Thermal Etching of 4H-SiC(0001) Si Faces in the Mixed Gas of Chlorine and Oxygen

摘要: 4H-SiC (0001)Si faces have been thermally etched at atmospheric pressure in a mixed gas of oxygen (O2) and chlorine (Cl2). Etch pits with definite shapes appeared independently the conduction type doping level SiC. The types dislocation can be easily identified from shape etch pits. Facets screw edge dislocations consist specific {110n} pyramidal planes. In dislocation-free areas, etching rate depended on Cl2 flow rate, temperature off-angle substrate. activation energy Arrhenius plots was about 54 kcal/mol, which did not change O2/Cl2=0-1. After thermal many concavities were formed. On basis these results, mechanisms are discussed.