| 摘要 |
PURPOSE:To obtain the FET having small ON-resistance by a method wherein a part of a gate electrode provided on a highly pure GaAs layer on an N type GaAlAs layer is stacked on the N<+> type GaAs layers on both the sides. CONSTITUTION:A non doped GaAlAs layer 12 is formed on a semiinsulating GaAs substrate 11, and the N type GaAlAs layer 13 and the highly pure N<-> type GaAs layer 14 are stacked. Ions are implanted in the layer 14 to form the low resistance N<+> type GaAs layers 15, a source electrode 16 and a drain electrode 17 are formed on the layers 15, and the Schottky gate electrode 18 is formed being adhered between them on the part 19 of the layer 14 not converted into low resistance stacking a part of the electrode metal on both the sides on the N<+> type layers 15. When a positive bias voltage is applied to the gate electrode 18, a two-dimentional electron gas layer 20 is generated in the hetero junction interface of the part 19 of the layer 14 and the N type layer 13, the low resistance layers 15 are connected directly thereto, and accordingly the FET having small ON-resistance can be obtained. When thickness of the layer 14, thickness of the layer 13 and the doping quantity are selected properly, and the two layers thereof are depleted according to the surface level of the layer 14, element isolation is also unnecesary. |
