The stability ranges of monatomic and diatomic steps on the Si(001) surface were determined by high-resolution spot-profile analysis of low-energy diffracted electrons. Diatomic steps were predominantly observed at temperatures below 1200K. With increasing annealing temperature the steps coagulate and (113) facets stabilized by a (3 x 1) reconstruction were identified. These facets were stable above 1200K, and up to 1450K. Annealing to higher temperatures results in the formation of monatomic steps with a terrace width above the experimental coherence length.

Kinetics and Reconstruction of Steps at the Si(001) Surface. W.Weiss, D.Schmeisser, W.Göpel: Physical Review Letters, 1988, 60, 1326-9