Modification of overlayer growth kinetics by surface interlayers: The Si(111)√7×√3-indium surface

Abstract

The growth of thin films of In on bare Si(111)-type substrate surfaces and on the so-called (√7×√3)–In monolayer structure on Si(111) as an interlayer surface has been studied comparatively by scanning tunneling microscopy (STM), Auger electron spectroscopy, and low-energy electron diffraction (LEED). The In uptake and the morphology of In islands formed on the two surfaces are remarkably different, and a nonwetting behavior of In on the (√7×√3) surface is observed. Due to the very high mobility of In adatoms on the (√7×√3)–In surface very few, but large, In islands are observed; they cover only a minor portion of the surface area, whereas on bare Si(111) surfaces the In islands are more uniformly distributed over the surface, indicating a more limited diffusion rate of In atoms. Epitaxially ordered In islands with In–In distances close to those in bulk In, as revealed by atomically resolved STM images and by LEED, are observed to grow at room temperature on Si(111) surfaces. On the (√7×√3)–In surface metastable In islands in a pseudomorphically grown structure, i.e., with In–In distances determined by the Si(111) lattice, have been detected.