The process of nucleation of 2D islands near a monatomic step at the initial stage of growing of a silicon film on the Si(111)-(7 × 7) surface is studied by means of in situ ultrahighvacuum reflection electron microscopy. The dependence of the depletion region width W near the step, where no islands are formed, on the deposition rate R is described by the expression W2 ∝ R-χ with the exponent χ = 1.18 and χ = 0.63 at temperatures of 650 and 680 °C, respectively. It is demonstrated that the change in χ is associated with the step structure, which provides the transformation from the growth kinetics limited by attachment of adatoms to the step to that limited by diffusion of adatoms. A competition of the processes of nucleation and attachment to the step leads to an increase in the critical size of the island nucleus from i = 1 far from the step to i = 3–5 near the step and to i = 6–8 on the terrace of critical width for 2D nucleation.
|Журнал||Optoelectronics, Instrumentation and Data Processing|
|Состояние||Опубликовано - 1 мая 2016|
|Опубликовано для внешнего пользования||Да|