AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Monday Sessions
       Session DI-MoM

Invited Paper DI-MoM7
Photoemission Study of High-k Gate Dielectric/Si(100) Heterostructures - Chemical Bonding Features and Energy Band Alignment

Monday, November 3, 2003, 10:20 am, Room 317

Session: Electronic Properties of High-k Dielectrics and their Interfaces
Presenter: S. Miyazaki, Hiroshima University, Japan
Correspondent: Click to Email
The characterization of chemical and electronic structures of high-k dielectrics as well as the quantification of defect state distributions is of great importance for the implementation of the high-k dielectric gate stack in sub-100nm technology generations. For some high-k dielectrics such as Ta@sub 2@O@sub 5@, Al@sub 2@O@sub 3@, ZrO@sub 2@ and HfO@sub 2@, we have experimentally determined the energy band alignments to Si(100) with an thin interfacial Si-oxide or nitride from high-resolution XPS measurements and defect state distributions in the high-k dielectrics and at the interfaces form total photoelectron yield measurements.@footnote 1-3@ We have extended our research to characterize the chemical and electronic structures of Y@sub 2@O@sub 3@, Pr-silicates and Hf-aluminates on Si(100) including interfacial SiO@sub x@. In this presentation, recent our results will be review to demonstrate how the energy bandgaps of practically-thin high-k dielectrics such as HfO@sub 2@ and Y@sub 2@O@sub 3@ and of an ultrathin Si-nitride barrier can be determined from the analysis of energy loss spectra of O1s (or N1s) photoelectrons and, for the system of Y@sub 2@O@sub 3@ formed on Si(100), how the energy band alignment can be determined with combination of the measured bandgap and the valence band lineup as obtained from the analysis of XPS valence band spectra of heterostructures with thin dielectrics. Also, we show that total photoelectron yield spectroscopy is a useful tool for quantifying the energy distribution of electronic defect states for thin high-k dielectric/Si(100) systems. @FootnoteText@@footnote 1@S. Miyazaki, J. Va. Sci. Technol. B19, (2001) 2212. @footnote 2@S. Miyazaki, M. Narasaki, M. Ogasawara and M. Hirose, Microelec. Eng., 59 (2001) 373. @footnote 3@M. Yamaoka, M. Narasaki, H. Murakami and S. Miyazaki, Proc. of 2nd Int. Semicond. Technol. Conf. (2002, Tokyo) Abst. No. 57.