An optical study of the correlation between growth kinetics and microstructure of mc-Si grown by SiH4-H2 PECVD

Fully microcrystalline silicon, mc-Si, thin films have been deposited on corning glass by plasma enhanced chemical vapor deposition (PECVD) using SiH4-H2. The effects of the surface treatment and of the deposition temperature on microstructure of mc-Si films are investigated by ‘‘in situ’’ laser reflectance interferometry (LRI), ‘‘ex situ’’ spectroscopic ellipsometry (SE) and Raman spectroscopy. LRI indicated the existence of a ‘‘crystalline seeding time’’, which is indicative of the crystallite nucleation, and depends on substrate treatments. Longer ‘‘crystalline seeding time’’ results in a lower density of crystalline nuclei, which grow laterally, yielding to complete suppression of the amorphous incubation layer and to growth of very dense, fully crystalline layer at a growth temperature as low as 120 8C.