The effect of the gold sputter-coated films in minimising damage in FIB-produced TEM specimens

Abstract

A sputter-coated gold film, of variable thickness, was used to protect the near surface region structure of an AlAs-InAs superlattice from damage during transmission electron microscope (TEM) specimen preparation using a focused ion beam (FIB) miller. This coating was applied before the deposition of any platinum protective film in the FIB. The extent of any damage in this specimen was investigated by TEM. Where the gold film was either locally absent or of low thickness (<15 nm), ion beam damage of this near surface region was evident. It was concluded that the deposition of platinum in the FIB may lead to surface modification of TEM specimens and that the application of a gold layer at lea..