Silicon and silicon nitride thin films were growth on Si and glass substrates at room temperature by ratio-frequency (r-f) magnetron sputtering. The electrical characteristics of the silicon nitride films were characterized using I-V and C-V measurement under different growth condition, including r-f power, nitrogen partial pressure, and hydrogen partial pressure. Minimum current leakages for MIS structure as low as 2¡Ñ10 A/cm were obtained at 1 MV/cm electrical field with hysteresis voltage about 2V. The root-mean square surface roughness of the silicon nitride film is less then 1nm. In addition, silicon nitride capacitors with indium-tin-oxide as electrodes were fabricated. Silicon thin films prepared by R.F. magnetron sputtering at room temperature are amorphous. The measurements on the variation of the photo-conductivity were used to characterize the characteristics of the Si film.