We have experimentally shown that crystallization of HfO2 and the subsequent formation of fixed charges localized at the HfO 2/SiO2 interface bring about a degradation of electron mobility. Systematic analyses of valence-band photoemission and transmission electron microscopy indicate that the oxygen transfer from the HfO2 layer to the Si substrate is promoted upon the crystallization of HfO 2 and the fixed charges are generated during the process. These findings highlight the importance of controlling the crystallinity of HfO 2 for realizing high performance metal gate high-*: field-effect transistors.
ASJC Scopus subject areas
- Physics and Astronomy(all)