SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

PURPOSE:To provide a method for manufacturing a GaAsMESFET in which number of steps is deleted. CONSTITUTION:The method for manufacturing a semiconductor device comprises the steps of forming an n-type active layer 2 on a semi-insulating GaAs substrate 1, forming a high melting point metal thin film WSi on an entire surface, and then processing the high melting point metal on the layer 2 to form a high melting point metal gate electrode 3. The method further comprises the steps of forming source and drain high concentration n-type regions 4 for forming source and drain electrodes at both sides of the electrode 3, and annealing it. The method further comprises the steps of then forming an insulating film 5 for protecting a surface of a silicon nitride film on the entire surface, and sequentially forming ohmic metals 6 AuGe, Ni, Au on the region 4 and the electrode 3. The method further comprises the step of forming source and drain ohmic electrodes 7 and a gate metal 8 of alloy, thereby completing a GaAsMESFET.