Growth Kinetics and Wall Stress Effects in Sublimation Growth of AlN Bulk Crystals

In the sublimation crystal growth process, source materials sublime at a higher temperature, and the resulting vapor transports to the seed crystal at a lower temperature where surface reaction and crystallization takes place. We have developed a two-dimensional numerical model to simulate the thermal and fluid fields in an AlN bulk growth system. A growth model that incorporates thermodynamic analyses, Stefan flow or diffusion transport, and growth kinetics has been developed to predict the growth rate of AlN bulk crystal. In addition, a thermomechanical stress model has also been developed to predict the thermal stress evolution in an AlN crystal.