UHV-REM Study of Changes in the Step Structures on Clean (100) Silicon Surfaces by Annealing

Abstract

Changes in the step structures on clean (100) silicon surfaces during annealing were observed by in situ ultra high vacuum reflection electron microscopy. After quenching from 1200°C, at about 800°C almost the entire surface was covered with periodic arrays of 2×1 and 1×2 reconstructed domains bounded by monolayer high steps. One type of reconstructed domain, with dimers parallel to the average tilt axis [011̄], grew over the other above 900°C. The terrace size became as large as a few microns. However, a small number of periodic arrays of reconstructed domains remained stable at above 1000°C even under apparent surface evaporation.