Hostname: page-component-7b7567c8c-7pwfn Total loading time: 0 Render date: 2026-11-15T00:48:14.186Z Has data issue: false hasContentIssue false

Vacancy Diffusion Kinetics on Si(111) and (001) Surfaces Studied by Scanning Reflection Electron Microscopy

Published online by Cambridge University Press:  15 February 2011

Heiji Watanabe
Affiliation:
Joint Research Center for Atom Technology Tsukuba, Ibaraki 305, Japan
Masakazu Ichikawa
Affiliation:
Joint Research Center for Atom Technology Tsukuba, Ibaraki 305, Japan
Get access

Abstract

The kinetics of vacancy diffusion on Si(111) and (001) surfaces are studied by using scanning reflection electron microscopy (SREM). Two types of layer-by-layer etching (reversal of step-flow growth and two-dimensional vacancy island nucleation) are observed during lowenergy Ar ion irradiation (500 eV) at elevated substrate temperatures. This means that vacancies created by low-energy ion impact diffuse on the surfaces, and are annihilated at the step edges. Although isotropic vacancy diffusion is observed on Si(111), anisotropic vacancy diffusion along the dimer rows and preferential vacancy annihilation at the SB steps are observed on Si(001). This anisotropic vacancy diffusion results in single-domain formation. The diffusion length of vacancies is estimated from the width of the denuded zones, which are formed on both sides of the atomic steps by thermal heating after the introduction of vacancies at room temperature. The activation energy of 3.0±0.2 eV obtained for Si(111) corresponds to the potential barrier both for surface adatom diffusion and for lateral binding energy to release adatoms from the step edges. For Si(001) surfaces, the activation energy obtained for vacancy diffusion along the dimer rows is 2.3±0.2 eV. The vacancy diffusion model mediated by dimer vacancy complexes, rather than by single-dimer vacancies, best accounts for our experimental results.

Information

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable