Sputter-induced random micro texturing on NiP plated aluminium and alternate substrates

Random micro texturing can be developed on both NiP/Al and alternate substrate disks by sputtering nonwetting and seed layers. The nonwetting layer was first sputtered on the substrate, then the seed layer, chrome underlayer, CoCrPtTa magnetic layer and carbon overcoat were sequentially deposited on top of the nonwetting layer. The seed layer melting point, film thickness, substrate surface energy, and temperature were found to be key parameters affecting the properties and characteristics of sputter-induced micro texturing (SIMT). The surface topography and roughness of micro texturing were characterized using SEM, Atomic Force Microscope (AFM), and glide height avalanche tests. Tribology tests were conducted using 1 RPM stiction test and a CSS test on disk drives equipped with semiconductor strain gauges. By carefully controlling process parameters, the number of texturing summits at the desired threshold level can be increased significantly without changing the surface roughness as measured by optical interferometry. Consequently, disk stiction can be greatly improved without deteriorating glide performance