Correlation Between Electrical Performance and Gate Width of GaN-Based HEMTs
Yue Sun, Haochen Zhang, Lei Yang, Kunpeng Hu, Zhanyong Xing, Kun Liang, Huabin Yu, Shi Fang, Yang Kang, Danhao Wang, Guangwei Xu, Haiding Sun, Shibing Long
Abstract
In this work, we comprehensively studied the correlation between the electrical characteristics and the gate width ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}$ </tex-math></inline-formula> ) of GaN-based HEMTs. On the one hand, as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}$ </tex-math></inline-formula> is scaled down from 100 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> down to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3~\mu \text{m}$ </tex-math></inline-formula> , the devices exhibit five-times-enhanced on-state drain current density and largely reduced on-resistance, thanks to the increased electron mobility and mitigated self-heating effects in the narrow- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}$ </tex-math></inline-formula> channels. On the other hand, the devices with a wider <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}$ </tex-math></inline-formula> exhibit reduced off-state leakage current and enhanced breakdown voltage, thanks to a decreased electric field and increased Schottky barrier height. Further temperature-dependent characterization reveals that the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{G}$ </tex-math></inline-formula> -modulation behavior on both on- and off-state device properties is still effective at a high temperature of 150°C. These experimental results can provide a straightforward approach for effective channel modulation and device optimization of GaN-based power devices of the future.