FORMATION OF TWO-DIMENSIONAL ISLANDS ON Si(111) SURFACE DURING HOMOEPITAXIAL GROWTH

Read more The nucleation of two-dimensional Si islands has been studied by in situ ultrahigh vacuum reflection electron microscopy on extra-large (~ 10–100 μm) atomically flat terraces of Si(111) surface. The dependence of two-dimensional island concentration N_2D on substrate temperature T and silicon deposition rate R is found to obey relation N_2D∝R^χexp(E_2D/kT) with χ≈0.58 or 0.82 and E_2D ≈ 1.77 eV or 1.02 eV on the Si(111) surface with (7×7) or (1×1) structure, respectively. The critical nucleus during the growth on the extra-large terraces is found to consist of i = 1 particle at T ~ 700°С, and the critical nucleus size increases to i = 7–10 on terraces with smaller width, which is caused by the competition between the 2D island nucleation and the interaction of adatoms with steps bordering the critical terrace.

Keywords:
silicon, epitaxial growth, two-dimensional islands, atomic steps, critical nucleus, surface diffusion, reflection electron microscopy. 
УДК 539.211 + 538.975

FORMATION OF TWO-DIMENSIONAL ISLANDS ON Si(111) SURFACE DURING HOMOEPITAXIAL GROWTH