Process optimization for homoepitaxial growth of thick 4H-SiC films via hydrogen chloride chemical vapor deposition

•A home-made vertical hot-wall chemical vapor deposition system was used.•Appropriate Cl/Si ratio will improve the quality of epitaxial film.•Surface quality degrades as the thickness of the epitaxial layer increases.•The formation of the triangular defect is due to particles on the surface.•A model of triangular defect caused by particles was proposed. We present process optimization for rapid homoepitaxial growth of thick 4H-SiC films on 4° off-cut substrates via hydrogen chloride chemical vapor deposition (HCVD). The gas used is a mixture of HCl additive, SiH4, C2H4 and H2. After characterization of the 4H-SiC films using Nomarski, AFM, Raman and XRD, we investigate the effect of HCl additive, Cl/Si ratio, on the quality of the epitaxial film and the growth rate. With the optimized chlorine based method HCVD, the 4H-SiC epitaxial growth rate was up to 52 μm/h in a home-made vertical hot-wall HCVD system. At a steady growth rate of 46 μm/h, a 4H-SiC epitaxial film with a thickness of 100 μm was obtained. The epitaxial films were of homogeneous 4H polytype, with a maximum root mean square roughness (RMS) of 1.3 nm.