STRUCTURE AND COMPOSITION STUDIES FOR SILICON-NITRIDE THIN-FILMS DEPOSITED BY SINGLE-ION BEAN SPUTTER-DEPOSITION

Silicon nitride films were deposited on Al/glass, NaCl, KBr, and silic on substrates by single ion beam sputter deposition. Films were prepar ed at various N-2(+) ion beam voltages over the range from 500 to 1200 V. The resulting films were characterized by using secondary ion mass spectrometry, Fourier transform infrared spectroscopy, transmission e lectron microscopy, and transmission electron diffraction. The stoichi ometry of these silicon nitride films was controlled by adjusting the ion beam voltage. Films deposited under conditions of ion beam voltage below about 700 V were nitrogen rich while films made with beam volta ges in excess of 900 V were silicon rich. The film structure changed w ith the substrate temperature from amorphous at room temperature to na nocrystalline/amorphous st 300 degrees C, The lowest occupied (LO) pho non band for stoichiometric Si3N4 was approximately 1124 cm(-1) and th e stoichiometry of thin silicon nitride films could be assessed with t he LO phonon position. (C) 1997 Elsevier Science S.A.