Theoretical Study of the Role of Chemistry and Substrate Characteristics in C60 keV Bombardment of Si, SiC, and Diamond by Molecular Dynamics Simulations

Abstract

This article presents a theoretical study aimed at understanding the reactive nature of carbon in secondary ion mass spectrometry experiments of Si with keV C60+. Molecular dynamics simulations are performed to model the bombardment of three different substrates, Si, SiC, and diamond, with normal incident C60 at kinetic energies ranging from 5 to 20 keV. Projectile atoms form strong covalent bonds with both Si and C and, therefore, are incorporated into the target material. Although these substrates have the same diamond lattice structure, they differ greatly in their cohesive energy and number density. The yield is found to be a factor of two times greater on SiC than on Si or diamond. The mesoscale energy deposition footprint model is used to understand the reasons for the differing behaviors of the substrates as a result of C60 bombardment.