Growth of DLC and BCN films by Magnetron Sputtering using sintered diamond and c-BN target

Naoto Ohtake

Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology.

2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan.

Abstract

This paper describes characteristics of DLC and BCN films grown from diamond and diamond-c-BN powder mixture targets.. Firstly, DLC films were prepared on silicon and silica glass substrates by DC-magnetron sputtering using a sintered diamond (polycrystalline diamond, PCD) target. The PCD target, which was 60 mm in diameter, was mounted on a DC-magnetron cathode, then the target was sputtered by argon and hydrogen gases. The hardness of the DLC film increased with increasing hydrogen flow rate, corresponding to a maximum at 10 cm³/min, followed by a drop above 15 cm³/min. The hardness of the DLC film grown from the PCD target was higher than that for a film grown from a graphite target, indicating that the target material has a significant effect on the quality of DLC films in sputtering deposition. The effect was very clear in the optical properties; it was found that the optical transmittance of the DLC film grown from the PCD target with an Ar ion laser beam (wavelength = 488 nm, 514.5 nm) was about four-fold larger than that grown from a graphite target. These results suggest that the DLC film grown from a PCD target has the potential to be applied to novel optical coatings. Secondly, BCN films were prepared from diamond and c-BN powder mixture target The diamond/c-BN ratio of the target was 4, and the substrate temperature was 373-773K. The carbon content in the BCN film decreased with increasing the substrate temperature. The BCN film, which was deposited at 773K, showed high wear resistance as well as high thermal resistance at 773 K in the air.

Key words: DLC, BCN, target material, magnetron sputtering, optical transmittance, mechanical property

Naoto Ohtake

Department of Mechanical Sciences and Engineering

Graduate School of Science and Engineering

Tokyo Institute of Technology

2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552,Japan.

TEL&FAX +81-3-5734-2504

ohtaken@mech.titech.ac.jp