Ion beam sputtering: an improved method of metal coating SEM samples and shadowing CTEM samples

Abstract

SUMMARY: An apparatus to ion beam sputter‐coat SEM samples has recently become available. The equipment uses a small saddle‐field ion source to sputter deposit metals on to samples. This eliminates the surface artefacts seen at high magnifications on samples coated by diode sputtering. Ion beam sputtering has also been used to shadow samples for CTEM and has been found to result in a grain size of 1.2 nm.This technique isolates the specimens from the high‐energy plasma and thus little or no heating of the sample occurs. The removal of the SEM samples from the high‐energy plasma and the use of diffusion pump vacuum conditions to prevent contamination are suggested as reasons for the improved coating quality over diode sputtering.