ZnO Growth on Macroporous Si Substrates by HF Magnetron Sputtering

It is the purpose of this work to research the formation process of zinc oxide by the method of HF magnetron sputtering on silicon substrates of orientation (100) with the previously applied system of macropores. Samples of porous silicon were obtained by electrochemical etching. n-type Si (100) wafers were used. Precipitation of thin ZnO films was carried out in an RF discharge in an argon atmosphere with oxygen by sputtering a zinc target. The target had a diameter of 80 mm and a thickness of 6 mm. The deposition time was 1200 s. The pressure in the growth chamber was maintained at a level of 10 – 3 Pa. The substrate temperature was fixed at 300 °C. X-ray examination of ZnO has shown that the films have a polycrystalline nature with a wurtzite-type structure and hexagonal phase. ZnO crystallites in the coatings are highly oriented along the c-axis and perpendicular to the substrate surface. The lattice constant along the crystallographic c-axis of ZnO film was 5.2260 Å. The average crystallite size calculated by the Selyakov-Scherrer formula was 12 nm. According to SEM, grain size was ~ 50-100 nm. These discrepancies are explained by the presence of microstrains in the atomic matrix of the sample, as well as instrumental factors. The microelement analysis revealed practically perfect stoichiometry of ZnO grown on porous-Si/Si.