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In this work the properties of Si3N4 and AIN thin films deposited onto unheated substrates by Reactive Low Voltage Ion Plating (RLVIP) and Reactive DC-Magnetron Sputtering (RDCMS) were investigated. In both experimental setups pure silicon and aluminum were used as starting materials. Working and reactive gas were argon and nitrogen respectively. All Si3N4 films showed amorphous structure in X-ray and electron diffraction whereas AIN films were found to be polycrystalline and could be indexed to the bulk hexagonal AIN lattice. The values of the film refractive index at 550 nm are 2.08 for RLVIP Si3N4, 2.12 for RLVIP AIN, 2.02 for RDCMS Si3N4, and 1.98 or 2.12 for AIN depending on the total pressure in the range of 8 E - 1 Pa and 1 E - 1 Pa during the process. The high optical transmission region for the Si3N4 films lies between 0.23 and 9.5 micrometers , and for AIN films between 0.2 and 12.5 micrometers . Purity and composition were measured by electron microprobe, infrared transmission, nuclear reactions, elastic recoil detection analysis and Rutherford backscattering spectroscopy. Transmission electron micrographs of Pt-C replicas of fracture cross sections of the films show their different microstructure and surface topography. Environmental tests proved the RLVIP Si3N4 films to be very hard, of high density and of strong adherence to glass.
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