Boron-doped hydrogenated microcrystalline silicon films were prepared by the r.f. magnetron sputtering technique with a conventional setup as well as by a modified set-up. The modification was in the form of immersion of the substrate in the field of an additional U-magnet. Both in the conventional as well as in the modified set-up, the thresholds of chamber pressure for microcrystalline formation were investigated. The modification with the U-magnet resulted in the enhancement of the microcrystalline phase in the entire range of chamber pressure studied and, at an optimum pressure range, highly conducting films were obtained. At relatively high chamber pressure, boron crystal segregation was observed with concomitant deterioration in the crystalline structure of the films. The films were characterized by conductivity measurements, Hall effect and thermoelectric power measurements, optical absorption measurements, X-ray diffractometry, infrared vibrational spectroscopy, Raman spectroscopy and transmission electron microscopy.