Crystallization of nanostructured silicon films deposited under a low-pressure argon–silane pulsed-glow discharge: Correlation with the plasma duration

In this work, we compare the thermal crystallization and the laser crystallization of hydrogenated nanostructured silicon (ns-Si:H) films in relation with their deposition conditions. The samples are grown in a low-pressure pulsed radio-frequency glow discharge of an argon–silane mixture. The laser crystallization shows a decrease of the crystallization threshold (Ecryst) and an increase of the induced crystalline fraction when the plasma duration (Ton) used for the deposition increases. No correlation with Ton is observed in the case of the thermal annealing, indicating that the modifications of the bulk structure of the film with Ton are not the main parameter in the determination of Ecryst. The role of the surface roughness in the lowering of the laser crystallization threshold is then emphasized.