Morphology and Surface Roughness of Cr-Coated Alternate Hard Disk Substrates for Ultra-High Density Magnetic Recording

Abstract

Morphology and surface roughness of Canasite, SiC, carbon, glass disk and cover glass substrates covered with 0 Å, 500 Å and 1000 Å of Cr film were studied using an atomic force microscope (AFM). This study resulted in precise qualitative and quantitative descriptions of the sample surfaces. It was demonstrated that the surface morphology of a hard disk substrate determined the appearance and surface roughness of a thinner Cr film (500 Å). Thicker Cr films (1000 Å) controlled surface roughness, when deposited on smooth surfaces, with a regular surface morphology (carbon, glass disk, cover glass). Very deep (or very high) surface roughness features of SiC and Canasite surfaces, with diameters exceeding average Cr grain size, were not only reproduced but even enhanced by the 1000 Å Cr film.