Site-specific plan-view TEM lamella preparation of pristine surfaces with a large field of view

TL;DR

This paper presents a new site-specific method for preparing high-quality, large field of view plan-view TEM lamellae, combining mechanical grinding with focused ion beam techniques for improved surface analysis.

Contribution

It introduces a novel combination of mechanical grinding and FIB lift-out to enhance site-specificity and field of view in TEM lamella preparation.

Findings

Enables site-specific lamella preparation with micrometer precision.

Achieves large field of view for pristine surface analysis.

Simplifies the process compared to existing methods.

Abstract

Transmission electron microscopy has become a major characterisation tool with an ever increasing variety of methods being applied in wide range of scientific fields. However, the probably most famous pitfall in related workflows is the preparation of high-quality electron-transparent lamellae enabling for extraction of valuable and reliable information. Particularly in the field of solid state physics and materials science, it is often required to study the surface of a macroscopic specimen with plan-view orientation. Nevertheless, despite tremendous advances in instrumentation, i.e. focused ion beam, the yield of existing plan-view lamellae preparation techniques is relatively low compared to cross-sectional extraction methods. Furthermore, techniques relying on mechanical treatments, i.e. conventional preparation, compromise site-specifity. In this paper, we demonstrate that by combining a mechanical grinding step prior to backside lift-out in the focused ion beam plan-view lamellae preparation becomes increasingly easy. The suggested strategy combines site-specifity with micrometer precision as well as possible investigation of pristine surfaces with a field of view of several hundred square micrometers.