Abstract
Formation processes of terraces on (100) silicon surfaces during annealing at 1000 °C were observed in situ by ultrahigh vacuum reflection electron microscopy. Terraces were formed on staircases made up of monoatomic steps, preferentially at the sites where stairs were larger than average. The sites are formed by surface undulation. It was found that the terrace grew, or extended, in both up‐step and down‐step directions almost at equal rates. The terrace thus grew not by sublimation, but by adhesion and removal of atoms at respective terrace edges. Thus, the interlayer migration of adatoms plays an important role in the terrace growth.