Td. Delarubia et al., DEFECT PRODUCTION AND ANNEALING KINETICS IN ELEMENTAL METALS AND SEMICONDUCTORS, Journal of nuclear materials, 251, 1997, pp. 13-33
We present a review of recent results of molecular dynamics (MD) and k
inetic Monte Carlo (KMC) simulations of defect production and annealin
g in irradiated metals and semiconductors. The MD simulations describe
the primary damage state in elemental metals Fe, V and Au, and in an
elemental semiconductor Si. We describe the production of interstitial
and vacancy clusters in the cascades and highlight the differences am
ong the various materials. In particular, we discuss how covalent bond
ing in Si affects defect production and amorphization resulting in a v
ery different primary damage state from the metals. We also use MD sim
ulations to extract prefactors and activation energies for migration o
f point defects, as well as to investigate the energetics, geometry an
d diffusivity of small vacancy and interstitial clusters. We show that
, in the metals, small interstitial clusters are highly mobile and gli
de in one dimension along the direction of the Burger's vector. In sil
icon, we show that, in contrast to the metals, the neutral vacancy dif
fuses faster than the neutral self-interstitial. The results for the p
rimary damage state and for the defect energetics and kinetics are the
n combined and used in a kinetic Monte Carlo simulation to investigate
the escape efficiency of defects from their nascent cascade in metals
, and the effect of dose rate on damage accumulation and amorphization
in silicon. We show that in fee metals Au and Pb at or above stage V
the escape probability is approximately 40% for 30 keV recoils so that
the freely migrating defect fraction is approximately 10% of the dpa
standard. In silicon, we show that damage accumulation at room tempera
ture during light ion implantation can be significantly reduced by dec
reasing the dose rate. The results are compared to scanning tunneling
microscopy experiments. (C) 1997 Published by Elsevier Science B.V.