THIN BN FILMS OBTAINED BY DUAL-ION-BEAM SPUTTERING - AN FT-IR AND SPECTROSCOPIC ELLIPSOMETRY CHARACTERIZATION

Thin BN films (100-250 nm) have been deposited on Si(100) substrates i n a double-ion-beam sputtering system from a h-BN target. The films ha ve been characterized by FT-IR spectroscopy and spectroscopic phase-mo dulated ellipsometry as a function of the deposition and irradiation p arameters. Assistance with Ar+ ions result in boron rich films with re fraction indexes above 2 or even higher as the deposited energy of the assisting ions increases. N-2(+)-bombardment causes stoichiometric an d even nitrogen-rich BN films characterized by refraction indexes arou nd 1.85. The stability of the films is enhanced when the deposited ene rgy of the N-2(+) ions is above 30 eV/atom and/or the deposition is pe rformed on substrates at temperatures above 100 degrees C.