SiC seeded boule growth

The commercial availability of relatively large diameter SiC wafers continues to fuel a high level of interest in SiC semiconductor technology. Projections that 50 - 75 mm SiC wafers will be available in the coming years continues to intensify this interest. Specific efforts were made in this work towards larger diameter and low micropipe high quality crystals. This has led to the development of >60 mm diameter boules and increased efforts to conduct fundamental material studies on SiC. Purity control is part of these studies, and the latest results in the growth of high purity material are presented. Additionally, thermal conductivity data on some of these materials will be presented. The primary material quality concern is the micropipe defect. Although several mechanisms, or combinations of mechanisms, cause micropipes in SiC boules grown by the seeded sublimation method, recent efforts have reduced micropipes by over two orders of magnitude. This data and results on the production of wafers with micropipe densities less than 1 cm(-2) (with >1 cm(2) areas void of micropipes), indicate that micropipes can be reduced to a level that makes high current devices viable and that these defects may be totally eliminated in the next few years. In this paper, evidence will be presented on several def:ct formation mechanisms as well as Synchrotron White Beam X-ray Topography studies which sinew recombination and elimination of micropipes.