Study on oxidation processes of 4H-SiC (0001) for investigation of the atomically flattening mechanism in plasma assisted polishing

摘要

In order to clarify the atomically flattening mechanism of 4H-SiC in plasma assisted polishing (PAP), a study on water vapor plasma oxidation of SiC was conducted. A cross-sectional transmission electron microscopy (XTEM) observation revealed that an atomically flat interface between the oxide layer and SiC was obtained. Three times of plasma irradiation and HF dipping were conducted on a diamond lapped surface, which completely removed the scratches, though an atomically flat surface was not obtained, due to the residual of silicon oxycarbide layer on the surface. It was considered that CeO_2 abrasives could remove both silicon oxide and silicon oxycarbide, therefore, a flat surface with well-ordered step/terrace structure could be generated by PAP.