| 摘要 |
PURPOSE:To contrive a decrease in the source and gate resistances and the ohmic contact resistance by a method wherein the semiconductor layer having its wide electron forbidden band width is provided on a region of the low-impurity concentration semiconductor layer, which includes the gate region, and the gate electrode is provided on the layer. CONSTITUTION:A non-doped GaAs layer 2 is formed on GaAS substrate 1 and a high- impurity concentration n<+> GaAs layer 3 is insularly formed thereon. Moreover, a (AlXGa1-X)As layer 5 is coated on the isolated part 21 of the layer 3 through anon- doped GaAs layer 4. Furthermore, a source electrode 6 and a drain electrode 6 are formed on the layer 3 and a gate electrode 7 is formed on the layer 5. In this construc tion, the electrodes 6 have a good ohmic characteristic as being formed on the layer 3. When the film thickness of the layer 4 is not zero, a two-dimensional electron layer having a high mobility is formed on the GaAs layer 4 in the interface between the layer 4 and the layer 5, the electrons spread in the layer 4 and as the interface is turned into a semiconductor junction of the same kind as the layer 3, the good ohmic electrode can be formed. Moreover, even through the film thickness of the layer 4 is zero, a good contact of the electrode with the layer 3 can be obtained be cause the two-dimensional electron layer is formed on the interface between the layer 2 and the layer 5. |
