Crater formation by ion bombardment as a function of incident angle

E.M. BRINGA; E. HALL; R.E. JOHNSON; R.M. PAPALEO

NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH B - BEAM INTERACTIONS WITH MATERIALS AND ATOMS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2002 vol. 193 p. 734 - 738

0168-583X

Ion bombardment of surfaces at an angle with respect to the surface normal produces surface modification with more varied and rich features than normal incidence bombardment. This allows more possibilities for nanopatterning and surface processing. Megaelectronvolt ion bombardment of insulators can create a track of electronic excitations which can decay non-radiatively and couple to the lattice, leading to sputtering and crater creation. Using molecular dynamics simulations we present a systematic study of the craters produced by a cylindrical track of excitations with its axis at several angles with respect to the surface normal (in the range Θ=0–80°). We also use different energy densities inside the track, from 0.5nU to 12.5nU, where n is the density of the material and U its binding energy. Crater length is found to vary as cos−1Θ.