ABSTRACT
Surface-state passivation is found to be an effective way to mitigate the state-related issues. The SiN surface passivation increases the DC performance. Compared to the conversional HEMT, a Metal-Insulator-Semiconductor High-Electron-Mobility Transistors (MIS-HEMT) has the advantages of low gate leakage, low power consumption, and improved drain current collapse performance. These merits enable GaN-based MIS-HEMTs to be popular for high-power and high-frequency device applications. Among the various materials for the gate dielectric in GaN MIS-HEMTs, Al2O3 have attracted great interest due to its excellent physics properties, including a wide bandgap, a high dielectric constant, and a high breakdown field. A simple technique to directly evaluate the quality of the thin film is the low-frequency C-V measurement. It is worth noting that the quantity of the trap density at the interface between the gate insulator and the nitride is inevitably underestimated using the above-mentioned C-V approaches. Hysteresis characteristics are a widely used method to check the interface quality of a MIS structure.
