Generation of the Si(111)-(2 × 1) surface reconstruction by a rapid radiation quench

Surface morphology of the Si(111) samples quenched with a cooling rate of about 350 degrees C s(-1) was studied by scanning tunnelling microscopy. In all quench experiments the (7 x 7) reconstruction was the main structure observed. No traces of other structures were found by means of low-energy electron diffraction. The formation of triangular residual islands in the middle of wide terraces was revealed by scanning tunnelling microscopy for initial quench temperatures in the range 1150-1250 degrees C. Formation of solid structureless residual islands resulted from a quench from temperatures of about 1300 degrees C. Upon quenching from even higher temperatures, (2 x 1) structure domains appear within solid islands. All island types must be the result of local compression of the adatom gas by the growing (7 x 7) reconstruction spots during quench.