with the condition of pH 4.0-6.8 at 80-90 deg.C by using oxidation-reduction reaction electroless nickel plating liquid containing sulfur compound with the aluminum electrode 12 of the semiconductor element as reaction accelerator. Thus, a nickel film 16 containing phosphorus and gold plating films 17 and 18 are obtained in all the aluminum electrodes 12 of the semiconductor element by executing substitution reaction electroless gold plating and oxidation reduction-type electroless plating.