Method for forming silver film

摘要

It is an object of the present disclosure to provide a method that allows uniformly forming a silver film by a solid electrolyte deposition. One aspect of this embodiment is a method for forming a silver film. The method includes disposing an anode, a substrate as a cathode, and a separator such that the separator is positioned between the anode and the substrate and the separator is in contact with a surface of the substrate, the separator including an electrolytic solution that contains silver ions, and applying a voltage between the anode and the substrate to form a silver film on the substrate. The separator is a porous membrane without ion exchange functional group. The electrolytic solution contains organic sulfonic acid ions. The substrate contains a crystalline metal, and a silver film is formed on the crystalline metal.