| 摘要 |
PURPOSE:To suppress the increase of a parasitic capacity by forming a gate resist pattern where the upper part is wider than the lower part, by depositing and lifting off a gate electrode metal and by forming a T-shaped gate in a gate recess through removing unnecessary deposited metal and spacer layer by dry etching. CONSTITUTION:The processing resist pattern 7 of spacer layers 6, 10 is formed and side etching of the spacer layer 10 and etching of GaAs substrate by the use of this resist pattern 7 as mask are conducted to obtain a gate recess 9 of arbitrary shape. Then, the resist pattern 7 is removed and a dummy gate- forming deposited metal 8 is deposited on the whole surface of a wafer. A resist 11 is applied to the whole surface of the wafer for the purpose of burying the gate recess 9 again and forming a gate electrode-forming resist pattern 11. A hole is made in the resist 11 in the gate recess by the use of the deposited metal 8 as mask. The resist in the gate recess is made into a thin film by oxygen ashing, etc., so that the resist remains in the manner of differing in level. Subsequently, the gate electrode metal is deposited and finally the deposited metal 8 and the spacer layers 6, 10 are removed by dry etching so that a T-shaped gate electrode 5 is obtained. |
