Focused high- and low-energy ion milling for TEM specimen preparation. Issue 9 (August 2015)

• Record Type: Journal Article
• Authors: Lotnyk, A.; Poppitz, D.; Ross, U.; Gerlach, J.W.; Frost, F.; Bernütz, S.; Thelander, E.; Rauschenbach, B.
• Is Part Of: Microelectronics and reliability. Volume 55:Issue 9/10(2015)
• Page Start: 2119
• Page End: 2125
• Publication Date: 2015-08
• Subjects: TEM specimen preparation -- Focused low-energy ion milling -- Thin films -- Interfaces -- GaN -- Phase change materials; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.07.005
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: For atomic-resolution aberration-corrected (Cs-corrected) scanning transmission electron microscopy (STEM) the quality of prepared TEM specimens is of crucial importance. High-energy focused gallium ion beam milling (FIB) is widely used for the production of TEM lamella. However, the specimens after conventional FIB preparation are often still too thick. In addition, damage and amorphization of the TEM specimen surface during the milling process occur. In order to overcome these disadvantages, low-energy Ar ion milling of FIB lamellae can be applied. In this work, we focus on TEM specimen preparation of different thin films (GaN, Ge2 Sb2 Te5, TiO2 ) and interface structures (GaN/6H-SiC, SrTiO3 /TiO2, Ge2 Sb2 Te5 /Si) using a combination of FIB with a focused low-energy Ar ion polishing. The results show that this combination enables the routine preparation of high quality TEM lamellae with a smooth surface and uniform thickness, even at the interface region between two different materials and over a lateral range of several micrometres. The prepared lamellae exhibit less surface damage and are well suited for atomic-resolution Cs-corrected STEM/TEM imaging at medium and low accelerating voltages. These results are in a good agreement with Monte Carlo simulations performed by the Stopping and Range of Ions in Matter (SRIM) software. Highlights: Combination of focused high- and focused low-energy ion milling for the routine preparation of high quality TEM lamellae Reproducible preparation of TEM specimens with uniform thickness of less than 20 nm over a range of several micrometres Suitability of the presented method for Cs-corrected HRSTEM imaging of different thin films and interface structures