Gallium nitride radio frequency device structure with high long-term reliability and preparation method thereof

Abstract

The invention relates to the technical field of semiconductor devices and manufacturing thereof, and discloses a gallium nitride radio frequency device structure with high long-term reliability and a preparation method of the gallium nitride radio frequency device structure. A source electrode and a drain electrode are arranged at two ends of the surface of a barrier layer, a gate electrode is arranged between the source electrode and the drain electrode, grooves are etched in a substrate layer and an III-N composite buffer layer; the metal layer is attached to the bottom of the substrate layer and the inner side wall of the groove, and is also attached to the side wall of the III-N composite buffer layer in the groove and the bottom of the channel layer, the groove is located near the gate electrode and close to one side of the drain electrode, and the channel layer and the barrier layer form a heterojunction. Two-dimensional electron gas 2DEG is formed on one side, close to the channel layer, of a heterojunction interface formed by the channel layer and the barrier layer and serves as a conducting channel of the gallium nitride device, and the metal layer can extract holes accumulated in the III-N composite buffer layer in a grounding mode. Therefore, hole accumulation in the composite buffer layer caused by high drain voltage during off-state operation is suppressed, and long-term stability and reliability of the device are improved.