Temperature-dependent surface modification of InSb(0 0 1) crystal by low-energy ion bombardment

Abstract

Structural and compositional modification of InSb(0 0 1) single crystal surfaces induced by oblique incidence 2–5 keV Ar and Xe ion irradiation have been investigated by means of scanning tunneling and atomic force microscopies, and time-of-flight mass spectroscopy of secondary ion emission. In general, ion-induced patterns (networks of nanowires, or ripples) are angle of incidence- and fluence-dependent. Temperature dependences (from 300 to 600 K) of the RMS roughness and of the ripple wavelength have been determined for the samples bombarded with various fluences. Secondary ion emission from an InSb(0 0 1) surface exposed to 4.5 keV Ar + ions has been investigated with a linear TOF spectrometer working in a static mode. Mass spectra of the sputtered In +, Sb + and In 2 + secondary ions have been measured both for the non-bombarded (0 0 1) surface and for the surface previously exposed to a fluence of 10 16 ions/cm 2. In + and In 2 + intensities for the irradiated sample are much higher in comparison to the non-bombarded one, whereas Sb + ions show a reversed tendency. This behavior suggests a significant In-enrichment at the InSb(0 0 1) surface caused by the ion bombardment.