MONTE-CARLO SIMULATION OF HOT-CARRIER NOISE IN SHORT N(+)NN(+) DIODES

The Monte Carlo method is applied to calculate the current and voltage noise in near micron n(+)nn(+) InP diodes. Quite different behavior o f the correlation functions and spectral densities of fluctuating macr oscopic quantities is observed under the voltage and current driven op erations. Under the constant voltage operation the time dependence of the current fluctuation correlation function exhibits damped oscillati ons at the transit-time and plasma frequencies. This results in appear ance of two spikes in the current noise spectrum at corresponding freq uencies. The transit-time oscillations and the corresponding noise are shown to be caused by the spontaneous formation of electron accumulat ion layers due to the negative differential resistance connected with the combined action of the velocity overshoot and Gunn-effects. In the contrast, the voltage noise spectrum is found to have a regular Loren tzian shape under the constant current operation. The observed feature s of the current and voltage noise spectra are shown to be in a good a greement with the frequency dependence of the small-signal admittance and impedance of the diode.