Characterization of silicon oxynitride films using ion beam analysis techniques

Heavy-ion elastic recoil detection analysis (HIERDA) is the ideal technique for quantitative analysis of silicon oxynitride films on silicon because o f its unique ability to measure simultaneously all elements of interest (i. e., H, C, N, O and Si), thereby permitting key parameters such as the O/N-r atio to be determined in a single measurement. However, high-energy acceler ators suitable for such HIERDA measurements are becoming much less readily available. Hence, the present paper investigates and calibrates an alternat ive IBA technique for simultaneous O, N and C analysis - namely, the use of (d,p) and (d,alpha) nuclear reactions. Under optimum analysis conditions ( 850 keV deuterons and 150 degrees detector angle), the Si background level sets a lower detection limit of similar to 1 x 10(16) nitrogen atoms/cm(2) and similar to 3 x 10(15) oxygen atoms/cm(2). II analysis is carried out se parately, using low-energy ERDA and a 2 MeV He-4 beam. Absolute cross-secti ons have been obtained for each of the (d.p) and (d,alpha) groups. Comparis on with data in the recent Handbook of Modern Ion Beam Materials Analysis s hows reasonable agreement (10-15%) for the (d,p) reactions on oxygen and ca rbon. However, in the case of nitrogen, the measured cross-section values a re similar to 70% larger than the Handbook data. Several silicon oxynitride samples have been analyzed, first at UWO using 850 keV deuterons, and subs equently at ANU using HIERDA and a 200 MeV Au beam. The resulting O/N-ratio s agree to within 10%. The relative importance of radiation damage effects is briefly discussed. (C) 2000 Elsevier Science B.V. All rights reserved.