Advanced diffusion models for submicron technologies

It is noted that for submicron technologies point-defect perturbations due to high-concentration impurity diffusion, long-range point-defect mediated enhancement or retardation of the diffusion, and the crystal damage can have a great impact on the final shape of the impurity profiles. These effects are addressed for various levels of complexity by a unified approach for impurity codiffusion in silicon. The model consists of coupled equations for the impurities and point defects in which all species, including structural defects, are treated on the same footing. The basic mechanism is the defect-impurity-pair diffusion as presented by B.J. Mulvaney an W.B. Richardson (1987) in a generalized description of the impurity-interstitial model by F.F. Morehead and R.F. Lever (1986). The key features of this model are the new equations for point defects coupled with impurity dynamics. They provide the local- and long-range coupling between the impurities.<>