Gallium oxide (Ga2O3), with its ultra-wide bandgap (∼4.8 eV) and high theoretical breakdown field (8 MV/cm), holds significant research value and promising application in power electronics and microwave radio-frequency (RF) devices. However, the extremely low thermal conductivity of Ga2O3 severely impedes the fabrication of complicated structures and the optimization of device performance. The wafer bonding technology, as a method to fabricate heterogeneous structures materials, newly applied on Ga2O3 to fabricate Ga2O3 hybrid materials. This paper reviews the wafer bonding technology for ultra-wide bandgap Ga2O3 material based on plasma activation and room-temperature surface activation, as well as the heterogeneous integration with silicon (Si), silicon carbide (SiC), and diamond. The effects of various wafer bonding methods on the bonding quality, thermal, and electrical properties are systematically summarized. Finally, the advancements of Ga2O3-based heterogeneous structures in the applications of power, RF, and optoelectronic devices are summarized. This review aims to address the key challenges in Ga2O3 material through an understanding of principles and development of bonding technology, thereby facilitating the practical application of Ga2O3-based devices.

中文翻译：

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超宽禁带 Ga2O3 的异质晶圆键合研究综述


氧化镓 （Ga2O3） 具有超宽禁带 （∼4.8 eV） 和高理论击穿场 （8 MV/cm） 等特点，在电力电子和微波射频 （RF） 器件中具有重要的研究价值和应用前景。然而，Ga2O3 的极低导热性严重阻碍了复杂结构的制造和器件性能的优化。晶圆键合技术作为一种制造异质结构材料的方法，新应用于 Ga2O3 以制造 Ga2O3 混合材料。本文综述了基于等离子体活化和室温表面活化的超宽带隙 Ga2O3 材料的晶圆键合技术，以及与硅 （Si）、碳化硅 （SiC） 和金刚石的非均相集成。系统总结了各种晶圆键合方法对键合质量、热和电气性能的影响。最后，总结了基于 Ga2O3 的非均相结构在功率、射频和光电器件应用中的进展。本文旨在通过了解键合技术的原理和发展来解决 Ga2O3 材料中的关键挑战，从而促进 Ga2O3 基器件的实际应用。