Gaseous etching effects on homoepitaxial growth of SiC on hemispherical substrates using CVD

In this study, homoepitaxial growth was carried out by atmospheric pressure CVD using Si(2)Cl(6)+C(3)H(8) gas system. To obtain further information about crystal orientation effects, hemispherically polished substrates of 6H-, 4H- and 15R-SiC were used. The effects of two types gaseous etching (H(2)+HCl and H(2)+C(3)H(8)) on grown epitaxial layers were studied. For C-face, 3D-nucleation of 3C-SiC along < 11 (2) over bar0 > was observed on the grown epilayers after the H(2)+HCl etching. In contrast, 3D nucleation did not extend along < 11 (2) over bar0 > of the grown epilayers after the H(2)+C(3)H(8) etching. This reason is attributed to the anisotropy of the H(2)+HCl etching and the difference of dangling bond energy at the step edge. For Si-face, characteristic features for each polytype were observed.