The invention discloses a stack gate enhanced GaN high-
electron-mobility
transistor containing a ferroelectric
gate dielectric, which mainly solves a problem of poor reliability of the existing similar devices. The stack gate enhanced GaN high-
electron-mobility
transistor comprises a substrate, an AlN
nucleation layer, a GaN buffer layer, an AlN
insertion layer, an AlGaN
barrier layer, a GaN cap layer, an SiN
passivation layer, a
gate dielectric layer and an SiN
protection layer from the bottom up, wherein the SiN
passivation layer is provided with a concave structure, the inner wall of the concave structure and the surface of the SiN
passivation layer are provided with the
gate dielectric layer, the gate
dielectric layer comprises an AlN or Al2O3
dielectric insertion layer and an HfZrO ferroelectric layer, two ends of the GaN buffer layer are provided with a source
electrode and a drain
electrode respectively, the middle of the gate
dielectric layer is provided with a gate
electrode, the source electrode and the drain electrode are provided with a
metal interconnection layer, and the gate electrode and the gate
dielectric layer at the surface of the passivation layer are covered with the SiN
protection layer. According to the invention, the reliability of the device is improved, gate leakage of the enhanced device is reduced, and the
transistor can be used as a switching device requiring high
threshold voltage.