Depth profiling of polycrystalline multilayers using a Buckminsterfullerene projectile

Depth resolution of 5 nm was achieved on a Ni:Cr multilayer structure using 15 keV C-60(+) ion bombardment for depth profiling. The results, acquired by monitoring the sputtered neutral flux of Ni and Cr atoms, are of equivalent quality to those achieved using low-energy obliquely incident atomic beams with sample rotation. The reason behind these improved results is shown to be due to the unique ability of this cluster ion to remove material without regard to crystallographic orientation, hence reducing the buildup of topography. (C) 2004 American Institute of Physics.