In situ microwave reflectivity measurements of the changes in surface recombination of crystalline silicon induced by the exposure to silane, silane/helium, and helium plasmas

Measurements of the transient photoconductivity detected via the change in microwave reflection after laser pulse illumination have been performed during the exposure of crystalline silicon substrates to a pure silane, silane/helium, and pure helium plasma. In all cases, a similar increase of the surface recombination rate is detected immediately after plasma start. While the surface recombination remains high in the case of the pure helium plasma, a decrease of the interface recombination is observed for the pure silane and silane/helium plasma, related to the deposition of hydrogenated amorphous silicon.