Precision Argon ion mill system

所要求的精密氩离子磨机是一种优秀的样品制备系统，用于制造高级透射电子显微镜（TEM）成像和分析所需的高质量薄样品。它将用于后fib（聚焦离子束）处理TEM薄片以及增强常规制备的样品。在FIB过程中形成的非晶态表面层，使用氩离子磨将显著减少。这大大提高了申请人研究小组分析TEM的图像质量，也为其他研究小组、研究所、院系和合作提供了服务。此外，精密氩离子磨是关键工具，特别是对于我们小组的纳米级发光研究：在我们先进的STEM （STEM- cl）中进行的低温纳米阴极发光光谱是一种独特的测量技术：实现半导体真实结构与电子和光学性质的直接关联，最终空间分辨率为1.8 nm。我们的STEM-CL系统是我们研究项目的重要组成部分。目前，我们正在将高温CL系统集成到FIB中，以精确靶向制备选定的感兴趣的样品区域，这些区域在FIB制备后仍然发光。然而，在STEM-CL实验中，Ga离子对光束的损伤和FIB过程引起的非晶薄表面层的形成对发射光子的量子效率和空间分辨率产生了负面影响。镓轰击产生的近表面点缺陷导致多余载流子的非辐射复合。基于申请人课题组多年的经验，开发了一种独特的STEM-CL标本制备技术。通过随后使用低能氩离子蚀刻对受损层进行温和铣削，可以减少光纤相关的表面损伤。因此，为了在FIB处理后最终制备最高光学质量（即最高CL效率）的TEM薄片，精密氩离子铣削是绝对必要的。在FIB处理后，薄片的最终减薄可直接减少非晶态表面层，改善样品表面。聚焦的氩气光束在点或扫描模式下精确地蚀刻几微米的特定区域。对于直接成像，使用二次电子探测器来观察离子束的位置并直接控制蚀刻过程。因此，可以制作出具有目标厚度、形状和无非晶表面层的TEM样品。这样的薄片是TEM分析的基本要求，以避免在制备的材料中产生误解甚至伪影。精密氩离子磨机能够温和地最终制备出最高质量的TEM样品，从而代表了现有制备方法的重要延伸。

The requested precision Argon ion mill is an excellent specimen preparation system for creating the high-quality thin specimens needed for advanced transmission electron microscopy (TEM) imaging and analysis. It will be used for both, post-FIB (focused ion beam) processing of TEM lamella as well as the enhancement of conventionally prepared specimens. Amorphous surface layers, formed during the FIB process, will be significantly reduced by using the Ar ion mill. This leads to a substantial improvement of the image quality in analytical TEM performed in the research group of the applicant as well as a service for other research groups, institutes, faculties and collaborations.Furthermore, the precision Argon ion mill is a key tool, in particular for the nanoscale luminescence investigations of our group: Low-temperature nano-cathodoluminescence spectroscopy performed in our sophisticated STEM (STEM-CL) is a unique measurement technique: realizing a direct correlation of the semiconductor real structure and the electronic and optical properties with an ultimate spatial resolution of 1.8 nm. Our STEM-CL system is an essential part of our research projects.We are currently integrating a He-temperature CL system in our FIB for a precise targeting preparation of selected sample areas-of-interest, which are still luminescent after FIB preparation. However, the beam damage by Ga ions and formation of thin amorphous surface layers induced by the FIB process negatively affect the quantum efficiency of the emitted photons and spatial resolution in STEM-CL experiments. Near-surface point defects generated by Ga bombardment lead to nonradiative recombination of excess carriers.Based on several years of experience in the research group of the applicant, a unique preparation technique for STEM-CL specimens has been developed. The FIB-related surface damage can be reduced by subsequent gentle milling of the damaged layers using low energy Ar ion etching. For the final preparation of TEM lamella of highest optical quality (i.e. highest possible CL efficiency) after FIB processing, a precision Argon ion milling is therefore absolutely essential.The final thinning of the lamella is used to reduce amorphous surface layers and improve the sample surfaces directly after FIB processing. A focused Ar beam precisely etches a specifically selected area of few micrometer in spot or scanning mode. For direct imaging, secondary electron detectors are used to observe the position of the ion beam and directly control the etching process. Thus, TEM specimens of targeted thickness, shape and free of amorphous surface layers can be produced. Such lamellas are an elementary requirement for TEM analysis in order to avoid misinterpretations or even artifacts in the prepared material.The precision Argon ion mill enables gentle final preparation of TEM specimens of the highest quality and thus represents an essential extension of existing preparation methods.