Electrical and optical properties of boron‐ or phosphorus‐doped new hydrofluorinated amorphous silicon (a‐Si:F:H) are experimentally studied. This newa‐Si:F:H is produced by using intermediate species SiF2and H2gas mixture instead of using SiH4gas or SiF4and H2gas mixture. It is found that the doping efficiency for boron or phosphorus in thisa‐Si:F:H film is slightly better than that of conventional hydrogenated amorphous silicon (a‐Si:H), and also that the optical band gap of thisa‐Si:F:H hardly changes for the increase of conductivity due to boron doping while that ofa‐Si:H is apparently decreased.