2D fin field-effect transistors integrated with epitaxial high-k gate oxide

• Published in: Nature (London) 2023-04, Vol.616 (7955), p.66-72
• Main Authors: Tan, Congwei, Yu, Mengshi, Tang, Junchuan, Gao, Xiaoyin, Yin, Yuling, Zhang, Yichi, Wang, Jingyue, Gao, Xinyu, Zhang, Congcong, Zhou, Xuehan, Zheng, Liming, Liu, Hongtao, Jiang, Kaili, Ding, Feng, Peng, Hailin
• Format: Article
• Language: English
• Subjects: 639/301/357/1018; 639/925/357/1018; Arrays; CMOS; Electron mobility; Energy efficiency; Epitaxy; Field effect transistors; Heterostructures; Humanities and Social Sciences; Interfaces; Low dimensional semiconductors; Microscopy; Mobility; Moore's law; multidisciplinary; Ratios; Science; Science (multidisciplinary); Semiconductor devices; Semiconductors; Single crystals; Symmetry; Transistors; Unit cell
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-023-05797-z

Precise integration of two-dimensional (2D) semiconductors and high-dielectric-constant ( k ) gate oxides into three-dimensional (3D) vertical-architecture arrays holds promise for developing ultrascaled transistors 1 – 5 , but has proved challenging. Here we report the epitaxial synthesis of vertically aligned arrays of 2D fin-oxide heterostructures, a new class of 3D architecture in which high-mobility 2D semiconductor fin Bi 2 O 2 Se and single-crystal high- k gate oxide Bi 2 SeO 5 are epitaxially integrated. These 2D fin-oxide epitaxial heterostructures have atomically flat interfaces and ultrathin fin thickness down to one unit cell (1.2 nm), achieving wafer-scale, site-specific and high-density growth of mono-oriented arrays. The as-fabricated 2D fin field-effect transistors (FinFETs) based on Bi 2 O 2 Se/Bi 2 SeO 5 epitaxial heterostructures exhibit high electron mobility ( μ ) up to 270 cm 2  V −1  s −1 , ultralow off-state current ( I OFF ) down to about 1 pA μm −1 , high on/off current ratios ( I ON / I OFF ) up to 10 8 and high on-state current ( I ON ) up to 830 μA μm −1 at 400-nm channel length, which meet the low-power specifications projected by the International Roadmap for Devices and Systems (IRDS) 6 . The 2D fin-oxide epitaxial heterostructures open up new avenues for the further extension of Moore’s law. The epitaxial synthesis of high-density, vertically aligned arrays of two-dimensional (2D) fin-oxide heterostructures is described, enabling the fabrication of 2D fin field-effect transistors with high electron mobility and desirable low-power specifications.