Growth of six inches N-type SiC single crystals with low dislocation defects

摘要

The superior power device and system performance will be enabled by the favorable physical properties of SiC substrate with high quality. Therefore, it is necessary to further reduce the density of one-dimensional dislocation defects in the SiC substrate. In this study, we present an efficient way to prepare 6 inches N-type SiC crystals with low dislocation defects by optimizing growth technics and temperature field distributions. The four different temperature fields with different growth system configurations were modeled by VR-PVT software. The polytypes of SiC crystals grown in different temperature fields were characterized by using Raman spectroscopy. And it certifies that other polytypes are easily formed in SiC crystal growing in a concave temperature field. The crystalline quality and lattice bending of SiC crystals grown in two different convex temperature fields were characterized by employing HRXRD and optical microscope. As a result, the obviously convex temperature field could cause large internal stress and propagation of dislocation defects in SiC crystals. Finally, the 6 inches N-type SiC single crystals with low dislocation defects density of 3.0×10^{3cm−2 were prepared by PVT method in the slightly convex temperature field.}