Vertical <i>β</i>-Ga₂O₃ Power Diodes: From Interface Engineering to Edge Termination
Junpeng Wen, Weibing Hao, Zhao Han, Feihong Wu, Qiuyan Li, Jinyang Liu, Qi Liu, Xuanze Zhou, Guangwei Xu, Shu Yang, Shibing Long
Abstract
Ultra wide bandgap semiconductor beta-gallium oxide ( <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) has the potential in fabricating the next generation of power devices applied at high temperature and high voltage due to its superior material properties and cost competitiveness. However, the performance of the existing <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 power diodes is far from the theoretical value because of the restriction of interface quality and edge electric field crowding effect. In this review, we introduce several effective interface engineering and edge termination techniques commonly used in vertical <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 diodes, highlighting their design principles, key fabrication processes, physical mechanism, and merit/demerit. To realize the actual applications, the representative large-size <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 diodes that can allow large level current to flow are also discussed. In addition, possible optimization strategies for these techniques are proposed for researchers’ reference. This article will help researchers understand the current study status of vertical <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 diodes and inspire researchers for future innovation in this emerging and exciting field. Moreover, the techniques and optimization strategies mentioned can also be applied to other semiconductors.