Frontiers in preparation of Si3N4 powder by radio frequency plasma chemical vapor deposition

Preparing ultrafine silicon nitride powder on a large scale is very important because of the unique properties of silicon nitride ceramic. Different kinds of methods for synthesizing ultrafine silicon nitride powder are reviewed briefly. The radio frequency plasma chemical vapor deposition (RFPCVD) method and its characteristics are given. It is pointed out that mathematical models are very useful for studying: the RF thermal plasma generator and RFPCVD reactor, and there are three kinds of models used nowadays: the thermodynamic models, hydrodynamic models and aerosol dynamic models which have respective features. Research work on thermodynamic: hydrodynamic, aerosol dynamic and technological studies for preparing ultrafine silicon nitride powder are given in detail. At last, six important research topics for the studies on RFPCVD technology are discussed.