High Five: Resolution, Sensitivity, in operando Control, Ultra High Vacuum and Ion Sectioning in a Single Instrument

拟议的仪器是一种新型的超高真空（UHV）等离子体聚焦离子束西姆斯（PFIB-SIMS）的组合，提供了一个阶跃变化的性能，最先进的仪器在分辨率，灵敏度和适用性方面。其他功能包括双动态正离子和负离子检测、微观结构分析、操作中性能研究的电气和热控制以及通过预处理室处理空气敏感材料。这种全球独一无二的设计将使复杂表面的化学定量具有纳米分辨率和3D化学和微观结构重建，填补了现有西姆斯和FIB技术的维度空白。所使用的配置和组件处于超高真空环境中材料切片和表面表征设计的最前沿。二次离子的源是气体等离子体聚焦离子束（FIB）源和柱，其可以产生具有最高横向分辨率的25 nm焦点的氧离子或氙离子。该源还能够通过3D连续切片和表征将硬材料和软材料切片到长达一毫米的长度尺度，以获得次表面块状特征。低能量表面铯剂量也可用于提高电负性元素（如O）的二次离子产率。同时正负西姆斯离子检测已率先在帝国理工学院，现在优化的离子轨迹建模在这个独特的西姆斯分析配置。具有粗糙度和形状的样品是合适的，因为低电场对于两个基于电四极杆的质谱仪的信号提取是固有的。除了通常用于UHV仪器的装载室外，还将配备第二个制备/装载室，用于通过温度控制和电接触进行样品处理，以反映主要的西姆斯分析室设施。此外，还可以通过气体分析设备将退火气体环境控制为大气压力。制备/加载锁定室提供了一种在真空或气体环境中从其他制备和表征设施（例如干燥手套箱、SEM、XPS和金刚石）转移空气敏感样品的方法。该仪器配置的一个独特之处在于能够从两个装载锁中的样品获得光学图像，包括用于形貌评估的光学干涉图像。该仪器配置的设计考虑到了固有的未来性，因为分析室和制备/装载锁都有大容量和备用入口。在分析室中，采用大工作距离，~ 15 mm，西姆斯信号的低电场提取和精确的5轴载物台移动意味着可以在分析室内的样品目标位置进行立体角访问。该仪器将放置在现有的专业表面分析实验室中，LEIS设备的位置和工作人员是永久的离子束专家，他们在优化离子束分析条件和方法方面具有世界领先的专业知识。最后，将向用户提供数据解释方面的援助以及High Five操作方面的专业知识。

The proposed instrument is a novel combination of ultra-high vacuum (UHV) Plasma Focused Ion Beam SIMS (PFIB-SIMS) that provides a step change in performance of state-of-the-art instrumentation in terms of resolution, sensitivity and applicability. Additional features are dual dynamic positive and negative ion detection, micro-structural analysis, electrical and thermal control for the performance of in operando studies and handling of air-sensitive materials by the incorporation of a pre-chamber. This design, unique worldwide, will enable the chemical quantification of complex surfaces with nanometric resolution and 3D chemical and microstructural reconstruction filling the dimensionality gap in the existing SIMS and FIB technology. The configuration and components used are at the forefront of materials sectioning and surface characterisation design in a UHV environment. The source of the secondary ions is the gas plasma focused ion beam (FIB) source and column that can produce either oxygen ions or xenon ions with a focus of 25nm for the highest lateral resolutions. This source is also able to section hard and soft materials to length scales of up to a millimetre for sub-surface bulk features by 3D serial-sectioning and characterisation. Low energy surface dosing with caesium is also available for enhancing the secondary ion yields of electronegative elements (e.g. O).Simultaneous positive and negative SIMS ion detection has been pioneered at Imperial College and is now optimised by ion trajectory modelling in this unique SIMS analysis configuration. Samples with both roughness and form are suitable as low electrical fields are inherent for signal extraction by the two electric quadrupole-based mass spectrometers. Sample cooling and heating is available, also in-situ-electrical contacts for IV testing and grounding at sample surfaces.Apart from the usual loadlock for a UHV instrument, there will be a second preparation/load-lock chamber for sample processing by temperature control and electrical contacts to mirror the main SIMS analysis chamber facilities. Additionally it will be possible to control the anneal gas ambient to atmospheric pressure with a gas analysis facility. The preparation/load-lock chamber provides a means of transferring air-sensitive samples in vacuum or gas environment from other preparation and characterisation facilities such as a dry Glove-box, SEM, XPS, and Diamond for example. A unique feature of the instrument configuration is the provision for obtaining optical images from samples in both load-locks including optical interference images for topography assessment.The instrument configuration is designed with inherent future-proofing in mind as both the analysis chamber and the preparation/load-lock have large volumes and spare access ports. In the analysis chamber, the use of a large working distance, ~15mm, low electric field extraction for the SIMS signal and accurate 5-axis stage movements means that there is available solid-angle access to the sample target position within the analysis chamber.The instrument will be placed in an existing specialist surface analysis laboratory where high performance SIMS/LEIS equipment is located and staffed by permanent ion beam specialists with world leading expertise in optimising ion beam analysis conditions and methodologies. Finally, assistance in data interpretation will be available to the user as well expertise in the operation of High Five.