The growth and properties of phosphorus-doped microcrystalline silicon (mu c-Si) films deposited by cathode-type radio frequency glow discharge were investigated. Doping effects on deposition rate, crystallinity, grain size and electrical properties were studied by means of optical, X-ray diffraction and Hall effect measurements. It is found that the grain size and crystallinity fraction of doped films increase with the addition of PH3 gas, and also with applied power and substrate temperature. An attempt was paid to explain the electrical properties of doped films using the grain boundary trapping model which has been used to interpret the transport properties of polycrystalline silicon. The mobility measured in the Hall effect and trapping state density and the grain boundary were, respectively, in the 6-9 cm(2) V-1 s(-1) range and 1.3 x 10(12) cm(-2) for the films deposited at higher r.f. power ( > 75 W) and a substrate temperature of 400 degrees C.