Direct ion beam deposition of hard (>30 GPa) diamond-like films from RF inductively coupled plasma source

Diamond-like carbon (DLC) films were deposited on Si substrates using highly reproducible direct ion beam deposition from a RF inductively coupled hydrocarbon plasma source. Combinations of gases, such as C2H4 and C2H4-CH4, were used to form the plasma. The mechanical, electrical and optical properties of the films were examined as a function of the deposition conditions and CH4 content in gas mixture. Hard DLC films with a hardness up to 40 GPa were obtained. By variation of the C2H4/CH4 ratio, hardness of the films can be adjusted in the range 22-40 GPa. Highly reproducible deposition rates (< 5% from run to run for over several 100 h) have been achieved. The deposition uniformity was within 5% over 9-inches round. For investigation of the bulk and surface electrically active defects (density, activation energies and capture cross-sections), charge-based deep-level transient spectroscopy (Q-DLTS) was used. (C) 2001 Elsevier Science B.V. Ah rights reserved.