Both B- and P- doped silicon films deposited by Low Pressure Chemical Vapor Deposition (LPCVD) at 300 °C (p-type) and 420 °C (n-type) have been characterized by optical absorption, Photothermal Deflection Spectroscopy (PDS), resistivity, Elastic Recoil Detection Analysis (ERDA), Transmission Electron Microscopy (TEM), Convergent-Beam Electron Diffraction (CBED) and Raman spectroscopy measurements. P-doped films, deposited at large PH3 flux rates, show a high degree of microcrystallinity, indicating that P activates the nucleation process even at low temperatures. In this case, values of activation energy of resistivity as low as 0.007 eV were obtained. Both TEM and RAMAN results confirm a volume percentage of micro crystallinity above 30%. On the contrary, B-doped samples are not microcrystalline at least in the doping range investigated, and show a behaviour not different from samples deposited by PECVD.