| 摘要 |
PURPOSE:To obtain the GaAs MESFET showing excellent working characteristics as far as to the region of high frequency by a method wherein the upper gate made of a low resistance conductive material is formed on the upper layer of electrolessly platable conductive film with which the base gate electrode is constituted. CONSTITUTION:An N-type channel layer 2 is selectively formed on a GaAs substrate 1. Then, a tungsten silicide film 10 and a molybdenum film 11 are formed, and a base gate electrode 3 is formed by selectively performing a patterning process on the two layers of films 10 and 11 using a photoengraving technique and an anisotropic etching method. Low resistance N<+> layers 4 and 4 are formed using said base gate electrode 3 as a mask, and a source electrode 5 and a drain electrode 6, which will be ohmic-contacted, are formed thinner than the tungsten silicide film 10. A plating catalyzer is adhered in the state wherein the upper layer of the base gate electrode 3, to be more precise, the surface including the circumferential face of the molybdenum film 11 is exposed, and the upper gate 13 consisting of nickel and gold is formed by adhesion on the surface part only including the circumferential side face of said molybdenum film 11.
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