edfas.org ELECTRONIC DEV ICE FA I LURE ANALYSIS | VOLUME 25 NO . 1 20 INTRODUCTION If you are a practitioner of transmission electron microscopy (TEM), most likely you have heard of focused ion beam (FIB) lift-out, which refers to a collection of now common TEM sample preparation methods using a nanomanipulator to remove a small sample piece cut out by the FIB, essentially performing a biopsy for inspection by electron microscopy. There are multiple inventors of FIB lift-out techniques. This is the story of how the mainstreamOmniprobe FIB lift-out solution was invented and delivered to the market. The origins of today’s commercial FIB lift-out systems can be traced to the semiconductor industry and more specifically, to three teams. Two of the teams were managed by creative individuals whowere either working for or had come fromCentral Research Labs (CRL) at Texas Instruments (TI) or from Bell Labs (by that time housed within Cirent in Orlando). The TI team focused on lift-out inside the FIB chamber, known today as in situ lift-out (INLO), while the Bell Labs team joined forces with the University of Central Florida to focus on lift-out done outside the FIB, in the technique known today as ex situ lift-out (EXLO). Both INLO and EXLO methods were being developed in parallel, each invisible to the other. On the other side of the world in Japan was another team of liftout inventors, this one from the Central Research Labs of Hitachi, a leading Japanese supplier of FIB instruments with strong ties to the semiconductor industry. TheHitachi team used the term “microsampling” to describe the in situ technique and published the first articles in theworld about micromanipulation inside the FIB. Their earliest journal publications focused on transistor transplantation and exploration of FIB as a “cutter” and “attacher.”[1,2] Sample preparation for TEM is demanding. The thick- ness of a TEM sample can range from < 20 nm for semiconductor analysis to a few hundreds of nmof thickness for TEM tomography of low-mass samples, such as those found in life sciences. Over the last three decades, focused ion beam scanning electron microscopy (FIBSEM) instruments have emerged as effective and efficient instruments for sample preparation. For a broad range of materials, FIB lift-out is the preferred TEM sample preparation method.[3] Many believe that EXLO was the “first” lift-out solution, but that is only partly true. Both INLOand EXLO techniques developed in parallel (Fig. 1), and first publications of each occurred in 1993, in forms of an EXLO journal paper and an INLO patent. However, EXLO had a faster market adoption because it required no hardware development. The standardmicroprobing stations suited the requirements at the time. Companies developing the technologies were not publishing due to the proprietary nature of the work, except for TI as discussed later. The eventual automation of both INLO and EXLO techniques enabled high quantities of TEM samples per day. At CRL, we jokedwith all seriousness that “TEMwill never be used INVENTOR'S CORNER TRANSFORMING AN INDUSTRY: AN INVENTOR’S TALE OF FIB IN SITU LIFT-OUT Cheryl Hartfield Carl Zeiss Microscopy LLC, Dublin, California cheryl.hartfield@zeiss.com Fig. 1 The timeline of adoption for the three main FIB methods for TEM sample preparation. EDFAAO (2023) 1:20-27 1537-0755/$19.00 ©ASM International®
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