| 摘要 |
PURPOSE:To contrive the improvement of the characteristics of a semiconductor device by a method wherein an InGaAs strain layer is used to GsAs and AlGaAs layers to prevent the leakage of a gate and the impurity non-doped AlGaAs layer is inserted between the impurity-doped AlGaAs layer and the impurity non-doped InGaAs layer and is used as a stopper to a mesa ethcing at the time of formation of a quantum wire. CONSTITUTION:An impurity non-doped GaAs layer 2, an impurity non-doped InGaAs layer 3 containing In in a molar ratio of 0.15, an Al0.5Ga0.85As layer 4 and an impurity- doped Al0.3Ga0.7As layer 5 are superposed on a semi-insulative GaAs substrate 1 and a resist mask is applied to perform a mesa etching on the layer 5. At this time, an RIE can be stopped on the surface of the layer 4 by a difference between the molar ratios of Al of the layers 4 and 5. Subsequently, ohmic source and drain electrodes 7 and 8 are attached to superpose a resist 11, a window is opened by the direct lithography of a charged particle beam 10 and a Ti/Al gate metal film 13 is deposited. The mask 11 is removed to form a gate electrode 6 at a right angle to the channel layer 3. By this constitution, the contact of the gate electrode metal film 13 with a quantum well, layer which is an active layer is avoided at the end edges of the mesa, the leakage of the gate is avoided and a semiconductor device having good characteristics is obtained. |
