Effects of the Porosity of the Source Materials on the Initial Growth of 6H-SiC Crystal

The source materials with different porosity were be prepared by different loading ways.Effects of the porosity(porosity: 50%,55%,60%) of the source materials on the crystal growth rate and the crystal quality in the initial stage of SiC crystal growth were investigated respectively.It is found that crystal growth rate rises and the crystal quality declines with the increase of the porosity of the source materials.The temperature distribution and mass transport in the source materials(porosity: 50%,55%,60%) as well as the growth rate in the initial growth stage are simulated by the finite element method.The heat transfer inside the source material under the typical growth temperature bases on thermal radiation between SiC granulas.The simulations indicate that it takes the least time to reach stationary heat transfer for the source materials with 60% porosity and its growth rate in the initial growth stage is the largest among them.Therefore,the simulations explain the results of the growth experiments very well.