| 摘要 |
PURPOSE:To prevent both the lowering of the contact resistance and the scatter in resistance values in an AuGe-Ta-Au three-layered electrode formed on a GaAs semiconductor substrate, by setting the Ge quantity in the AuGe layer so as to be 2-7%. CONSTITUTION:The electrode of a GaAs semiconductor device such as a Hall sensor is formed on a GaAs substrate 4 on which a GaAs epitaxial layer 4a has been formed. After an AuGe alloy layer 7, a Ta layer 8 and an Au layer 9 have been deposited by evaporation through a patterned SiO2 film 5, unnecessary parts are removed to obtain a substrate device as shown in the figure. Setting the Ge concentration in the AuGe layer 7 so as to be 2-7% permits the contact resistance of the three-layered electrode to be small. In addition, an appropriate thickness of the Ta layer 8 is the order of 0.1-0.3mum. |
