Extended study of the atomic step-terrace structure on hexagonal SiC (0 0 0 1) by chemical-mechanical planarization

Abstract

The atomic step-terrace structure on hexagonal silicon carbide (0001) surface is significant in that it guides the improvement of chemical-mechanical planarization (CMP) and epitaxial technique. The final state of atomic step-terrace structure can be used as a feedback for improving the CMP process, the formula of slurry and the epitaxial technique. In this paper an extended study of the atomic step-terrace structure on 4H- and 6H-SiC (0001) planarized by CMP is presented. Surface topography of the (0001) facet plane of 4H- and 6H-SiC wafers during CMP process was studied by atomic force microscopy (AFM). The results demonstrate that high-definition atomic step-terrace structure of the (0001) facet plane of both 4H- and 6H-SiC can be obtained by appropriate CMP process, and during CMP process, the formation of step-terrace structure had a certain rule. We studied the relationship between the CMP process and the characteristics of the atomic step-terrace structure, and analyzed the possible impact of the CMP process on the status of terraces. We studied the distribution of terraces in different areas of the wafer, and the origin of this distribution was discussed briefly. We also describe the formation of dislocations in hexagonal SiC. The results of this paper may provide some ideas and suggestions for CMP, crystal growth and epitaxy research.