Influence of low-energy ion-beam treatment by hydrogen on electrical activity of grain boundaries in polycrystalline silicon

The results of investigation into the effect of hydrogen plasma treatment and annealing on the electrical activity of grain boundaries (GBs) in silicon ribbons manufactured with the edge-defined film-fed growth (EFG) technique are presented. It is shown that hydrogenation with small doses of introduced hydrogen leads to decrease of the GB electrical activity, whereas further growth of hydrogenation time gives rise either to saturation or increase of electrical activity for annealed and non-annealed ribbons, respectively. The latter is explained in terms of a model taking into account the concurrence of GB defects passivation and neutralization of boron ions in the vicinity of GB during hydrogenation.