GaSb纳米线表面态的转变规律及调控机制研究

As a technologically important p-type semiconductor, GaSb is considered as one of the best replacement candidate for p-type silicon in the future microelectronic circuits, owing to its highest hole mobility among all III-V semiconductors. However, the surface states caused by the dangling bonds limit the applications of III-V nanowires (NWs). Firstly, the dangling bonds make III-V NWs easily to be oxidized or etched, resulting in the property of sensitive environmental stability. On the other hand, dangling bonds are easy to form charge traps on NWs surfaces, which result in the surface Fermi level pinning of NWs and reduce the performance of III-V NWs-based devices. In this proposal, the translation law of surface states in GaSb NWs-based devices working environment and fabrication process will be studied by in-situ HRTEM, XPS and other technologies. Meanwhile, dangling bonds of NWs will be passivated by the selected optimal liquid-phase chemical reagents and solid-phase high-k dielectric materials, followed by XPS and HRTEM technologies etc. to explore the passivation mechanism. In the end, based on the explored regulatory mechanism of surface states, stable high-performance GaSb NWs-based all-around-gated field-effect-transistors will be fabricated. Based on the successful implementation of this proposal, we will sum up the translation law of III-Vs NWs surface states and the corresponding regulatory mechanism, providing the theoretical and technical supports for the development of microelectronic devices in "post-Moore".

GaSb具有III-V族半导体中最高的空穴迁移率，被认为是未来微电子电路中替代p型硅的半导体材料之一。然而，纳米线表面的大量悬挂键引起的丰富表面态限制了III-V纳米线的进一步应用。悬挂键不仅使得III-V纳米线易于被氧化或侵蚀，还易于形成“电荷陷阱”中心，引起表面费米能级钉扎效应，从而降低III-V纳米线光电器件的性能。本项目拟通过原位HRTEM、XPS等技术研究GaSb纳米线表面态在器件工作环境和制备工艺中的转变规律：选择合适的液态化学试剂与固态高k材料对纳米线表面悬挂键进行钝化，利用XPS，HRTEM等手段探索表面、界面悬挂键的成键钝化机理，总结出III-V纳米线的表面态调控机制，进一步指导实现高性能稳定的全包栅结构纳米线场效应管。通过本项目的成功实施，有望总结出III-V半导体纳米线表面态的转变规律以及相对应的调控机制，为“后摩尔”时代微电子器件的发展提供理论基础与技术支持。

锑化物具有带隙窄、迁移率高等优点，被认为是实现新一代高性能红外探测器和高速芯片的理想沟道新材料之一。本项目围绕“GaSb纳米线表面态的转变规律及调控机制研究”开展工作，研究发掘出金属辅助催化生长纳米线方法对生长衬底的弱外延依赖性规律，实现了在任意衬底上大面积生长锑元素分布均匀的小直径GaSb纳米线；针对载流子输运过程中的散射作用强导致迁移率低的难题，揭示了调控载流子库伦散射的新机制，研发出空穴迁移率最高的纳米线场效应晶体管；针对纳米线表面态严重、载流子浓度高、光生载流子复合严重的难题，构筑出肖特基接触的源栅晶体管光电探测原型器件，加速光生载流子的分离和收集，抑制暗电流，降低功耗。项目资助发表高质量论文14篇，包括Nano Letters 1篇， Small 2篇，中文特邀综述论文1篇；获发明专利授权3项；在学术会议上做邀请报告5次；培养博士2名、硕士4名。项目直接经费23万元，实际支出16.3688万元，剩余6.6312万元，剩余经费计划用于本项目研究的后续支出。