Capability for wafer-level sub-nanometre scale imaging

正如最近的BEIS报告“英国半导体产业”所强调的那样，英国半导体研究能力的重要性被认为是国家战略的一部分。研究方面的特别优势集中在位于学术机构的一些洁净室设施上。南安普顿大学拥有一系列尖端的纳米制造工具，使电子和光子器件的一系列研究活动成为可能。当在大晶圆上加工时，半导体器件和电路的制造变得具有成本效益。然而，只有具有材料表征系统的超高分辨率扫描电子显微镜（SEM）能够提供高通量反馈结果，以改进制造并促进新工艺开发，才能实现工艺效率。手动操作的sem是学术研究中常用的表征成像工具，但需要在整个工艺流程中对晶圆进行自动在线成像，以实现快速成像并缩短制造过程的检查时间。该提案的目的是在南安普顿大学获得一台能够对直径达200毫米的晶圆进行材料表征的超高分辨率扫描电镜（UHR-SEM）。随着器件特征尺寸的减小，晶圆上的尺寸和性能变化成为一个问题，必须在制造的早期阶段加以缓解。因此，提议的UHR-SEM在英国学术领域将是独一无二的，因为它将以亚纳米分辨率对直径达200毫米的整个晶圆进行自动在线成像和分析。该系统在样品上具有较低的着陆电压，以减少在精细器件和图案电阻成像过程中的表面损伤，以及对厚多层材料的检查具有良好的聚焦深度。UHR-SEM将解决大型晶圆成像的主要挑战，如在纳米尺度上生成相关的表面计量信息，并创建显示各种材料参数（如化学成分和缺陷分布）的详细地图。

The critical importance of capabilities for semiconductor research in the UK is recognised as part of a national strategy, as stressed in the recent BEIS Report 'The semiconductor industry in the UK'. Particular strength in research is centred around a number of cleanroom facilities located at academic institutuions. The University of Southampton hosts a range of cutting-edge nanofabrication tools which enable a range of research activities in electronic and photonic devices. Fabrication of semiconductor devices and circuits becomes cost effective when processed on a large wafer. However, process efficiency can only be achieved if an ultra-high-resolution scanning electron microscope (SEM) with material characterisation system is available to provide high throughput feedback results to improve fabrication and facilitate novel process development. Manually operated SEMs are a common imaging tool for characterisation used in academic research but automated in-line imaging of wafers throughout a process flow is required to achieve fast imaging and shorten inspection time from fabrication processes.The aim of the proposal is to acquire an ultra-high-resolution SEM (UHR-SEM) capable of material characterisation for wafers up to 200 mm in diameter at the University of Southampton. As device feature sizes are reduced, dimension and performance variations across the wafer become an issue which must be mitigated at the early stage of the fabrication. Therefore, the proposed UHR-SEM will be unique within the UK academic landscape since it will perform automated in-line imaging and analysis of entire wafers up to 200 mm in diameter at sub-nm resolution. The system will also have a low landing voltage on samples to reduce surface damage during imaging of delicate devices and patterned resists, as well as a good depth of focus for the inspection of thick multi-stack materials. The UHR-SEM will address the main challenges in large wafer imaging such as generating relevant surface metrology information at nanoscale dimensions and creating a detailed map showing various material parameters such as chemical composition and defect distribution.