PECVD silicon nitride film was deposited on P-type (100) silicon wafer in a parallel plate type reactor. The effect of different process parameters such as substrate temperature, RF power, and feed gas composition on the properties of silicon nitride layer was studied. Hydrogen content of nitride film was strongly influenced by substrate temperature and decreased with increasing substrate temperature. RF power influenced the type of bond configuration in the film. Si-H bond was dominant at the RF power lower than 40 W, while N-H bond became dominant at the RF power higher than 40 W. Etch rate in buffered HF solution was increased with the increment of hydrogen content in the film. The films deposited in N₂ diluent showed hydrogen content and etch rate higher than those deposited in H₂ diluent. Interface charge density decreased as the flow rate of ammonia increased.