Deposition of cluster-free P-doped a-Si: H films using SiH4+PH3 multi-hollow discharge plasma CVD

We deposited cluster-free P-doped a-Si:H films using a SiH4+PH3 multi-hollow discharge plasma CVD method. The deposition rate sharply increased from 0.49 nm/s with an increasing gas flow rate ratio R = [PH3]/[SiH4] from 0% to 1.17 nm/s at R = 1.0%, then slightly increased to 1.27 nm/s for R = 10%. SiH* emission intensity monotonically increased with increasing R. The increase in deposition rate with increasing R was much higher than that of the SiHx generation rate. The surface reaction probability β of SiH3 increased from 0.33 for R = 0% to 0.62 for R = 0.6%, then remained nearly constant for R > 0.6%. The sticking probability s of SiH3 increased from 0.1 for R = 0% to 0.162 for R = 0.6%, then slightly increased to 0.181 for R = 10%. These results suggest that PHx radicals enhance the surface reaction probability and surface sticking probability of SiH3 radicals. We successfully deposited P-doped a-Si:H films with a low stabilized defect density of 2.9 × 1015 cm–3. This defect density is much lower than that of conventional doped a-Si:H films (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)