Tunability of Atomic Layer Deposition of Yttria-Stabilized Zirconium Oxide for use in Solid Oxide Fuel Cells

Abstract

Thin films of yttria-stabilized zirconium oxide (YSZ) were successfully deposited using atomic layer deposition (ALD) for use in solid oxide fuel cells (SOFCs). YSZ was deposited on p-Si(100) by ALD using Tris(isopropyl-cyclopentadienyl)yttrium [(iPrCp)3Y] and tris(dimethylamino)cyclopentadienylzirconim [ZyALD] as metal precursors and ozone as oxidant. The normalized ALD cycle ratio of yttria cycles / total cycles used in making these films was varied to investigate the tunability of this process. Spectral ellipsometry was used to measure the thickness of the films. X-ray photoelectron spectroscopy (XPS) analyses were used to evaluate the composition and binding environments of as-deposited YSZ films. The normalized cycle ratio and the yttrium atomic percentage (Y atoms / metal atoms) have a linear relationship with a strong correlation, implying excellent tunability for this process. The binding environment analyses determine the oxidation state of the metals and show that decreasing the cycle ratio decreases the extent of yttrium hydroxidation.