Observation of an intrinsic5×5reconstruction on the clean Si(111) surface

Abstract

Low-temperature annealing of the cleaved Si(111)2×1 surface revealed the existence of an intrinsic 5×5 reconstruction on the clean Si(111) surface. The electronic structure of the Si(111)5×5 surface, obtained with angle-resolved photoemission, is almost identical to that of the 7×7 reconstruction. This is strong evidence that the 5×5 reconstruction is also of the dimer–adatom–stacking-fault (DAS)-type. The experimental observation of a 5×5 reconstruction supports recent theoretical results that the 7×7 and 5×5 DAS models are very close in total surface energy.