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Title: Effects of vacuum ultraviolet irradiation on trapped charges and leakage currents of low-k organosilicate dielectrics

Abstract

Vacuum ultraviolet (VUV) photoemission spectroscopy is utilized to investigate the distribution of trapped charges within the bandgap of low dielectric constant (low-k) organosilicate (SiCOH) materials. It was found that trapped charges are continuously distributed within the bandgap of porous SiCOH and the center of the trapped states is 1.3 eV above the valence band of the tested sample. By comparing photoemission spectroscopic results before and after VUV exposure, VUV irradiation with photon energies between 7.6 and 8.9 eV was found to deplete trapped charge while UV exposure with photon energies less than 6.0 eV induces more trapped charges in tested samples. Current-Voltage (IV) characteristics results show that the reliability of dielectrics is improved after VUV irradiation with photon energies between 7.6 and 8.9 eV, while UV exposure results in an increased level of leakage current and a decreased breakdown voltage, both of which are harmful to the reliability of the dielectric. This work shows that VUV irradiation holds the potential to substitute for UV curing in microelectronic processing to improve the reliability of low-k dielectrics by mitigating the leakage currents and trapped charges induced by UV irradiation.

Authors:
; ; ;  [1];  [2];  [3]
  1. Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)
  2. GLOBALFOUNDRIES, Albany, New York 12203 (United States)
  3. Stanford University, Stanford, California 94305 (United States)
Publication Date:
OSTI Identifier:
22399051
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 106; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; DIELECTRIC MATERIALS; ELECTRIC CONDUCTIVITY; EMISSION SPECTROSCOPY; ENERGY GAP; EV RANGE; FAR ULTRAVIOLET RADIATION; IRRADIATION; LEAKAGE CURRENT; PERMITTIVITY; PHOTOELECTRON SPECTROSCOPY; PHOTOEMISSION; PHOTONS; POROUS MATERIALS; POTENTIALS; SILICATES; TRAPPING; VALENCE

Citation Formats

Zheng, H., Guo, X., Pei, D., Shohet, J. L., Ryan, E. T., and Nishi, Y. Effects of vacuum ultraviolet irradiation on trapped charges and leakage currents of low-k organosilicate dielectrics. United States: N. p., 2015. Web. doi:10.1063/1.4921271.
Zheng, H., Guo, X., Pei, D., Shohet, J. L., Ryan, E. T., & Nishi, Y. Effects of vacuum ultraviolet irradiation on trapped charges and leakage currents of low-k organosilicate dielectrics. United States. doi:10.1063/1.4921271.
Zheng, H., Guo, X., Pei, D., Shohet, J. L., Ryan, E. T., and Nishi, Y. Mon . "Effects of vacuum ultraviolet irradiation on trapped charges and leakage currents of low-k organosilicate dielectrics". United States. doi:10.1063/1.4921271.
@article{osti_22399051,
title = {Effects of vacuum ultraviolet irradiation on trapped charges and leakage currents of low-k organosilicate dielectrics},
author = {Zheng, H. and Guo, X. and Pei, D. and Shohet, J. L. and Ryan, E. T. and Nishi, Y.},
abstractNote = {Vacuum ultraviolet (VUV) photoemission spectroscopy is utilized to investigate the distribution of trapped charges within the bandgap of low dielectric constant (low-k) organosilicate (SiCOH) materials. It was found that trapped charges are continuously distributed within the bandgap of porous SiCOH and the center of the trapped states is 1.3 eV above the valence band of the tested sample. By comparing photoemission spectroscopic results before and after VUV exposure, VUV irradiation with photon energies between 7.6 and 8.9 eV was found to deplete trapped charge while UV exposure with photon energies less than 6.0 eV induces more trapped charges in tested samples. Current-Voltage (IV) characteristics results show that the reliability of dielectrics is improved after VUV irradiation with photon energies between 7.6 and 8.9 eV, while UV exposure results in an increased level of leakage current and a decreased breakdown voltage, both of which are harmful to the reliability of the dielectric. This work shows that VUV irradiation holds the potential to substitute for UV curing in microelectronic processing to improve the reliability of low-k dielectrics by mitigating the leakage currents and trapped charges induced by UV irradiation.},
doi = {10.1063/1.4921271},
journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 106,
place = {United States},
year = {2015},
month = {5}
}