By using the 3-dimensional Monte Carlo model, the effect of monovacancies upon diffusive exchanges between steps on the (111) surface of a diamond-like crystal during sublimation was investigated. The critical terrace width, Lc (distance from the step-edge to the nearest stable vacancy island), was determined as a function of the relationship between the energy of adatom formation at the smooth terrace, En, and the energy of adatom desorption from the terrace, Ed, with retention of the sum of these energies, Es = En + Ed; which characterized sublimation. It was found that a pronounced maximum existed in the obtained dependence of Lc on En. A formula was suggested which describes well the Lc(En) dependence, for various values of Es. Extrapolation of the dependence Lc(En), to the value Es = 4.2eV (which was characteristic of Si), permitted a comparison of the model results with published experimental data. This offered a possible explanation for 3-fold increase in terrace width which was observed experimentally at about 1500K.

The Effects of Monovacancies on the Terrace Width during Sublimation from the (111) Surface of a Diamond-Like Crystal. A.V.Zverev, I.G.Neizvestny, N.L.Shvartz, Z.S.Yanovitskaja: Semiconductors, 2003, 37[6], 649-55