Intrinsic limitations of doping diamonds by heavy-ion implantation

The local environment of 111In implanted into diamonds has been studied by means of the perturbed angular correlation technique as a function of annealing temperature and of implantation dose. It is found that even when the diamond is heated under vacuum to the highest possible temperature before graphitization occurs (2100 K), the implants are not driven to spherically symmetric sites in the lattice. This lack of annealing, if common to all heavy implants, may have serious consequences on the usefulness of doping of diamond by heavy-ion implantation.