【Member News】Sanan Optoelectronics Partners with Alliance Council Members Xidian University and Garen Semiconductor to Breakthrough Critical Gallium Oxide Epitaxy Technology

      With the rapid development of high-voltage scenarios such as new energy vehicles (NEVs), smart grids, and rail transit, the market demand for power semiconductor devices with high voltage resistance and low loss continues to grow. As a core material of the fourth-generation semiconductors, gallium oxide (Ga₂O₃), with its advantages of low conduction loss and high voltage resistance, is regarded as a strategic material for the next generation of high-voltage power electronics and has been incorporated into China's key strategic emerging industries.

      For a long time, the transition of gallium oxide from material advantage to mass-produced chips has been hindered by high-quality homoepitaxial technology, which remains the primary technical bottleneck for its industrialization. On internationally mainstream gallium oxide crystal planes, epitaxial growth is highly prone to defects. This causes device yields and actual breakdown voltages to fall far short of theoretical expectations, restricting the industry's large-scale commercialization process.

      Recently, Sanan Optoelectronics, in collaboration with the National Engineering Research Center for Wide Bandgap Semiconductors at Xidian University and Hangzhou Garen Semiconductor Co., Ltd., achieved a critical breakthrough in gallium oxide homoepitaxial technology. Utilizing the Metal-Organic Chemical Vapor Deposition (MOCVD) method, the joint team precisely optimized initial nucleation conditions and successfully suppressed twin defects, obtaining high-quality homoepitaxial layers on 2-inch substrates. Test results indicate that the root-mean-square (RMS) roughness across the entire wafer surface is below 0.5 nm, the crystal quality is comparable to that of the substrate, and the electron mobility reaches 100 cm²/(V-s).

      Based on these epitaxial wafers, the joint team prioritized the development of lateral power devices. Compared to vertical structures—which require conductive substrates and thick epitaxial layers, and face the inherent challenge of difficult p-type doping in gallium oxide—lateral devices can fully leverage the advantages of semi-insulating substrates in isolating leakage current. They allow for the flexible design of gate-to-drain spacing to withstand higher voltages while remaining highly compatible with existing planar silicon fabrication processes. Without the use of special termination structures, the lateral device achieved a breakdown voltage of 1420 V, an on/off ratio of 10 to the 5th power, and a threshold voltage uniformity exceeding 91%, validating the overall process capability from materials to devices.

      Currently, the joint team possesses the capabilities for 2-inch gallium oxide epitaxy and device fabrication, along with the technological foundation to scale up to 6-inch and larger dimensions. This industry-academia-research technological breakthrough by Sanan Optoelectronics, Xidian University, and Garen Semiconductor provides critical technical support for the deployment of gallium oxide in high-voltage scenarios such as smart grids and new energy vehicles, and will effectively accelerate the commercialization of fourth-generation semiconductor technology.