A STUDY OF THE TRANSITION BETWEEN GROWTH OF STOICHIOMETRIC AND SILICON-EXCESS SILICON-CARBIDE BY CVD IN THE SYSTEM MTS H-2/

Under conditions of medium decomposition of MTS (10-90 %), a transitio n between region A (growth of nearly stoichiometric SiC) and region B (Si-excess SIC deposition) may be induced by the variations of total f low rate, total pressure or temperature in relatively small intervals, After the modification of one of these parameters, the growth rate re aches rapidly a new stationary value unless the modification leads to a transition from B to A, in this case, the growth rate increases duri ng a transient stage before reaching the steady-state mode, A growth m odel is presented which explains these observations, A TEM study confi rms a prediction of this model.