Reconstructions of the Si-terminated (100) surface inβ−SiC: A theoretical study

Using a self-consistent-charge density-functional based tight-binding approach the structural properties and relative stabilities of Si-terminated reconstructions of the (100) surface in $\beta -\mathrm{SiC}$ are discussed. All low-energy surfaces are found to be semiconducting. Over a wide range of growth conditions a model with $2\times 3$ periodicity has a low formation energy. Only in a Si-rich environment does a $3\times 2$ structure become stable.