Study on the mechanism for the deposition of a porous zinc thin film by using a modified DC magnetron sputtering system

The mechanism for the deposition of zinc to form porous thin films is not clearly understood. In this study, a modified direct current (DC) sputtering system was used to deposit polycrystalline porous zinc thin films on an amorphous glass substrate to elucidate the mechanism. Subsequently, the properties of the thin films, such as its film thickness, the average particle size, and its porosity, were investigated under different experimental parameters, including pressure, DC discharge power, and the gas ratio between Ar and He. The plasma properties were also studied using a Langmuir probe. An increase in deposition pressure and DC discharge power was found to increase the deposition thickness and the particle size in the thin films whereas an increase in the He content increased the thickness and decreased the particle size. The investigation of the growth mechanism revealed that the zinc particles were oriented in different planes at early and later stages of deposition. Moreover, the properties of the thin films were observed to be affected by the energy loss of the zinc atoms and the bonding force between the substrate and the zinc particles. This understanding of the mechanism of thin-film formation will help to guide the optimization of experimental parameters in the fabrication of high-quality thin films.