REFLECTION ELECTRON MICROSCOPY OBSERVATION OF THE BEHAVIOR OF MONOATOMIC STEPS ON THE SILICON SURFACES

Abstract

Ultrahigh vacuum reflection electron microscopy (UHV REM) has been applied to imaging of monoatomic steps on silicon surfaces (111) and (100). The reversible rearrangements of the monoatomic step trains to the step bands and step antibands were found from direct observation of monoatomic step motion during sublimation. The influence of the direction of the electric current heating the specimen was observed. The recent data on atomic mechanisms of step bunching and debunching were reviewed. The monoatomic step behavior on the (100) silicon surface as well as (7×7)-(1×1) phase transition on the (111) surface was described. Direct observations of homoepitaxial processes were carried out. Transition from the step flow growth mode to the nucleation of two-dimensional islands was studied depending on the deposition rate and the substrate temperature. The initial stages of the heteroepitaxial process of germanium, gold and calcium fluorite on the silicon (111) surface were investigated. Finally, the mechanism of step rearrangements during the formation of superstructure domains leading to monoatomic step clustering was discussed.