MICROPIPE AND DISLOCATION DENSITY REDUCTION IN 6H-SIC AND 4H-SIC STRUCTURES GROWN BY LIQUID-PHASE EPITAXY

We investigated silicon carbide (SiC) epitaxial layers grown by liquid phase epitaxy (LPE). The layers were grown on 6H-SiC and 4H-SiC well- oriented (0001) 35 mm diameter commercial wafers as well as on 6H-SiC Lely crystals. A few experiments were also done on off-axis 6H-SiC and 4H-SiC substrates. Layer thickness and growth rate ranged from 0.5 to 50 microns and 0.5 to 10 mu m/h, respectively. Layers were investigat ed by x-ray diffraction, x-ray topography, and selective chemical etch ing in molten KOH. It was found that dislocation and micropipe density in LPE grown epitaxial layers were significantly reduced compared wit h the defect densities in the substrates.