Temperature-dependent growth and transient state of hydrogen-induced nanocavities in silicon

Silicon samples H-implanted to a dose of 3x1016 cm-2 were analyzed by positron annihilation and ion backscattering techniques to investigate the growth of H-induced nanocavities at different annealing temperatures (400-900 deg. C). Positron annihilation lifetime spectroscopy revealed a constant increase in the vacancy cluster size (i.e., nanocavity size) as the annealing temperature increased. On the other hand, Doppler broadening and ion channeling measurements suggested strong interaction between the implanted H and the defects depending on the annealing temperature. Furthermore, Au-gettering experiments revealed that transient gettering sites are formed at 600 deg. C between the H projected range and the surface. These results indicated that H desorption is one of the key factors in the optimization of the gettering process with H-induced nanocavities