GOALI: Electrochemistry-based Atomic Layer Etching of Metals for Integrated Circuits

微处理器和存储设备是电子设备的核心，几乎用于现代生活的方方面面。微处理器的核心是一个复杂的集成电路，它由数十亿个复杂制造的纳米结构组成。微电路结构的小型化和随之而来的计算速度和处理能力的指数增长遵循了摩尔定律的预测。这种激进的小型化要求从传统的制造方法向用于原子精确操纵、沉积和蚀刻的新的纳米制造技术的范式转变。尽管付出了许多努力，但目前还没有一种通用的原子精确刻蚀技术来满足成本和原子级控制的要求。这个GOALI学术联络机会(GOALI)项目通过创建原子精度的金属剪裁和蚀刻路径，促进了可扩展、低成本的电化学工艺方面的知识。该项目连接了科学和工程领域的不同学科，包括化学、电化学工程、工艺设计和材料表征。这项研究为研究生和本科生提供教育经验、工业培训机会和奖学金，包括来自代表性不足群体的学生。与业界的接触有助于开发一个产学研合作的模式平台，为下一代集成电路的尖端电化学技术开展合作。到目前为止，在半导体的原子层刻蚀方面已经取得了很大进展。然而，金属的原子层蚀刻仍处于初级阶段。等离子体辅助蚀刻金属的方法遇到了许多技术障碍，包括挥发性副产物对表面的污染以及缺乏原子级的精度。该项目研究了一种用于金属原子层刻蚀的新的液态电化学方法。通过使用新的自限电化学反应和选择性蚀刻化学，这项研究在原子精确蚀刻铜等金属方面取得了进展。对原子层刻蚀的基本化学方面进行了研究，从而确定了集成电路精密刻蚀的工艺参数。为了评估原子层刻蚀工艺的放大潜力，在大面积硅片上创建了纳米图形几何图形，并进行了现场诊断和工艺监测。由此产生的工艺可能成为未来纳米电子电路中原子精密制造结构的推动者。

Microprocessors and memory devices are central to electronic gadgets used in virtually every aspect of modern life. At the heart of a microprocessor is a complex integrated circuitry, which consists of billions of intricately fabricated nanostructures. Miniaturization of micro-circuit structures and ensuing exponential increase in computing speed and processing power has followed the predictions of "Moore's Law". Such aggressive miniaturization necessitates a paradigm shift from traditional manufacturing approaches to newer nanomanufacturing technologies for atomically precise manipulation, deposition and etching of materials. In spite of numerous efforts, a versatile technology for atomically precise etching that meets the requirements of cost and atomic-level control is presently unavailable. This Grant Opportunity for Academic Liaison with Industry (GOALI) project advances knowledge in scalable, low-cost electrochemical processes with the creation of pathways for tailoring and etching of metals with atomic precision. The project bridges various disciplines in science and engineering, including chemistry, electrochemical engineering, process design, and materials characterization. The research provides educational experiences, industrial traineeships and fellowships to graduate and undergraduate students including students from underrepresented groups. Engagement with industry helps develop a model platform for industry-university collaboration on cutting-edge electrochemical technologies for next generation integrated circuits. To date, much progress has been made in the atomic layer etching of semiconductors. However, atomic layer etching of metals is still in its infancy. Plasma-assisted approaches to etch metals have encountered many technical hurdles including surface contamination by volatile byproducts and lack of atomic-level precision. The project investigates a new liquid-phase electrochemical approach for the atomic layer etching of metals. Through the use of novel self-limiting electrochemical reactions and selective etching chemistries, this research advances knowledge in atomically precise etching of metals such as copper. Fundamental aspects of the chemistry of atomic layer etching are investigated leading to the identification of process parameters for precision etching of integrated circuits. To assess the scale-up potential of the atomic layer etching process, nano-patterned geometries on large area silicon wafers are created with in situ diagnostics and process monitoring and studied. The resulting process could become an enabler of atomically precise manufacturing of structures in future nanoelectronics circuits.