Redistribution of Impurities During Solid Phase Epitaxy

Abstract

It is found that impurities are redistributed during solid phase epitaxy, which cannot be explained by normal diffusion theory. A model is proposed, where the driving force of the redistribution is the phase transition from amorphous and crystalline forms. The model has parameters of a segregation coefficient m, which is between amorphous and crystalline Si, and an introduced parameter of reaction length l, that is, the distance where impurities are exchanged. The model reproduces various experimental data by using corresponding parameter values with the same theoretical framework.

Keywords: Ion implantation, solid phase epitaxy, pile-up, arsenic, phosphorous, boron, reaction length, segregation, amorphous layer, regrowth, diffusion, crystalline layer, amorphous/crystal interface, phase transition, thermal annealing, lattice site, phase field model.