Infrared spectroscopic investigations on h-BN and mixed h/c-BN thin films

The integrated absorptions of the IR active bands at about 1390 cm(sup -1), 1080 cm(sup -1) and 780 cm(sup -1) were used to determine the content of hexagonal boron nitride h-BN (sp(sup 2) bonding state) and cubic boron nitride c-BN (sp(sup 3) bonding state) modifications in RF sputtered stoichiometric BN films. For the calculation of oscillator number densities in hexagonal boron nitride (h-BN) from integrated absorptions, calibration constants A(sub h) can be used, which are found to be 1.7×10(sup 19) cm(sup -2) for the B-N stretching vibration at 1390 cm(sup -1) and 9.1×10(sup 19) cm(sup -2) for the B-N-B bending vibration at 780 cm(sup -1), respectively. It is shown that the ratio of the volume fractions f(sub c)/f(sub h) of mixed h/c-BN films can be determined from the ratios of the absorption coefficients alpha(1080 cm(sup -1)/alpha(1390 cm(sup -1)) and at 1080 cm(sup -1))/alpha(780 cm(sub -1)) multiplied by factors of 0.6 and 0.19, respectively.