| 摘要 |
PURPOSE:To reduce contact resistance and improve flatness of electrodes, by performing vacuum evaporation on an n<+> GaAs layer from an ionized Ge- vaporizing source and a P or the like-vaporizing one, to form a metallic layer on it. CONSTITUTION:An epitaxial wafer making an n<+> GaAs layer 12 and n<+> GaAs layer 13 to grow on a semi-insulating GaAs substrate 11 is covered with an insulating film 14. Then, a Ge film is put on the wafer in a vacuum atmosphere by the use of a clustered ion-ray source. As is then concurrently evaporated as a donor impurity from another crucible. P or Sb can be used as the donor impurity. Then, an unnecessary part of the n<+> Ge layer is removed to put the second-layered metallic layer 16. Finally, a gate-electrode covered part of the insulating film 14 is opened and then the n<+> GaAs layer 13 is removed by etch ing. Thus, contact specific resistance of ohmic electrodes can be reduced, with flatness of the electrodes improved without using alloy reaction.
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