Reconstruction of the Si-terminated β-SiC(100) surface

We have determined the atomic structure of the c(4 x 2) reconstructed Si-terminated beta-SiC(100) surface by comparing experimental height profiles with theoretical ones calculated with the scanning tunneling microscopy (STM)-elastic scattering quantum chemistry (ESQC) method. A large number of possible atomic configurations are considered. We found that the better fit between experiments and theory is obtained if half of the Si dimers have their altitude lowered by 0.1 Angstrom. Consequently, we conclude that the c(4 x 2) reconstruction is caused by alternative up and down dimers within the dimer rows, the lower dimers being not visible in the STM images. (C) 1998 Elsevier Science S.A.