混合维度范德瓦尔斯异质结TFET的输运关键技术研究

Abstract：The rapid development of the Artificial Intelligence Technology, Internet of Things, Biological Detection, Wearable, Intelligent Security, and 5G Technology has put forward urgent needs and severe challenges for ultra-low power integrated circuits and ultra-sensitive sensors. Traditional devices are faced with difficulties in power, performance and switching characteristics. Novel devices based on two dimensional materials make it possible to overcome the difficulties of traditional devices. At the same time, new opportunities and challenges have emerged. The Van Der Waals hybrid dimensional heterojunction TFET device combines the advantages of different dimensional materials in material properties and manufacturing technology, respectively. Thus, it has enormous potential and expected to be applied to ultra-low power integrated circuits and ultra-sensitive sensors in the future. However, research of the related fundamental physics problems is still a blank, currently. This project focuses on the key technology of transport, the device manufacture technology and the testing technology of Ge/MoS2 Van Der Waals hybrid dimensional heterojunction TFET. A device transport simulation platform combining energy band calculation and multi scattering mechanism is proposed and verified by experiments. This work provides a theoretical guidance for the designs, optimizes and manufactures of this device, and promotes the application of the device in the field of ultra-low power and ultra-sensitive sensing.

人工智能技术、物联网、生物检测、可穿戴、智能安防、以及5G等技术的飞速发展对超低功耗集成电路及超灵敏传感器提出了迫切的需求与严峻的挑战，传统器件面临功耗、性能、开关特性等方面的困难。基于二维材料的新型器件的出现，使克服传统器件的困难成为了可能，同时也面临新的机遇与挑战。混合维度范德瓦尔斯异质结TFET器件结合了不同维度材料各自在材料特性、加工工艺等方面的优势，具有巨大潜力，有望在未来超低功耗集成电路和超灵敏传感器中应用。然而，对该器件中混合维度体系的能带结构以及输运特性的相关基础物理问题，目前国内外研究仍十分缺乏。本项目聚焦研究Ge/MoS2范德瓦尔斯混合维度异质结TFET的输运关键技术、器件制备技术与测试技术，拟建立结合能带计算、多散射机制的器件输运模拟平台并进行实验验证。为该器件的设计、优化与制造提供理论指导，推动该器件在超低功耗及超灵敏传感领域的应用。

随着器件尺寸不断缩小，体材料工艺难度不断增加、量子效应的影响愈发严重。小尺寸TFET器件、尤其是超薄体TFET器件，界面态导致的沟道迁移率退化、沟道厚度波动、掺杂波动以及异质材料界面缺陷等问题已经严重影响了TFET性能。二维材料具有不受悬挂键影响的原子级光滑表面、高度一致的薄膜厚度等优点，为解决上述问题提供了可行方案。通过本项目研究，成功搭建了实验平台，研究了二硫化钼的生长、异质结的制备、光谱特性的研究和器件的应用等方面。通过常压化学气相沉积法和微机械剥离法生长制备了大尺寸、高质量二硫化钼二维薄膜。并针对不同衬底上二硫化钼材料的光谱特性进行了研究。制备了基于二硫化钼材料的异质结，并对二硫化钼基异质结的光谱特性进行研究。为后续的研究任务奠定坚实的基础。建立了Ge/MoS2混合维度范德瓦尔斯异质结的能带结构的计算方法，确定了MoS2层数对Ge/MoS2范德瓦尔斯混合维度异质结能带结构的具体影响。确定Ge/MoS2范德瓦尔斯混合维度异质结TFET载流子输运过程的散射机制，建立带有多种散射机制的器件散射模型。通过数值计算得到不同参数条件下隧穿晶体管的输入输出特性、电容特性以及频率特性，确定器件的敏感工艺参数以及薄弱环节。