High-temperature scanning-tunneling-microscopy observation of phase transitions and reconstruction on a vicinal Si(111) surface

Abstract

The step structure of a vicinal Si(111) surface misoriented 10° to [112¯] is studied using high-temperature scanning tunneling microscopy (STM). Phase transitions on the vicinal Si(111) surface are observed in real time on an atomic scale. During cooling from above the (1×1)-to-(7×7) transition temperature, slender (111) facets with a 7×7 structure appear, and these facets widen as the temperature decreases. At the initial stage of step bunching, no surface reconstruction is observed on the step bunch. Below 700 °C, however, nucleation of reconstructed (331) facets starts on the step bunch. These STM results are compared with our previous reflection high-energy electron-diffraction results [Jpn. J. Appl. Phys. 30, 1337 (1991)].