In this paper, thick 4H-SiC epilayers of 147 mu m demanded for ultra-high-voltage power devices has been obtained at a high growth rate of 85 mu m/h under optimized growth conditions. We have attempted to improve the quality and reduce the surface defect density of thick epilayers. The surface defect density is obviously reduced from 3.46 cm(-2) to 0.85 cm(-2), owing to the addition of the etching process. The effect of the etching process on the surface defect is discussed based on the measured results. The results demonstrate that the fast epitaxial growth system can grow ultra thick 4H-SiC epilayers with high quality that satisfies the requirement of ultra-high-voltage devices.