Modélisation et simulation de la diffusion de l’antimoine dans le germanium

Abstract

Germanium is a good candidate to replace silicon in advanced microelectronic devices, due to its high charge carriers mobility. The purpose of this work is to know better the phenomenon of dopant diffusion in germanium by modeling and simulating the antimony diffusion in germanium, which is essential to perform efficient circuits. After the modelling of the diffusion using the vacancy mechanism, taking account of the antimony effective diffusion coefficient dependence of the square and the cube of the free electrons concentration and the numerical solution of partial differential equation of the second Fick law by finite differences method, we were able to simulate the Sb experimental profiles at temperature700°C. Which shows the contribution of doubly negatively charged (2-) and triply negatively charged (3-) vacancies in this diffusion, where the contributions ratio is β=11.5