An integrated materials nanofabrication workstation to stack membranes for the Quantum Materials and Device Foundry

该提案是为了紧急购买用于堆叠膜的集成纳米纤维工作站，该工作站基于精确的惰性气氛手套箱，该手套箱具有计算机控制的显微镜，直接连接到量子材料和器件铸造厂（UBC量子材料研究所（QMI）的一部分）中现有的分子束外延（MBE）系统。在工作站中，我们将采用独特的“剥离和堆叠”技术相结合，首次从MBE生长的薄膜中创建独立的原子级薄氧化物和硫属化物堆叠。剥离技术几乎总是应用于石墨烯或硫属化物材料，其晶体可以优先在其弱键合的“货车der Walls”（vdW）层之间被拉开;但到目前为止，从未成功报道过氧化物和硫属化物的原子级薄层的堆叠。关键是，为硫属化物材料开发的标准剥离技术不适用于氧化物，因为绝大多数技术上感兴趣的氧化物（铁电、铁磁或反铁磁、多铁性）是强三维键合的，没有弱键合的vdW层。相反，最近在2019年开发了一种新的钙钛矿氧化物“剥离”技术，使用水溶性牺牲缓冲层，一旦溶解，即可使上面的氧化物自由漂浮。令人惊讶的是，所得到的层甚至在几个原子层的厚度下保持其铁性。这为创建和堆叠氧化物和硫属化物层提供了基础，开辟了一个巨大的材料组合领域，这些材料组合可能具有新的和完全出乎意料的电子特性。为了避免空气暴露造成的污染，工作站设计需要真空装载锁，以便从我们的MBE超洁净转移到手套箱中，在手套箱中进行制备和堆叠。该工作站的主要目标是通过将在我们的MBE中生长为薄膜的材料组合成独立的原子层堆栈，为设计和构建新型量子材料创造新的尖端能力。我们将专注于材料的组合，可以提供一个平台，与QMI大挑战（https：//qmi.ubc.ca/grand-challenges）中的相关研究目标相一致的新兴特性。更广泛地说，新的量子材料是加拿大未来量子技术路线图的关键部分，该提案为具有战略重要性的高素质人员（HQP）提供了广泛的有用培训机会。拟议的工作站的创新能力完全可以在UBC的QMI和UBC以外的加拿大外部机构内产生凝聚态物理和纳米科学社区的新合作。

This proposal is for the urgent purchase of an integrated nanofabrication workstation for stacking membranes, based on a precision inert-atmosphere glovebox with computer-controlled microscope interfaced directly to the existing molecular-beam epitaxy (MBE) systems in the Quantum Materials and Devices Foundry, part of the Quantum Materials Institute (QMI) at UBC. In the workstation, we will apply a unique combination of "exfoliation and stacking" techniques to create, for the first time, freestanding atomically-thin stacks of oxides and chalcogenides from thin films grown by MBE. Exfoliation techniques are nearly always applied to graphene or chalcogenide materials whose crystals can be preferentially pulled apart between their weakly-bonded "van der Walls" (vdW) layers; but so far, stacking of atomically-thin layers of oxides and chalcogenides has never been successfully reported. Critically, standard exfoliation techniques developed for chalcogenide materials do not work for oxides because the vast majority of technologically interesting oxides (ferroelectric, ferro- or antiferromagnetic, multiferroic) are strongly 3-dimensionally bonded with no weakly-bonded vdW layers. Instead, a new "lift-off" technique for perovskite oxides has been recently developed in 2019 using a water-soluble sacrificial buffer layer that, once dissolved, allows the overlying oxide to float off freely. Surprisingly, the resulting layers keep their ferroic properties even down to thicknesses of a few atomic layers. This provides the groundwork for creating and stacking together oxide and chalcogenide layers, opening up a huge playground of materials' combinations never before studied that may possess new and completely unexpected electronic properties. To avoid contamination from air exposure, the workstation design requires a vacuum loadlock allowing ultra-clean transfer from our MBEs into the glovebox where the preparation and stacking will be done. The primary goal of the workstation is to create new cutting-edge capabilities for designing and constructing novel quantum materials by combining materials, grown as thin films in our MBEs, into freestanding atomic-layer stacks. We will focus on combinations of materials that can provide a platform for emergent properties aligned with relevant research thrusts within the QMI Grand Challenges (https://qmi.ubc.ca/grand-challenges). More broadly, new quantum materials form a key part of Canada's roadmap for future quantum technologies and this proposal offers a broad range of useful training opportunities for highly qualified personnel (HQP) of strategic importance. The innovative capabilities of the proposed workstation is perfectly placed to generate new collaborations in condensed matter physics and nanoscience communities within the QMI at UBC, and external Canadian institutions beyond UBC.