ANALYSIS OF NON-FICKIAN DIFFUSION DATA USING THE INTERSTITIAL-SUBSTITUTIONAL EQUILIBRIUM MODEL.

Abstract

A refinement of the Interstitial-Substitutional Equilibrium Model is proposed in which the concentration of holes in the host crystal is replaced by hole activity. The result is a refined model in which the diffusion coefficient is proportional to a power of the diffusant concentration. Unlike past approaches, however, the introduction of hole activity relaxes the restriction that the concentration exponent be an integer. Generalized numerical solutions are presented for a range of concentration exponents. Analyses based on the refined model have been completed using experimental data from the literature for Zn in GaAs, Cu in GaAs, Sb in Ge, and P in Si. In each case, the data reviewed was labeled anomalous or non-fickian. In general, good agreement was found between computed profiles and experimental profiles using two adjustable parameters. A mathematical criterion for computing the deviation of a computed profile from an experimental profile was established and a wide range of parameters was examined. Parameter values corresponding to minimum deviation of computed from experimental data were recorded for each of the data sets examined. (Author)

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1968
Accession Number
AD0677380

Entities

People

  • David W. Yarbrough

Organizations

  • United States Army Communications-Electronics Command

Tags

DTIC Thesaurus Topics

  • Agreements
  • Coefficients
  • Data Sets
  • Diffusion
  • Diffusion Coefficient
  • Experimental Data
  • Literature

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  • Materials Science and Engineering.
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