Channel Properties of Ga₂O₃-on-SiC MOSFETs
Yibo Wang, Wenhui Xu, Genquan Han, Tiangui You, Fengwen Mu, Haodong Hu, Yan Liu, Xinchuang Zhang, Hao Huang, Tadatomo Suga, Xin Ou, Xiaohua Ma, Yue Hao
Abstract
We report the characterization of the channel mobility properties of metal-oxide-semiconductor fieldeffect transistors (MOSFETs) on the heterogeneous β-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> -on-SiC (GaOSiC) substrate fabricated by an ion-cutting process. The mobility of GaOSiC MOSFETs is significantly improved as the postannealing temperature of 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> channel increases from 900 °C to 1200 °C. The GaOSiC transistor annealed at 1200 °C exhibits mobility consistent with the β-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> donor wafer, which suggests that the defects in 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> channel induced by the H <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> implantation for the ion-cutting step can be eliminated by the high-temperature annealing. As the ambient temperature (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">amb</sub> ) increases from 0 °C to 150 °C, the mobility within the accumulation regime of GaOSiC MOSFETs decreases with the temperature following a T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> amb law, which is limited by the phonon scattering. The results of this work will be critically important for designing the transport properties of the GaOSiC channel, significantly advancing the development of 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> power devices on high thermal conductivity substrate.