Optimization of machining conditions of basic-type CMP/P-CVM fusion processing using SiC substrate

We proposed a high-efficiency planarization method that combines two processes, namely mechanical polishing, wherein the convex part of the work surface is converted to a damaged layer, and atmospheric-pressure plasma etching, wherein the damaged convex area is efficiently removed. For the effective generation of the damaged layer, we used cross-sectional transmission electron microscopy to investigate machining conditions using SiC substrates. Results revealed that the thickness of the damaged layer increased with the processing pressure, but it was insensitive to the processing time and rotation speed. By optimizing the machining conditions, a decreasing rate of the step height approximately seven times larger than its value during simple mechanical polishing was obtained using combined processing.