Mg. Meere et al., ASYMPTOTIC ANALYSIS OF A MODEL FOR SUBSTITUTIONAL-INTERSTITIAL DIFFUSION, Zeitschrift fur angewandte Mathematik und Physik, 45(5), 1994, pp. 763-783
A substitutional-interstitial model for impurity diffusion in semi-con
ductors is discussed. In particular we consider a surface-source probl
em and obtain asymptotic solutions in the limit of the surface concent
ration of impurity being much greater than the equilibrium vacancy con
centration. In the absence of vacancy generation, a double error funct
ion impurity curve is obtained. These double profiles reproduce some o
f the qualitative features of diffusion in many III-V semiconductor sy
stems. We also discuss how vacancy generation modifies the analysis an
d show that in the limit of high vacancy generation, the problem becom
es one of linear diffusion with the diffusion curves then being single
error function complements.