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Title: Surface self-diffusion of silicon during high temperature annealing

The atomic-scale mechanisms driving thermally activated self-diffusion on silicon surfaces are investigated by atomic force microscopy. The evolution of surface topography is quantified over a large spatial bandwidth by means of the Power Spectral Density functions. We propose a parametric model, based on the Mullins-Herring (M-H) diffusion equation, to describe the evolution of the surface topography of silicon during thermal annealing. Usually, a stochastic term is introduced into the M-H model in order to describe intrinsic random fluctuations of the system. In this work, we add two stochastic terms describing the surface thermal fluctuations and the oxidation-evaporation phenomenon. Using this extended model, surface evolution during thermal annealing in reducing atmosphere can be predicted for temperatures above the roughening transition. A very good agreement between experimental and theoretical data describing roughness evolution and self-diffusion phenomenon is obtained. The physical origin and time-evolution of these stochastic terms are discussed. Finally, using this model, we explore the limitations of the smoothening of the silicon surfaces by rapid thermal annealing.
Authors:
 [1] ;  [2] ; ;  [3] ;  [1]
  1. CEMES-CNRS and Université de Toulouse, 29 Rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 4 (France)
  2. (France)
  3. Corporate R and D, SOITEC, Parc Technologique des Fontaines, Chemin des Franques, 38190 Bernin (France)
Publication Date:
OSTI Identifier:
22273679
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; ATOMIC FORCE MICROSCOPY; DIFFUSION EQUATIONS; EVAPORATION; FLUCTUATIONS; OXIDATION; ROUGHNESS; SELF-DIFFUSION; SILICON; SPECTRAL DENSITY; STOCHASTIC PROCESSES; SURFACES; TEMPERATURE DEPENDENCE