Chemical Stability of Titania and Alumina Thin Films Formed by Atomic Layer Deposition

• DOI: 10.1021/acsami.5b03278
• Publication Date: 2015-06-24T15:14:10Z
• Authors: Gabriela C. Correa; Bo Bao; Nicholas C. Stran...
• Keywords: Diffusion barrier; Chemical Stability; Thermal Stability; Ellipsometry

Thin films formed by atomic layer deposition (ALD) are being examined for a variety of chemical protection and diffusion barrier applications, yet their stability in various fluid environments is not well characterized. The titania alumina thin air, 18 MΩ water, 1 M KCl, HNO3, H2SO4, HCl, KOH, mercury was studied. Films were deposited at 150 °C using trimethylaluminum–H2O tetrakis(dimethylamido)titanium–H2O chemistries titania, respectively. A subset samples heated to 450 900 inert atmosphere. spectroscopic ellipsometry, force microscopy, optical scanning electron X-ray diffraction. Notably, found be unstable pure acid, basic the as-synthesized state after thermal treatment. In dissolution–precipitation mechanism hypothesized cause surface roughening. greatly enhanced annealing acidic solutions. Titania stable acid or above °C. All showed composition-independent increase measured thickness when immersed mercury. These results provide stability-processing relationships that important controlled etching protective layers.