Simulation of Single Particle Displacement Damage in Si1-xGex alloys – Interaction of Primary Particles with the Material and Generation of the Damage Structure

Primary interaction simulations with neutrons are performed on Si1-xGex alloys with a Monte-Carlo (MC) code using the Binary Collision Approximation (BCA). Then, a statistical study of the collisions cascades development in Si0.8Ge0.2, Si0.7Ge0.3 and Si0.5Ge0.5 is carried out using Molecular Dynamics (MD) starting from both Si and Ge Primary Knock-On Atoms (PKAs) of 1 keV, 5 keV and 10 keV. The well-known Stillinger-Weber (SW) MD potential which can be employed to study Si, Ge and Si1-xGex is here coupled to the Ziegler-Biersack-Littmark (ZBL) Universal Potential to better describe the collisions between atoms. To account for the stopping power of the electrons the Two-Temperature Model (TTM) is combined with MD. Similar studies are performed on pure Si and pure Ge in order to be able to compare our Si-Ge alloys damage structures with reference materials. Moreover, data obtained with TTM-MD on Si, Ge and Si1-xGex is compared with collision cascades statistical data from MC codes.