A new type of chemical vapor deposition method, named ‘‘Catalytic‐CVD’’ method, is presented. In the method, deposition gases are decomposed by catalytic or pyrolytic reaction between deposition gases and a heated catalyzer, and films are thermally grown on a substrate at temperatures lower than 300 °C without any help from glow discharge plasma. Hydro‐fluorinated amorphous silicon (a‐Si:F:H) films are deposited by this method using both a SiF2and H2gas mixture and a SiH2F2and H2mixture. It is found that a very high qualitya‐Si:F:H film can be obtained, and for instance, that the photosensitivity for AM‐1 of 100 mW/cm2exceeds 106and the spin density is as low as 6×1015cm−3.