Optical Characterization of Plasma‐Deposited SiO₂‐Like Layers on Anisotropic Polymeric Substrates

Abstract

In this paper, the characterization of the optical anisotropy of poly(ethylene‐2,6‐naphthalate) (PEN) by means of Transmission Generalized Ellipsometry coupled with reflection multi‐angle Spectroscopic Ellipsometry (SE) measurements is presented. This study is functional to the determination of the refractive index of atmospheric pressure plasma‐deposited SiO2‐like layers deposited on PEN. The effect of the plasma duty cycle (DC) on the film properties is investigated. From the analysis of the optical properties, complemented with chemical and morphological studies, it is concluded that the increase in DC is responsible for the layer densification process, eventually causing an improvement in the PEN/SiO2 system barrier properties.magnified image

The role of carrier gas flow in roll-to-roll AP-PECVD synthesized silica moisture barrier films

“…To describe the PEN substrate and the silica-like film a Cauchy dispersion function was applied for both materials. The substrate anisotropy was not [20][21][22][23][24][25][26] implemented into the model [40], however the sample orientation was kept the same for each measurement.…”

“…As the Mocon apparatus characterizes the effective WVTR, the type of permeation channels determining the moisture barrier performance is not taken into account, i.e. intrinsic porosity, nano defects or large pinholes defects [5,18,[22][23][24]27,40,41,46], and thus the origin of the decrease in the effective barrier performance may be different. In order to determine whether pinholes are responsible for the degraded moisture barrier performance the solvent vapor penetration test analysis is performed on the 80 nm single barrier films.…”

Towards Roll‐to‐Roll Deposition of High Quality Moisture Barrier Films on Polymers by Atmospheric Pressure Plasma Assisted Process

“…[33] In the case of fixed input power and complete precursor depletion in the plasma the variation in monomer flow will result in scaling of both DDR value and energy spent per monomer molecule. In [34] we already showed that the variation of specific energy dissipated in the discharge has a strong effect on both the refractive index and OTR value of the silica-like films. For the specific case study here under analysis, it is found that the rate of surface reactions and structure of the deposited film are strongly influenced by the substrate temperature.…”

Defect prevention in silica thin films synthesized using AP-PECVD for flexible electronic encapsulation

“…It is known that single layer encapsulation performance is limited by the presence of defects, such as cracks or pinholes in the inorganic layer [1][2][3][4]9,24,25]. Studies have shown that the use of multilayer encapsulation barriers [1,[3][4][5][6][7][10][11][12]24], deposited using techniques such as sputtering, atomic layer deposition and molecular layer deposition processes, can prevent the formation [1,[3][4][5], and propagation [3], of such defects.…”