Dielectric properties of and charge transport in columnar microfibrous thin films of Parylene C

Ibrahim H. Khawaji, Chandraprakash Chindam, Osama O. Awadelkarim, Akhlesh Lakhtakia

Research output: Contribution to journalArticle

5 Citations (Scopus)

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 languageEnglish (US)
Article number7945486
Pages (from-to)3360-3367
Number of pages8
JournalIEEE Transactions on Electron Devices
Volume64
Issue number8
DOIs
StatePublished - Aug 1 2017

Fingerprint

Dielectric properties
Charge transfer
Thin films
Temperature
Electric potential
Capacitance
Flexible electronics
Gene Conversion
Vapor deposition
parylene
Energy barriers
Leakage currents
Field emission
Integrated circuits
Permittivity
Activation energy
Experiments
Polarization
Scanning electron microscopy

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this

@article{df3db9ca61044215841738463377d7e3,
title = "Dielectric properties of and charge transport in columnar microfibrous thin films of Parylene C",
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.",
author = "Khawaji, {Ibrahim H.} and Chandraprakash Chindam and Awadelkarim, {Osama O.} and Akhlesh Lakhtakia",
year = "2017",
month = "8",
day = "1",
doi = "10.1109/TED.2017.2711481",
language = "English (US)",
volume = "64",
pages = "3360--3367",
journal = "IEEE Transactions on Electron Devices",
issn = "0018-9383",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "8",

}

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 journalArticle

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.

UR - http://www.scopus.com/inward/record.url?scp=85020703628&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85020703628&partnerID=8YFLogxK

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 -