REMOVAL OF POLISHING-INDUCED DAMAGE FROM 6H-SIC(0001) SUBSTRATES BY HYDROGEN ETCHING

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