PLASMA CONDITIONS FOR THE DEPOSITION OF WEAR-RESISTANT CARBON-COATINGS

The properties of sputter and microwave-ECR plasmas have been investig ated with a plasma emission monitor (PEM) in the range between 280 and 820 nm with various resolutions. Additional Langmuir probe measuremen ts of the sputter plasma were performed to determine the spatial varia tion of electron density and temperature. Using helium as an additiona l measuring gas, the electron temperature has been determined by compa ring the intensities of an argon and a helium emission line. The conce ntration of atomic hydrogen and CH radicals can be determined by actin ometry. A comparison between the two types of plasmas shows similar el ectron temperature dependencies on the plasma power, the argon partial pressure and the acetylene partial pressure. The electron temperature s determined from PEM and Langmuir probe measurements correlate very w ell. When the microwave ECR plasma is used at the same time as the spu tter plasma the electron temperature in the sputter plasma is reduced because of the charged particle current flowing out of the ECR plasma. The electron temperature in the ECR plasma varies only slightly when the sputter plasma is switched on but the concentration of atomic hydr ogen increases because of the additional conversion of the acetylene o n the target surface. (C) 1997 Elsevier Science S.A.