Stages of Cr, Zn, Cu, Si, Ag, and Al Nucleation under Quasi-equilibrium Condensates of Ion-sputtered Atoms

The paper represents the research on the nucleation processes during Cr, Zn, Cu, Si, Ag, and Al condensation at deposition of ultra-weak flows of magnetron sputtered substance under quasi-equilibrium conditions in deeply purified Ar. Such a broad spectrum of metals and Si has been chosen with the aim to establish the most general features of the nucleation process of quasi-equilibrium condensates. As a substrate material, fresh (001) KCl cleavages and glass were used. The structural and morphological characteristics of the obtained condensates have been studied using scanning and transmission electron microscopy. The phase composition of the condensates was studied using electron microdiffraction. The ultra-low vapor flows of ion-sputtered substance have been formed using a vacuum setup equipped with three direct current magnetron sputters. In order to form ultra-low vapor flows, increased pressures of the working gas (6-8 Pa) and a large distance from the target to the substrate (80-100 mm) were used. The results of TEM and SEM investigations have shown that plasma action onto the (001) KCl surface determines the formation of a continuous amorphous film at the first stage of nucleation. As the film thickness increases, the nucleation of the crystalline phase occurs. An essential feature of the nucleation processes is the formation of the basic amorphous layer discovered in this work. An increase in the thickness of the amorphous base film reduces the effect of (001) KCl surface modification by plasma and local transitions to crystalline phases occur. It has been shown that a more prolonged condensation process leads to the formation of either a system of individual faceted crystals or porous nanosystems depending on the structural and morphological characteristics of the base layer.