Effect of hydrogen etching on 6H SiC surface morphology studied by reflection high-energy positron diffraction and atomic force microscopy

Hydrogen-etched 6H SiC (0001) surfaces have been studied by reflection high -energy positron diffraction and atomic force microscopy. It was found that residual damage on the surfaces were effectively removed by the hydrogen e tching as compared to the HF etching after the oxidation. The hydrogen-etch ed surfaces were atomically flat. After the oxidation following the hydroge n etching, the surface roughness was found to increase and an anomalous dip structure appeared in the rocking curve of the reflection high-energy posi tron diffraction. (C) 2000 American Institute of Physics. [S0003-6951(00)02 209-9].