Bombardment induced surface chemistry on Si under keV C ₆₀ impact

Molecular dynamics simulations of the sputtering of Si by C ₆₀ keV bombardment are performed in order to understand the importance of chemical reactions between C atoms from the projectile and Si atoms in the target crystal. The simulations predict the formation of strong covalent bonds between the C and Si atoms, which result in nearly all of the C atoms remaining embedded in the surface after bombardment. At low incident kinetic energies, little sputtering of Si atoms is observed and there is a net deposition of solid material. As the incident kinetic energy is increased, the sputtering yield of Si atoms increases. At 15 keV, the yield of sputtered Si atoms is more than twice the number of C atoms deposited, and there is a net erosion of the solid material.