A study of ta-C, a-C : H and Si-a : C : H thin films on polymer substrates as a gas barrier

GA Abbas, JAD McLaughlin, E Harkin-Jones

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Two types of diamond-like carbon (DLC) films were grown on Poly (ethylene terepthalate) (PET) substrates have been investigated for density, internal stress, gas permeability and structural properties by an X-ray reflectometry, surface profilometer, Raman spectroscopy and water vapour permeation analysis system, respectively. The high density tetrahedral amorphous carbon (ta-C) films (3.27 g/cm(3)) prepared by filtered vacuum cathodic arc (FCVA) showed unexpected high water vapour transmission rate (WVTR) (1.3 g/m(2) day) and a surface covered by a network of deep micro-cracks, which is due to intrinsic stress inside the ta-C films (up to 12 GPa). The soft Si doped hydrogenated amorphous carbon (Si-a:C:H) films prepared by plasma enhanced chemical vapour deposition (PECVD) exhibited low transmission rate (0.03 g/m(2) day) with a water vapour reduction factor up to 98% and a surface almost completely free of micro-cracks. Si incorporation in the a-C:H films reduced both the film density from 2.3 g/cm(3) to 1.85 g/cm(3) and the compressive stress to < 0.5 GPa. This could be understood by two possibilities. Firstly, the increasing in the hydrogen content within the films (as indicated by increasing the Raman background slope) developed more polymer-like bonds, which weakens the microstructure. Second, replacing the stronger C-C bonds (3.7 eV) by C-Si (3.21 eV) bonds where the relaxation of residual stress would occur with large strains in the C-Si bonds. (C) 2003 Elsevier B.V. All rights reserved.
LanguageEnglish
Pages1342-1345
JournalDiamond and Related Materials
Volume13
Issue number4-8
DOIs
Publication statusPublished - Apr 2004

Fingerprint

Amorphous carbon
Steam
Polymers
Gases
Water vapor
Thin films
Carbon films
Amorphous films
Substrates
Residual stresses
Cracks
Diamond like carbon films
Gas permeability
Plasma enhanced chemical vapor deposition
Compressive stress
Permeation
Raman spectroscopy
Structural properties
Hydrogen
Ethylene

Keywords

  • DLC
  • coatings
  • diffusion
  • surface characterization

Cite this

@article{0b28814a896645de81dd032cff443394,
title = "A study of ta-C, a-C : H and Si-a : C : H thin films on polymer substrates as a gas barrier",
abstract = "Two types of diamond-like carbon (DLC) films were grown on Poly (ethylene terepthalate) (PET) substrates have been investigated for density, internal stress, gas permeability and structural properties by an X-ray reflectometry, surface profilometer, Raman spectroscopy and water vapour permeation analysis system, respectively. The high density tetrahedral amorphous carbon (ta-C) films (3.27 g/cm(3)) prepared by filtered vacuum cathodic arc (FCVA) showed unexpected high water vapour transmission rate (WVTR) (1.3 g/m(2) day) and a surface covered by a network of deep micro-cracks, which is due to intrinsic stress inside the ta-C films (up to 12 GPa). The soft Si doped hydrogenated amorphous carbon (Si-a:C:H) films prepared by plasma enhanced chemical vapour deposition (PECVD) exhibited low transmission rate (0.03 g/m(2) day) with a water vapour reduction factor up to 98{\%} and a surface almost completely free of micro-cracks. Si incorporation in the a-C:H films reduced both the film density from 2.3 g/cm(3) to 1.85 g/cm(3) and the compressive stress to < 0.5 GPa. This could be understood by two possibilities. Firstly, the increasing in the hydrogen content within the films (as indicated by increasing the Raman background slope) developed more polymer-like bonds, which weakens the microstructure. Second, replacing the stronger C-C bonds (3.7 eV) by C-Si (3.21 eV) bonds where the relaxation of residual stress would occur with large strains in the C-Si bonds. (C) 2003 Elsevier B.V. All rights reserved.",
keywords = "DLC, coatings, diffusion, surface characterization",
author = "GA Abbas and JAD McLaughlin and E Harkin-Jones",
note = "14th European Conference on Diamond, Diamond-like Materials, Carbon Nanotubes, Nitrides and Silicon Carbide, Salzburg, AUSTRIA, SEP 08-12, 2003",
year = "2004",
month = "4",
doi = "10.1016/j.diamond.2003.10.084",
language = "English",
volume = "13",
pages = "1342--1345",
number = "4-8",

}

A study of ta-C, a-C : H and Si-a : C : H thin films on polymer substrates as a gas barrier. / Abbas, GA; McLaughlin, JAD; Harkin-Jones, E.

