Implantation profiles of 32P channeled into silicon crystals

Abstract

Concentration profiles of 32P ions implanted into silicon crystals have been studied over the energy range 10–110 keV, using an electromagnetic separator. Beam directions near the major channeling axes [Formula: see text] and [Formula: see text] were chosen. After implantation, the profiles were determined by the method of anodic stripping, and the beta activity of each oxide layer removed was measured in a low-background proportional counter. Concentration profiles were studied as a function of the ion energy, crystal orientation, crystal temperature, and ion dose. Precise crystal orientation was achieved by a proton-channeling technique making use of protons of around 10 MeV energy from the Harwell tandem generator. The maximum penetration of channeled ions along the [Formula: see text] axis was found to vary with the energy, E, approximately as E0.6. Significant temperature effects were observed, and the influence of radiation damage on ion channeling was studied and is related to other observations.