Effect of Hydrogen-Radical Annealing for SiO 2 Passivation

It is shown that hydrogen-radical postannealing of SiO 2 on Si wafers can result in high effective lifetime (τ eff ), low surface recombination velocity ( S eff ) and low midgap interface state density at the SiO 2 /Si interface ( D ito ). The annealing effect appeared above 200° C within a very short annealing time to a greater degree than in 3% H 2 forming gas annealing at 400° C. This annealing method is suitable for the surface passivation process of solar cell devices.