Fabrication and Characterization of Back-Gate and Front-Gate Ge-on-Insulator Transistors for Low-Power Applications
Year: 2025
Type: article
Abstract: Germanium (Ge) has long been regarded as a promising channel material, owing to its superior carrier mobility and highly tunable electronic band structure. The new generation of low-power electronics is approaching the formation of fully depleted (FD) transistors on Si-on-insulator (SOl) and Ge-on-insulator (GOl) substrates. In this work, we present a full process of a novel FDGOI transistor formed on a strained GOI with low defect density. This scalable and industry-compatible approach enables the formation of uniform 50 nm thick Ge layers by using spinning wet etch with ultrasmooth surfaces (RMS roughness = 0.262 nm) and a low etch-pit density of ~105 cm−2. Electrical measurements reveal excellent carrier transport properties, with back-gate (BG) transistors achieving mobilities of 550–600 cm2/V·s, while front-gate (FG) devices exhibit sharp switching behavior and steep subthreshold slopes, yielding ION/IOFF ratios up to 105. Temperature-dependent measurements further demonstrate a pronounced enhancement of device performance: the ION/IOFF ratio increases to 106, the subthreshold swing (SS) decreases from 179 mV/dec at room temperature to 137 mV/dec at 120 K, and the threshold-voltage shift with temperature is as low as 1.87 mV/K across the range of 30–300 K. Such behavior highlights the potential of band-gap engineering for precise threshold-voltage control. Taken together, these results establish GOI as a CMOS-compatible material platform and provide a solid technological basis for the development of next-generation low-power transistors beyond conventional CMOS scaling.
Source: Electronics
Authors: Yuhui Ren, Jiale Su, Jiahan Ke, Hongxiao Lin, Ben Li, Zhenzhen Kong, Yiwen Zhang, Junhao Du, Renrong Liang, Jun Xu, Xiangliang Duan, Tianyu Dong, Xueyin Su, Tianchun Ye, Xuewei Zhao, Yuanhao Miao, Henry H. Radamson
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,896
OpenAlex ID: W4416722086