Atomic and Electronic Structures of Reconstructed Si(100) Surfaces

Abstract

New structural models for 2\ifmmode\times\else\texttimes\fi{}1 and 4\ifmmode\times\else\texttimes\fi{}2 reconstructed (100) surfaces of Si determined from energy-minimization claculations are presented. The optimal 2\ifmmode\times\else\texttimes\fi{}1 and 4\ifmmode\times\else\texttimes\fi{}2 structures are found to correspond to asymmetric dimer geometries with partially ionic bonds between surface atoms, resulting in semiconducting surface electronic bands. The atomic and electronic structures for the 2\ifmmode\times\else\texttimes\fi{}1 and 4\ifmmode\times\else\texttimes\fi{}2 reconstructed surfaces are discussed.