Using Xe Plasma FIB for High-Quality TEM Sample Preparation

Abstract

A direct comparison between electron transparent transmission electron microscope (TEM) samples prepared with gallium (Ga) and xenon (Xe) focused ion beams (FIBs) is performed to determine if equivalent quality samples can be prepared with both ion species. We prepared samples using Ga FIB and Xe plasma focused ion beam (PFIB) while altering a variety of different deposition and milling parameters. The samples’ final thicknesses were evaluated using STEM-EELS t/λ data. Using the Ga FIB sample as a standard, we compared the Xe PFIB samples to the standard and to each other. We show that although the Xe PFIB sample preparation technique is quite different from the Ga FIB technique, it is possible to produce high-quality, large area TEM samples with Xe PFIB. We also describe best practices for a Xe PFIB TEM sample preparation workflow to enable consistent success for any thoughtful FIB operator. For Xe PFIB, we show that a decision must be made between the ultimate sample thickness and the size of the electron transparent region.

Local Structural Modifications in Metallic Micropillars Induced by Plasma Focused Ion Beam Processing

“…But the micropillars from magnesium are larger in diameter and we see significantly less implantation of Xe ions on their top surface. On the sidewalls of micropillars the Xe ions should impact with glancing angles (80-90 • ) and implantation depths are lower [13,28,29] and radial. Implantation of Xe in the sidewalls should lead to amorphization as seen in lamellas prepared for TEM studies [10,13,28,29].…”

“…On the sidewalls of micropillars the Xe ions should impact with glancing angles (80-90 • ) and implantation depths are lower [13,28,29] and radial. Implantation of Xe in the sidewalls should lead to amorphization as seen in lamellas prepared for TEM studies [10,13,28,29]. It has been shown that the thickness of amorphization for samples prepared with Xe ions is ~40% less compared to those prepared using a Ga-beam [10].…”