Enhanced GaN HEMTs with low gate leakage current and preparation method thereof

The invention discloses an enhanced GaN HEMTs with low gate leakage current and a preparation method thereof, the GaN HEMTs comprise a substrate, a buffer layer, a channel layer, a barrier layer, a source contact electrode, a drain contact electrode, a p-GaN-based self-aligned T-type gate control structure and a passivation layer, and the p-GaN-based self-aligned T-type gate control structure comprises a P-GaN cap layer, a gate passivation layer and gate metal; the buffer layer, the channel layer, the barrier layer and the P-GaN cap layer are sequentially arranged on the substrate from bottom to top, the source contact electrode and the drain contact electrode are both arranged on a part of the upper surface of the barrier layer and located on the two sides of the p-GaN-based self-aligned T-type grid control structure respectively, and the grid metal is arranged on a part of the upper surface of the P-GaN cap layer and located on the two sides of the p-GaN-based self-aligned T-type grid control structure resp