Plated substrate for hard disk medium

Abstract

In plating on an Si substrate, it has been strongly demanded to apply a treatment for providing an excellent adhesion so as to resist a post-processing such as polishing and for facilitating plating. Then, provided is a plated substrate adapted for hard disk medium comprising an Si single crystal; an amorphous layer on the substrate, the amorphous layer having thickness of 2 to 200 nm and containing Si and one or more metals selected from a group consisting of Ni, Cu and Ag; a multicrystal layer on the amorphous layer, the multicrystal layer having thickness of 5 to 1000 nm and containing Si and one or more metals selected from a group consisting of Ni, Cu and Ag. Moreover, provided is a method for manufacturing a plated substrate adapted for hard disk medium comprising steps of applying a chemical etching treatment of a natural oxide film and a surface Si portion on an Si single crystal substrate; and forming a film on the etched surface of the substrate in a sulfate or hydrochloride bath containing no reductant within a pH range of 7.2 to 12.8 at liquid temperature of 70 to 100° C.