Electron emission Si-based resonant-tunneling diode

摘要

A new type of field emission resonant tunneling diode has been proposed and investigated both theoretically and experimentally. The diode is based on an Si-SiO_x-Si multilayer cathode containing an SiO_x layer as the input potential barrier, an Si layer as the quantum well, and a vacuum layer as the output potential barrier of a double barrier quantum structure. The calculation predicted the existence of the resonant maxima (three or four depending on the input barrier height) of the current density-electric field dependencies. Frequency dependencies of the diode microwave impedance pointed to the existence of negative conductance resulting from resonant tunneling through an energy level in the quantum well (QW) at electron transit angle values in the interval from zero up to near 2π/3. Also found is a peak of negative conductance on the frequency dependence with the greatest peak value ~57 S/cm at a frequency of 0.63 THz. The maximum upper frequency of the negative conductance band of more than 2 THz at a transit angle near 0.45π is reached when resonant tunneling occurs through the third resonant level in the QW. Experimental results confirmed the existence of the resonance peak in the investigated resonant-tunneling structure.