O2+ versus Cs+ for high depth resolution depth profiling of III-V nitride-based semiconductor devices

Optimum depth resolution with adequate sensitivity for the elements of interest is required to obtain the information desired from SIMS analysis of multilayer nitride III-V structures. For many of the species of interest, particularly the p-type dopants, O2+ bombardment at low energy is often used. Use of Cs+ bombardment and detection of the cesium attachment secondary ions (CsM+ where M is the element of interest) may provide several advantages over O2+ analysis. Using similar low primary ion impact energy analysis conditions for O2+ and Cs+ on CAMECA IMS-6f and IMS-4f instruments, the depth resolution obtained for positive secondary ions is compared