Monte Carlo method for the simulation of electronic noise in semiconductors

We present a general theory to investigate the electronic noise in the presence of scattering as well as of generation-recombination processes. An exact decomposition procedure of the current spectral density is given that, in addition to fluctuations in carrier velocity and number, shows the presence of a cross term coupling both fluctuations. Four correlation functions are thus found to be needed to evaluate all terms. To this purpose, the Monte Carlo method is shown to provide a unifying microscopic calculation of these functions. We consider the case of p-type Si at 77 K with a generation- recombination mechanism given by the capture at shallow impurities assisted by acoustic phonons. Then, the theoretical results are compared with existing mesoscopic theories as well as with available experimental results.