Methods of making Si-containing films that contain relatively high levels of Group III or Group V dopants involve chemical vapor deposition using trisilane and a dopant precursor. Extremely high levels of substitutional incorporation may be obtained, including crystalline silicon films that contain at least about 3.times.10.sup.20 atoms cm.sup.-3 of an electrically active dopant. Substitutionally doped Si-containing films may be selectively deposited onto the crystalline surfaces of mixed substrates by introducing an etchant gas during deposition.