hBN/Graphene 2D Heterostructures: from scalable growth to integration

hBN/石墨烯二维异质结构：从可扩展增长到集成

• 批准号: 436545422
• 负责人: Dr. Mindaugas Lukosius
• 金额: --
• 依托单位: Institut dÉlectronique de Microélectronique et de Nanotechnologie (IEMN)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/436545422?language=en
• 关键词: hBN; Graphene; 2D; Heterostructures; scalable

Graphene is a 2D material, famous for its exceptional electronic properties. However, to exploit these properties in real devices, the electronic coupling with the substrate and with any surrounding material must be strongly reduced. Hexagonal boron nitride (hBN), another 2D material, is very promising for this purpose. It could be used both to insulate graphene from the substrate and as a gate dielectric material. Although devices obtained by mechanical exfoliation and transfer did confirm the strong potentialities of graphene/hBN heterostructures, a scalable and reliable growth technique remains to be demonstrated: the development of new approaches to the fabrication of 2D heterostructures is of high importance. By combining the know-how and resources of the project partners, the aim of the proposed study is to explore and develop various ways to fabricate graphene/hBN heterostructures on substrates compatible with Si microelectronics. Towards these goals, graphene/hBN heterostructures will be grown by two major methods: molecular beam epitaxy and chemical vapor deposition. The process may be improved by specific nucleation-enhanced lateral patterning to be developed in the course of the project. Advanced microscopy and spectroscopy techniques will be applied to provide information on the morphological, crystallographic, chemical and electrical properties of the films. Atomistic calculations by ab initio density functional theory complemented with large scale kinetic Monte Carlo simulations will be conducted to understand the growth mechanisms and optimal process conditions.Moreover, while keeping in mind the ultimate goal that goes beyond this project, i.e., the growth of such heterostructures for device applications, the studies will result in the disclosure of the nucleation and growth mechanisms specific to hBN on graphene and to graphene on hBN. Such mechanisms should be generalized to generic Van der Waals (VdW) systems, to which both hBN and graphene belong. This will be made possible by performing the experiments on VdW substrates obtained in various ways and thus containing various types of nucleation centers, and by in-depth examination of typical samples by advanced imaging techniques augmented by theoretical calculations to elucidate the details of the chemical reactions involved and to simulate the growth. To understand the mechanisms is not only of fundamental scientific interest, but it is as well important for further development of graphene/hBN and similar systems. The experiments will be carried out on CMOS compatible materials, making this study unique, as its results might directly pave the way to the further graphene/hBN integration and device prototyping within the mainstream Si technologies.

石墨烯是一种2D材料，以其特殊的电子特性而闻名。然而，为了在真实的器件中利用这些特性，必须大大减少与衬底和与任何周围材料的电子耦合。另一种二维材料--六方氮化硼（hBN）在这方面非常有前途。它既可以用来将石墨烯与衬底绝缘，也可以用作栅极电介质材料。虽然通过机械剥离和转移获得的器件确实证实了石墨烯/hBN异质结构的强大潜力，但可扩展和可靠的生长技术仍有待证明：开发制造2D异质结构的新方法非常重要。通过结合项目合作伙伴的专业知识和资源，拟议研究的目的是探索和开发在与Si微电子兼容的衬底上制造石墨烯/hBN异质结构的各种方法。为了实现这些目标，石墨烯/hBN异质结构将通过两种主要方法生长：分子束外延和化学气相沉积。该过程可以通过在项目过程中开发的特定成核增强横向图案来改进。先进的显微镜和光谱技术将被应用于提供有关薄膜的形态，晶体学，化学和电学性质的信息。通过从头计算密度泛函理论进行原子计算，并辅以大规模动力学蒙特卡罗模拟，以了解生长机制和最佳工艺条件。此外，在牢记超出本项目的最终目标的同时，对于器件应用的这种异质结构的生长，该研究将导致对石墨烯上的hBN和hBN上的石墨烯特有的成核和生长机制的公开。这种机制应该推广到hBN和石墨烯都属于的通用货车范德华（VdW）系统。这将通过在以各种方式获得的VdW衬底上进行实验，从而包含各种类型的成核中心，并通过理论计算增强的先进成像技术对典型样品进行深入检查，以阐明所涉及的化学反应的细节并模拟生长。了解这些机制不仅具有基本的科学意义，而且对于石墨烯/hBN和类似系统的进一步开发也很重要。实验将在CMOS兼容材料上进行，使这项研究独一无二，因为其结果可能直接为主流Si技术中的进一步石墨烯/hBN集成和器件原型设计铺平道路。