H diffusion for impurity and defect passivation: a physical model for solar cell processing

We propose a physical model for diffusion of H in Si containing impurities and defects. The diffusion occurs via several parallel mechanisms, involving complex formation (trapping) and dissociation (detrapping) at impurities and defects, hopping in lattice interstitial sites, and charge-state conversion. The role of bulk and process-induced traps is considered to explain observations from plasma, ion implantation, and PECVD-nitridation processes.