Atomistic Simulation of Boron Diffusion with Charged Defects and Diffusivity in Strained Si/SiGe

Abstract

We discuss the boron diffusion in a biaxial tensile strained {001} Si and SiGe layer with kinetic Monte Carlo (KMC) method. We created a strain in silicon by adding a germanium mole fraction in silicon in order to perform a theoretical analysis. The generation of a strain in silicon influences in the diffusivity as well as the penetration profile during the implantation. The strain energy for the charged defects has been calculated from the ab-initio calculation while the diffusivity of boron was extracted from the Arrhenius formula. Hereby, the influence of the germanium content on the dopant diffusivity was estimated. Our KMC study revealed that the diffusion of the B atoms was retarded with increasing Germanium mole fraction in a strained silicon layer. Furthermore, we derived a functional dependence of the in-plane strain as well as the out-of-plane strain on the germanium mole fraction, which lies in the distribution of equivalent stresses along the Si/SiGe interface.