Theoretical investigation on the formation process of the stacking-fault triangle in the Si(111)-7x7 structure

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abstract
The formation process of stacking-fault(SF) triangles during the Si(111) 1x1-> 7x7 reconstruction has been studied using the quantum chemical theoretical calculations.On the basis of the propagation and subsequent merging mechanism of the SF areas proposed by one of authors(I.O.),several reaction paths to complete a single SF triangle have been examined.Themost probable formation process of SF triangles has been determined from the their lowest energy reaction paht.A comparison of total energy formation of 7x7 dimer-stacking-fault(DS)structure,which was compatible with the recent experimental results suggesting the important role of oxygen in the 7x7 reconstruction.The effect of the step edge has also been discussed.