Physical modeling of the time constant of transient enhancement in the diffusion of ion-implanted dopants in silicon
The supersaturation of point defects in silicon during the annealing of implantation damage causes a transient enhanced diffusion of dopants. A model describing the time constant for the transient enhanced diffusion of implanted dopants was developed based on the annealing characteristics of ion-implantation damage. This study examined self-amorphizing high-dose implants of dopants which generate point-defect clusters distributed throughout the implanted layer and end-of-range (EOR) dislocation loops just beyond the original amorphous/crystalline interface after the regrowth of the surface amorphous layer. The dissolution of point-defect clusters modeled as spheres of self-interstitials exhibits a 4.3 eV activation energy. The annealing of EOR dislocation loops following the dissolution of point-defect clusters is modeled by a process similar to Ostwald's ripening process with the surface acting as a sink for point defects.
