The redistribution of implanted atoms and radiation damage during the implantation doping of diamond

The dopant atoms 7Li and 11B 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 11B(p,γ)12C resonance and the 441 keV 7Li(p,γ)8Be 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 (≅ 90 K) ion implantation, and their annealing at elevated temperatures. In order to do this, 13C ions were implanted into natural type IIa diamond held at an implantation temperature of ≅ 90 K and profiled using the 550 keV 13C(p,γ)14N 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 ≅ 0.25 μm) containing highly mobile single defects, and a deeper region (extending beyond the calculated ion range to ≅ 1.5 μm) containing more stable extended defects. The channelling results also show evidence for the possible hydrogenation of the damaged region. (orig.)