Window for better reliability of nitride heterostructure field effect transistors

Phase-noise technique was applied to monitor channel degradation of nitride heterostructure field effect transistors (HFETs) subjected to a fixed drain voltage stress at different fixed gate voltages. The slowest degradation and the lowest noise were found for the electron-density window centered at ∼1 × 1013 cm−2 where ultrafast decay of hot phonons took place. A possibility to shift the window towards higher sheet densities was demonstrated experimentally and accounted by plasmon-assisted dissipation of Joule heat.