STRUCTURE FORMATION IN LOW-ENERGY METHYL RADICAL COLLISIONS ONTO DIAMOND (100) - AN MD STUDY

This work presents a molecular dynamics study of low-energy methyl rad ical deposition onto diamond (100). The total energy and interatomic f orces are calculated within a density-functional based tight-binding s cheme. Varying target temperatures and impact energies between 10 and 100 eV at normal incidence lead to a range of penetration depths and t hreshold energies for penetration or displacements. During the collisi on regions of local stress and disorder are formed in the surface and subsurface layers. Using a simulated cooling technique the model syste ms are equilibrated, and the generated structures after a final conjug ate gradient relaxation are analyzed. As a main outcome a favourable r ange of ion energies between 20 and 40 eV for low-energy homoepitaxial diamond growth in [100] direction could be determined. This range is shifted to higher energies with increasing substrate temperatures.