| 摘要 |
PURPOSE:To obtain a GaAs FET with a recessed gate accurately with a good yield rate, by forming a gate electrode in the dug part of a semiconductor active layer. CONSTITUTION:A recessed part is formed and a gate electrode is deposited. The part is coated by a photoresist film. Then, by utilizing the difference in thickness of a photoresist film 7 at the opening part and a part other than the opening part, O2 plasma treatment is performed on the entire surface. The photoresist film at the part other than the opening part is incinerated and separated, and a recessed gate structure is obtained. Thus the overhang part of the photoresista can be eliminated. the remaining part of a gate electrode metal 6, a second thin layer 4 or a first thin layer 3 due to ethcing can be entirely eliminated. |
