Abstract
Parylene-C microfibrous thin films (μ FTFs), grown using oblique-angle physicochemical vapor deposition, were examined for potential use as low-relative-permittivity (i.e., low- κ ) interlayer dielectrics in integrated circuits and, more importantly, flexible electronics. These films were characterized using capacitance-voltage-temperature (CVT) and current-voltage-temperature experiments at different temperatures (ranging from 298 to 420 K) and frequencies (ranging from 1 kHz to 1 MHz). Field emission scanning electron microscopy revealed the Parylene Cμ FTFs to be highly porous. Consequently, their κ values are at least 20% lower than those of bulk Parylene C. The dependences of κ on frequency and temperature suggest that molecular dipole oscillations are responsible for charge polarization in theμ FTFs. The dc leakage current in theμ FTFs at temperatures not exceeding 100 °C (373 K) was found to arise from Poole-Frenkel (PF) emissionmechanism with a barrier energy of about 0.77 eV. Moreover, when fitted to the PF model, the experimental data yielded high-frequency values κ∞ of κ in agreement with those obtained from CVT experiments, thus confirming our identification of PF as themajor responsiblemechanism and confirming the low- κ characteristic of microfibrous Parylene C. The ac current transport in theμ FTFs was found attributable to small-polaron-tunneling hopping conduction and characterized by the power law ωs, with s ϵ [0.082,0.85] increasing with temperature. AC conduction in theμ FTFs is temperature-activated with an activation energy that decreases from 0.020 to 0.012 eV as frequency increases from 1 kHz to 1 MHz.
| Original language | English (US) |
|---|---|
| Article number | 7945486 |
| Pages (from-to) | 3360-3367 |
| Number of pages | 8 |
| Journal | IEEE Transactions on Electron Devices |
| Volume | 64 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 1 2017 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
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Dielectric properties of and charge transport in columnar microfibrous thin films of Parylene C. / Khawaji, Ibrahim H.; Chindam, Chandraprakash; Awadelkarim, Osama O.; Lakhtakia, Akhlesh.
In: IEEE Transactions on Electron Devices, Vol. 64, No. 8, 7945486, 01.08.2017, p. 3360-3367.Research output: Contribution to journal › Article
TY - JOUR
T1 - Dielectric properties of and charge transport in columnar microfibrous thin films of Parylene C
AU - Khawaji, Ibrahim H.
AU - Chindam, Chandraprakash
AU - Awadelkarim, Osama O.
AU - Lakhtakia, Akhlesh
PY - 2017/8/1
Y1 - 2017/8/1
N2 - Parylene-C microfibrous thin films (μ FTFs), grown using oblique-angle physicochemical vapor deposition, were examined for potential use as low-relative-permittivity (i.e., low- κ ) interlayer dielectrics in integrated circuits and, more importantly, flexible electronics. These films were characterized using capacitance-voltage-temperature (CVT) and current-voltage-temperature experiments at different temperatures (ranging from 298 to 420 K) and frequencies (ranging from 1 kHz to 1 MHz). Field emission scanning electron microscopy revealed the Parylene Cμ FTFs to be highly porous. Consequently, their κ values are at least 20% lower than those of bulk Parylene C. The dependences of κ on frequency and temperature suggest that molecular dipole oscillations are responsible for charge polarization in theμ FTFs. The dc leakage current in theμ FTFs at temperatures not exceeding 100 °C (373 K) was found to arise from Poole-Frenkel (PF) emissionmechanism with a barrier energy of about 0.77 eV. Moreover, when fitted to the PF model, the experimental data yielded high-frequency values κ∞ of κ in agreement with those obtained from CVT experiments, thus confirming our identification of PF as themajor responsiblemechanism and confirming the low- κ characteristic of microfibrous Parylene C. The ac current transport in theμ FTFs was found attributable to small-polaron-tunneling hopping conduction and characterized by the power law ωs, with s ϵ [0.082,0.85] increasing with temperature. AC conduction in theμ FTFs is temperature-activated with an activation energy that decreases from 0.020 to 0.012 eV as frequency increases from 1 kHz to 1 MHz.
AB - Parylene-C microfibrous thin films (μ FTFs), grown using oblique-angle physicochemical vapor deposition, were examined for potential use as low-relative-permittivity (i.e., low- κ ) interlayer dielectrics in integrated circuits and, more importantly, flexible electronics. These films were characterized using capacitance-voltage-temperature (CVT) and current-voltage-temperature experiments at different temperatures (ranging from 298 to 420 K) and frequencies (ranging from 1 kHz to 1 MHz). Field emission scanning electron microscopy revealed the Parylene Cμ FTFs to be highly porous. Consequently, their κ values are at least 20% lower than those of bulk Parylene C. The dependences of κ on frequency and temperature suggest that molecular dipole oscillations are responsible for charge polarization in theμ FTFs. The dc leakage current in theμ FTFs at temperatures not exceeding 100 °C (373 K) was found to arise from Poole-Frenkel (PF) emissionmechanism with a barrier energy of about 0.77 eV. Moreover, when fitted to the PF model, the experimental data yielded high-frequency values κ∞ of κ in agreement with those obtained from CVT experiments, thus confirming our identification of PF as themajor responsiblemechanism and confirming the low- κ characteristic of microfibrous Parylene C. The ac current transport in theμ FTFs was found attributable to small-polaron-tunneling hopping conduction and characterized by the power law ωs, with s ϵ [0.082,0.85] increasing with temperature. AC conduction in theμ FTFs is temperature-activated with an activation energy that decreases from 0.020 to 0.012 eV as frequency increases from 1 kHz to 1 MHz.
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U2 - 10.1109/TED.2017.2711481
DO - 10.1109/TED.2017.2711481
M3 - Article
VL - 64
SP - 3360
EP - 3367
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
SN - 0018-9383
IS - 8
M1 - 7945486
ER -