| 摘要 |
PURPOSE:To reduce a large parasitic capacitance and obtain a field-effect transistor with excellent radio frequency characteristics by a method wherein a gate electrode is formed on a semiconductor channel layer or on an insulating film formed on the channel and a wiring floated spatially above the upper surface of the gate electrode is formed and an external lead wiring is composed of the floated wiring. CONSTITUTION:A thick photoresist pattern 11 in which an aperture is made at a gate pad part is formed and baked at a high temperature to be fluidized and its surface is made to be flat. Then the photoresist 11 is etched by dry etching with 02 and the top surface of a gate is exposed and, further, metal 12, which is used as a gate lead wiring, a foundation layer of the pad and also as a wiring forplating, for instance TiPt, is evaporated. Then, a photoresist pattern 13 which has apertures at the gate lead part and at the pad for plating is formed and an Au plating layer 14 is formed. Finally, the photoresist 13 for plating is removed and the foundation metal layer 12 is etched with the Au plating layer 14 as a mask and, further, the lower photoresist layer 11 is removed to complete the device.
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