An intrinsic silicon thin film passivation layer is deposited by the microwave remote-plasma enhanced chemical vapor deposition at temperature of $175^{circ}C$ and various gas ratios for solar cell applications. The good quality amorphous silicon films were formed at silane $(SiH_4)$ gas flow rates above 15 seem. The highest effective carrier lifetime was obtained at the $SiH_4$, flow rate of 20 seem and the value was about 3 times higher compared with the bulk lifetime of 5.6 ${mu}s$ at a fixed injection level of ${Delta}n;=;5{ imes}10^{14};cm^{-3}$. An annealing treatment was performed and the carrier life times were increased approximately 5 times compared with the bulk lifetime. The optimal annealing temperature and time were obtained at 250 $^{circ}C$ and 60 sec respectively. This indicates that the combination of the deposition of an amorphous thin film at a low temperature and the annealing treatment contributes to the excellent surface and bulk passivation.