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 fra mework of a Monte Carlo and a hydrodynamic simulative approach. We obs erve a long-time oscillation of the correlation function of the voltag e drop fluctuations between the resistor terminals. The oscillations a re 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 biasin g conditions above threshold for microwave generation. The frequency o f the noise peak is shown to correspond to the highest generation freq uency for the given load resistance. The noise power-spectra calculate d 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 sp ectrum is found to compare well with the results obtained from the noi se analysis of the Monte Carlo simulation.