Surface Observation of 4H-SiC (0001) Planarized by Catalyst-Referred Etching
We have developed a novel planarization method called catalyst-referred etching (CARE), which can planarize SiC substrates without the use of an abrasive. In this method, platinum is used as an oxidation catalyst. The surface of CARE-processed 4H-SiC (0001) substrates are atomically flat all over the wafer. It is found that the surface of CARE-processed substrates is composed of alternating wide and narrow terraces with single bilayer-height steps, regardless of the off-cut angle. This unique structure is induced by the differences in the chemical stabilities of the terraces.
W.B. Lee, C.F. Cheung and S. To
S. Sadakuni et al., "Surface Observation of 4H-SiC (0001) Planarized by Catalyst-Referred Etching", Key Engineering Materials, Vol. 516, pp. 452-456, 2012