| 摘要 |
PURPOSE:To obtain an excellent Schottky barrier, by inserting first-third etching stopping layers between desired semiconductor layers, and appropriately utilizing the etching stopping layers when the semiconductor layers are etched. CONSTITUTION:From on top of a semi-insulating GaAs substrate 1, the following layers are sequentially grown: a non-doped GaAs layer 2; an N-type AlGaAs layer 3A; an N-type GaAs layer 3B; an N-type AlGaAs layer 3C; an N-type GaAs layer 4; an N-type AlGaAs layer 5; an N-type GaAs layer 6; an N-type AlGaAs layer 7; and an N-type GaAs layer 8. Then the layers 7 and 8 at regions where an enhancement type transistor part is to be formed are partially removed. The layers 3C and 4 are etched to form a recess for forming a gate electrode reaching the layer 3B. In a depletion type transistor part, the layers 5 and 6 are etched to form recesses for forming a gate electrode reaching the layer 4 at the same time. Thus the gate electrode 15 and 16 are simultaneously formed. |
