Hafnium oxide (HfO 2 ) gate dielectric film was prepared by Hf sputtering in oxygen, and the thermal instability of HfO 2 was investigated by rapid thermal annealing ͑RTA͒ in nitrogen. X-ray photoelectron spectroscopy study reveals that the HfO 2 film is thermally unstable at postmetallization annealing temperatures (Ͼ500°C). The HfO 2 film decomposes and some oxygen atoms are released upon the RTA in nitrogen. In addition, the current-voltage characteristics of the Al/HfO 2 /Si capacitor are also highly unstable at temperatures higher than 300 K. These observations suggest that although HfO 2 has a much higher dielectric constant, it may not be suitable for the gate dielectric application because the postdeposition thermal treatment deteriorates both the physical and the electrical properties of the HfO 2 film.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.