Identification of the 6H-SiC(0001) 3 x 3 surface reconstruction core-levelshifted components

We investigate the 6H-SiC(0001) 3 x 3 surface reconstruction by Si 2p and C ls core-level photoemission spectroscopy using synchrotron radiation provid ing the first identification of surface core-level shifted components. Spec ific spectral features at the Si 2p core level, including bulk (B) and two surface shifted (SS1 and SS2) components, show a surface reconstruction str ucture involving several silicon atomic planes. In comparison, the C Is cor e level shows no involvement of carbon atoms in the 6H-SiC(0001) 3 x 3 surf ace reconstruction structure. These results, obtained by an attenuation lay er model, indicate that SS1 is related to the Si adatom and that SS2 is rel ated to the Si adlayer + trimer of the 6H-SiC(0001) 3 x 3 surface reconstru ction. (C) 2000 Elsevier Science B.V. All rights reserved.