PROFILING OF SEMICONDUCTOR SURFACE-LAYERS BY HEAVY-ION TOF-E-ERD

We have adapted the elastic recoil detection (ERD) technique to analys e passivation layers of SixNyO1-x-y grown on Si substrates in low pres sure CVD process. Sample targets were bombarded by 9.87 MeV Cl-35 ions to recoil Si, 0, N and C atoms incorporated in the sample film. The a tomic species of recoils have been identified through eventwise regist ration of flight time (TOF) and kinetic energy (E). Using an unfolding program developed by Bachmann the depth profile for each element has been calculated from the TOF energy spectrum. The unfolding program is based on an iterative algorithm that takes into account the interplay between the stopping of projectiles as well as recoils and the stoich iometry of the sample. The chemical composition as a function of depth is discussed in the context of sample preparation conditions.