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We investigate the sputtering behavior and depth resolution upon low energy ion irradiation during Secondary Ion Mass Spectrometry (SIMS) depth profiling of GaAs. We present a systematic and quantitative study of the impact of ion species, primary ion impact energy, and incident angle on the evolution of depth resolution, using a well-defined InGaAs/GaAs multilayer structure with highly abrupt hetero-interfaces. We demonstrate that for low energy O2+ ion beam irradiation, SIMS depth resolution becomes progressively degraded by (transient) incorporation of high surface O-concentration levels in the altered layer, leading to detrimental ion-beam induced formation of topography. In case of low energy oblique Cs+ ion beam irradiation, sputtering behavior of GaAs is well-behaved with no significant transient yield changes and a constant depth resolution. This enables SIMS depth profiling of sharp hetero-epitaxial III-V compound semiconductor structures and shallow dopant profiles with sufficiently good depth resolution with good detection efficiency.

We review formation of an electron hologram in TEM for analysis of p-n junctions in semiconductor devices. It is shown on the basis of comparison of results of electron holography and SIMS that the method can provide quantitative information directly, i.e. without consideration of "dead layers" in both bulk Si and SOI structures. Unique information provided by electron holography addresses a wide range of problems concerned with understanding dopant diffusion, process integration and physical failure analysis. In particular, it is proved that laser anneal does not cause lateral dopant diffusion of As to resolution of the method and demonstrated that junction overlap can be achieved with "laser-only" integration scheme We show how position of p-n junctions prior to annealing can be deduced from holography analysis to help tune process integration. Examples concerning physical failure analysis cover blocked implants, effect of STI proximity on dopant depletion.