Energy- and angle-resolved depth of origin of isotopes sputtered from an elemental target

Abstract

Secondary-ion mass spectrometry and mass-resolved low-energy ion-scattering spectrometry have been combined in situ to measure sputter profiles through the interface between isotopically pure layers of (Formula presented) and (Formula presented) From the spacing between the two normalized depth profiles the mean depth of origin of (Formula presented) ions, ejected with (Formula presented) at 48° to the surface normal, was found to be (Formula presented) below the outermost atomic layer. Arguments are presented which suggest that the result holds for sputtered neutrals as well. © 1997 The American Physical Society.