1/f^γ noise in thick-film resistors as an effect of tunnel and thermally activated emissions, from measures versus frequency and temperature

Measurements of the frequency and temperature dependence of the noise spectrum and of its frequency exponent have been performed on thick-film resistors and, together with the direct plots versus the frequency logarithm of the spectrum-frequency product, they are used to check the island model of the flicker noise. It is shown that the wide dispersion of the island relaxation times, necessary to originate the flicker noise, is due to tunnel emission and/or thermal activation processes of electrons from localized states, and to the exponential dependence of their emission probability on random variable distances and activation energies, whose distribution functions, means, and variances are determined both theoretically and experimentally.