Improved Performance of Fully-Recessed High-Threshold-Voltage GaN MIS-HEMT With <i>in Situ</i> H₂/N₂ Plasma Pretreatment
Bin Zhang, Jinyan Wang, Xin Wang, Chen Wang, Chengyu Huang, Jiayin He, Maojun Wang, Jianghui Mo, Yansheng Hu, Wengang Wu
Abstract
In this letter, we demonstrate a high-threshold-voltage and high-current-density normally-off SiN/AlN/ GaN-on-Si MIS-HEMT with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> low-damage H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> plasma pretreatment. The <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> plasma pretreatment was performed in a plasma enhanced atomic layer deposition (PEALD) system prior to the PEALD-AlN deposition, which effectively suppress the interface trap densities between the AlN/GaN interface and increase the mobility of electrons to 198.80 cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{{2}}/\text {V} \cdot \text {s}$ </tex-math></inline-formula> . Therefore, the devices demonstrate state-of-art characteristics with a competitive maximum drain current of 683.75 mA/mm at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V} _{\textit {GS}} =15\text{V}$ </tex-math></inline-formula> and a high threshold of 6.28 V. The devices also show ON/OFF current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{8}}$ </tex-math></inline-formula> and off-state breakdown voltage of 1778 V.