Room temperature interactions of water vapor with HfO2 films on Si

Hf O 2 ∕ Si O 2 ∕ Si ( 001 ) thin film structures were exposed at room temperature to water vapor isotopically enriched in H2 and O18 followed by quantification and profiling of these nuclides by nuclear reaction analysis. We showed (i) the formation of strongly bonded hydroxyls at the HfO2 surface; (ii) room temperature migration of oxygen and water-derived oxygenous species through the HfO2 films, indicating that HfO2 is a weak diffusion barrier for these oxidizing species; (iii) hydrogenous, water-derived species attachment to the SiO2 interlayer, resulting in detrimental hydrogenous defects therein. Consequences of these results to HfO2-based metal-oxide-semiconductor devices are discussed.