高质量InAs/GaSb异质结纳米线分子束外延生长及隧穿场效应器件研究

隧穿场效应晶体管具有超陡亚阈斜率，可实现超低功耗电路，是下一代集成电路最具竞争力的备选器件之一。InAs/GaSb异质结纳米线具有破隙型能带结构，可以进行无需势垒层的带间隧穿，是制备高性能隧穿场效应晶体管的理想材料。本项目拟通过分子束外延技术，在Si衬底上用Ag做催化剂制备高质量InAs/GaSb异质结纳米线，对其形貌、结构、光学及电学性质进行表征；研制InAs/GaSb异质结纳米线隧穿场效应晶体管；研究器件性能与纳米线制备条件、结构及物理性质之间的关系；在不断优化材料质量及器件加工工艺的基础上，制备出具有小亚阈值摆幅及大开态电流的InAs/GaSb异质结纳米线隧穿场效应晶体管。本项目旨在为最终研制亚阈值摆幅小于Si基CMOS理论极限且满足实际应用的隧穿场效应器件提供材料基础、物理原理和技术指导。

Tunnel field-effect transistors (TFETs) have emerged as one of the top alternative devices for the next generation integrated circuits owing to their ultra-steep subthreshold slopes and potential applications in ultra-low power electronic circuits. InAs/GaSb heterostructure nanowires are ideal materials for TFET applications, due to their broken type-II band alignments which allow for interband tunneling without any barrier. This project aims at the fabrication of high-quality InAs/GaSb heterostructure nanowires on Si substrates using molecular-beam epitaxy. A comprehensive characterization will be performed for these heterostructure nanowires including the morphological, structural, optical and electrical properties. We also plan to fabricate the InAs/GaSb heterostructure nanowire TFETs and set up the relationship between preparation condition, structure, physical property and device performance. Based on the optimization of material quality and the device fabrication processing, we attempt to fabricate the InAs/GaSb heterostructure nanowire TFETs with a low subthreshold swing and large on-state current. It is expected that this project can provide a material, physical and technical guidance for future commercial TFETs with a subthreshold swing lower than the Si-based CMOS physical limit.