Influence of deposition method and dielectric layer on structure and electrical properties of Mn discontinuous films

Abstract

Two groups of Mn films with different mass thicknesses were obtained on quartz-glass substrates under vacuum conditions (p=10−4 Pa). The films of the first group were thermally evaporated, and the films of the second were obtained by electron gun evaporation. After deposition, the temperature dependencies of the resistance were measured in vacuo in situ for both groups, and the activation energies of the resistance were determined. The results of structural examinations (electron diffraction patterns and microstructures) are also presented. The electrical properties, structure, and content of the thermally evaporated Mn films are distinctly different from those of the films obtained using electron gun evaporation. The films of the second group reach higher resistance and activation energies of resistance values. Indexed electron diffraction patterns show a higher content of MnO in the films of this group. It has been found that the resistance increases with time and that the grains consist of α-Mn, β-Mn, and MnO. The appearance of MnO content with high resistivity (ρ∼1017–1019 Ω m) causes a significant increase in resistance. In order to protect from oxidation, after deposition the Mn films were covered with dielectric MgF2 layers.