Experimental Investigation on Threshold Voltage Instability for <i>β</i>-Ga<sub>2</sub>O<sub>3</sub> MOSFET Under Electrical and Thermal Stress
Zhuolin Jiang, Yuxi Wei, Yuanjie Lv, Jie Wei, Yuangang Wang, Juan Lu, Hongyu Liu, Zhihong Feng, Hong Zhou, Jincheng Zhang, Guangwei Xu, Shibing Long, Xiaorong Luo
Abstract
A <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> -Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> MOSFET is fabricated and its 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">$({V}_{\mathrm{TH}})$ </tex-math></inline-formula> instability mechanisms are experimentally investigated under different gate-biased voltages and ambient temperatures. Under the condition of the positive bias stress (PBS) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{GS}} = 4$ </tex-math></inline-formula> V for 1000 s at room temperature, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> positive shift of 0.61 V is mainly caused by the electrons trapped by border traps in Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> . Combining the hysteresis with temperature-dependent performance analysis, the clockwise to anticlockwise hysteresis inversion at 125 °C is discovered in <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> -Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> MOSFET for the first time, which is probably caused by the activation of deep-level acceptor-type interface states. The deep-level acceptor-type interface states with a fitting activation energy of 114 meV are found, and they also affect the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> instability at high temperature. With the stress of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{GS}} =4$ </tex-math></inline-formula> V at 125 °C for 1000 s, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> is increased by 0.9 V. Analyzing electrical parameters, such as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> , subthreshold slope ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> ), and hysteresis width, can distinguish the quantitative contributions of interface states and border traps to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> instability under electrical stress and thermal stress (TS). This work reveals an important indication for investigating the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathrm{TH}}$ </tex-math></inline-formula> instability of <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> -Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> MOSFET in high-power applications.