Influence of Different Hydrocarbons on Chemical Vapor Deposition Growth and Surface Morphological Defects in 4H‐SiC Epitaxial Layers

Controlled epitaxial growth of 4H‐SiC is essential for advancing both power electronics and quantum technologies. This study explores how different carbon sources—methane and propane—affect the surface morphology of these epitaxial layers. By varying C/Si ratios and using the two mentioned hydrocarbons as the carbon source in chloride‐based epitaxial growth of 4H‐SiC layers, it is unveiled that methane results in an exceptionally smooth surface. However, it pronounces surface irregularities such as short step bunching and dislocation‐related etch pits. Moreover, methane amplifies the overgrowth of triangular defects with the 4H polytype. In contrast, the introduction of propane causes a step‐bunched surface together with inclined line‐like surface morphological defects. Notably, a majority of the triangular defects exhibit a pure 3C character without an overgrown 4H polytype. It is shown that these outcomes could be attributed to different sticking coefficients and diffusivity of the molecular species resulting from different carbon sources on the 4H‐SiC surface during the epitaxial growth. This research also uncovers the underlying origins and mechanisms responsible for various surface morphological defects.