| 摘要 |
PURPOSE:To provide IC device having high switching speed and high voltage gain by forming the same conductive type high resistance layer and electric conductive layer as channels on a substrate and forming FET of enhancement and depression types. CONSTITUTION:N-type GaAs high resistance layer 2, n-type GaAs electrical conductive layer 3 are stacked on a semi insulative GaAs substrate 1 and the layer 3 is photoetched into mesa form and Au.Ge source, drain electrodes S, D are selectively formed and heat treated to metalize with the layer 3. Window 3E is provided on the layer 3 of gate part and coated with CVDSiO24 and window 3E is again opened and another window 3D is provided on other gate part. Gate film oxide 5E, 5D are formed by plasma oxidation method and the like through the windows 3E, 3D and Al electrodes 6E, 6D are attached. Thus, enhancement type FET as making the layer 2 channel and depression type FET as making the layer 3 channel are formed on a same substrate and a device of E/D system having high ability can be obtained. |
