Hydrogen diffusion in B-ion-implanted and B-doped homo-epitaxial diamond: passivation of defects vs. passivation of B acceptors

摘要

Drastic differences in diffusion of H (deuterium) in diamond, B-doped by ion implantation and during homo-epitaxial film growth, and its influence on electrical properties are found by SIMS depth profiling, and by electrical (Hall effect) measurements. Type IIa natural diamond, B-doped by ion implantation and high quality homo-epitaxial B-doped diamond films were subjected to D plasma treatment under similar conditions. The results of SIMS measurements clearly show a huge difference in D diffusion profile for these two samples. While the sample doped during growth was totally deuterated, the implanted one showed only minor D penetration. Electrical measurements indicated that while the homo-epitaxial samples became insulating or showed strong decrease in their free hole concentration following deuteration, the identical treatment to the B-ion implanted sample caused only slight changes in electrical properties. The electrical properties and their dependence on annealing are correlated with the deuterium diffusion into diamond. A possible mechanism of (B, H) and (defect, H) pair formation is suggested as a possible explanation of the observed differences.