CHARACTERIZATION OF THIN SPUTTERED SILICON-NITRIDE FILMS BY NRA, ERDA, RBS AND SEM

Thin, amorphous silicon nitride (a-SIN(x)) films were deposited on n-t ype (100) silicon substrates using an argon ion beam for sputtering a HPSN block under high vacuum conditions. The substrates were kept at r oom temperature. Nitrogen depth distributions were determined by NRA u sing the resonance reaction N-15(p,alphagamma)C-12 at 429 keV. Hydroge n profiles were analysed by NRA ((H(N, alphagamma)C)-H-1-N-15-C-12 at E(o) = 6.385 MeV) and by ERDA (Ne-20(2+), E(o) = 10 MeV). The NRA was used to determine the depth distributions (concentration vs. areal den sity) of nitrogen and hydrogen taking calibration standards into consi deration. The silicon depth distributions and the N/Si ratios of the d eposited a-SiN(x) films were determined by RBS (He-4+, E(o) = 2.0 MeV) . Film thicknesses were obtained by SEM. The density of the deposited a-SiN. films was found to be rho = 2.7 (+/- 0.1) g/cm3 by correlating RBS data and real film thicknesses as obtained by SEM.