OBSERVATION OF NEAR-BAND-GAP LUMINESCENCE FROM BORON-NITRIDE FILMS

We report results from cathodoluminescence spectroscopy of boron nitri de films grown on Si(100) substrates by ion-source-assisted magnetron sputtering of a hexagonal BN target. Three main peaks are observed in the near-band-gap region for hexagonal boron nitride films at energies of 4.90, 5.31, and 5.50 eV. We also report deep-level emission spectr a of predominantly cubic boron nitride films which are correlated with sample growth conditions. In particular we show that the emission int ensity, position, and linewidth are strongly dependent on the substrat e bias voltage used during sample growth.