It was shown that the relative formation energies of stacking faults, dimer rows, and re-bonded corner holes could be determined by analyzing the size distribution of dimer stacking-fault structures that were found along extended <11¯2> step lengths of the Br-passivated (111)-1 x 1 surface. By using this method, an energy of 1.75eV was deduced for re-bonded corner holes which were associated with the dimer stacking-fault structures. These energies were then used to predict the partitioning of dimer stacking-fault structures along short <11¯2> step lengths. This yielded results that were in good agreement with experiment. A model was developed which described dimer stacking-fault structures as being an ordered collection of vacancies which were subject to the topological bonding constraints of the Si diamond lattice. It was thus established that there was a thermodynamic driving force for the coalescence and formation of large isolated dimer stacking-fault structures on adsorbate-stabilized (111)-1 x 1 terraces. This result had important implications for the feasibility of forming defect-free bulk-terminated Si(111) surfaces by exposure of the Si(111)-7 x 7 surface to H or halogens.

M.Fouchier, J.J.Boland: Physical Review B, 1998, 57[15], 8997-9002