Segregation of Gold At dislocations conirmed by GOLD Diffusion into highly dislocated Silicon

摘要

We report on Au-diffusion experiments performed between 850 degree and 1100 degree into plasticaly deformed si monocyrstals, undoped and uniformly doped with a B ocncentration of 3*10 sup 19 cm sup -3. After indiffusion, Au profiles were monitored with neutron activation analysis in conjunction with mechanical sectioning. The profiles show Au-difusion to be faster in heavily B-doped SI than in undoped samples. Fittingof the experimental proiles which are accurately desicribed with ocmpelmentary error functions yields an effective diffusion cefficient and a boundary ocncentration C sub au(x=0). The segregatio of Au at dislocations is found to increase with devreasing temperature with an activation enthalpy of about -1.9eV. From the influence of doping obsrved on AU diffusion into dislocated Si, we deduce that interstitial Au is positively charged in p-type Si and introduces a fonor level at about 0.47eV above the valence-band edge.