AlGaN/GaN HEMT transistor and making method thereof

The invention provides an AlGaN/GaN HEMT transistor and a making method thereof. A source electrode and a drain electrode of the device are directly connected with a SiC substrate adopted by the device through a high-thermal conductivity material. Heat generated by a gate electrode of the device is radiated to the SiC substrate through the high-thermal conductivity material connected with the source electrode and the drain electrode. The AlGaN/GaN HEMT device also comprises a high-thermal conductivity material to connect the gate electrode of the device and the SiC substrate, the heat generated by the gate electrode of the device is radiated to the SiC substrate through the high-thermal conductivity material connected with the gate electrode, and the heat radiation ability of the device is further enhanced.