Demonstration of Germanium Vertical Gate-All-Around Field-Effect Transistors Featured by Self-Aligned High-κ Metal Gates with Record High Performance

Lu Xie; Huilong Zhu; Yongkui Zhang; Xuezheng Ai; Junjie Li; Guilei Wang; Jinbiao Liu; Anyan Du; Hong Yang; Xiaogen Yin; Weixing Huang; Chen Li; Yangyang Li; Qi Wang; Shunshun Lu; Zhenzhen Kong; Jinjuan Xiang; Yong Du; Jun Luo; Junfeng Li; Henry H Radamson; Wenwu Wang; Tianchun Ye

doi:10.1021/acsnano.3c02518

Demonstration of Germanium Vertical Gate-All-Around Field-Effect Transistors Featured by Self-Aligned High-κ Metal Gates with Record High Performance

ACS Nano. 2023 Nov 28;17(22):22259-22267. doi: 10.1021/acsnano.3c02518. Epub 2023 Oct 12.

Authors

Lu Xie^{1

2}, Huilong Zhu^{1

2}, Yongkui Zhang¹, Xuezheng Ai¹, Junjie Li¹, Guilei Wang¹, Jinbiao Liu¹, Anyan Du¹, Hong Yang¹, Xiaogen Yin^{1

2}, Weixing Huang^{1

2}, Chen Li^{1

2}, Yangyang Li^{1

2}, Qi Wang¹, Shunshun Lu¹, Zhenzhen Kong¹, Jinjuan Xiang¹, Yong Du¹, Jun Luo¹, Junfeng Li¹, Henry H Radamson^{1

2}, Wenwu Wang¹, Tianchun Ye¹

Affiliations

¹ Key Laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 37823534
DOI: 10.1021/acsnano.3c02518

Abstract

A special Ge nanowire/nanosheet (NW/NS) p-type vertical sandwich gate-all-around (GAA) field-effect transistor (FET) (Ge NW/NS pVSAFET) with self-aligned high-κ metal gates (HKMGs) is proposed. The Ge pVSAFETs were fabricated by high-quality GeSi/Ge epitaxy, an exclusively developed self-limiting isotropic quasi atomic layer etching (qALE) of Ge selective to both GeSi and the (111) plane, top-drain implantation, and ozone postoxidation (OPO) channel passivation. The Ge pVSAFETs, which have hourglass-shaped (111) channels with the smallest size range from 5 to 20 nm formed by qALE, have reached a record high I_on of ∼291 μA/μm and exhibited good short channel effects (SCEs) control. The integration flow is compatible with mainstream CMOS processes, and Ge pVSAFETs with precise control of gate lengths/channel sizes were obtained.

Keywords: Ge; hourglass-shaped channels; nanosheet (NW/NS); nanowire; ozone postoxidation (OPO); p-type vertical sandwich gate-all-around field-effect transistors (pVSAFETs); self-aligned metal gates.