Fast Deposition of Microcrystalline Silicon Using High-Density SiH₄ Microwave Plasma

Abstract

A novel microwave discharge utilizing a spokewise antenna was applied for the fast deposition of hydrogenated microcrystalline silicon (µc-Si:H) film from SiH 4 and Ar without the H 2 dilution method. Systematic deposition studies were employed with total pressure, H 2 dilution ratio and flow rate of SiH 4 , Fr[SiH 4 ], as variables, combined with optical emission spectroscopy (OES) and Langmuir probe characterizations. It was found that the deposition rate exhibits a maximum at 40–50 mTorr at the axial distance of 10 cm from the quartz glass plate and the film crystallinity strongly depend on the total pressure. Correlation among OES signal intensity, SiH, the intensity ratio, I H α / I Si * , deposition rate and film crystallinity were demonstrated. By combining the SiH 4 depletion and lower pressure conditions, a high deposition rate of 40 Å/s was achieved in µc-Si:H growth with high crystallinity and photosensitivity from SiH 4 and Ar plasma.