Stacking Faults in 4H-SiC Single Crystal

Abstract

Thenitrogen doped and unintentional nitrogen doped 4H-SiC single crystals were grown by PVT method on the C-terminated 4H seeds offcut by 4° from the c-face towards the <11¯20> axis, respectively. Optical microscope was used to investigate the characteristic of stacking fault defects and the effects of nitrogen doped onstacking fault defects in 4H-SiC single crystals etched by molten KOH etching. The result shows that the lines of the basal plane dislocation defect of the 4H-SiC wafer surface are corresponding to stacking fault defects in 4H-SiC single crystals, and the direction of the lines is parallel to <1¯100>. There are more stacking fault defects in 4H-SiC single crystals doped with nitrogen than that of unintentional nitrogen doped 4H-SiC single crystals. This phenomenon is consistent with published literatures in which high concentrations of nitrogen caused the formation of stacking fault defects in 4H-SiC single crystals. However, there is no stacking fault defect in the facet area for nitrogen doped 4H-SiC single crystals, although the nitrogen concentration in the facet area is higher than that in the other area, which is presumably due to specific crystal growth habit in the facet area of 4H-SiC single crystal.