Novel Reconstruction Mechanism for Dangling-Bond Minimization: Combined Method Surface Structure Determination ofSiC(111)-(3×3)

The $\mathrm{SiC}\left(111\right)-\left(3\times 3\right)$ phase was analyzed by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED) holography, density functional theory (DFT), and conventional LEED. A single adatom per unit cell found in STM acts as a beam splitter for the holographic inversion of discrete LEED spot intensities. The resulting 3D image guides the detailed analyses by LEED and DFT which find a Si tetramer on a twisted Si adlayer with cloverlike rings. This twist model with one dangling bond left per unit cell represents a novel $\left(n\times n\right)$-reconstruction mechanism of group-IV (111) surfaces.