Phosphorus-incorporated polycrystalline diamond films were grown on Si substrates by hot-filament chemical vapor deposition using a low-risk organic phosphorus solution as a source gas, similarly to metal-organic chemical vapor deposition. The effects of growth conditions, including stage temperature, and C/H ratio, on the nucleation and crystal growth on Si surfaces, were investigated. We demonstrated that the polycrystalline films with smooth facets are formed at a stage temperature of 700 degrees C and a C/H ratio of 0.3%. Phosphorus incorporation into the films was confirmed from wavelength dispersive spectrometric measurements equipped with an electron probe microanalyzer.