Effect of the Deposition Angle on Structural and Optical Properties of Tantalum Oxide Nanolayers Deposited by Electron Gun Evaporation as a Function of Thickness

— Tantalum oxide nanolayers of different thicknesses (30, 60, 90, and 120 nm) were deposited by physical evaporation on glass substrates at a deposition angle of 10° under high vacuum conditions at room temperature using an electron gun. There was no specific peak on the X-ray diffraction patterns because of amorphous nature of these layers. The results of atomic force microscopy showed that surface roughness reduced with increasing layer thickness. Field emission scanning electron microscopy images showed nucleation, growth, accession and integration as interconnected islands in the case of thinner layers and re-nucleation in the case of thicker ones (120 nm). Optical coefficients calculated using the Kramers–Kronig relations showed that with increasing layer thickness, dielectric properties, absorption coefficient, and band gap energy increased.