ELECTRON-MICROSCOPIC PHASE-ANALYSIS OF BN-THIN FILMS

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.