The structure of the Si-terminated 3C-SiC(001)-c(4 x 2) surface reconstruction was determined using synchrotron-radiation-based X-ray photo-electron diffraction from the Si2p and C1s core levels. Only the alternating up-and-down dimer model reproduces satisfactorily the experimental results. The refinement of the alternating up-and-down model led to a height difference of 0.4Å between the up and down Si-Si dimers. Also, the top and bottom dimers have alternating bond lengths at 2.5 and 2.2Å, respectively. These results were in excellent agreement with ab initio density-functional calculations, which also further support the high sensitivity of this reconstruction on lateral strain and on the presence of defects. Finally, beyond well-established synchrotron-radiation-based core-level photo-emission spectroscopy, an assignment was made on the structural origin of each Si2p surface and sub-surface shifted component, based upon their different photoelectron diffraction patterns.

Atomic Structure Determination of the 3C-SiC(001) c(4 x 2) Surface Reconstruction - Experiment and Theory. A.Tejeda, E.Wimmer, P.Soukiassian, D.Dunham, E.Rotenberg, J.D.Denlinger, E.G.Michel: Physical Review B, 2007, 75[19], 195315 (13pp)