Effect of basal plane bending on the atomic step morphology of the 4H-SiC substrate surface

The atomic step morphology of the SiC (0001) surface is determined by the crystal structure of SiC and reflects the real crystal morphology of the SiC substrate surface. The atomic step morphology can be used as feedback in final processing of the substrate and can reflect the characteristics and defects of the crystal itself. However, the widths and orientations of the atomic steps in different regions of the same wafer surface are often quite different. In this paper, atomic force microscopy (AFM) was used to systematically study the atomic steps of the 4H-SiC substrate (0001) surface without surface damage. The results show that the distributions of the atomic step morphology on the surfaces of wafers obtained from the same crystal are consistent. Based on a comparison of high-resolution X-ray diffraction (HRXRD) results, basal plane bending is the fundamental reason for the change in the atomic step morphology in different regions of the substrate. The results of this paper deepen the understanding of the surface morphology of SiC substrates and reveal the two-dimensional distribution of the bending characteristics of the basal plane throughout the entire substrate.