Current noise in thin discontinuous films

Measurements have been made of the current noise in thin discontinuous platinum films deposited on glass substrates with surface sensitivities in the range 1.5 to 5.0*10 3 k Omega sq -1 . The influence of film temperature and gaseous ambients on the variation of the spectral noise power density current flowing through the film, noise-channel frequency and surface resistance is described. The experimental data are interpreted in terms of a noise model based on quantum mechanical tunnelling through a surface layer containing adsorbed gaseous ions. The relationship between activation energies determined from conductance temperature and noise against temperature plots is investigated and it is shown that for activation energies epsilon >or=kT the noise mechanism is thermally activated.