Amorphous-Microcrystalline Silicon Films Obtained Using Hydrogen Dilution in a DC Saddle-Field Glow-Discharge

Amorphous-microcrystalline Si has been grown with hydrogen dilution using the DC saddle-field glow-discharge deposition technique. The five-electrode saddle-field system allows for independent control of the discharge parameters and of the substrate bias. The film structure was studied using Raman spectroscopy and SEM. We find that the structure of the films depends mainly on hydrogen dilution, substrate bias, electrical conductivity of the substrate, and chamber pressure. The deposition conditions, which promote growth of microcrystals, have been identified. It was found that the local electric field at the substrate surface plays a key role in obtaining microcrystallinity.