Abstract
We report on highly resolved core-level and valence-band photoemission spectroscopies of hydrogenated, unreconstructed and using synchrotron radiation. In the C core level spectra of a chemically shifted surface component due to C-H bonds is observed at a binding energy higher than that of the bulk line. The Si core-level spectra of SiC(0001) suggest the presence of a surface component as well but a clear identification is hindered by a large Gaussian width, which is present in all spectra and which is consistent with values found in the literature. The effect of thermal hydrogen desorption was studied. On the desorption of hydrogen at is accompanied by a simultaneous transformation to the Si-rich reconstruction. On first signs of hydrogen desorption, i.e., the formation of a dangling bond state in the fundamental band gap of SiC, are seen at temperatures around while the periodicity is conserved. At a reconstruction is formed. The formation of these reconstructions on thermally hydrogenated and is discussed in the light of earlier studies of surfaces. It will be shown that by using the hydrogenated surfaces as a starting point it is possible to gain insight into how the and reconstructions are formed on and respectively. This is due to the fact that only hydrogen-terminated surfaces possess a surface carbon to silicon ratio of
- Received 31 October 2002
DOI:https://doi.org/10.1103/PhysRevB.67.205304
©2003 American Physical Society