Atomic layer etching through controlled surface chemistry

金属薄膜的复杂多层结构（异质结构）对于开发先进的纳米电子和纳米光子器件至关重要，这些器件在传感器，高密度信息存储和磁光器件中具有重要应用。由于许多适用于这种器件的金属具有低反应性，因此它们的受控蚀刻是一项非常具有挑战性的任务。拟议研究的目的是了解潜在的表面反应动力学，产生金属成分和性能的方向性变化，从而能够开发一种受控的蚀刻工艺，其化学对比度需要以原子级精度选择性地去除材料。拟议的研究项目将侧重于：a）描绘可行的定向原子层蚀刻工艺的反应机理，以控制复杂金属异质结构的图案化中的蚀刻速率和选择性，B）表征导致自限反应和定制组成的表面反应，c）测量反应产物的类型和浓度以确认反应机理，和d）将这些顺序反应步骤与复杂的金属异质结构结合以检查可获得的分布。该项目的成功完成可能会导致金属去除的原子级控制，图案化复杂金属异质结构的更大选择性，更好地控制器件集成的高密度，并将为系统地改进更复杂材料系统和架构的精确图案化奠定基础。拟议研究产生的数据将广泛传播给研究界。研究成果将被整合到现有的研究生和本科等离子体加工课程。将支持两名研究生攻读博士学位。等离子体科学与工程多学科领域的学位。来自代表性不足群体的本科生和高中生将被招募从事高级研究项目和暑期研究实习。项目将提供给参加技术营的女高中生，以促进她们在科学和工程领域追求事业的兴趣。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Complex multi-layer structures (heterostructures) of thin metal films are essential for developing advanced nano-electronic and nano-photonic devices that have important applications in sensors, high-density information storage and magneto-optical devices. Since many metals that are suitable for such devices have low reactivity, their controlled etching is a very challenging task. The objective of the proposed research is to understand the underlying surface reaction kinetics that produce directional changes in metal composition and properties, thereby enabling the development of a controlled etching process with the chemical contrast needed to selectively remove the materials with atomic level precision. The proposed research project will focus on: a) delineating the reaction mechanisms underlying a viable directional atomic layer etch process to control the etch rate and selectivity in the patterning of complex metal heterostructures, b) characterizing the surface reactions leading to self-limited reaction and tailored composition, c) measuring the type and concentration of the reaction products to confirm the reaction mechanisms, and d) integrating these sequential reaction steps with a complex metal heterostructure to examine the attainable profiles. A successful completion of the project may lead to atomic level control in metal removal, greater selectivity in patterning complex metal heterostructures, better control in achieving high density in device integration, and will lay the foundation to systematically improve the precise patterning of even more complex material systems and architectures. The data generated from the proposed research will be broadly disseminated to the research community. Research outcomes will be integrated into an existing graduate and undergraduate course on Plasma Processing. Two graduate students will be supported to pursue Ph.D. degrees in the multidisciplinary field of Plasma Science and Engineering. Undergraduate and high school students from underrepresented groups will be recruited to pursue senior research projects and summer research internships. Projects will be offered to female high school students participating in a Technology Camp to promote their interests in pursuing careers in Science and Engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.