title: Mass redistribution causes the structural richness of ion-irradiated surfaces.
abstract: We show that the "sputter patterning" topographical instability is determined by the effects of ion impact-induced prompt atomic redistribution and that erosion--the consensus predominant cause--is essentially irrelevant. We use grazing incidence small angle x-ray scattering to measure in situ the damping of noise or its amplification into patterns via the linear dispersion relation. A model based on the effects of impact-induced redistribution of those atoms that are not sputtered away explains both the observed ultrasmoothening at low angles from normal incidence and the instability at higher angles.
authors.affiliation: Harvard School of Engineering and Applied Sciences, Cambridge Massachusetts 02138, USA.
authors.forename: Charbel S
authors.initials: CS
authors.lastname: Madi
authors.forename: Eitan
authors.initials: E
authors.lastname: Anzenberg
authors.forename: Karl F
authors.initials: KF
authors.lastname: Ludwig
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Aziz