Relation between Growth Temperature and the Structure of SiC Crystals Grown by Sublimation Method

Abstract

Abstract : The relationship between growth temperature and the polytypes of SiC crystals has been studied experimentally at 2200 degrees C to 2600 degrees C under conditions of low supersaturation. The results are summarized as follows: (1) In the present experiment, excluding one example in which the 4 H-type was involved, the structure of all crystals consisted of the 6 H-, 15 R- and other long c-period types exceeding 21. Of the elemental structures of SiC, 2 H, 3 C, 4 H, 15 R, 6 H, and 21 R, only 6 H and 15 R were found. (2) In the range of 2200 degrees C - 2600 degrees C, 6 H and 15 R have the most thermal stability among the structures considered as elemental. However, the effect of impurity in the crystal and the shift from stoichiometry were neglected. (3) The relative amount of 15 R increased with decreasing temperature while 6 H showed the opposite tendency. (Author)