Current noise in finite-sized specimens

The spatial correlation of generation-recombination noise in intrinsic germanium is investigated. In an analytical model the specimen is assumed to consist of mutually uncorrelated elements of resistance fluctuation. By comparison with measured values the size of the mutually uncorrelated elements is found to be approximately equal to four times the diffusion length of excess carriers in the semiconductor. A plausible explanation of the above results is indicated. Potential fluctuations at various terminals are calculated utilizing the analytical model and are found to agree with experimentally measured values. It is shown that the potential fluctuations at any pair of terminals is due to both the resistance fluctuations of individual elements and the associated current redistribution in the specimen. The latter gives rise to negative coefficients of spatial correlation which were experimentally verified.