Irradiating diamond: Aspects of defect generation, accumulation and annealing

It is postulated that for diamond the activation barrier E-c that a diffusing point defect has to scale before being trapped, is in general larger than the activation barriers E-D that it has to scale during diffusion. By taking this into account, one can explain why the residual damage decreases with increasing target temperature during ion implantation, and why vacancies seem to diffuse "uphill" while being attracted by A-centres in electron irradiated type la-A diamonds. The general applicability of this model indicates strongly that the defects formed during ion implantation of diamond are, as in the case of electron-irradiation, primarily individual vacancies and interstitial atoms. Recent results on the properties of interstitials in diamond also give credence to the latter conclusion as well as the postulates on which the Cold-Implantation-Rapid-Annealing (CIRA) routine for ion-beam doping of diamond is based.