Growth and Thermal Stability of Ultra-thin Silver Oxide Films
Abstract
We have investigated growth and thermal stability of ultra-thin (<100nm) silver oxide films with atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Films were grown at room temperature on r-cut sapphire using electron-cyclotron resonance (ECR) oxygen plasma-assisted e-beam evaporation of Ag and also via post-deposition ECR oxidation of pure Ag films. XPS results show that a Ag_2O stoichiometry is produced, and that post-deposition annealing causes these Ag_2O films to thermally evaporate from the sapphire at ~200^oC. AFM of films quenched after in vacuo thermal treatments near the desorption temperature indicate that individual crystallites ( ~100 nm in size) initially evaporate while adjacent crystallites are left intact. Additionally, large circular areas of sapphire devoid of silver oxide (tens of microns diameter) evolve around the initial desorption sites, presumably due to inhomogeneities in local stoichiometry. Small metallic silver features remain within the silver oxide-free areas with heights greater than the original film thickness, suggesting that they are precipitates formed during the desorption process.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARK40062R