2D island nucleation controlled by nanocluster diffusion during Si and Ge epitaxy on Si(1 1 1)-(7 × 7) surface at elevated temperatures

A. S. Petrov, D. I. Rogilo, D. V. Sheglov, A. V. Latyshev

Research output: Contribution to journalArticle

Abstract

We have studied two-dimensional (2D) island nucleation at the initial stages of Si and Ge epitaxial growth near monatomic steps and on wide (up to 10 μm) terraces on the Si(1 1 1)-(7 × 7) surface in 500–750 °C interval by in situ ultrahigh vacuum reflection electron microscopy (UHV REM) and ex situ atomic force microscopy (AFM). Concentration of 2D islands nucleated on the terraces and depletion zone width near the steps have been measured as functions of deposition rate and substrate temperature. We have shown that Ge[sbnd]Si and Si nanoclusters are dominating diffusion species providing surface mass transport on the Si(1 1 1)-(7 × 7) surface during Ge and Si epitaxial growth at temperatures above 500 °C and 600 °C, respectively; the activation energy of Ge[sbnd]Si nanocluster diffusion has been first estimated at 1.3–1.4 eV. The kinetics of 2D island nucleation and growth near the steps (both for Si and Ge epitaxy) and on the wide terraces (for Ge epitaxy) is limited by surface diffusion only, and critical nucleus consists of i ≫ 1 nanoclusters.

Original languageEnglish
Article number125347
Number of pages6
JournalJournal of Crystal Growth
Volume531
DOIs
Publication statusPublished - 1 Feb 2020

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Keywords

  • A1. Nucleation
  • A1. Surface processes
  • A3. Molecular beam epitaxy
  • B2. Semiconducting germanium
  • B2. Semiconducting silicon
  • Nucleation
  • MAGIC ISLANDS
  • SILICON
  • TRANSITION
  • CLUSTERS
  • GROWTH
  • Molecular beam epitaxy
  • ATOMS
  • Semiconducting silicon
  • SCANNING-TUNNELING-MICROSCOPY
  • Surface processes
  • Semiconducting germanium
  • TRANSFORMATIONS
  • INITIAL-STAGES
  • STEPS

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