Partially amorphous silicon nitride thin films were deposited using plasma enhanced chemical vapor deposition technique using the two gas systems: SiH4/NH3 and SiH4/N2. Fourier Transform infrared spectroscopy was employed to derive the relative changes in the bonded hydrogen content with increasing flow rates of NH3 and N2. Surface morphology was monitored using atomic force microscopy. Root mean square surface roughness was found to be dependent on the NH3 and N2 flow rates, unlike silicon nitride films deposited by rf magnetron sputtering with variation in (N2/Ar) (Li et al. Thin Solid Films 334 (1998) 140). The discrepancy has been explained in the light of bonded hydrogen content in these films. The X-ray diffraction technique has also been used to observe the phases of the nitride films which showed the presence of silicon nitride grains oriented in (200), (400) and (221) directions in the predominantly amorphous as-deposited SiN(x):H films.