Importance of ion beam parameters on self-organized pattern formation on semiconductor surfaces by ion beam erosion

Abstract

Ion beam sputtering i.e. the removal of material from a surface due to the impact of energetic ions or atoms, is an inherent part of numerous surface processing techniques. Due to self-organization caused by the process of low-energy ion beam erosion, nanostructures with different shape and high order arrangement can be evolved. In this work, results for Ar + ion beam erosion of silicon and III/V semiconductor surfaces under oblique ion incidence with simultaneous sample rotation are presented. The evolution of the surface topography and patterns are analyzed by scanning force microscopy (AFM). Especially, the influence of different settings of the used Kaufman-type broad beam ion source on nanostructures is discussed. The ion beam is extracted and formed by a multiaperture two-grid system. Beside the ion energy, the divergence of the ion beam as well as the angular distribution of the ions within the ion beam can influence the pattern formation. By a careful adjustment of the individual ion source settings regular nanopatterns on various surfaces can be achieved. Examples are given for InP, GaSb, InAs, and Si.