Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Oberflächenphysik
O 29: Poster session II (Nanostructures, Magnetism, Particles and clusters, Scanning probe techniques, Time-resolved spectroscopy, Structure and dynamics, Semiconductor surfaces and interfaces, Oxides and insulators, Solid-liquid interfaces)
O 29.70: Poster
Mittwoch, 29. März 2006, 14:30–17:30, P2
Temperature Induced Phase Transformation on the 4H-SiC (1120) Surface — •U. Starke1, W.Y. Lee1, and S. Soubatch1,2 — 1Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 2present address: lnternational University Bremen, Germany
The demand for better SiC devices has initiated an increased focus the non-polar 4H-SiC(1120) surface which has a lower defect density than basal-plane surfaces and can serve as alternative growth orientation. In the present work, we have studied this surface after hydrogen etching as well as after Si deposition as a function of temperature using XPS, LEED, AES and AFM. Results show that despite having a smooth, featureless surface (as observed by AFM), the ’just-loaded’ hydrogen etched surface exhibits a (1×1) LEED pattern, although weak. Chemically, the surface appears to be C-rich, indicated by XPS and AES spectra with an additional small amount of oxygen present. The oxygen peak vanishes upon heating to about 1150∘C. A well ordered surface can be obtained by Si deposition and subsequent annealing. The LEED pattern remains (1×1). However, the LEED intensities show a sharp change around 1000∘C indicating a structural phase transformation. The chemical composition also changes during annealing, however in a more gradual manner. The results will be discussed in detail, focusing on the chemical and structural properties of the two distinct phases observed.