XPS study of CMP mechanisms of NiP coating for hard disk drive substrates

Chemical mechanical polishing (CMP) mechanisms of NiP coating plated on Al-Mg alloy substrates have been investigated with an X-ray photoelectron spectroscope (XPS). The XPS results indicate that after cleaning, the disk surface contains a thin layer of Ni(CH)(2) and P2O3, followed by a thin NiO and P2O3 layer. It is also deduced that during polishing, the disk surface has an oxidization layer with Ni2+ and p(3+) species. The experimental investigations reveal that the CMP mechanisms involve a simultaneous process of surface chemical passivation and nano-particle wear. (C) 2009 Elsevier Ltd. All rights reserved.