Evaluation of amorphous diamond-like carbon-nitrogen films as wear protective coatings on thin film media and thin film head sliders

Abstract

As the magnetic data storage industry strives to achieve ultra-high recording densities requiring fly heights of less than one microinch, the tribology of the head-disk interface (HDI) is a limiting factor in disk drive design. Amorphous diamond-like-carbon (DLC) films have been the materials of choice for wear-protective coatings. Various amorphous DLC type coatings have been developed. The earliest DLC material was DC magnetron sputtered pure carbon films. Recent developments have produced C:H (hydrogenated-carbon) and C:N (carbon-nitrogen) films with greater wear-resistance than pure C film. Our intent is to describe and evaluate the wear-resistance performance of amorphous C:N films as wear-protective overcoats on thin film media and thin film sliders. Both C:H and C:N films have demonstrated superiority over DC magnetron sputtered pure carbon films. The bond character, microhardness, surface roughness features, and the physical nature of initial wear damage influence wear-resistance performance significantly. A recent report of nano-indentor measurements and wear-resistance performance confirmed the superiority of RF diode and DC magnetron Facing Target Sputtering (FTS) of thin C:N coatings over other DLC films.