| 摘要 |
PURPOSE:To control several threshold voltages independently with high accuracy by forming MESFETs of three kinds to semiconductor layers of two kinds on the same semiconductor substrate. CONSTITUTION:An N type GaAs layer 42 is formed on the surface of a GaAs substrate 41, and an N type AlxGa1-xAs layer 43 is further shaped. One part of the layer 43 is removed, and a source 44 and a drain 45 for an enhancement type MESFET are formed by a gold germanium alloy. A source 46 and a drain 47 for a depletion type MESFET are shaped simultaneously by an alloy. A gate 48 for the enhancement type MESFET is formed on the layer 42, and a gate 49 for the depletion type MESFET is shaped on the layer 43. Accordingly, threshold voltage can be controlled with high accuracy. |
