Charge Trapping Layer Enabled Normally-Off <i>β</i>-Ga<sub>2</sub>O<sub>3</sub> MOSFET
Minghao He, Kangyao Wen, Chenkai Deng, Mujun Li, Yifan Cui, Qing Wang, Hongyu Yu, Kah‐Wee Ang
Abstract
In this work, a normally-OFF <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 MOSFET enabled by charge trapping layer (CTL) is demonstrated for the first time. The CTL consists of Al:HfO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{x} 1$ </tex-math></inline-formula> :5 and the tunneling barrier (TB) is Al2O3/HfOx/Al2O3 stack. The developed Ga2O3 MOSFET exhibits a wide <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}$ </tex-math></inline-formula> tuning range to normally-OFF operation and a long-lasting retention characteristic of −0.3 V (ten years). The device obtains a breakdown voltage (BV) of 1815 V, showing high reverse blocking capability based on the proposed CTL technique. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </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">${V}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </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">${V}$ </tex-math></inline-formula> analyses are carried out under various temperatures to study the mechanism and explore the charge trapping and de-trapping processes. The results indicate a promising method to achieve E-mode operation for Ga2O3 MOSFET with low charge loss and stable <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}$ </tex-math></inline-formula> .