Progress in state-of-the-art technologies of Ga ₂ O ₃ devices

Gallium oxide (Ga 2 O 3 ), an emerging ultra-wide-bandgap semiconductor, has the desirable properties of a large bandgap of 4.6–4.9 eV, an estimated critical breakdown field of 8 MV cm −1 , decent electron mobility of 250 cm 2 V s −1 and high theoretical Baliga figures of merit (BFOMs) of around 3000. Bolstered by their capability of an economical growth technique for high-quality bulk substrate, β -Ga 2 O 3 -based materials and devices have been highly sought after in recent years for power electronics and solar-blind ultraviolet photodetectors. This article reviews the most recent advances in β -Ga 2 O 3 power device technologies. It will begins with a summary of the field and underlying semiconductor properties of Ga 2 O 3 , followed by a review of the growth methods of high-quality β -Ga 2 O 3 bulk substrates and epitaxial thin films. Then, brief perspectives on the advanced technologies and measurements in terms of ohmic contact and interface state are provided. Furthermore, some state-of-the-art β -Ga 2 O 3 photoelectronic devices, power devices and radiofrequency devices with distinguished performance are fully described and discussed. Some solutions to alleviating challenging issues, including the difficulty in p-type doping, low thermal conductivity and low mobility, are also presented and explored.