Dj. Kester et al., GROWTH AND CHARACTERIZATION OF CUBIC BORON-NITRIDE THIN-FILMS, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 12(6), 1994, pp. 3074-3081
Citations number
30
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
Boron nitride (BN) thin films have been grown on [100] oriented single
crystal Si, diamond, Cu and Ni substrates by ion beam assisted deposi
tion using electron beam evaporation of boron together with simultaneo
us bombardment by nitrogen and argon ions. Characterization by Fourier
-transform infrared spectroscopy and high-resolution transmission elec
tron microscopy showed that the films bn Si and diamond consisted of i
nitial noncubic (amorphous and hexagonal BN) layers, followed by the g
rowth of cubic BN (c-BN). This growth sequence was attributed primaril
y to increasing compressive intrinsic stress with increased film thick
ness. Increasing the substrate temperature above 400 degrees C led to
the onset of c-BN at a greater film thickness while increased ion flux
resulted in earlier growth of this phase. These results may be explai
ned by the relaxation of the intrinsic stress in the films at higher t
emperatures due to increased adatom mobility and to increased intrinsi
c stress in the films resulting from increased ion bombardment. Lower
temperatures led to mixed phase growth. A minimum substrate temperatur
e (200-300 degrees C) is required for nucleation and growth of single
phase c-BN by this technique. It is believed that the interstitial Ar
observed in Rutherford backscattering spectrometry studies is primaril
y responsible for the stress generation in the films. A combination of
h-BN and c-BN was deposited on Ni; only h-BN was obtained on Cu subst
rates.