| 摘要 |
PURPOSE:To form the semiconductor device constructed in such a manner that the Al thereon is protected and no unnecessary diffusion for GaAs is generated by a method wherein the first layer metal consisting of Al surface of compound semiconductor is formed and then the second layer metal consisting of Ni is formed on the first layer metal. CONSTITUTION:An N type GaAs layer is formed on a semiinsulating GaAs substrate 64, and an SiO2 film 62 is grown using a CVD method. Then, a PR mask 61 is provided for the purpose of forming a window at the part where a gate will be formed, and the window is provided by performing an etching on the SiO2 film. Then, an Al layer of 65-7,000Angstrom and an Ni layer of 66-3,000Angstrom are vapor-deposited successively, and a lift- off is performed using the PR mask. Then, a CVD SiO2 67 is grown for the purpose of protecing the gate section. Subsequently, a window is provided at the ohmic part which will be turned to a source and drain electrode, and an ohmic electrode is formed. According to this GaAsMESFET, the corrosion generating on an Al gate due to the application of a high temperature current and the generation of wire disconnection due to electromigration can be prevented by an Ni layer and, in addition, the diffusion of Ni into GaAs can also be prevented even when a high temperature storage test is performed, thereby enabling to remove the cause of increase in a gate leak current and the deterioration of withstand voltage thereof. |
