The relationship between local order, long range order, and sub-bandgap defects in hafnium oxide and hafnium silicate films

Published

May 9, 2008

Author(s)

D. H. Hill, Robert A. Bartynski, Nhan Van Nguyen, Albert Davydov, Deane Chandler-Horowitz, Martin M. Frank

Abstract

We have measured X-ray absorption spectra (XAS) at the oxygen K-edge for hafnium oxide (HfO2) films grown by chemical vapor deposition (CVD) and atomic layer deposition (ALD), as well as hafnium silicate (HfSiO) films grown by CVD.  The XAS results are compared to X-ray diffraction (XRD) and spectroscopic ellipsometry (SE) data from the same films. Features characteristic of crystalline HfO2 are observed in XAS spectra from all CVD-grown HfO2 films, even for a thickness of 5 nm where XRD is not sensitive..  XAS and XRD spectra from the ALD-grown HfO2 films exhibit the signature of crystallinity only for films that are 20 nm or thicker.  These characteristic XAS features are absent in all HfSiO films measured, which is consistent with their being amorphous.  The appearance of these peaks in XAS and XRD is correlated with sub-bandgap emission in the SE spectra, which appear to be intrinsic to crystalline HfO2 in the monoclinic phase.

Citation

Journal of Applied Physics

Pub Type

Journals

Keywords

HfO2, HfSiO, High-k dielectric, X-ray diffraction, X-ray absorption, Spectroscopi Ellipsometry, defects, MOS

Citation

Hill, D. , Bartynski, R. , Nguyen, N. , Davydov, A. , Chandler-Horowitz, D. and Frank, M. (2008), The relationship between local order, long range order, and sub-bandgap defects in hafnium oxide and hafnium silicate films, Journal of Applied Physics (Accessed April 24, 2024)