Defect structure and electronic properties of SiOC:H films used for back end of line dielectrics

T. A. Pomorski, B. C. Bittel, Patrick M. Lenahan, E. Mays, C. Ege, J. Bielefeld, D. Michalak, S. W. King

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Back end of the line dielectrics (BEOL) with low dielectric constants, so called low-k dielectrics, are needed for current and future integrated circuit technology nodes. However, an understanding of the defects which limit reliability and cause leakage currents for these films is not yet developed. We primarily utilize conventional electron paramagnetic resonance (EPR) and leakage current measurements to investigate amorphous hydrogenated carbon doped oxide (a-SiOC:H) dielectrics, the most important in current BEOL technology. The resonance measurements were complemented by transmission Fourier-transform infra-red spectroscopy, x-ray reflectivity, and Rutherford backscattering measurements. Various compositions of a-SiOC:H films were deposited on 300 mm diameter Si (100) wafers. They exhibit a wide range of dielectric constant, composition, and porosity. Variations in deposition method, process chemistry, and post deposition curing were also investigated. We observe a remarkable range of paramagnetic defect populations within the films. In a large subset of the films with similar defect structure, we observe a strong correlation between carbon dangling bond paramagnetic defect densities and leakage currents, especially at lower electric fields. This correspondence strongly suggests that, in this subset, defects observed by EPR are in a large part responsible for the leakage currents at low electric fields. In addition, the results suggest that the observed defects likely limit the dielectric reliability in problems such as time dependent dielectric breakdown and stress induced leakage current in many of these films. However, the EPR results are complex, and a simple universal correspondence between defect populations and leakage does not seem to be present.

Original languageEnglish (US)
Article number234508
JournalJournal of Applied Physics
Volume115
Issue number23
DOIs
StatePublished - Jun 21 2014

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leakage
defects
electronics
electron paramagnetic resonance
set theory
permittivity
electric fields
carbon
curing
integrated circuits
backscattering
breakdown
infrared spectroscopy
wafers
chemistry
porosity
reflectance
oxides
causes
x rays

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Pomorski, T. A. ; Bittel, B. C. ; Lenahan, Patrick M. ; Mays, E. ; Ege, C. ; Bielefeld, J. ; Michalak, D. ; King, S. W. / Defect structure and electronic properties of SiOC:H films used for back end of line dielectrics. In: Journal of Applied Physics. 2014 ; Vol. 115, No. 23.
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Pomorski, TA, Bittel, BC, Lenahan, PM, Mays, E, Ege, C, Bielefeld, J, Michalak, D & King, SW 2014, 'Defect structure and electronic properties of SiOC:H films used for back end of line dielectrics', Journal of Applied Physics, vol. 115, no. 23, 234508. https://doi.org/10.1063/1.4882023

Defect structure and electronic properties of SiOC:H films used for back end of line dielectrics. / Pomorski, T. A.; Bittel, B. C.; Lenahan, Patrick M.; Mays, E.; Ege, C.; Bielefeld, J.; Michalak, D.; King, S. W.

In: Journal of Applied Physics, Vol. 115, No. 23, 234508, 21.06.2014.

Research output: Contribution to journalArticle

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AU - Pomorski, T. A.

AU - Bittel, B. C.

AU - Lenahan, Patrick M.

AU - Mays, E.

AU - Ege, C.

AU - Bielefeld, J.

AU - Michalak, D.

AU - King, S. W.

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