COMPOUND SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

The method includes the steps of sequentially forming an AlGaAs buffer layer (33), a GaAs active layer (35), an AlGaAs spacer layer (37) and an AlGaAs spacer layer (37) and an N AlGaAs donar layer (39) on a semi-insulating GaAs substrate (31), forming a passivation film (42), i.e., Si3N4 film on the layer (39) to etch the film (42) and layer (39) to implant ions thereinto with rapid thermal annealing to form an ion implantation region (43), forming source and drain electrodes on the region (43) to form a gate electrode (47) on the layer (39), thereby performing a shallow ion implantation process to reduce the crystal defects.