Hydrogenated microcrystalline silicon thin films (μc-Si:H) were deposited by plasma assistant magnetron sputtering in Ar-H 2 gas mixture. The effects of growth temperature from 150 to 450 C on properties of deposited Si films were investigated at two different hydrogen diluted gases with [H 2 ]/([Ar]+[H 2 ]) of 10% and 50% at 3 Pa. The crystallinity of Si films examined by Raman scattering exhibited higher degrada- tion by lowering growth temperature from 250 to 150 C in low hydrogen diluted gas of 10% than that in high hydrogen diluted gas of 50%. The IR absorption band around 845 and 890 cm 1 as well as calculated concentration of bonded hydrogen showed more obvious decrease of samples deposited in low hydrogen diluted gas of 10% than that in high hydrogen diluted gas of 50%. The optical band gasps of both groups of samples measured by ultraviolet-visible optical absorption were decreased with increasing temperature in both gas conditions. Hydrogenated microcrystalline silicon thin films (μc-Si: H) were deposited by plasma-assisted magnetron sputtering in Ar-H 2 gas mixture. The effects of growth temperature from 150 to 450 C on properties of deposited Si films were investigated at two different hydrogen diluted gases with [H 2] / ([Ar] + [H 2]) of 10% and 50% at 3 Pa. The crystallinity of Si films examined by Raman scattering phenomenon higher degradation by lowering growth temperature from 250 to 150 C in low hydrogen diluted gas of 10% than that in high hydrogen diluted gas of 50%. The IR absorption band around 845 and 890 cm 1 as well as calculated as the concentration of bonded hydrogen showed more obvious decrease of samples deposited in low hydrogen gas 10% than that in high hydrogen diluted gas of 50%. The optical band gasps of both groups of samples measured by ultraviolet-visible optical absorption were decreased with increasing temperature in both gas conditions.