Extended study of the atomic step-terrace structure on hexagonal SiC (0001) by chemical-mechanical planarization

• Published in: Applied surface science Vol. 284; pp. 195 - 206
• Main Authors: Shi, Xiaolei, Pan, Guoshun, Zhou, Yan, Zou, Chunli, Gong, Hua
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2013; Elsevier
• Subjects: Atomic force microscope; Atomic force microscopy; Atomic structure; Chemical-mechanical planarization; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Epitaxy; Exact sciences and technology; Formations; Physics; Planarization; Planes; Silicon carbide; Step-terrace structure; Surface roughness; Terraces; Surface roughness; Silicon carbide; Step-terrace structure; Chemical-mechanical planarization; Atomic force microscope; Atomic force microscopy; Planarization; Terrace; Inorganic compounds; Roughness; Step; Atomic structure
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.07.080

•Demonstrates CMP of SiC with a colloidal silica slurry and successfully obtain the high-definition atomic step-terrace structure.•The formation rules of step-terrace structure during CMP process is described and explained.•The relationship between CMP technique and step-terrace structure is studied.•The change of polishing direction cause the change of the step-terrace structure topography.•The distribution of terraces is described and explained. 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.