| 摘要 |
PURPOSE:To eliminate an influence due to a charge trap by providing the following: a superlattice where two or more semiconductor thin films of two kinds whose electron affinity differs from each other are laminated alternately; a first semiconductor layer whose average electron affinity is larger than that of the superlattice and which is not doped with an impurity; an electron channel which has been formed inside or on the first semiconductor layer; an electrode used to control conductivity. CONSTITUTION:GaAs which is not doped with an impurity is grown as a buffer layer 2 on a semiinsulating GaAs substrate 1 ; in succession, a superlattice 3 composed of ten layers formed by alternately laminating a GaAs thin film 7 not doped with an impurity and an AlxGa1-xAs thin film, an undoped GaAs layer 4 not doped with the impurity as a layer on which a two-dimensional electron gas layer 5 is formed and AlxGa1-xAs doped with Si of a concentration of 2X10<18>cm<-3> as an electron supply layer 6 to supply an electron to the two-dimensional electron gas layer 5 are continuously grown in succession. A gate electrode coming into Schottky contact with the electron supply layer 6 is formed on the electron supply layer 6; a source electrode and a drain electrode which come into contact with the two-dimensional electron gas layer 5 through the electron supply layer 6 are formed on both sides of the gate electrode. |
