| 摘要 |
PURPOSE:To make a valley current small to increase the ratio of it to a peak current of a diode so as to improve a semiconductor element of this design in performance by a method wherein layers other than a quantum well layer constituting a tunnel diode are formed of a semiconductor layer whose valence band width is large. CONSTITUTION:The following are provided onto an N-type InAs substrate 6 to constitute a diode: an N-type InAs layer 7; an undoped GaAs layer 1 of 7nm thickness, an undoped AlNb layer 2 of 3nm thickness; an undoped InAs layers 3 of 7nm thickness; an undoped AlNb layer 4 of 3nm thickness; and an undoped GaAs layer 5 of 50nm thickness. And an n-type InAs layer 8 is epitaxially grown thereon, an electrode 10 of AuGeNi alloy is fitted to the layer 8, and an electrode 9 like the electrode 10 is fitted to the rear side of the substrate 6. The diode is composed as mentioned above, and when a voltage is applied to the electrode 9 as an anode and the electrode 8 as a cathode, a quantum level in each InAs layer is located lower than the valence band of the layers 5 and 3, so that a tunnel current penetrates the layers 5 and 4 and flows to the layer 1 penetrating the layer 2 via the quantum level of the layer 3. If the voltage is made to increase furthermore, electrons are blocked by the layer 1 and consequently a current does not flow. |
