| 摘要 |
<p>PURPOSE:To improve the yield and the reliability of an ohmic electrode and to reduce the cost thereof by forming the electrode of germanium, nickel and aluminum to rigidly and easily bonding it via wire. CONSTITUTION:A wafer made of n-type GaAs substrate 1 or the like is heated at 100-450 deg.C in vacuum, and Ge is vacuum evaporated through a mask on the surface of the substrate 1 thus heated to form a Ge layer thereon. Then, Ni is similarly vacuum evaporated on the Ge layer to form an Ni layer thereon, and aluminum is similarly vacuum evaporated on the Ni layer to form an aluminum layer thereon. Thereafter, the wafer formed with the Ge, Ni and Al layers is heated at 450- 550 deg.C in inert or reducing atmosphere or in vacuum. Thus, ohmic electrodes 5 made of a number of Ge, Ni and Al are selectively formed on the substrate 1.</p> |
