Effects of the ion energy on damage production in MeV ion-implanted GaAs

Abstract

The influence of the ion energy on damage production in GaAs was investigated by implanting Br ions with energies ranging from 0.6 to 9 MeV at room temperature and 100 K. At room temperature the defect concentration in the maximum of the distributions decreases with increasing ion energy even if the nuclear deposited energy density is kept constant for all energies. The behavior observed correlated with the nuclear energy deposited per ion and unit length which also decreases with the ion energy due to increasing range straggling. This increased range straggling for a given depth results in a reduction of the local current density and consequently in a more pronounced in situ defect annealing. A reduction of the macroscopic ion current density has a similar influence as the ion energy. At T I=100 K the damage production is neither influenced by the ion energy nor by the macroscopic current density. The results obtained are discussed in the framework of the model of critical temperatures.