Atomistic Model for Ge Condensation under SiGe Oxidation

Abstract

Oxidation of a dilute Si(Ge) alloy is modeled using an original protocol based on molecular dynamicssimulation and rules for the oxygen insertions. These rules, deduced from ab-initio calculations,favor the formation of SiO2 against GeO2 oxide which leads to segregation of Ge atoms into the alloyduring the oxidation front advance. Ge condensation is then observed close to the SiO2/Ge interfacedue to the strain induced by oxidation in this region. From the analysis of the simulations process, wepropose a one-dimensional description of Ge condensation which reproduces the evolution of the Geconcentration during oxidation of the SiGe alloy.