Molecular Dynamics Studies of the Ion Beam Induced Crystallization in Silicon

Abstract

We have studied the ion bombardment induced amorphous-to-crystal transition in silicon using molecular dynamics techniques. The growth of small crystal seeds embedded in the amorphous phase has been monitored for several temperatures in order to get information on the effect of the thermal temperature increase introduced by the incoming ion. The role of ion-induced defects on the growth has been also studied.

Ion beam induced recrystallization of amorphous silicon: A molecular dynamics study

“…This increase in the growth rate is mainly due to the higher driving force ⌬g for crystallization when the amorphous phase melts or when high-energy particles ͑de-fects͒ are introduced close to the growth interface, as suggested by some authors from experimental results, 13,47 and to the increase of the atom mobility, materialized through a reduction of the activation energy E . 48 Moreover, there is a reduction of the critical size for growth due to the amorphous-to-liquid transition produced by the ion bombardment. This lowers the incubation time and thus steady state conditions for the nucleation and growth processes are reached earlier.…”

Including a distribution of threshold displacement damage energy on the calculation of the damage function and electron's Non Ionizing energy Loss

“…This classical approach, despite its simplicity has proven its reliability [3,4]. But, more recently both Molecular Dynamics (MD) simulations and first principle calculations have been used to study the damaging process more accurately [21][22][23][24][25][26][27][28][29][30][31][32][33][34]. The usage of MD simulations is limited by its complexity.…”

“…But the threshold displacement energy region remains complex to model and a large uncertainty exist in the choice of the E d value. It is widely reported in the literature [4,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] and references in there, that the NRT approach presents different shortcomings and specifically near the threshold region for low PKA energies. MD simulations clearly demonstrate that the probability to displace an atom increases gradually rather than having an abrupt threshold [4].…”

“…E d can be averaged over all the crystallographic directions. However, the use of a single threshold displacement energy to describe the damaging cascade process is admitted to be a rough approximation [4,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. Some recent MD papers have proven the existence of a continuous distribution of E d values, even in monoatomic materials [4,[36][37][38][39].…”

Statistical spread on the displacement damage degradation of irradiated semiconductors

“…The ion implantation process, widely used in semiconductor industry, has also lead to many studies [29][30][31][32][33][34][35][36][37]. Computer simulations have also been performed over the years to provide a scientific understanding of radiation effects in semiconductor materials [38][39][40][41][42][43][44][45]. Generally speaking, optoelectronic components are particularly sensitive to the amount of defects produced by irradiations.…”