Method of texture by in-situ masking and etching for thin film magnetic recording medium

Abstract

A magnetic recording medium controllably textured by performing sputter etching or reactive ion etching either on the surface of a smooth substrate, which can be nickel-phosphorous/aluminum-magnesium (Al--Mg) substrate, or on the surface of a protective layer, such as a carbon overcoat. Both types of etching processes described above are carried out in a sputtering apparatus and have an etching mask of discrete hemi-spherical structures formed by the agglomeration of a low melting point metal or alloy such as indium or Pb--Sn, which has been deposited on a non-wetting surface such as the oxidized surface of NiP layer or the protective carbon overcoat prior to etching. The morphology of the textured surface can be controlled by adjusting the average thickness of the deposited masking materials, the gas composition, as well as the base pressure during etching. An optimum texture created by either sputter etching or reactive ion etching on a magnetic recording medium provides better wear resistance and a lower flying height of a magnetic head as compared to conventional mechanical texturing techniques. In addition, the manufacturing processes of the magnetic recording medium thus defined including the deposition of underlayer, magnetic layer and protective overcoat and the creation of surface texture can be successively performed within a single vacuum system without breaking vacuum; the present invention thus possesses the advantages of process automation, improving quality, and lowering manufacturing cost.

Dependencies are inferred from the claim text.