Observation of the multiple negative-differential-resistance of metal-insulator-semiconductor-like structure with step-compositioned In/sub x/Ga/sub 1-x/As quantum wells

An interesting multiple negative-differential-resistance (MNDR) device, based on an AlGaAs-InGaAs-GaAs metal-insulator-semiconductor (MIS)-like structure, has been fabricated and demonstrated. Three and six switching phenomena have been observed at room temperature and -105/spl deg/C, respectively. The impressive MNDR behaviors are believed to be caused by the sequential accumulation process of carriers at In/sub x/Ga/sub 1-x/As subwells and the successive barrier lowering and potential redistribution effects. These effects yield the step by step enhancement of tunneling through the "insulated" AlGaAs barrier. It is known that, from experimental results, the temperature variation plays an important role on carriers transport and experimental current-voltage (I-V) characteristics.