Y. Kido et al., LATTICE LOCATION OF ER IN GAAS DETERMINED FROM MONTE-CARLO SIMULATIONOF ION CHANNELING SPECTRA, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 85(1-4), 1994, pp. 484-489
We have determined the lattice location of Er doped into GaAs single c
rystals grown by metal-organic chemical vapor deposition (MOCVD) using
the ion channeling effect. A strong flux peaking is observed for 2.0
MeV He+ ions incident along the GaAs [110] axis, whereas a significant
shadowing effect is seen for the [111] and [100] incidence. Monte Car
lo simulation of ion trajectories has revealed that almost all Er atom
s occupy the lattice position shifted by 0.6 angstrom from the tetrahe
dral interstitial site toward the hexagonal site. This suggests that t
he dopant Er atom is loosely combined with an impurity carbon atom rep
lacing a lattice As atom. In this paper, we propose a new multistring
model to simulate ion trajectories and compare it with the single row
approximation in the context of accuracy and computing time.