Gallium oxide (GaO) heterogeneous and heterojunction power devices.

Due to its high critical breakdown electrical field and the availability of large-scale single crystal substrates, Gallium oxide (GaO) holds great promise for power electronic and radio frequency (RF) applications. While significant advancements have been made in GaO material and device research, there are still challenges related to its ultra-low thermal conductivity and the lack of effective p-type doping methods. These limitations hinder the fabrication of complex device structures and the enhancement of device performance. This review aims to provide an introduction to the research development of GaO heterogeneous and heterojunction power devices based on heterogeneous integration technology. By utilizing ion-cutting and wafer bonding techniques, heterogeneous substrates with high thermal conductivity have been realized, offering a viable solution to overcome the thermal limitations of GaO. Compared to GaO bulk devices, GaO devices fabricated on heterogeneous substrates integrated with SiC or Si exhibit superior thermal properties. Power diodes and superjunction transistors based on p-NiO/n-GaO heterojunctions on heterogeneous substrates have demonstrated outstanding electrical characteristics, presenting a feasible method for the development of bipolar devices. The technologies of heterogeneous integration and heterojunction address critical issues related to GaO, thereby advancing the commercial applications of GaO devices in power and RF fields. By integrating GaO with other materials and leveraging heterojunction interfaces, researchers and engineers have made significant progress in improving device performance and overcoming limitations. These advancements pave the way for the wider adoption of GaO-based devices in various power and RF applications.