1/f noise and nonlinear effects in thin metal films

Work on 1/f noise and nonlinear effects in thin metal films is reviewed. The experimental dependences of the noise level and the I-V cubic nonlinearity coefficient of films on their thickness, temperature, and internal mechanical stresses are presented. The data on the effect of film microstructure on the 1/f- noise level are also given. The 1/f-noise spectral density and the I-V nonlinearity coefficient both show an activation temperature dependence and an exponential internal-mechanical-stress dependence, for metal films with elevated mobile-defect concentrations. A physical model of the 1/f noise and I-V nonlinearity is analyzed which involves the creation and annihilation of quasi-equilibrium vacancies in the bulk of the metal film and enables the observed relationship between the experimental data and the 1/f noise and the I-V nonlinearity to be explained.