Atomic Layer Deposition of Gadolinium Aluminate using Gd((PrCp)-Pr-i)(3), TMA, and O-3 or H2O

Abstract

For future generations of non-volatile memory applications, the replacement of the interpoly dielectric by a suitable high-K material is required. Rare-earth aluminates are potential candidates because they are predicted to combine a high dielectric permittivity with a large band gap. We demonstrate the atomic layer deposition (ALD) of GdxAl2O3 layers using Gd((PrCp)-Pr-i)(3), trimethyl-aluminum (TMA), and H2O or O-3. Process windows for both H2O and O3 as oxidants are explored. H2O is shown to lead to better GdxAl2-xO3 film properties than O-3, although the accessible composition range is limited because of the hygroscopic nature of Gd2O3.