The influence of surface structures on sputtering: Angular distribution and yield from faceted surfaces

Solid surfaces subject to energetic particle bombardment generally develop characteristic structures, which may significantly change the total and differential sputtering yield. The change is due to two competing effects, a yield-increase by an enhanced effective projectile incidence angle, and a yield-reduction by recapture of obliquely ejected particles. Both effects have been included in calculations of the sputtering yields from faceted surfaces in the regime where the plane surface yield follows a cos^−v dependence on the incidence angle. Except at very low energies, the total sputtering yield is always increased by faceting. The angular distribution function is mainly influenced at large polar angles and may significantly deviate from that of the corresponding flat surface. This has important consequences both in comparisons between experimental and theoretical distribution functions as well as in applications such as thin film production, plasma contamination, secondary ion mass spectrometry etc. EURAT0M Association.