CLEAVED SI(111) SURFACES - GEOMETRICAL AND ANNEALING BEHAVIOR

The conversion of the Si(111)-2 × 1 metastable cleavage structure to the stable Si(111)-7 × 7 structure was followed by measuring the LEED I/V spectra of the (00) spot as well as of superstructure spots of both structures in the range between 30 and 150 eV after anneals at temperatures up to 500°C for 10 min. The 2 × 1 structure directly transforms to the 7 × 7 structure with no intermediate structure. The conversion is first observed on the most wide cleavage steps after an anneal at 200°C. The activation barrier amounts to ΔG = 1.5 eV. The structural conversion on the narrower treads occurs during anneals at higher temperatures. © 1979.