Dresden 2006 – wissenschaftliches Programm
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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 29.69: Poster
Mittwoch, 29. März 2006, 14:30–17:30, P2
SiC Pore Surfaces: Surface Studies of 4H-SiC(1102) and 4H-SiC(1102) — •U. Starke1, W.Y. Lee1, M. Hetzel1, C. Virojanadara1, C. Coletti2, S.E. Saddow2, R.P. Devaty3, and W.J. Choyke3 — 1Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany — 2University of South Florida, Tampa, USA — 3University of Pittsburgh, USA
Porous SiC has shown intriguing perspectives for a variety of possible applications in electronics, sensors, fuel cells and bio-technology. One important pore type found is a triangular shaped channel with surfaces inclined by about 62∘ with respect to SiC(0001). The respective single crystal surface, 4H-SiC(1102), and its isomorphic opposite, i.e. the 4H-SiC(1102) surface have been studied in this work using AFM, LEED, STM and AES. The mechanically polished samples were etched in hydrogen flux at about 1500∘C which eliminates the polishing damage as monitored by AFM. Both surfaces immediately display a sharp LEED pattern of bulk-like periodicity. An apparent thin oxide layer termination is inferred from AES. Further annealing in UHV leads to the removal of oxygen after flashing to about 1200∘C. Si deposition and subsequent annealing lead to a well ordered surface with the best LEED pattern obtained after heating to about 1120 and 1000∘C, respectively. Also the Si/C composition ratio increases up to this temperature regime until it drops at higher temperatures. A tendency towards a (2×1) reconstruction is observed. The interpretation of LEED spot intensity curves indicates a different structure for the UHV treated surface as compared to the ’as-etched’ surface condition.