直立SiO2/Si芯壳双曲结构纳米硅可控制备及应变调控研究

Using gate-all-around device structure with strain-engineering to acquire high-performance 5 nm node (channel length) Si base nano-transistor is a one of the promising strategies for further developing of Si-based integrated circuits. This project is focused on the nano-fabrication of vertically aligned 5-nm-Si-channel with strain engineering using the innovated SiO2/Si core-shell hyperbolic structure. The works will contributed on the material and device physics related issues. Firstly, methods with related mechanisms will be developed for the nano-fabrication the SiO2/Si core-shell hyperbolic structure and the achieving of well control strain engineering. The effect of the strain on trap density at the SiO2/Si interface, lattice dislocation in Si, dopant distribution in the Si-channel and the correlation between the above factors and the crystal-orientation, energy-band structure, electron/hole mobility will be clarified. Secondly, based on the findings, effects will be realize extreme strain on the Si-channel, by using the combining of elastic and plastic deformation of the SiO2/Si core-shell hyperbolic structure. Finally, the finds from the strain engineering will employed for developing prototype gate-all-around transistors with high carrier mobility, for both electron and hole. The work provides not only strong theoretical but also technical potentials for supporting the further development of Si-based nano-electronics.

结合直立环栅结构和应变工程实现高性能5nm节点（沟道长度）硅基晶体管是集成电路发展的重要前沿课题之一。直立5nm节点硅沟道的制备及新型应变硅原理是研究热点和难点。本项目从新材料和新结构的基础原理出发，探究利用热氧化过程中SiO2/Si芯壳纳米双曲结构中Si和SiO2几何参量和物性的差异产生应力，研究并实现直径小于10nm，长度为5nm的硅沟道的精确制备及应变调控。通过项目实施，理解纳米双曲结构应力调控方法和机理；厘清应力对纳米硅界面缺陷、晶格位错、杂质分布的影响规律；掌握上述因素与纳米硅的晶向、能带结构、电子及空穴迁移率的相关性；掌握结合弹性形变和塑性形变实现纳米硅极限应变的条件及机理，探索突破硅基材料载流子迁移率瓶颈的可能性；探索实现双曲结构各具（或兼具）高电子和空穴迁移率的方法及机理；获得应力硅沟道及其阵列；为发展高性能集成电路元件提供理论参考和技术支撑。

本项目研究基于硅纳米双曲结构的直立环栅晶体管。项目开展从新型器件结构的设计、纳米加工原理和方法创新，到器件物理模型构建的链条式研究，突破纳米加工难题，厘清集成器件相关的材料物理和器件物理，验证环栅晶体管在有源控制场发射电子源的电子发射上的应用可行性。项目工作成果可为发展新型硅基环栅晶体管器件，促进硅基固体电子器件和真空电子器件的混合集成提供新方法。项目的研究成果包括：发展了利用Si/SiO2核壳结构热氧化应力辅助纳米加工的新方法。构建Si/SiO2核壳双曲结构界面非单轴应力模型，掌握调节应力的技术，制作出特征尺寸为10纳米的硅双曲纳米结构阵列，为研制硅基直立环栅晶体管提供支撑。构建应力辅助热氧化杂质分凝扩散模型，揭示了不同掺杂类型（元素）的硅双曲纳米沟道环栅晶体管的器件物理，分别研制出环栅金属-氧化物-半导体场效应晶体管和环栅隧穿场效应晶体管。研制出集成直立环栅晶体管的硅微尖锥电子源芯片，利用直立环栅晶体管实现了硅微尖锥场发射电流的精确调节，厘清了环栅晶体管和集成电子“抽取电极”的硅微尖锥片上一体化集成器件的器件物理。