Size Kinetic Effects in Polycrystalline Films

The theoretical and experimental studies of electrophysical properties (conductivity and temperature coefficient of resistance) of metal films with a polycrystalline structure are performed in this paper. It is shown, that the numerical values of these kinetic coefficients in thin conductors are essentially different from the corresponding transport coefficients in thick samples. The reason of this difference lies in the simultaneous realization in thin polycrystalline films both of the internal size effects (relaxation of charge carries at the grain boundaries) and the external size effects (electron scattering at the outer boundaries of the sample). As a result, the kinetic coefficients essentially depend on the internal structure, thickness, and degrees of surface roughness of the conductor. The size effects considered in the review are used to analyze the transport effects in polycrystalline films, and the given asymptotic expressions are used to calculate the electron transport parameters in Al and Ni monoblock films. Shown, that agreement between the experimental and theoretical values of conductivity and temperature coefficient of resistance in each specific case is achieved by using the grain-boundary scattering coefficient as the adjusted parameter. The value of this coefficient is: 0,37÷0,46 (Ni films) and 0,09÷0,3 (Al films) while calculating the conductivity, and 0,37÷0,40 (Ni films) and 0,15÷0,36 (Al films) while calculating the temperature coefficient of resistance.