The (00•1)Si faces were thermally etched, at atmospheric pressure, in a mixture of O2 and Cl2. Etch pits having definite shapes appeared, independently of the conduction type and doping level of the SiC. The dislocation types could be easily identified from the shape of the etch pits. The facets in the etch pits of screw and edge dislocations consisted of specific {110n} pyramidal planes. In dislocation-free areas, the etching rate depended upon the Cl2 flow rate, temperature and off-angle of the substrate. The activation energy deduced from Arrhenius plots of the etching rate was about 54kcal/mol; which did not change for O2/Cl2 ratios ranging from zero to unity. Following thermal etching of dislocation-free areas, many concavities were formed.

Thermal Etching of 4H-SiC(0001) Si Faces in the Mixed Gas of Chlorine and Oxygen. T.Hatayama, T.Shimizu, H.Kouketsu, H.Yano, Y.Uraoka, T.Fuyuki: Japanese Journal of Applied Physics, 2009, 48[6], 066516