NEB: Scalable Perpendicular All-Spin Non-Volatile Logic Devices and Circuits with Hybrid Interconnection

摘要：本项目由美国国家科学基金会多个部门和半导体研究公司纳米电子研究计划支持，在2020年纳米电子学及未来竞赛中获奖。该研究将提供基于全自旋逻辑器件的CMOS技术的替代方案。虽然纳米磁学在现有的磁存储技术中起着重要的作用，但传统上，处理的实现需要将磁信息（自旋）转换为电荷，然后在处理步骤完成后再转换为自旋。然而，这种方法没有实现纯自旋电流的任何优点，纯自旋电流承诺更低的功耗和潜在的更大的可扩展性。受半导体和金属自旋电子学十年来进步的启发，全自旋逻辑概念将实现全自旋操作，但前提是能够克服实质性的材料工程、加工和集成挑战。一个跨学科的团队已经成立，具有独特的定位来解决这些挑战，其中包括(1)工程比特可以作为磁隧道结自旋注入器（输入）或巨磁电阻（GMR）传感器（低阻抗输出），(2)集成这些比特与互连通道由普通金属，石墨烯或ZnO制造，(3)开发一种过程，该过程将提供比特的输入和输出阶段隔离，同时保留互连的理想自旋输运特性；(4)基于自旋输运物理和电路设计原则的测试协议；(5)明确的集成路径。该方法解决了实际自旋电子学的严重障碍之一，即需要在满足经济且完全可扩展的处理技术的同时，在界面上进行有效的自旋输运。该团队由垂直磁各向异性材料和自旋电子器件工程专家（Wang）、自旋输运物理学家（Crowell）、电路设计和制造工程师（Kim）、半导体材料和器件工程师（Koester）和半导体自旋电子材料工程师（Ding，国际合作者）组成。更广泛的影响：材料工程、器件物理、工艺工程和电路设计的独特结合将导致一个新的逻辑器件家族。同样重要的是，这四个技术组成部分将在培训将在2020年以后进行纳米电子研究的工程师和科学家方面发挥关键作用。该团队为多个部门的研究生提供真正的跨学科指导。除了至少两门学科的技术培训外，pi将强调学生与工业合作伙伴的互动，并参与让学生向公众解释纳米技术和自旋电子学的活动。该计划的参与者还将与明尼苏达大学和周边社区的磁性，半导体器件物理研究人员的活跃社区进行持续互动。这将使不同的项目参与者群体为从基础研究到新技术实施的连续职业做好准备。指导年轻学生，包括本科生研究人员，也是该计划的重要组成部分。该项目将积极招募少数族裔、女性和代表性不足的群体，并利用全校现有的努力来促进多样性和拓展。

ABSTRACTIntellectual Merit: This project is awarded under the Nanoelectronics for 2020 and Beyond competition, with support by multiple Directorates and Divisions at the National Science Foundation as well as by the Nanoelectronics Research Initiative of the Semiconductor Research Corporation. The research will provide an alternative to CMOS technology based on an all-spin logic device. Although nanomagnetism plays a fundamental role in existing magnetic storage technologies, the implementation of processing has traditionally required the conversion of magnetic information (spin) to charge and then back to spin after the processing step is complete. This approach, however, realizes none of the advantages of working with pure spin currents, which promise much lower power dissipation and potentially greater scalability. An all-spin logic concept that has been inspired by a decade of progress in semiconductor and metallic spintronics would achieve all-spin operation, but only if substantial materials engineering, processing, and integration challenges can be overcome. An interdisciplinary team has been assembled that is uniquely positioned to address these challenges, which include (1) engineering of bits which can function as either magnetic tunnel junction spin injectors (for inputs) or giant magnetoresistance (GMR) sensors (for low impedance outputs), (2) integrating these bits with interconnecting channels fabricated from either normal metals, graphene or ZnO, (3) developing a process that will provide for isolation of the input and output stages of the bits while preserving the desirable spin transport properties of the interconnects, (4) a test protocol grounded in both spin transport physics and circuit design principles, and (5) a clear path for integration. The approach addresses one of the severe roadblocks to practical spintronics, which is the need for efficient spin transport across interfaces while meeting the simultaneous demands of an economic and fully scalable processing technology. The team consists of an expert on perpendicular magnetic anisotropy materials and spintronic device engineering (Wang), a spin-transport physicist (Crowell), a circuit design and fabrication engineer (Kim), a semiconductor materials and device engineer (Koester), and a semiconductor spintronic materials engineer (Ding, an international collaborator). Broader Impacts: The unique combination of materials engineering, device physics, process engineering, and circuit design in this program will lead to a new family of logic devices. Just as importantly, these four technical components will play a critical role in training the engineers and scientists who will be carrying out nanoelectronic research well beyond 2020. The team provides true interdisciplinary mentorship for graduate students in multiple departments. In addition to technical training in at least two disciplines, the PIs will emphasize student interaction with industrial partners and participation in activities that allow students to explain nanotechnology and spintronics to the public. The participants in this program will also interact continuously with an active community of researchers in magnetism, semiconductor device physics at the University of Minnesota and in the surrounding community. This will prepare the diverse group of project participants for careers spanning a continuum from basic research to the implementation of new technologies. Mentorship of younger students, including undergraduate researchers, is also a critical component of the program. The project will proactively recruit minorities, women, and under-represented groups as well as leverage existing university-wide efforts for promoting diversity and outreach.