Investigation of NEV Au++ implanted silicon

Abstract

There has recently been increasing use of MeV ion beams for materials modification. When compared to more common lower, keV-energy implantation, MeV-ion irradiation has a broader variation in the type of damage along the ion path. This is because of the more significant difference between damage and range distributions in the case of MeV implants as opposed to keV implants. Previous works showed that MeV-implanted Si-ions react differently with various types of lattice damage in silicon; interactions range from simple point-defect annihilation to the formation of extended defects. Earlier investigations of Au implanted into previously amorphized silicon have observed Au segregation as a result of its being expelled from the recrystallizing amorphous layer during ion-beam irradiation. In this study, the interaction of MeV Au++ atoms with the different types of damage produced along the MeV-ion beam path is investigated.Silicon (100) single crystal wafers were given a HF dip and were then mounted on a copper sample stage; the stage functions as a heat-sink. The stage together with the specimen was then placed in a Tandem ion-implanter. The specimens were implanted with gold; implant-energies varied from 1.8 - 4.4 MeV and fluences ranged between 0.1 - 10×1016 Au++/cm2.