Water absorption and interface reactivity of yttrium oxide gate dielectrics on silicon

摘要: High dielectric constant insulators deposited at low temperatures rapidly absorb water during exposure to the atmosphere, and resulting OH leads detrimental interface reactions. We report effect of atmospheric on ultrathin yttrium oxide, details silicon substrate reactions postdeposition anneals. Infrared absorption analysis indicates significant vapor exposure, even for very short times (<15 min). X-ray photoelectron spectroscopy demonstrates that after absorption, a thermally activated reaction proceeds with an activation energy 0.33 eV, consistent present in film. The rate is reduced annealed films or when capping layers are situ. Similar oxidation processes expected occur other high-k materials interest, where will depend deposition process material thermal history.