Focused ion beam system for TEM sample preparation

Successful development of microdevices and new materials requires the ability to observe the cross section of these materials at any specified location. A focused ion beam (FIB) is a powerful tool for cross-sectioning of samples. This paper describes sample preparation techniques for cross-sectional transmission electron microscopy (TEM) using FIB cross-sectioning. Both high positioning accuracy of the cross-sections and high-speed milling have been achieved with an FIB system (Hitachi FB-2000) equipped with a high-performance ion optical column. In addition, a common sample holderfor FIB and TEM has been employed to facilitate the handling of samples between the two systems. This has helped users with sample handling and has prevented damage, contamination, cracking, or loss during sample transfer. The entire process, from FIB milling to TEM observation, is performed at a throughput of 2-3 samples/day, which is larger by an order of magnitude than the conventional process consisting of mechanical polishing and ion thinning. Applications of FIB milling to TEM sample preparation have been shown using a silicon gate array device and zinc-plated steel.