Studies of growth processes from the vapour phase of silicon carbide epitaxial layers: III. Thermodynamics of the high temperature processes in the system SiC-N 2 at constant volume

Abstract

The thermodynamic analysis of high temperature processes in the SiC-N 2 system has been carried out at different initial pressures of nitrogen in the closed system 4, 200, 400, 600, 760, 1140 and 1520 Torr in the temperature interval (1500–3000) K. On the basis of thermodynamic analysis data it has been established that the stoichiometric relationship of silicon and carbon containing components in the vapour phase greatly depends on nitrogen pressure and temperature and this dependence is to be taken into account when analysing the phenomena of luminescence and polytypism in the course of growing silicon carbide monocrystals and epitaxial layers from the vapour phase. The “extent of development” of silicon carbide/nitrogen interaction reactions has been estimated and it has been shown that to certain temperatures (which depend on initial nitrogen pressure i P N 2 and shift toward higher temperatures under the increase of i P N 2 ) it is most likely the reaction, accompanied by the formation of liquid silicon and gaseous cyanogen.