Simulation of oxide sputtering and SIMS depth profiling of delta-doped layer

Using the dynamic Monte Carlo code, ACAT-DIFFUSE, the oxide sputtering and the SIMS depth profiling of a multilayered thin film sample was investigated. The ACAT-DIFFUSE code is based on the binary collision approximation, taking into account the generation of interstitial atoms and vacancies, annihilation of vacancies, diffusion and the relaxation of target materials according to the packing condition which include not only beam and target particles but also defects (interstitial atoms and vacancies). The observed shift of the delta layer peak to the surface in SIMS depth profiles can be reproduced by the ACAT-DIFFUSE simulation. It is found that this peak shift is mainly due to the relaxation or expansion caused by defects produced behind the delta layer, not due to preferential sputtering.