Full 3D numerical modelling is done for a VHF (very high frequency > 30 MHz) MHC (multi hollow cathode) based PECVD (plasma enhanced chemical vapor deposition) of Si thin film in tandem or triple junction solar cells. The purpose of VHF-MHC is confining high density plasma into small holes while maintaining large area deposition uniformity. ICP gives high plasma density (> 10E11 #/cm3) but poor uniformity and thin film quality (electron mobility and photo sensitivity) in addition to particle generation issues. For optimization of hole geometry and hole array configurations, numerical models for Ar, H2, and SiH4 are developed based on fluid model. CFD-ACE+ is used for calculation of each parameter set. For Ar, 1 Torr and 40 MHz was good enough for confining into a few mm diameter holes, but H2 needs higher plasma density. SiH4 needs more complicated plasma chemistry sets including negative ions and higher order silanes. The concentration ratio of SiH3/SiH2 was accurately modeled using electron energy distribution function calculation.