| 摘要 |
PURPOSE: A method for fabricating a gate electrode is to improve frequency characteristics of a gate by decreasing a capacitance generated by an overhang of the gate electrode. CONSTITUTION: An InAlAs layer and an SiN layer are formed on an InGaAs crystallization layer(200) for MOSFET/HEMT(High Electron Mobility Transistor) in this order. An SiN pattern layer(222) is formed on a gate electrode forming region by selectively etching only the SiN layer, using a photoresist pattern. An InAlAs pattern layer(212) having an opening part is formed on a gate electrode forming region by a wet etching process using an HCl solution as an etchant, and using the SiN pattern layer as an etching mask. Thereby, the undercut is generated at the InAlAs pattern layer. Then, a gate electrode(230) is completed by filling the opening parts of the SiN pattern layer and the InAlAs pattern layer with metal.
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