Preparation of SiO2 thin films on high speed steel substrates by RF reactive magnetron sputtering

Silicon dioxide thin films have been deposited successfully on high speed steel (HSS) substrates by means of microwave electron cyclotron resonance (MW-ECR) plasma source enhanced RF reactive magnetron sputtering of a pure silica target in an oxygen and argon mixture. The films are characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Chemical composition of the thin films on HSS substrates have been investigated as a function of the gas volume ratio [O-2]/[Ar], RF. power and substrate bias. A comparative study of the SiO2 thin films deposited at -20 V DC bias and -80 V RF bias is presented. An improvement of the SiO2 thin film properties due to increased energetic substrate bombardment has been found. It is concluded that SiO2 thin films deposited on HSS substrates by this method are compact and dense, and have good stoichiometry and electrical insulation properties.