Removal of polishing-induced damage from 6H-SiC(0001) substrates by hydrogen etching

We use atomic force microscopy and ultra-high vacuum scanning tunneling microscopy to show that polishing-induced damage on 6H-SiC(0001) on-axis wafers is efficiently removed by hydrogen etching in a hot-wall chemical vapor deposition reactor. The obtained surfaces exhibit a highly regular step structure with typically 1500 Angstrom wide terraces separated by steps with the height of a single unit cell (15 Angstrom). The corresponding low-energy electron diffraction pattern is threefold symmetric as expected for a surface with a single preferred domain. These results are compared with results obtained for as-polished and sublimation etched SiC(0001) wafers.