In this study, the effects of specific power (1–100 W/cm²), operating pressure (0.5–3.0 Pa), and voltage frequency (20–500 kHz) on film growth kinetics, morphology, and silicon entrainment were investigated to optimize magnetron sputtering for producing thin silicon films suitable for lithium-ion battery anodes. Silicon films were deposited on copper substrates using the Caroline D12C system. The film thickness and morphology were determined using scanning electron microscopy and atomic force microscopy. It was found that the porosity of the films increases with increasing pressure in the working chamber. It was found that the film morphology is non-uniform up to a thickness of 100–150 nm. After that, the film thickness becomes uniform over the entire substrate surface, and the deposition rate increases sharply, i.e., an induction period is observed. The induction period duration decreases with increasing voltage power and frequency. At the same time, silicon removal increases. Frequency has a greater effect on both parameters. The paper specifies a strategy for the technical and economic optimization of the magnetron sputtering process, which determines a compromise between the positive effect of increasing productivity and the negative effect of silicon removal.

The article examines the features of the microstructure of a new type of silicon film, based on a previously unstudied form of nanosilicon, obtained by magnetron sputtering. Microstructural analysis was carried out using a Jeol JSM-6490LA scanning electron microscope, a JEM2100 transmission electron microscope, and a Ntegra atomic force microscope (AFM) Therma. Raman spectroscopic analysis of silicon films was carried out on a Horiba system Jobin – Yvon HR800UV (France). It has been established that the new form of nanosilicon under the studied conditions for obtaining silicon films is represented by fibers with a diameter of 10 to 150 nm. From a microstructural point of view, a silicon film, when a significant proportion of a new type of nanosilicon is formed in the film composition, acquires a porous cellular structure resulting from the interweaving of silicon nanofibers. The cells have an elongated oval shape with a width and length of about 1 and 3 µm, respectively. The obtained microphotographs are compared with similar data obtained when creating thin silicon films, which contain various polymorphic modifications of silicon in order to further classify the visual display of polymorphism and non-ideality of silicon nanostructures.