| 摘要 |
PURPOSE:To increase mutual conductance of a HEMT and decrease control electrode capacitance, by laminating an n-type Ge layer, a non-doped GaAs layer, and an electron supply layer on a semi-insulation GaAs substrate and then by causing the n-type Ge layer to function as backgate, thereby mounting electrodes which perform ohmic-contact with the n-type Ge layer. CONSTITUTION:An n-type Ge layer 3, a non-doped GaAs layer 4, and an electron supply layer 5 are laminated on a semi-insulation GaAs substrate 1 one after another and this device allows GaAs layer 4 to generate a two-dimensional electron gas 4e. The installation of input/output electrodes 7 and 7 that perform the ohmic-contact with the two-dimensional electron gas 4e and the first control electrode 8 that performs Schottky contact with the electron supply layer 5 and also the electrodes 9 and 9 that perform the ohmic contact with the Ge layer 3 permits the Ge layer 3 to function as second control electrode for the two-dimensional gaselectron 4e. Thus high electron mobility as well as mutual conductance are contrived by impressing a positive constant voltage to the Ge layer and mobility of the two-dimensional electron gas is also modulated by impressing control signals and then electrode capacitance is lowered by increasing mutual conductance and other advantages are anticipated. |
