Zhu Jiaduo, Ning Jing, Wang Dong, Zhang Jincheng, Guo Lixin, Hao Yue
Wide Bandgap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi'an, 710071, China.
Shaanxi Joint Laboratory of Graphene, Xidian University, Xi'an, 710071, China.
Nanoscale Res Lett. 2019 Aug 15;14(1):277. doi: 10.1186/s11671-019-3106-8.
Two-dimensional (2D) InSe-based field effect transistor (FET) has shown remarkable carrier mobility and high on-off ratio in experimental reports. Theoretical investigations also predicated the high performance can be well preserved at sub-10 nm nodes in the ballistic limit. However, both experimental experience and theoretical calculations pointed out achieving high-quality ohmic has become the main limiting factor for high-performance 2D FET. In this work, we proposed a new sandwiched ohmic contact with indium for InSe FET and comprehensively evaluated its performance from views of material and device based on ab initio methods. The material properties denote that all of fundamental issues of ohmic contact including tunneling barrier, the Schottky barrier, and effective doping are well concerned by introducing the sandwiched structure, and excellent contact resistance was achieved. At device performance level, devices with gate length of 7, 5, and 3 nm were investigated. All metrics of sandwiched contacted devices far exceed requirement of the International Technology Roadmap for Semiconductors (ITRS) and exhibit obvious promotion as compared to conventional structures. Maximum boost of current with 69.4%, 50%, and 49% are achieved for devices with 7, 5, and 3 nm gate length, respectively. Meanwhile, maximum reduction of the intrinsic delay with 20.4%, 16.7%, and 18.9% are attained. Moreover, a benchmark of energy-delay product (EDP) against other 2D FETs is presented. All InSe FETs with sandwiched ohmic contact surpass MoS FETs as well as requirement from ITRS 2024. The best result approaches the upper limit of ideal BP FET, denoting superior preponderance of sandwiched structures for InSe FETs in the next generation of complementary metal-oxide semiconductor (CMOS) technology.
二维（2D）基于铟硒（InSe）的场效应晶体管（FET）在实验报告中展现出了卓越的载流子迁移率和高开/关比。理论研究也预测，在弹道极限下，其高性能在小于10纳米的节点处仍能得到良好保持。然而，实验经验和理论计算均指出，实现高质量的欧姆接触已成为高性能二维FET的主要限制因素。在这项工作中，我们为InSe FET提出了一种新的含铟夹心欧姆接触，并基于从头算方法从材料和器件的角度全面评估了其性能。材料特性表明，通过引入夹心结构，欧姆接触的所有基本问题，包括隧穿势垒、肖特基势垒和有效掺杂，都得到了很好的解决，并实现了优异的接触电阻。在器件性能层面，我们研究了栅长为7纳米、5纳米和3纳米的器件。夹心接触器件的所有指标都远远超过了国际半导体技术路线图（ITRS）的要求，与传统结构相比有明显提升。栅长为7纳米、5纳米和3纳米的器件分别实现了69.4%、50%和49%的最大电流提升。同时，本征延迟分别最大降低了20.4%、16.7%和18.9%。此外，还给出了与其他二维FET相比的能量延迟积（EDP）基准。所有具有夹心欧姆接触的InSe FET均超过了二硫化钼（MoS）FET以及ITRS 2024的要求。最佳结果接近理想的黑磷（BP）FET的上限，这表明夹心结构在下一代互补金属氧化物半导体（CMOS）技术的InSe FET中具有卓越的优势。
