The self-heating effect is a severe issue for high-power semiconductor devices, which degrades the electron mobility and saturation velocity, and also affects the device reliability. On applying an ultrafast and high-resolution thermoreflectance imaging technique, the direct self-heating effect and surface temperature increase phenomenon are observed on novel top-gate β-Ga₂O₃ on insulator field-effect transistors. Here, we demonstrate that by utilizing a higher thermal conductivity sapphire substrate rather than a SiO₂/Si substrate, the temperature rise above room temperature of β-Ga₂O₃ on the insulator field-effect transistor can be reduced by a factor of 3 and thereby the self-heating effect is significantly reduced. Both thermoreflectance characterization and simulation verify that the thermal resistance on the sapphire substrate is less than 1/3 of that on the SiO₂/Si substrate. Therefore, maximum drain current density of 535 mA/mm is achieved on the sapphire substrate, which is 70% higher than that on the SiO₂/Si substrate due to reduced self-heating. Integration of β-Ga₂O₃ channel on a higher thermal conductivity substrate opens a new route to address the low thermal conductivity issue of β-Ga₂O₃ for power electronics applications.

中文翻译：

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的热力学研究的β-Ga ₂ ö ₃纳米膜场效应晶体管上的蓝宝石基板

对于高功率半导体器件，自热效应是一个严重的问题，它会降低电子迁移率和饱和速度，并影响器件的可靠性。上施加一超快和高分辨率热反射成像技术，直接自加热效应和表面温度上升的现象是在新颖顶栅的β-Ga观察到₂ ö ₃绝缘体上的场效应晶体管。在这里，我们证明，通过利用更高的导热性的蓝宝石衬底，而不是由SiO ₂ / Si基板上，温度上升高于室温的β-Ga ₂ ö ₃绝缘体场效应晶体管上的电阻可以减小3倍，从而显着降低了自热效应。热反射特性和仿真均验证了蓝宝石衬底上的热阻小于SiO ₂ / Si衬底上的热阻的1/3 。因此，在蓝宝石衬底上实现了535 mA / mm的最大漏极电流密度，由于自发热降低，该密度比SiO ₂ / Si衬底高70％。的β-Ga的积分₂ ö ₃更高的导热性基板上的信道打开一个新的路线，以解决的β-Ga的低导热性问题₂ ö ₃为电力电子应用。