Numerical modeling of fluctuation phenomena in semiconductor devices

A method enabling numerical modeling of fluctuation phenomena in semiconductor devices is presented. The method is based on the assumption that fluctuations of generation-recombination processes and carrier mobility result in the fluctuations of carrier and ionized impurity concentrations. These, in turn, may be expressed by the fluctuations of the electrical potential and quasi-Fermi levels. Fluctuations of the electrical potential and quasi-Fermi-levels were calculated by solving the set of "transport equations for fluctuations" in which the fluctuations of generation-recombination processes (both thermal and optical) and fluctuations of mobility play roles of random source terms. The method enables the calculation of fluctuations of all physical quantities enclosed in a set of transport equations. The spatial distribution of the fluctuations of the electrical potential, electron concentration, and noise current density is shown. The noise spectrum in selected, cooled, long-wavelength HgCdTe photoresistors is calculated and the contribution of different noise sources is determined. Theoretical results are compared with experimental data. (C) 2001 American Institute of Physics.