Diamond-based gallium nitride transistor preparation method and diamond-based gallium nitride transistor

The invention is suitable for the technical field of semiconductor devices, and provides a diamond-based gallium nitride transistor preparation method and a diamond-based gallium nitride transistor, and the method comprises the steps: preparing an electrode field plate region on the upper surface of a silicon-based gallium nitride wafer; sputtering a first metal layer on the upper surface of the silicon-based gallium nitride wafer and the upper surface of the silicon wafer, and performing pre-bonding; carrying out temporary bonding on the carrier and the silicon wafer; removing a silicon substrate of the silicon-based gallium nitride wafer to obtain a gallium nitride epitaxial layer supported by the silicon wafer, and sputtering a second metal layer or depositing a dielectric layer on the lower surface of the gallium nitride epitaxial layer and the upper surface of the diamond for bonding; removing the carrier, the silicon wafer and the first metal layer to obtain a diamond-based gallium nitride wafer; and pe