Increased ultraviolet reflectivity of magnetron deposited Al films

Magnetron sputtering systems are widely used in deposition technology for coatings of different functionality. Optical properties of aluminum coatings deposited by the original method have been investigated in this paper. Film deposition was performed using the planar magnetron with aluminum cathode (99.995%) on the installation for magnetron coating deposition. Medium frequency supply source was used in the installation. The working gas was argon. The working pressure in the chamber upon sputtering was 0.15 Pa. The Halltype source of Ar ions was used in a number of experiments. The experimental technique was the following. One part of glass samples was deposited by aluminum films using a conventional method. The thickness was determined using AvaSpec USB2 spectrometer. Another part of samples was deposited also by aluminum films with the same thickness, but using the original method. The reflection factor of obtained samples from glass was measured on SF-256 spectrophotometer. Photometric studies showed that samples with film aluminum coatings have increased reflection factor in the ultraviolet area in comparison with the films that were deposited using a conventional method. In our opinion, the reason for the increased reflection factor can be due to the changes that occurred in the coating structure. Electron-microscopic studies (SM 12, "Philips") and x-ray diffractometric studies (Shimadzu XRD6000, "Shimadzu") of deposited coatings have been performed to check this supposition.