Electronic noise and impedance field of submicron n⁺nn ⁺ InP diode generators

We investigate the electronic noise and impedance field of submicron n ⁺nn⁺ diode generators when loaded by an external resistance in the framework of a Monte Carlo and a hydrodynamic simulative approach. We observe a long-time oscillation of the correlation function of the voltage drop fluctuations between the resistor terminals. The oscillations are in turn responsible for a peak in the noise power-spectrum which is caused by the spontaneous formation of electron accumulation layers. The drift of these layers through the n-region is monitored for biasing conditions above threshold for microwave generation. The frequency of the noise peak is shown to correspond to the highest generation frequency for the given load resistance. The noise power-spectra calculated for three different values of the load resistance are used to obtain the small-signal and noise characteristics of the intrinsic unloaded diode. The parallel hydrodynamic calculation of the diode impedance spectrum is found to compare well with the results obtained from the noise analysis of the Monte Carlo simulation.