DOPING OF POLYCRYSTALLINE DIAMOND BY BORON ION-IMPLANTATION

Polycrystalline diamond films, heavily implanted with boron ions (2 X 10(16) cm-2, 60 keV) are found to exhibit, following annealing and graphite removal, electrical properties similar to those obtained for chemical vapor deposited diamond, heavily doped with B during film growth. Control experiments in which carbon ions were implanted and annealed under identical conditions did not show any significant electrical conductivity, verifying that the measured effects are caused by chemical doping due to the presence of B. It is therefore concluded that doping of polycrystalline diamond by ion implantation is possible and graphitization along grain boundaries, that one might have expected to occur as a result of implantation and annealing, does not seem to severely affect the electrical properties of the implantation-doped material.