【International Papers】Monolithically Integrated RTL-Based Inverters for Gate Driver IC Using β-Ga₂O₃ MOSFETs

      Researchers from the King Abdullah University of Science and Technology (KAUST) have published a dissertation titled "Monolithically Integrated RTL-Based Inverters for Gate Driver IC Using β-Ga₂O₃ MOSFETs" in IEEE Transactions on Electron Devices.

Background

      β-Ga₂O₃ possesses excellent power electronic figures of merit and economically feasible wafer fabrication, driving significant progress toward high-performance devices and approaching commercial viability. The next step is the development of integrated circuits for power switching, where monolithic integration of gate drivers with power MOSFETs can reduce parasitics and enhance switching speed and stability. Due to the lack of high-performance p-channel devices, β-Ga₂O₃ logic circuits adopt topologies similar to GaN, with RTL offering a simple and practical solution. While prior studies demonstrated device potential, challenges remain in achieving high-frequency, high-power gate drivers, making the development of monolithically integrated β-Ga₂O₃ gate driver ICs a critical step toward commercialization.

Abstract

      The gate driver interfaces power MOSFETs with digital control circuits by providing the necessary drive current for rapid switching. This work demonstrates a monolithically integrated gate driver integrated circuit (IC) based on β-Ga₂O₃ resistor-transistor logic (RTL) inverter, utilizing enhancement-mode multifinger (MF) MOSFETs and recessed epitaxy-based resistors. The 0.785-mm² chip integrates two RTL inverters in a noninverting configuration and achieves voltage gains of 11.9 and 12.2 V/V with high/low noise margins of 3.4 /1.3 V and 3.0/1.6 V at a 15-V supply. Dynamic characterization shows a switching speed of 9.4 μs with a 5-V control input, producing output swings up to 15 V. These results validate the suitability of RTL-based gate drivers for β-Ga₂O₃ power ICs and highlight their potential for scalable monolithic integration.

Conclusion

      A monolithically integrated RTL-based gate driver IC using β-Ga₂O₃ enhancement-mode MOSFETs and recessed epitaxy-based resistors was designed, fabricated, and characterized. RTL inverters achieved voltage gains exceeding 12 V/V, with robust noise margins and cascaded operation. Static characterization revealed high ON/OFF current ratios (>10⁹), V_TH of 2.4 V, and R_ON,sp of 16.8 m·cm².

      Dynamic switching measurements demonstrated rise/fall times of 4.8/4.6 µs and a maximum switching frequency of 106.4 kHz, with performance governed by MOSFET capacitances and interconnect parasitics. C–V analysis highlighted the drain-bias dependence of gate-to-drain capacitance, while breakdown voltages near 150 V confirmed device robustness. These results validate the potential of RTL-based architecture for compact, high-voltage β-Ga₂O₃ power ICs and lay the groundwork for scalable monolithic integration in ultra-wide bandgap electronics.