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

微处理器和存储设备是现代生活中几乎无处不在的电子设备的核心。微处理器的核心是一个复杂的集成电路，它由数十亿个复杂的纳米结构组成。微电路结构的小型化以及随之而来的计算速度和处理能力的指数级增长遵循了“摩尔定律”的预测。这种激进的小型化需要从传统制造方法转向新的纳米制造技术，用于原子精确操作，沉积和蚀刻材料。尽管经过了许多努力，但目前还没有一种满足成本和原子级控制要求的通用的原子精确蚀刻技术。该学术与工业联络资助机会（GOALI）项目通过创建原子精度的金属裁剪和蚀刻途径，推进了可扩展、低成本电化学工艺的知识。该项目结合了科学和工程的各个学科，包括化学、电化学工程、工艺设计和材料表征。该研究为研究生和本科生提供教育经验、行业培训和奖学金，包括来自代表性不足群体的学生。与工业界的合作有助于为下一代集成电路的尖端电化学技术开发一个产学研合作的模型平台。迄今为止，在半导体的原子层刻蚀方面已经取得了很大的进展。然而，金属的原子层蚀刻技术仍处于起步阶段。等离子体辅助蚀刻金属的方法遇到了许多技术障碍，包括挥发性副产品的表面污染和缺乏原子级精度。该项目研究了一种新的液相电化学方法用于金属的原子层蚀刻。通过使用新的自限制电化学反应和选择性蚀刻化学，本研究推进了铜等金属的原子精确蚀刻知识。研究了原子层刻蚀的基本化学方面，从而确定了精确刻蚀集成电路的工艺参数。为了评估原子层蚀刻工艺的放大潜力，通过原位诊断和工艺监控，在大面积硅片上创建了纳米图形几何形状，并进行了研究。由此产生的过程可能成为未来纳米电子电路中原子精确制造结构的推手。

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.