Robotic fabrication of high-quality lamellae for aberration-corrected transmission electron microscopy

TL;DR

This paper presents a fully automated robotic FIB system for preparing high-quality lamellae for aberration-corrected STEM, significantly improving throughput and consistency in atomic-level materials imaging.

Contribution

It introduces a novel robotic fabrication method for STEM lamellae using FIB with full automation, enhancing efficiency and success rates.

Findings

Robotic FIB achieves high success rate in lamellae preparation

Automated system produces atomic-resolution STEM images of Si, SrTiO3, and sapphire

Optimized FIB parameters improve lamella quality for atomic imaging

Abstract

Aberration-corrected scanning transmission electron microscopy (STEM) is widely used for atomic-level imaging of materials. To accelerate the discovery of new materials based on atomic-level investigations, the throughput of aberration-corrected STEM experiments becomes more and more important. However, the throughput of the full workflow of aberration-corrected STEM is still quite low. A fundamental problem is that the preparation of high-quality thin STEM samples (lamellae) depends on manual operation. Here, inspired by the recent successes of "robot scientists", we demonstrate robotic fabrication of high-quality lamellae by focused-ion-beam (FIB) with full automation software. First, we show that robotic FIB can prepare lamellae with a high success rate, where the robotic FIB controls rough-milling, lift-out, and final-thinning processes. Then, we optimize the FIB parameters of the final-thinning process for single crystal Si. Aberration-corrected STEM imaging of these Si lamellae shows atomic-level images with 55 pm resolution. We also demonstrate robotic fabrication of high-quality lamellae of SrTiO3 and sapphire. The robotic FIB system will resolve the current bottleneck of the full workflow of aberration-corrected STEM analysis and accelerate materials discovery based on atomic-level imaging.