Vol. 13, No. 4-8, 04.2004, p. 1342-1345.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A study of ta-C, a-C : H and Si-a : C : H thin films on polymer substrates as a gas barrier

AU - Abbas, GA

AU - McLaughlin, JAD

AU - Harkin-Jones, E

N1 - 14th European Conference on Diamond, Diamond-like Materials, Carbon Nanotubes, Nitrides and Silicon Carbide, Salzburg, AUSTRIA, SEP 08-12, 2003

PY - 2004/4

Y1 - 2004/4

N2 - Two types of diamond-like carbon (DLC) films were grown on Poly (ethylene terepthalate) (PET) substrates have been investigated for density, internal stress, gas permeability and structural properties by an X-ray reflectometry, surface profilometer, Raman spectroscopy and water vapour permeation analysis system, respectively. The high density tetrahedral amorphous carbon (ta-C) films (3.27 g/cm(3)) prepared by filtered vacuum cathodic arc (FCVA) showed unexpected high water vapour transmission rate (WVTR) (1.3 g/m(2) day) and a surface covered by a network of deep micro-cracks, which is due to intrinsic stress inside the ta-C films (up to 12 GPa). The soft Si doped hydrogenated amorphous carbon (Si-a:C:H) films prepared by plasma enhanced chemical vapour deposition (PECVD) exhibited low transmission rate (0.03 g/m(2) day) with a water vapour reduction factor up to 98% and a surface almost completely free of micro-cracks. Si incorporation in the a-C:H films reduced both the film density from 2.3 g/cm(3) to 1.85 g/cm(3) and the compressive stress to < 0.5 GPa. This could be understood by two possibilities. Firstly, the increasing in the hydrogen content within the films (as indicated by increasing the Raman background slope) developed more polymer-like bonds, which weakens the microstructure. Second, replacing the stronger C-C bonds (3.7 eV) by C-Si (3.21 eV) bonds where the relaxation of residual stress would occur with large strains in the C-Si bonds. (C) 2003 Elsevier B.V. All rights reserved.

AB - Two types of diamond-like carbon (DLC) films were grown on Poly (ethylene terepthalate) (PET) substrates have been investigated for density, internal stress, gas permeability and structural properties by an X-ray reflectometry, surface profilometer, Raman spectroscopy and water vapour permeation analysis system, respectively. The high density tetrahedral amorphous carbon (ta-C) films (3.27 g/cm(3)) prepared by filtered vacuum cathodic arc (FCVA) showed unexpected high water vapour transmission rate (WVTR) (1.3 g/m(2) day) and a surface covered by a network of deep micro-cracks, which is due to intrinsic stress inside the ta-C films (up to 12 GPa). The soft Si doped hydrogenated amorphous carbon (Si-a:C:H) films prepared by plasma enhanced chemical vapour deposition (PECVD) exhibited low transmission rate (0.03 g/m(2) day) with a water vapour reduction factor up to 98% and a surface almost completely free of micro-cracks. Si incorporation in the a-C:H films reduced both the film density from 2.3 g/cm(3) to 1.85 g/cm(3) and the compressive stress to < 0.5 GPa. This could be understood by two possibilities. Firstly, the increasing in the hydrogen content within the films (as indicated by increasing the Raman background slope) developed more polymer-like bonds, which weakens the microstructure. Second, replacing the stronger C-C bonds (3.7 eV) by C-Si (3.21 eV) bonds where the relaxation of residual stress would occur with large strains in the C-Si bonds. (C) 2003 Elsevier B.V. All rights reserved.

KW - DLC

KW - coatings

KW - diffusion

KW - surface characterization

U2 - 10.1016/j.diamond.2003.10.084

DO - 10.1016/j.diamond.2003.10.084

M3 - Article

VL - 13

SP - 1342

EP - 1345

IS - 4-8

ER -