Chinese firm makes gallium oxide breakthrough
As reported on the Asian Gallium Oxide Alliance website, Shanghai GaChi Power Technology, has achieved a breakthrough in the field of ultra-wide-bandgap semiconductors by completing the first-stage iterative tape-out and validation of a vertical gallium oxide (β-Ga₂O₃) MOSFET chip.
It's claimed to be the world’s first enhancement-mode vertical β-Ga₂O₃ MOSFET device with an on-state current exceeding 1 A and a breakdown voltage greater than 900 V.
β-Ga₂O₃ offers an exceptionally high breakdown electric field, low conduction losses, and high-temperature tolerance, making it promising material for high-voltage, high-efficiency power devices. But achieving stable and controllable p-type doping has remained a a long-standing challenge in the development of high-power and commercially viable gallium oxide MOSFETs.
For this reason, vertical β-Ga₂O₃ MOSFETs have generally suffered from limited current-handling capability, insufficient breakdown voltage, and relatively high leakage current.
To address this, the GaChi Power technical team have developed a novel β-Ga₂O₃ MOSFET unit-cell structure and a dedicated termination structure, enabling precise control over the internal device architecture and electric-field distribution to improve device stability and breakdown voltage.
At the process level, the team overcame key challenges in the self-aligned ion implantation process for β-Ga₂O₃ MOSFET channels, addressing difficulties in precise channel formation and uniform doping control in vertical devices. These advances established a dedicated process platform tailored to high-power β-Ga₂O₃ devices, enabling the successful completion of the first full fabrication run and electrical characterisation.
The device is reported as achieving a measured threshold voltage of 3.9 V and operated stably in enhancement mode, with parameters meeting the requirements for commercial power devices. It delivered an on-state current of 1.2 A and a specific on-resistance of 33 mΩ·cm².
The device was designed for a 750 V voltage platform and achieved a measured breakdown voltage exceeding 900 V, with leakage current maintained below 3 μA. Its leakage performance is said to approach the levels of mature commercial silicon and SiC power devices, addressing a major challenge associated with high leakage in β-Ga₂O₃ devices and demonstrating strong potential for commercial applications.
