The invention discloses a method for manufacturing a high-power
nitride semiconductor microwave transistor on a
gallium nitride substrate. The method mainly solves the problems that an existing device has a parasitic electric leakage channel at a homoepitaxial interface and is low in
breakdown voltage. According to the scheme, the method comprises the following steps: firstly, selecting a p-type
gallium nitride single-
crystal substrate, carrying out surface pretreatment on the p-type
gallium nitride single-
crystal substrate to obtain a p-type
gallium nitride single-
crystal substrate containing a p-type AlN electric leakage
isolation layer, and then sequentially growing a GaN channel layer, an AlN
insertion layer and a
barrier layer on the pretreated substrate; and finally, preparing an insulated
gate dielectric layer and a gate
electrode on the
barrier layer, and manufacturing a source
electrode and a drain
electrode on two sides to complete device manufacturing. Through in-situ compensation of donor impurities based on the p-type AlN electric leakage
isolation layer and
ion implantation, complete isolation of a parasitic electric leakage channel at a homoepitaxial interface and a 2DEG
conductive channel at a homoepitaxial GaN
heterojunction interface is realized, transverse electric leakage of the device is effectively inhibited, and the
voltage endurance capability and the output power of the device are improved.