Nanostencil Lithography for Atomic-Scale Fabrication Scale-Up

在这个项目中，学生将开发超高真空(UHV)纳米模版技术[1]，用于与原子精密扫描探针显微镜(SPM)光刻技术的集成。氢阻光刻是一种制造技术，在这种技术中，掺杂原子以原子精度被结合到硅晶格中，使用扫描隧道显微镜(STM)的尖端来形成单个氢原子层的图案，从而为掺杂提供掩蔽层[2]。这是唯一能够制造出确定性的、原子精确的电子器件的制造技术。因此，它有望对未来的集成电路技术产生重大影响，并可能导致量子计算机等外来设备架构的进步[3]。为了实现这一前景，必须开发扩大原子级器件制造的途径。UHV纳米模板荫罩图案化与基于UHV-STM的制造兼容，并可以通过并行图案化器件的所有最精细细节来促进原子级制造的放大，从而提供扫描探头可以工作的接触框架。为了将纳米模板图案化与扫描隧道显微镜的制造相结合，必须开发兼容的材料和工艺。这需要设计纳米模版工具，并研究图案化结构的表面和材料科学。在这个项目中，将使用标准的洁净室微制造技术(电子束光刻(EBL)、聚焦离子束(FIB)等)设计和制造纳米模板荫罩，然后用于UHV-STM系统中的器件图案化。作为开发过程的一部分，在UCL制造的层状和图案化结构将定期使用SPMat UCL和Imperial的二次离子质谱仪(SIMS)进行表征，而在合作机构较少使用各种先进和新颖的表征技术[4]，从而允许制造过程和测量技术的发展。等，美国计算机学会纳米，14,3316(2020)[3]C.D.希尔等人。艾尔，科学。1，e1500707(2015).[4]N.D‘Anna et.艾尔，艾伦森上将。《物质》，2201212(2023年)

In this project the student will develop ultrahigh vacuum (UHV) nanostencilling techniques [1] for integration withatomically-precise scanning probe microscopy (SPM) lithographies. Hydrogen resist lithography is a fabricationtechnique in which dopant atoms are incorporated into a silicon lattice, with atomic precision, using the tip of ascanning tunnelling microscope (STM) to pattern a single atomic layer of hydrogen providing a masking layer fordopant incorporation [2]. This is the only fabrication technique capable of producing deterministic, atomically-preciseelectronic devices. As such, it promises significant impact on future integrated circuit technologies and may lead toadvances in exotic device architectures such as quantum computers [3]. In order to achieve this promise, pathwaysto scale-up of atomic-scale device fabrication must be developed.UHV nanostencil shadow mask patterning is compatible with UHV-STM based fabrication, and can facilitate scale-upof atomic-scale fabrication by parallel patterning all but the finest details of a device, thus providing a contactframework within which the scanning probe can operate. In order to integrate nanostencil patterning with STMfabrication, compatible materials and processes must be developed. This requires engineering nanostencilling tools,and studying the surface and materials science of patterned structures. In this project, nanostencil shadow masks willbe designed and fabricated using standard cleanroom microfabrication techniques (electron beam lithography (EBL),Focused ion beam (FIB), etc) and then used to pattern devices in a UHV-STM system. As an integral part of thedevelopment process, layered and patterned structures fabricated at UCL will be characterised regularly using SPMat UCL and secondary ion mass spectrometry (SIMS) at Imperial, and less frequently using a variety of advanced andnovel characterization techniques at partner institutions [4], thus allowing development of both the fabricationprocesses and the measurement techniques.[1] A. Linklater and J. Nogami, Nanotech., 19, 285302 (2008).[2] T.J.Z. Stock, et. al., ACS Nano, 14, 3316 (2020).[3] C. D. Hill et. al., Sci. Adv., 1, e1500707 (2015).[4] N. D'Anna et. al., Adv. Electron. Mater., 2201212 (2023)