Deposition of cBN films by ion sputtering of SiB6 and AlB12 boron-base materials

Films of cubic boron nitride were deposited on to Mo, Si, WC-Co substrates heated up to 600-800 degrees C in a three-electrode d.c. device with a disc harge localization by magnetic field. During SiB6 and AlB12 sputtering in A r-N-2 and Ar-N-2-H-2 atmospheres, the low-frequency (LF) substrate bias ran ged from 50 to 500 V (20 kHz), and the total pressure was 1.5 mTorr. The ef fects of gas atmosphere, LF substrate bias and ionization energy on structu re formation and composition of the films being deposited have been studied . The film structure and composition were examined using IR spectroscopy an d X-ray diffraction analysis. The deposited films have polycrystal structur es with a hexagonal, wurtzitic or cubic symmetry. The predominated quantity of cubic phase is observed in films deposited using SiB6 in Ar-N-2 atmosph ere at a LF substrate bias of 500 V. By introducing hydrogen into the gas a tmosphere at a ratio of three parts of N-2 to seven parts of H-2, a wurtzit ic phase forms in the film. The cubic BN phase is observed in films obtaine d using AlB12 if the LF substrate bias is between 200 and 300 V. The Vicker s microhardness of the films produced reaches 30.0-35.0 GPa. (C) 1998 Publi shed by Elsevier Science S.A. All rights reserved.