A systematic study was made of various reconstructions obtained after depositing Au on the (√3 x √3)-R30°-4H-SiC(00•1) surface. For 1 to 2ML of Au and an annealing temperature of l~675C, a 3 x 3 reconstruction was observed. For 4ML Au and an annealing temperature of l~650C, a (2√3 x 2√3)-R30° reconstruction appeared, while 5ML Au annealed at 700C reconstructed to give a (6√3 x 6√3)-R30° pattern. From the Si 2p and Au 4f core-level components, interface models were proposed; depending upon the amount of Au on the surface, and the annealing temperature. For 1 to 4ML Au annealed at 650 to 675C, gold diffused under the top-most Si into the SiC and formed a silicide. An additional Si component in the Si 2p spectra was related to the interface between the silicide and SiC. For 5ML Au annealed at 700C, silicide was also formed at the surface, covering unreacted Au on top of the SiC substrate. The interface Si component was also observed in the Si 2p spectra of this surface. The key role in Au/√3-4H-SiC(00•1) interface formation was played by diffusion and the silicon-richness of the surface.

A High-Resolution Core-Level Photoemission Study of the Au/4H-SiC(0001)-(√3 x √3) Interface. D.Stoltz, S.E.Stoltz, L.S.O.Johansson: Journal of Physics - Condensed Matter, 2007, 19[26], 266006 (8pp)