A series of BN films was deposited by means of r.f. magnetron sputteri
ng of a h-BN target onto Si(100) surfaces. Hereby, the substrate bias
voltage was varied. Special interest is focussed to the influence of t
he deposition parameters on the orientation of the growing hexagonal B
N film with respect to the substrate. For structural investigation, cr
oss section samples were prepared. In addition to HRTEM and diffractio
n investigations, especially electron energy loss spectroscopy (EELS)
was applied successfully for phase identification. For negative bias v
oltages of U-B = -300 V and U-B = -350 V, we found a phase system cons
isting of a first-grown 25 nm thick layer of hexagonal structure with
the c axis parallel to the substrate surface followed by the cubic pha
se.