Substrate for magnetic recording medium, method for manufacturing the same and magnetic recording medium

摘要

Provided is a substrate for a magnetic recording medium, preferably a substrate having a small diameter of not more than 65 mm, which is advantageous in respect of physical properties and cost. More specifically, provided is a substrate for a magnetic recording medium, using a monocrystalline silicon wafer which has been heated and/or etched at least once before. Moreover, provided is a method for manufacturing a substrate for a magnetic recording medium, the method comprising a step of coring for obtaining a plurality of doughnut-shaped substrates having an outer diameter of not more than 65 mm from a monocrystalline silicon wafer having a diameter of at least 150 mm and at most 300 mm which has undergone heating and/or etching at least once. The method may preferably further comprise a step of chamfering for removing edges of inner and outer circumferential faces of said doughnut-shaped substrate; and a step of circumferential face-polishing for polishing the chamfered inner and outer circumferential faces.