Monte Carlo calculation of electronic noise in semiconductors

We present a general theory to investigate the electronic noise in the presence of scattering as well of generation recombination processes under the application of an electric field of arbitrary strength. An exact decomposition procedure of the current spectral density is given which, 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 and thus of each term contributing to the total spectral density. In this way, scatterings in the conducting band as well as capture to and release from the traps are treated for the first time on the same kinetic level of description. In particular, the Poole-Frenkel effect is included when necessary. As an application, we consider the case of p-Si at77 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.