Lattice position and thermal stability of diluted As in Ge

We present a lattice location study of the n-type dopant arsenic after ion implantation into germanium. By means of electron emission channeling experiments, we have observed that the implanted As atoms substitute the Ge host atoms and that, in contrast to several implanted metal impurities in Ge, no significant fraction of As is found on interstitial sites. The substitutional As impurities are found to be thermally stable up to 600 C. After 700 C annealing a strong reduction of emission channeling effects was observed, in full accordance with the expected diffusioninduced broadening of the As profile.