Abstract: A preparation method of a double-T-shaped gate based on double-layer passivation accurate etching includes: sequentially growing two passivation layers on an epitaxial structure, where the two passivation layers include a bottom passivation layer and a top passivation layer; performing a first exposure on the top passivation layer and etching the top passivation layer and the bottom passivation layer in a first exposure region from top to bottom to form a gate root region; performing a second exposure on the top passivation layer and etching the top passivation layer in a second exposure region to form a lower gate cap region; and performing a third exposure on the top passivation layer to form a top gate cap exposure region and performing metal evaporation and removing a photoresist to form a double-T-shaped gate structure in the two passivation layers.

Abstract: The present invention provides a GaN/two-dimensional AlN heterojunction rectifier on a silicon substrate and a preparation method therefor and belongs to the field of rectifiers. The rectifier comprises a silicon substrate, a GaN buffer layer, a carbon-doped semi-insulating GaN layer, a two-dimensional AlN layer, a non-doped GaN layer, a non-doped InGaN layer and a SiNx passivation layer that are stacked in sequence. The rectifier further comprises a mesa isolation groove and a Schottky contact electrode that are arranged at one side. The mesa isolation groove is in contact with the non-doped GaN layer, the non-doped InGaN layer, the SiNx passivation layer and the Schottky contact electrode. The Schottky contact electrode is in contact with the mesa isolation groove and the non-doped GaN layer. The thickness of the two-dimensional AlN layer is only several atomic layers, thus the received stress and polarization intensity are greater than those of the AlGaN layer.