INFLUENCE OF SPATIAL CORRELATIONS ON THE ANALYSIS OF DIFFUSION NOISE SUBMICRON SEMICONDUCTOR STRUCTURES

We present a microscopic analysis of the influence of the spatial corr elations between local diffusion noise sources on the noise calculatio n in a submicron GaAs n(+) nn(+) diode under different applied voltage s. The simulation is carried out using an ensemble Monte Carlo simulat ion. We demonstrate that in the case of submicron nonhomogeneous struc tures the use of the diffusion coefficient to characterize the local n oise sources is not correct, specially under far-from-equilibrium cond itions. The nonuniformity of the electric field and the nonstationary behavior of the electrons lead to significant changes in the spatial c orrelations with respect to the case of an homogeneous semiconductor. Therefore, the diffusion noise at the terminals must be calculated in terms of the correlations between the local noise sources. (C) 1995 Am erican Institute of Physics.