Segregation of gold at dislocations confirmed by gold diffusion into highly dislocated silicon

H. Bracht, A. Rodriguez Schachtrup, I. Yonenaga

Research output: Contribution to journalArticle

Abstract

We report on Au-diffusion experiments performed between 850°C and 1100°C into plastically deformed Si monocyrstals, undoped and uniformly doped with a B concentration of 3×1019 cm-3. After indiffusion, Au profiles were monitored with neutron activation analysis (NAA) in conjunction with mechanical sectioning. The profiles show Au-diffusion to be faster in heavily B-doped Si than in undoped samples. Fitting of the experimental profiles which are accurately described with complementary error functions yields an effective diffusion coefficient DAueff and a boundary concentration CAu(x=0). Data for DAueff and CAu(x=0) obtained for diffusion temperatures lower than 1000°C are considerably lower and higher, respectively, than expected from the extrapolation based on the high-temperature results. The unusual temperature dependence of DAueff and CAu(x=0) is explained taking into account segregation of Au at dislocations in addition to the kick-out diffusion mechanism which is the generally accepted process for Au diffusion in dislocation-free Si. The segregation of Au at dislocations is found to increase with decreasing temperature with an activation enthalpy of about -1.9 eV. From the influence of doping observed on Au diffusion into dislocated Si, we deduce that interstitial Au is positively charged in p-type Si and introduces a donor level at about 0.47 eV above the valence-band edge.

Original languageEnglish
Pages (from-to)1783-1788
Number of pages6
JournalMaterials Science Forum
Volume258-263
Issue number9993
DOIs
Publication statusPublished - 1997 Jan 1

Keywords

  • Dislocations
  • Gold
  • Neutron-activation analysis
  • Segregation
  • Silicon

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Segregation of gold at dislocations confirmed by gold diffusion into highly dislocated silicon'. Together they form a unique fingerprint.

  • Cite this