Deposition of cubic boron nitride layers - Characterisation of substrate-layer interface

Cubic boron nitride (c-BN) layers were deposited on (111)-oriented silicon and high-speed steel substrates in a hollow cathode are evaporation device. The films have a maximum cubic phase content of about 95%. Film growth processes were studied ex situ in dependence on duration of deposition by Fourier transform infrared (FTIR) transmission spectroscopy. Structure of the films was investigated by high resolution transmission electron microscopy (HRTEM) and transmission electron diffraction (TED). c-BN content, ratio of the in-plane vibration (1380 cm(-1)) to the out-of-plane vibration (780 cm(-1)) of hexagonal BN, the half-width of the phonon structures and the stress in the films are determined from infrared spectra. On silicon the growth sequence amorphous BN (a-BN)-hexagonal BN (h-BN)-c-BN was observed by the measuring techniques used. An in-situ FTIR reflectance spectrometer was set up in order to monitor growth processes on line. In-situ reflectance measurements on silicon and high-speed steel substrates reveal differences in the growth processes. In contrast to silicon it has been observed that on high-speed steel h-BN and c-BN grow simultaneously.