HYDROGEN MOBILITY IN DIAMOND STUDIES USING HI-ERDA MICROSCOPY

Hydrogen plays a significant role in the growth of diamond and in the determination of its physical, electrical and optical properties. Howe ver, despite this significance, the configuration, chemistry and behav iour of hydrogen in the diamond lattice is still not very well underst ood. In this work, the stability of a collimated hydrogen implant dist ribution, as well as the intrinsic hydrogen distribution in a single c rystal natural type IIa diamond are studied by imaging with the micro- scanned Heavy-Ion Elastic Recoil Detection Analysis (mu HI-ERDA) techn ique in three dimensions, To investigate possible trapping of hydrogen at vacancies a shallow pre-damaged layer was created between the impl anted hydrogen distribution and the surface by collimated bombardment of the sample with 50 keV C-12 ions. NO evidence of migration of the i mplanted or the intrinsic hydrogen to the pre-damaged region was obser ved even after annealing at 1473 K. The stability of the implanted hyd rogen indicates the deep trapping of this species within its own impla nted range distribution. The results confirm similar measurements prev iously performed on a natural type Ia diamond as well as on a syntheti c type Ib diamond. The current sample was exceptionally pure, enabling an extension of these measurements to a situation where the intrinsic hydrogen concentration, as well as the hydrogen trapping behaviour mi ght be expected to be different. Our results suggest complex trap conf igurations for hydrogen in diamond, not necessarily associated with ni trogen related defects.