Dealing with inaccuracies in the analysis on solvent-induced swelling of transparent thin films using in situ spectroscopic ellipsometry in the visible wavelength range

Kristianne Tempelman, Emiel Kappert, Michiel J.T. Raaijmakers, Herbert Wormeester, Nieck Edwin Benes (Corresponding Author)

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
105 Downloads (Pure)

Abstract

The accuracy of spectroscopic ellipsometry studies of transparent polymer films in the visible wavelength range is greatly reduced in the presence of a liquid ambient. The relatively high refractive index of a liquid ambient strongly amplifies the effects of experimental non-idealities, such as window birefringence and an unknowingly inaccurate description of the optical properties of the ambient. In particular for thin films (approximately <100 nm), the implications of even small non-idealities are substantial, and large deviations in the thickness and refractive index are found. The concurrent low root mean square error (MSE) values show that a good MSE does not show that the optical model is correct; it just shows a good agreement between the experimental and fitted data. This implies that quantitative in situ ellipsometry studies for thin films are intricate, and derived properties like sorption behaviour should be treated with caution. Here, we show that quantitative in situ ellipsometry swelling measurements in solvents require a very accurate solvent dispersion relation, a high-quality temperature control, especially to prevent temperature differences between the cell, its content and exterior ambient, and accurate quantification of window effects, in particular for polymer films with thicknesses of approximately below 100 nm, depending on the optical contrast of the polymer–solvent system
Original languageEnglish
Pages (from-to)538-547
JournalSurface and interface analysis
Volume49
Issue number6
DOIs
Publication statusPublished - 1 Jun 2017

Fingerprint

Spectroscopic ellipsometry
Ellipsometry
Polymer films
swelling
Mean square error
ellipsometry
Swelling
Refractive index
Thin films
Wavelength
Liquids
thin films
Birefringence
Temperature control
wavelengths
refractivity
Sorption
Optical properties
root-mean-square errors
temperature control

Keywords

  • METIS-318950
  • IR-102142

Cite this

@article{fe53a7f64fa240dd8dc7927a2f23fc53,
title = "Dealing with inaccuracies in the analysis on solvent-induced swelling of transparent thin films using in situ spectroscopic ellipsometry in the visible wavelength range",
abstract = "The accuracy of spectroscopic ellipsometry studies of transparent polymer films in the visible wavelength range is greatly reduced in the presence of a liquid ambient. The relatively high refractive index of a liquid ambient strongly amplifies the effects of experimental non-idealities, such as window birefringence and an unknowingly inaccurate description of the optical properties of the ambient. In particular for thin films (approximately <100 nm), the implications of even small non-idealities are substantial, and large deviations in the thickness and refractive index are found. The concurrent low root mean square error (MSE) values show that a good MSE does not show that the optical model is correct; it just shows a good agreement between the experimental and fitted data. This implies that quantitative in situ ellipsometry studies for thin films are intricate, and derived properties like sorption behaviour should be treated with caution. Here, we show that quantitative in situ ellipsometry swelling measurements in solvents require a very accurate solvent dispersion relation, a high-quality temperature control, especially to prevent temperature differences between the cell, its content and exterior ambient, and accurate quantification of window effects, in particular for polymer films with thicknesses of approximately below 100 nm, depending on the optical contrast of the polymer–solvent system",
keywords = "METIS-318950, IR-102142",
author = "Kristianne Tempelman and Emiel Kappert and Raaijmakers, {Michiel J.T.} and Herbert Wormeester and Benes, {Nieck Edwin}",
year = "2017",
month = "6",
day = "1",
doi = "10.1002/sia.6191",
language = "English",
volume = "49",
pages = "538--547",
journal = "Surface and interface analysis",
issn = "0142-2421",
publisher = "Wiley",
number = "6",

}

Dealing with inaccuracies in the analysis on solvent-induced swelling of transparent thin films using in situ spectroscopic ellipsometry in the visible wavelength range. / Tempelman, Kristianne; Kappert, Emiel; Raaijmakers, Michiel J.T.; Wormeester, Herbert; Benes, Nieck Edwin (Corresponding Author).

In: Surface and interface analysis, Vol. 49, No. 6, 01.06.2017, p. 538-547.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Dealing with inaccuracies in the analysis on solvent-induced swelling of transparent thin films using in situ spectroscopic ellipsometry in the visible wavelength range

AU - Tempelman, Kristianne

AU - Kappert, Emiel

AU - Raaijmakers, Michiel J.T.

AU - Wormeester, Herbert

AU - Benes, Nieck Edwin

PY - 2017/6/1

Y1 - 2017/6/1

N2 - The accuracy of spectroscopic ellipsometry studies of transparent polymer films in the visible wavelength range is greatly reduced in the presence of a liquid ambient. The relatively high refractive index of a liquid ambient strongly amplifies the effects of experimental non-idealities, such as window birefringence and an unknowingly inaccurate description of the optical properties of the ambient. In particular for thin films (approximately <100 nm), the implications of even small non-idealities are substantial, and large deviations in the thickness and refractive index are found. The concurrent low root mean square error (MSE) values show that a good MSE does not show that the optical model is correct; it just shows a good agreement between the experimental and fitted data. This implies that quantitative in situ ellipsometry studies for thin films are intricate, and derived properties like sorption behaviour should be treated with caution. Here, we show that quantitative in situ ellipsometry swelling measurements in solvents require a very accurate solvent dispersion relation, a high-quality temperature control, especially to prevent temperature differences between the cell, its content and exterior ambient, and accurate quantification of window effects, in particular for polymer films with thicknesses of approximately below 100 nm, depending on the optical contrast of the polymer–solvent system

AB - The accuracy of spectroscopic ellipsometry studies of transparent polymer films in the visible wavelength range is greatly reduced in the presence of a liquid ambient. The relatively high refractive index of a liquid ambient strongly amplifies the effects of experimental non-idealities, such as window birefringence and an unknowingly inaccurate description of the optical properties of the ambient. In particular for thin films (approximately <100 nm), the implications of even small non-idealities are substantial, and large deviations in the thickness and refractive index are found. The concurrent low root mean square error (MSE) values show that a good MSE does not show that the optical model is correct; it just shows a good agreement between the experimental and fitted data. This implies that quantitative in situ ellipsometry studies for thin films are intricate, and derived properties like sorption behaviour should be treated with caution. Here, we show that quantitative in situ ellipsometry swelling measurements in solvents require a very accurate solvent dispersion relation, a high-quality temperature control, especially to prevent temperature differences between the cell, its content and exterior ambient, and accurate quantification of window effects, in particular for polymer films with thicknesses of approximately below 100 nm, depending on the optical contrast of the polymer–solvent system

KW - METIS-318950

KW - IR-102142

U2 - 10.1002/sia.6191

DO - 10.1002/sia.6191

M3 - Article

VL - 49

SP - 538

EP - 547

JO - Surface and interface analysis

JF - Surface and interface analysis

SN - 0142-2421

IS - 6

ER -