Iron redistribution and compensation mechanisms in semi-insulating Si-implanted InP

The Si and Fe depth distributions have been measured in Si-implanted semi-insulating (SI) InP as a function of implant temperature and post-implant annealing technique (either furnace annealing or rapid thermal annealing). Depth profiles obtained by secondary ion mass spectrometry and damage measurements obtained by Rutherford backscattering demonstrate that Fe redistributes into regions of residual damage during thermal processing. The active electrical carrier profiles measured by electrochemical profiling show differences between atomic and electrical carrier profiles which depend on whether the substrate is semi-insulating or undoped, and on the implant temperature. These differences are interpreted in terms of three different compensating mechanisms: (a) the amphoteric nature of Si impurities in InP, so that Si can be self-compensating, (b) carrier compensation caused by the redistribution of Fe, and (c) implantation-related damage effects and/or stoichiometry imbalance induced by the Si implant.