Proposal and experimental demonstration of ultrathin-body (111) InAs-on-insulator nMOSFETs with L valley conduction
Proposal and experimental demonstration of ultrathin-body (111) InAs-on-insulator nMOSFETs with L valley conduction
复制标题
具有 L 谷导通的超薄体 (111) InAs 绝缘体 nMOSFET 的提案和实验演示
DOI：
10.1109/ted.2021.3049455
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
and S. Takagi
中科院分区：
文献类型：
--
作者：
K. Sumita;K. Toprasertpong;M. Takenaka;and S. Takagi
超薄体(UTb)(111)InAs-OI(InAs-OI)n沟道金属氧化物半导体场效应晶体管(NMOSFET)被提出作为一种利用III-V沟道的L谷导的新技术助推器。传统的UTB III-V nMOSFET的性能受到山谷导电的基本能带特性的限制，如低态密度导致低反转电容，以及沿限制方向的光有效质量导致强烈的厚度涨落散射。(111)表面取向和UTb InAs-Oi结构对电子的强烈限制有望使电子转移到比L谷重得多的InAs-Oi谷，从而导致更高的半导体电容和厚度涨落散射的抑制。我们还在实验上演示了UTB(111)InAs-OI nMOSFET的工作原理，通过智能切割和数字刻蚀工艺实现了InAs沟道变薄至3 nm。沟道厚度调整通过扩展有效带隙来改善关断电流和导通电流。结果表明，从4.8nmInAs-OI厚度减小到4.4nm时，测量到的迁移率随InAs-OI厚度的减小而增加，这归因于电子在L谷的占有率的增加。
Ultrathin-body (UTB) (111) InAs-On-Insulator (InAs-OI) n-channel metal–oxide–semiconductor field-effect transistors (nMOSFETs) are proposed as a new technology booster using the L valley conduction in III–V channels. The performance of the conventional UTB III–V nMOSFETs is limited by the essential band features of thevalley conduction such as the low density of states, resulting in low inversion capacitance, and the light effective massalong the confinement direction, resulting in strong thickness fluctuation scattering. The strong confinement of electrons by a combination of (111) surface orientation and UTB InAs-OI structures is expected to transfer the electrons into the L valley with much heavierthan in thevalley, leading to higher semiconductor capacitance and suppression of thickness fluctuation scattering. We also experimentally demonstrate the UTB (111) InAs-OI nMOSFETs operation with thinning the InAs channels down to 3 nm, realized by the smart-cut and digital etching process. Channel thickness scaling improves both the OFF- and ON-currents by expansion of the effective bandgap. It is shown that the measured mobility increases with decreasing InAs-OI thickness from 4.8 to 4.4 nm, which is attributable to the increase in the electron occupancy in the L valley.