Abstract Amorphous and microcrystalline silicon thin films are used in solar cells as a multi-junction photovoltaic device. Plasma enhanced chemical vapor deposition is used and high deposition rate of a few nm/s is required while keeping film quality. SiH 4 is used as a precursor diluted with H 2. Electron impact processes give complex interdependent plasma chemical reactions. Many researchers suggest keeping high H/SiH x ratio is important. Numerical modeling of this process for capacitively coupled plasma and inductively coupled plasma is done to investigate which process parameters are playing key roles in determining it. A full set of 67 volume reactions and reduced set are used. Under most of conditions, CCP shows 100 times higher H/SiH 3 ratio over ICP case due to its spatially localized two electron temperature distribution. Multi hollow cathode type CCP is also modeled as a 2 × 2 hole array. For Ar, the discharge is well localized at the neck of the hole at a few Torr of gas pressure. H 2 and SiH 4 + H 2 needed higher gas pressure and power density to get a multi hole localized density profile. H/SiH 3 was calculated to be about 1/10.