高迁移率二维料铟硒及其异质结构的物性、量子输运性质调控和器件应用研究

The emerging two-dimensional (2D) materials reveal great promise for continuing the "Moore's Law" with the benefits of superior gate control capability, controllable bandgap and mobility, et al. 2D materials have attracted extensive attentions, most of which are focusing on graphene graphene-like materials and Transition metal dichalcogenide (TMDC). However, the intrinsic limitations of these materials in the electronic properties (very small bandgap or very low mobility) constrain their applications in the microelectronics industry. In addition, the weak spin orbit coupling strength or the direct bandgap structure in these materials are adverse in developing the spin/valley-related properties..In this project, we propose both theoretical and experimental researches on the noval 2D material indium selenide (InSe) based nanostructures and Van der Waals heterostructures, accounting for their physical properties, quantum transport properties and manipulation. The main advantages of InSe are the high room temperature mobility as well as an enough band gap, that exactly match the requirements of making high-speed low-power logic devices. The project presents high accurate calculation of the electronic structures, electronic states in the InSe-based nanostructures and heterostructures by employing the employing the state-of-the-art ab initio methods, tight-binding methods and effective mass method. Furthermore, we illustrate the effect of doping, external electric field, magnetic field and stress on the electronic structures and electronic states. The non-equilibrium Green function method is employed to study quantum transport properties of specially designed heterostructures and specific shaped nanoribbons under various manipulation schemes. Based on the accurate calculation of physical properties and transport properties and reliable theoretical analysis, the key process, integration and device characteristics of InSe nanoribbon transistors are studied..Beside researches on electronic properties, we use stacking angle and interface design of InSe based Van der Waals stacked structures and heterostructures so as to obtain desired Brillouin folding (with formation of supercell in the real space). It is an effective way to manipulate the energy band, especially the valley structure. By employing proximity effect or built-in electric field, we can manipulate the spin-orbit coupling strength. Finally we propose several ways to generate or control the spin/valley polarized current and suggest several prototype spin/valleytronic devices. A major feature of this project is the close combination of theory and experiment. Based on the advanced microelectronics R & D platform of institute of Microelectronics CAS, especially hyperfine electron beam etching process, we integrate the key processes and make width controllable InSe nanoribbon transistors with high on-off ratios. The success of the project, will promote the practical device application and industrialization of 2D materials.

新兴二维材料凭借其优越的栅控能力，能带、迁移率可调节等优势被认为有望解决摩尔定律瓶颈而被广泛研究。目前这些研究聚焦于类石墨烯和过渡金属硫族化合物。但是材料中带隙过小或迁移率过低等材料本征缺陷制约了其在微电子器件中的应用。另外这些材料中自旋轨道耦合强度小或能带表现为直接带隙，不利于挖掘自旋/能谷相关的新奇物性。本项目另辟蹊径针对二维材料铟硒及其异质结构开展物性，量子输运特性及调控的理论和实验研究。铟硒载流子迁移率高带隙足够大，为实现高速低功耗器件提供了保证。除了传统电学特性研究，本项目创新之处是通过铟硒及其异质结构的叠层堆垛和界面设计，实现对能谷结构或自旋轨道耦合的调控，探索基于铟硒的自旋/谷电子学器件的新方案。本项目另一特色是理论和实验紧密结合，依托国内领先的微电子研发平台，发展超精细电子束刻蚀工艺，研制出高开关比铟硒纳米带晶体管。项目取得成功，必将推动二维晶体材料的前沿探索和产业化进程。

新兴二维材料凭借其优越的栅控能力，能带、迁移率可调节等优势被认为有望解决摩尔定律瓶颈，在未来半导体产业中应用。研究载流子基本输运特性，迁移率，光跃迁系数等不同器件关键参数的调控机理具有重要意义。本项目系统性研究了MoS2,WSe2,InSe等二维晶体材料用于集成电路中CMOS晶体管所需的源漏接触，高k栅介质，超短沟道等关键工艺，在微电子研究所工艺平台建立了上述关键工艺模块和集成技术，完成MoS2,WSe2,InSe等多种二维材料晶体管的研发制备，得到较好性能。对二维晶体材料及其纳米带微结构和异质结构中电子结构、迁移率、载流子浓度等电学特性进行了系统分析，提出并计算验证了应力优化迁移率方案。进一步研究了低维材料在自旋电子学中的应用。提出了多种自旋极化，自旋塞贝克系数，等自旋性质调控以及自旋开关，自旋存储等原型器件设计的可行性方案。总体上圆满完成了项目预定目标。项目实施后共发表论文33篇，其中SCI论文31篇，包括Carbon 2篇， Nanotechnology 5篇，IEEE TED及JEDS合计6篇。