Demonstration of High Voltage (>1.7kV) GaN Negative-Capacitance Ferroelectric HEMTs Using HZO Gate Stack Achieving 47.89 mV/dec SS and Reduced ON-Resistance
Student Contest:
No
Affiliation Type:
Academia
Keywords:
GaN HEMT, Negative Capacitance, Ferroelectric Gate Stack, NC-FeHEMTs, Hf₀.₅Zr₀.₅O₂ (HZO).
Abstract:
This work reports the first kilovolt-class GaN negative-capacitance ferroelectric HEMTs (NC-FeHEMTs) using an Hf₀.₅Zr₀.₅O₂ (HZO) gate stack for power switching applications. Three structures are systematically compared: a conventional MIS-HEMT, an HZO device with a 1-nm Al₂O₃ IL, and an optimized HZO device employing a single-cycle (~0.1 nm) Al₂O₃ IL. Aggressive IL scaling effectively suppresses depolarization fields and enhances polarization coupling to the GaN channel. Structural analysis confirms a well-defined TiN/HZO/Al₂O₃ stack with mixed orthorhombic/tetragonal HZO phases. Only the optimized device exhibits near frequency-independent C–V behavior and negligible hysteresis, confirming stabilized, hysteresis-free NC operation. Consequently, the NC-FeHEMT achieves a minimum subthreshold swing of 47.9 mV/dec, a 47% reduction in specific on-resistance (3.14 mΩ·cm²), and an OFF-state breakdown voltage exceeding 1.7 kV at room temperature, while maintaining >1.2 kV blocking capability up to 200 °C. These results highlight the strong potential of GaN NC-FeHEMTs for high-voltage power switching applications.
Track ID:
4
Track Name:
GaN & Nitride-Based Compound Materials: Device & Technology (GAN)
