THE REDISTRIBUTION OF IMPLANTED ATOMS AND RADIATION-DAMAGE DURING THE IMPLANTATION DOPING OF DIAMOND

The dopant atoms Li-7 and B-11 were implanted into natural type Ia and type IIa diamond at temperatures ranging between 90 and 670 K. Nuclear reaction analysis was used to determine the depth distributions of the implanted dopants using the 165 keV B-11(p, gamma)C-12 resonance and the 441 keV Li-7(p, gamma)Be-8 resonance. Implants performed at 90 K were annealed at 360 K for 30 min and were then reprofiled to study the annealing characteristics of the dopants. In order to achieve optimum doping of diamond it is of importance to understand the damage processes that occur during low temperature (approximately 90 K) ion implantation, and their annealing at elevated temperatures. In order to do this, C-13 were implanted into natural type IIa diamond held at an implantation temperature of approximately 90 K and profiled using the 550 keV C-13(p, gamma)N-14 resonance, together with RBS channelling measurements made along the <100>, <110>, and <111> axes. This implant was then annealed at 670 K for 30 min and re-examined. The results indicate the presence of two defect regions in the implanted region: a near-surface region (extending to approximately 0.25-mu-m) containing highly mobile single defects, and a deeper region (extending beyond the calculated ion range to approximately 1.5-mu-m) containing more stable extended defects. The channelling results also show evidence for the possible hydrogenation of the damaged region.