Li Chen, Habler Gerlinde, Baldwin Lisa C, Abart Rainer
Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria; Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.
Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
Ultramicroscopy. 2018 Jan;184(Pt A):310-317. doi: 10.1016/j.ultramic.2017.09.011. Epub 2017 Sep 28.
Focused ion beam (FIB) sample preparation technique in plan-view geometry allows direct correlations of the atomic structure study via transmission electron microscopy with micrometer-scale property measurements. However, one main technical difficulty is that a large amount of material must be removed underneath the specimen. Furthermore, directly monitoring the milling process is difficult unless very large material volumes surrounding the TEM specimen site are removed. In this paper, a new cutting geometry is introduced for FIB lift-out sample preparation with plan-view geometry. Firstly, an "isolated" cuboid shaped specimen is cut out, leaving a "bridge" connecting it with the bulk material. Subsequently the two long sides of the "isolated" cuboid are wedged, forming a triangular prism shape. A micromanipulator needle is used for in-situ transfer of the specimen to a FIB TEM grid, which has been mounted parallel with the specimen surface using a simple custom-made sample slit. Finally, the grid is transferred to the standard FIB grid holder for final thinning with standard procedures. This new cutting geometry provides clear viewing angles for monitoring the milling process, which solves the difficulty of judging whether the specimen has been entirely detached from the bulk material, with the least possible damage to the surrounding materials. With an improved success rate and efficiency, this plan-view FIB lift-out specimen preparation technique should have a wide application for material science.
平面视图几何形状的聚焦离子束（FIB）样品制备技术能够通过透射电子显微镜将原子结构研究与微米级特性测量直接关联起来。然而，一个主要的技术难题是必须在样品下方去除大量材料。此外，除非去除围绕TEM样品部位的非常大的材料体积，否则很难直接监测铣削过程。在本文中，引入了一种用于平面视图几何形状的FIB取出样品制备的新切割几何形状。首先，切割出一个“孤立”的长方体形样品，留下一个将其与块状材料连接的“桥”。随后，对“孤立”长方体的两个长边进行楔入，形成三棱柱形状。使用微操作针将样品原位转移到FIB TEM网格上，该网格已使用简单的定制样品狭缝与样品表面平行安装。最后，将网格转移到标准FIB网格支架上，通过标准程序进行最终减薄。这种新的切割几何形状为监测铣削过程提供了清晰的视角，解决了判断样品是否已完全从块状材料上分离的难题，同时对周围材料的损伤最小。通过提高成功率和效率，这种平面视图FIB取出样品制备技术在材料科学中应具有广泛的应用。
