High Quality Uniform Thick Epitaxy of 4H-SiC for High Power Device Applications

Growth of thick SiC epilayers has been investigated in a horizontal hot-wall CVD reactor capable of growing 3x2-in wafers or single wafer with a diameter up to 100mm. Good uniformity of lower than 3% for thickness and lower than 20% for doping has been obtained on 2-in or 3-in epi wafers with thickness of 60 - 120 μm. Low intentional nitrogen doping of 5.8x1014 cm-3 was achieved on a 3-in epi wafer with a thickness of 120 μm. A higher growth rate of 10 μm/h was achieved while good uniformity was maintained. Surface morphology of the thick epilayers was carefully examined and smooth surface was observed for epilayers thicker than 100 μm. The defect density of the thick epilayers was also discussed and the high purity of the thick epi was verified by low temperature PL measurement.