| 摘要 |
PURPOSE:To prevent change of threshold voltage in the process after the adjustment of the threshold voltage, by removing unreacted metals after the adjustment of threshold voltage by etching. CONSTITUTION:An active layer 12 is formed on a semi-insulative GaAs crystal 11. Then a source electrode 13 and a drain electrode 14 are formed. At least one of Pt, Ti and Pd is deposited as a gate electrode and threshold voltage is adjusted by forming a compound between the electrode metal and the layer 12 by heat treatment. The heat treatment is stopped when the desired threshold voltage is obtained. Unreacted gate metal is removed by etching. This prevents change of the threshold voltage in heat treatment process after the adjustment of the threshold voltage. |
