Effect of lead on the thermal dispersion of continuous polycrystalline copper films. (August 2017)

• Record Type: Journal Article
• Authors: Petrushenko, S.I.; Dukarov, S.V.; Sukhov, V.N.
• Is Part Of: Vacuum. Volume 142(2017)
• Page Start: 29
• Page End: 36
• Publication Date: 2017-08
• Subjects: Thin film -- Thermal dispersion -- Stimulate disintegration -- Activation energy; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2017.04.037
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: It has been found that the kinetics of heating has an essential effect on copper films dispersion temperature. Annealing of nonequilibrium defects slightly slow down the diffusion processes in comparison with unannealed samples and it naturally increases the temperature of de-wetting of continuous films. It has been shown that the formation of liquid lead in continuous Cu-Pb polycrystalline films accelerates their thermal dispersion compared to the copper films of the same thickness. Minimum concentration of lead that can stimulate de-wetting of polycrystalline copper films of 50 nm thickness, is 3 wt %. Structural studies using electron and X-ray diffraction have shown that Cu and Cu-Pb films annealing and dispersing do not result in new phases and crystalline modifications. Only a slight increase in the solubility of the given system in comparison with bulk samples was found. The activation energy of de-wetting processes in Cu and Cu-Pb films, (which is equal to 1.6 and 0.2 eV respectively) has been determined by means of electron microscopic studies of kinetics of through pores growth. This process may be considered as the liquid phase mass transfer not the diffusive one due to the low activation energy of de-wetting for the films containing lead. Highlights: Thermal stability of Cu and Cu-Pb films has been studied. Influence of heating kinetics and lead content on the decay of the films has been found. Activation energy of diffusion in Cu and Cu-Pb films has been determined. It is found that lead drastically reduces thermal stability.