| 摘要 |
PURPOSE:To further enlarge the maximum current, to improve a gate in its voltage-withstanding capability, and to reduce leak currents by a method wherein an undoped AlGaAs epitaxial crystal layer is provided on the surface of an electron channel layer belonging in a compound semiconductor layer containing In. CONSTITUTION:On a semi-insulating InP substrate 11, undoped InP layer 12 to serve as a channel, undoped AlGaAs layer 12, n<+>-InP source.drain regions 14 and 15, gate electrode 16, source electrode 17, and drain electrode 18 are formed. When the composition ratio of Al is set at 0.3 in an AlGaAs layer, the AlGaAs layer will be a high barrier of approximately 0.7eV against the Inp surface channel electrons. The AlGaAs layer will also be a high barrier of approximately 1eV against the gate electrode. The resistance in an undoped AlGaAs layer is so high as to be equivalent to that in a MIS structure. |
