High-Current E-Mode InGaN/GaN p-FET on p-GaN Gate HEMT Platform
Jingjing Yu, Jin Wei, Junjie Yang, Teng Li, Han Yang, Yingming Song, Jiawei Cui, Sihang Liu, Xuelin Yang, Maojun Wang, Bo Shen
Abstract
The low current density in E-mode GaN p-FET presents a severe challenge for its application in complementary logic (CL) circuits. In this work, a high-current E-mode InGaN/GaN p-FET is demonstrated on a p-GaN gate HEMT platform with p-InGaN/p-GaN/AlGaN/GaN heterostructure. The proposed heterostructure introduces a net polarization charge at the InGaN/GaN interface, leading to an enhanced 2DHG. With a negative gate bias, a buried 2DHG channel is formed prior to the surface MIS channel. As a result, the recess-gate InGaN/GaN p-FET with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L}_{\text {G}} = 2~\mu $ </tex-math></inline-formula> m achieves a large maximum current (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\max }\text {)}$ </tex-math></inline-formula> exceeding −20 mA/mm. The InGaN/GaN p-FET obtains a low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}_{\text {ON}}$ </tex-math></inline-formula> of 0.64 k<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega \cdot $ </tex-math></inline-formula> mm and a high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {ON}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {OFF}}$ </tex-math></inline-formula> ratio exceeding <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{7}}$ </tex-math></inline-formula>. The device presents E-mode operation with a threshold voltage (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {TH}}\text {)}$ </tex-math></inline-formula> of −1.8 V and a low subthreshold swing (SS) of 144 mV/dec. Furthermore, an E-mode n-channel GaN HEMT is fabricated on the same platform, validating the potential of the proposed InGaN/GaN p-FET for GaN CL circuits.