Doping and diffusion behaviour of Fe in MOVPE grown InP layers

Doping and diffusion characteristics of Fe in semi-insulating AP-MOVPE grown InP layers were assessed using the SIMS technique. Fairly flat Fe depth profiles and a linear doping curve were obtained at concentrations of up to the lower range of 1017 cm-3. Accumulation of Fe at the substrate/layer interface was found on quite a few samples indicating a gettering effect of the substrate. Very little, if not negligible, diffusion was observed on alternately Fe-doped/undoped structures even after high-temperature heat treatment as long as the Fe content was in the midrange of 1016 cm-3, or lower.