Bihun R. Electronic phenomena of charge transport in two-component nanoscale metal film systems.

In the thesis for the first time, the integral and generalized results on the establishment of phenomenon in the formation of the structure, electrical and optical properties of simple (Au, Ag, Cu) and transition metals (Ni, Pd, Cr) films formed on the surface of surface-active substances (Ge, Si, Sb) in an ultrahigh vacuum (the pressure of the residual gases is not higher than 10-7 Pa) after the percolation range of thickness (d > dc), with predetermined properties we obtained. Thanks to the developed method of "quench deposition" (Tsub < 0,1 Tm, where Tm is the melting temperature of the metal) and surface-active underlayers (Ge, Si, Sb), the instrument for controlled growth of polycrystalline metal films with the desired structure (the value of the average linear dimensions of crystallites D, the isotropic properties of metal with known parameters of macroscopic surface inhomogeneities), electrical and optical properties were developed. The first consistent theory of the electron transport in thin metal films was suggested by K. Fuchs who offered the model of a uniform and homogeneous parallel plane layer. The theory was developed for free electron Sommerfeld metal films. There are two sources of electron scattering in thin films: the background (volume) scattering available in bulk materials, and surface scattering the relative contribution of which depends on the thin film thickness d. An expression for thin film conductivity is derived by considering the statistical distribution of all the electrons and by solving the Boltzmann transport equation with the appropriate boundary conditions. J.T. Fuchs originally assumed that the electrons were diffusely scattered on the surface and lost their momentum in the direction of the applied electrical field (i.e. all the electrons were unspecularly reflected), and then he modified his theory by assuming that the p fraction of the electrons was reflected specularly from the surface and the (1-p) fraction of the electrons was scattered from the surfaces nonspecularly. J.J. Sondheimer extended this theory to galvanomagnetic effects. The classical theory assumes film to be a plane parallel layer. The real film is not a plane parallel slab. There are macroscopic thickness nonuniformities in a real film. Some of the mentioned deficiencies of the F-S theory were improved in further investigations. Namba suggested to include the effect of the geometrical nonuniform cross-section of the film due to the macroscopic surface roughness into the expression for the thin film resistivity. The surface roughness profile was presented as a one-dimensional function in the current flow direction. It presupposed that the deviation of the local film thickness from the average thickness could be expressed by a sine-shaped function. But the Namba model does not take into account the structure of thin films including the existence of grain-boundaries.