| 摘要 |
PURPOSE:To remove the fear of gate leak by so setting the Al mol ratio within the Al GaAs layer, to which impurities are added that it decreases stepwise from the surface side to the substrate side. CONSTITUTION:AlGaAs layer 2, to which impurities are added, is grown in proper thickness on a semiinsulating GaAs substrate 1, and successively an AlxGa1-xAs layer, to which impurities are added, is grown, but the mol ratio in this place is set such that it increases stepwise from the substrate side to the surface side. That is, the AlGaAs layer 3, to which impurities are added, is grown in succession as an n<+>-Al0.1Ga0.9As layer 3A, an n<+>-Al0.2Ga0.8As layer 3B, and an n<+->Al0.3Ga0.7As 3C. Hereby, since the gate electrode always exists in the AlGaAs layer 3, the problem of gate leak, which occurs by contact of a gate electrode 5 metal with a secondary electron gas layer (2DEG), being the channel, at the mesa etching part, can be avoided. |
