skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Chemical Analysis of HfO2/Si (100) Film Systems Exposed to NH3 Thermal Processing

; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 101
Country of Publication:
United States
national synchrotron light source

Citation Formats

Lysaght,P., Barnett, J., Bersuker, G., Woicik, J., Fischer, D., Foran, B., Tseng, H., and Jammy, R. Chemical Analysis of HfO2/Si (100) Film Systems Exposed to NH3 Thermal Processing. United States: N. p., 2007. Web. doi:10.1063/1.2422746.
Lysaght,P., Barnett, J., Bersuker, G., Woicik, J., Fischer, D., Foran, B., Tseng, H., & Jammy, R. Chemical Analysis of HfO2/Si (100) Film Systems Exposed to NH3 Thermal Processing. United States. doi:10.1063/1.2422746.
Lysaght,P., Barnett, J., Bersuker, G., Woicik, J., Fischer, D., Foran, B., Tseng, H., and Jammy, R. Mon . "Chemical Analysis of HfO2/Si (100) Film Systems Exposed to NH3 Thermal Processing". United States. doi:10.1063/1.2422746.
title = {Chemical Analysis of HfO2/Si (100) Film Systems Exposed to NH3 Thermal Processing},
author = {Lysaght,P. and Barnett, J. and Bersuker, G. and Woicik, J. and Fischer, D. and Foran, B. and Tseng, H. and Jammy, R.},
abstractNote = {},
doi = {10.1063/1.2422746},
journal = {Journal of Applied Physics},
number = ,
volume = 101,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
  • Nitrogen incorporation in HfO{sub 2}/SiO{sub 2} films utilized as high-k gate dielectric layers in advanced metal-oxide-semiconductor field effect transistors has been investigated. Thin HfO{sub 2} blanket films deposited by atomic layer deposition on either SiO{sub 2} or NH{sub 3} treated Si (100) substrates have been subjected to NH{sub 3} and N{sub 2} anneal processing. Several high resolution techniques including electron microscopy with electron energy loss spectra, grazing incidence x-ray diffraction, and synchrotron x-ray photoelectron spectroscopy have been utilized to elucidate chemical composition and crystalline structure differences between samples annealed in NH{sub 3} and N{sub 2} ambients as a function ofmore » temperature. Depth profiling of core level binding energy spectra has been obtained by using variable kinetic energy x-ray photoelectron spectroscopy with tunable photon energy. An 'interface effect' characterized by a shift of the Si{sup 4+} feature to lower binding energy at the HfO{sub 2}/SiO{sub 2} interface has been detected in the Si 1s spectra; however, no corresponding chemical state change has been observed in the Hf 4f spectra acquired over a broad range of electron take-off angles and surface sensitivities. The Si 2p spectra indicate Si-N bond formation beneath the HfO{sub 2} layer in the samples exposed to NH{sub 3} anneal. The NH{sub 3} anneal ambient is shown to produce a metastable Hf-N bond component corresponding to temperature driven dissociation kinetics. These findings are consistent with elemental profiles across the HfO{sub 2}/Si(100) interface determined by electron energy loss spectroscopy measurements. X-ray diffraction measurements on similarly treated films identify the structural changes resulting from N incorporation into the HfO{sub 2} films.« less
  • Employing the newly developed high-resolution pulsed field ionization-photoelectron (PFI-PE)-photoion coincidence (PFI-PEPICO) technique, we have examined the dissociation of energy-selected NH{sub 3}{sup +} to form NH{sub 2}{sup +} + H near its threshold. The breakdown curves for NH{sub 2}{sup +} and NH{sub 3}{sup +} thus obtained yield a value of 15.765 {+-} 0.001 eV for the 0 K dissociation threshold or appearance energy (AE) for NH{sub 2}{sup +} from NH{sub 3}. This value, together with the known ionization energy (IE=10.1864 {+-} 0.0001 eV) and 0 K bond dissociation energy (D{sub 0} = 4.6017 {+-} 0.0025 eV) for NH{sub 3}, allows themore » determination of the D{sub 0}(NH{sub 2}{sup +}-H) and IE(NH{sub 2}), which are 5.5786 {+-} 0.0010 and 11.1633 {+-} 0.0025 eV, respectively. Using the known 0 K heats of formation ({Delta}H{sup 0}{sub f0}) for NH{sub 3} and H and the AE(NH{sub 2}{sup +}), we obtain the {Delta}H{sup o}{sub f0}(NH{sub 2}{sup +}) = 302.60 {+-} 0.08 kcal/mol. The PFI-PE spectrum for NH{sub 3} exhibits a step-like feature at the 0 K AE(NH{sub 2}{sup +}), indicating that the dissociation of excited NH{sub 3} in high-n (n {ge} 100) Rydberg states at energies slightly above the dissociation threshold occurs on a time scale {le}10{sup -7} s. This step confirms the AE(NH{sub 2}{sup +}) value derived from the PFI-PEPICO measurements. Highly accurate energetic data with well-founded error limits, such as those obtained in the present and other studies using the PFI techniques, are expected to play an important role for the development of the next generation of ab initio quantum computation procedures. This experiment has stimulated a state-of-the-art ab initio quantum chemical calculation (Dixon et al., J. Chem. Phys., accepted). The comparison between theoretical predictions and the best experimental results for the NH{sub 2}/NH{sub 2}{sup +} and NH{sub 3}/NH{sub 3}{sup +} systems indicates that the accuracy of the computational scheme used is {le}0.4 kcal/mol.« less
  • The effects of rapid thermal annealing (RTA) on amorphous hydrogenated carbon-coated film on Si wafer, deposited by CH{sub 4}/Ar dielectric barrier discharge plasma (at half of the atmospheric pressure), was examined. Bubbles-like structures were formed on the surface of the deposited carbon-coated film. The surface morphology studied by scanning electron microscopy (SEM), which showed that the effect of RTA on the film changing the morphological property drastically at 600 deg. C and most of the bubbles started evaporating above 200 deg. C. The inbuilt energy dispersive x-ray in SEM gives the quantitative analysis of the annealed surface. X-ray photoelectron spectroscopymore » results of the as-deposited films agree with the IR results in that the percent of Si-CH{sub 3}, Si-O-Si and C-O(H) stretching vibrational band in the film. Most of these bands disappeared as the sample was annealed at 600 deg. C in Ar medium.« less
  • A model is proposed here to understand the nucleation of III–V semiconductor nanowires (NW). Whereas the classical nucleation theory is not adequately sufficient in explaining the evolution of the shape of the NWs under different chemical environment such as flow rate or partial pressure of the precursors, the effect of adsorption and desorption mediated growth, and diffusion limited growth are taken into account to explain the morphology and the crystal structure of In{sub x}Ga{sub 1−x}As nanowires (NW) on Silicon (100) substrates grown by a metalorganic chemical vapor deposition technique. It is found that the monolayer nucleus that originates at themore » triple phase line covers the entire nucleus-substrate (NS) region at a specific level of supersaturation and there are cases when the monolayer covers a certain fraction of the NS interface. When the monolayer covers the total NS interface, NWs grow with perfect cylindrical morphology and whenever a fraction of the interface is covered by the nucleus, the NWs become curved as observed from high resolution transmission electron microscopy images. The supersaturation, i.e., the chemical potential is found to be governed by the concentration of precursors into the molten silver which in the present case is taken as a catalyst. Our study provides new insights into the growth of ternary NWs which will be helpful in understanding the behavior of growth of different semiconducting NWs.« less