Scattering parameter measurements of resonant tunneling diodes up to 40 GHz

The scattering parameters (S parameters) of double barrier quantum well resonant tunneling diodes have been measured at various biases with on-wafer probing techniques. Impedances up to 40 GHz for AlGaAs/GaAs diodes with asymmetric spacer layers were obtained. It was found that the impedances could be accurately described by the lumped equivalent circuit representation. With the conductance-voltage characteristic derived from high frequency S parameter measurement, the portions of current-voltage curve that were distorted by oscillation in the dc measurement are recovered. Peaks corresponding to the process of electrons discharging from the quantum well are found in the capacitance-voltage (C-V) characteristic