HREM study of ion implantation in 6H-SiC at high temperatures

Implantation of aluminium into 6H-SiC at high temperature and at a high dose results in the formation of aluminium precipitates with a definite orientation relationship to the matrix. [21101(6H-SiC)//[011](Al) and [0001](6H-SiC)//[111](Al). Under these implantation conditions the polytypic transformation of 6H-SiC into 3C no longer occurs by gliding but through the generation of interstitial semi-loops at the precipitates. It is shown that the formation of Al precipitates is strongly dependent on the dose of implantation. In the absence of precipitates in the 6H-SiC the usual glide mechanism for the polytypic transformation is maintained. These conclusions are based on high-resolution electron microscopy observations.