Arc ion plating process monitoring by optical emission spectroscopy exemplified for chromium containing coatings

Abstract

The coating process stability is one of the key features for a constant performance of coated tools. Common parameters monitored during the coating deposition in conventional AIP PVD processes are cathode voltage and current, deposition pressure, substrate temperature, and gas flow. However, these external recorded parameters do not reveal the plasma composition and its influence on the coating properties. Optical emission spectroscopy (OES) measurements were carried out to close this gap. The OES values measured during the deposition of (Cr,Al)N and (Cr,Al)ON were correlated with their thin film composition and mechanical properties. Film properties were determined by nanoindentation, adhesion test, calo test, and EDS. The experiments have shown a strong correlation between partial pressure, ionization of nitrogen atoms, and film properties. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.