SPUTTER COATING ON HIGH-SPEED STEEL TUBE USING A HYBRID PLASMA PRODUCED BY COAXIAL ECR AND MAGNETRON DISCHARGES

We have developed a hybrid plasma source with a magnetic field for coating on ferromagnetic substrates such as high speed steel (HSS) cutting tools. Two types of plasmas were simultaneously produced by a coaxial electron cyclotron resonance discharge inside the substrate and by a coaxial magnetron discharge outside the tube. Discharge characteristics of both plasma sources were investigated for varying target bias voltage and magnetic flux density under various gas pressures. The measurements of plasma parameters (density and temperature) showed that the high electron density of 10(11) cm-3 was obtained at an input microwave power of 30 W and a gas pressure of 7 x 10(-4) Torr. Titanium nitride coatings on HSS tools were produced by the hybrid plasma sources developed. The substrate temperature was increased during the processes, but could be maintained below 500-degrees-C. Simultaneous coating on the inside, outside and edge of a cylindrical cutting tool was possible with the newly developed hybrid plasma sources.