Electrical Comparison of ${\rm HfO}_{2}$ and ${\rm ZrO}_{2}$ Gate Dielectrics on GaN

A low-temperature atomic layer deposition technique for high-κ dielectric films on GaN templates was investigated for MOS applications. This improved growth method produced capacitance densities and a field effect mobility approaching 375 cm²/Vs for ZrO₂ and 250 cm²/Vs for HfO₂ films on GaN. Furthermore, the low density of dielectric-semiconductor interface traps confirmed a reliable cohesion between the high-κ and GaN. The improved gate dielectric deposition technique has the capabilities to improve the overall quality of GaN-based MOSFETs.