Surface morphology and interface chemistry under ion irradiation – Simultaneous atomistic simulation of collisional and thermal kinetics

A novel program package has been developed which allows for the simultaneous treatment of atomistic kinetics in collision cascades caused by energetic ion impacts and thermally activated relaxation and diffusion. In this 3D program named TRIDER (TRansport of Ions in matter with DEfect Relaxation) the collision cascades treated in the framework of the Binary Collision Approximation has been combined with kinetic lattice Monte-Carlo simulations of the atomistic relaxation and diffusion. TRIDER simulations allow a more realistic description of ion-induced surface patterning because subsurface defect kinetics can be included in the simulations, which is demonstrated for low-energy Ar+ ion irradiation of silicon. A deeper understanding of ion beam mixing of bimetal interfaces can also be achieved: it is shown that the conventional Gaussian mixing profile is changed substantially for immiscible metals due to precipitation and for chemically active metals due to formation of intermetallics of different stoichiometry.