New results on the quenched "1×1" structure of Si{111} surfaces

Abstract

The "1×1" structure known to form from the 7×7 structure at high temperatures on Si{111} surfaces was studied at room temperature after quenching from 1200°C. Comparisons of low-energy electron diffraction spectra both at normal and off-normal incidence from this quenched phase with corresponding spectra from the Te-stabilized 1×1 surface show that these two phases are not the same. The quenched phase exhibits weak but sharp ½-order beams that reveal the presence of large 2×1 domains. There is some indication that the 2×1 distortion may be similar to that of the cleaved 2×1 structure, thus implying that the 2×1 phase of Si{111} is not metastable, as heretofore believed, but indeed very stable.