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

Journal Article · Mon May 11 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4921271· OSTI ID:22399051

Zheng, H.; Guo, X.; Pei, D.; Shohet, J. L. ^[1]; Ryan, E. T. ^[2]; Nishi, Y. ^[3]

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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)

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.

• OSTI ID: 22399051
• Journal Information: Applied Physics Letters, Vol. 106, Issue 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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