Simultaneous determination of optical constants, local
thickness, and local roughness of thin films by imaging
spectroscopic reflectometry

D 2015

Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry

NEČAS, David, Ivan OHLÍDAL, Jiří VODÁK, Miloslav OHLÍDAL, Daniel FRANTA et. al.

Basic information

Original name

Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry

Name in Czech

Současné určení optických konstant, lokální tloušťky a lokální drsnosti tenkých vrstev pomocí zobrazovací spektroskopické refektometrie

Authors

NEČAS, David (203 Czech Republic, guarantor, belonging to the institution), Ivan OHLÍDAL (203 Czech Republic, belonging to the institution), Jiří VODÁK (203 Czech Republic, belonging to the institution), Miloslav OHLÍDAL (203 Czech Republic) and Daniel FRANTA (203 Czech Republic, belonging to the institution)

Edition

9628. vyd. BELLINGHAM, USA, Conference on Optical Systems Design - Optical Fabrication, Testing, and Metrology V, p. "96280C-1"-"96280C-9", 9 pp. 2015

Publisher

SPIE-INT SOC OPTICAL ENGINEERING

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10302 Condensed matter physics

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

Publication form

printed version "print"

RIV identification code

RIV/00216224:14310/15:00094362

Organization unit

Faculty of Science

ISBN

978-1-62841-817-0

ISSN

DOI

http://dx.doi.org/10.1117/12.2190091

UT WoS

000366832100005

Keywords in English

thin films; roughness; scalar diffraction theory; Rayleigh-Rice theory; spectrophotometry; ellipsometry; imaging techniques; zinc selenide

Abstract

V originále

A new optical characterization method based on imaging spectroscopic reflectometry (ISR) is presented and illustrated on the characterization of rough non-uniform epitaxial ZnSe films prepared on GaAs substrates. The method allows the determination of all parameters describing the thin films exhibiting boundary roughness and non-uniformity in thickness, i.e. determination of the spectral dependencies of the optical constants, map of local thickness and map of local rms values of heights of the irregularities for the rough boundaries. The local normal reflectance spectra in ISR correspond to small areas (37x37 pm2) on the thin films measured within the spectral range 270-900 nm by pixels of a CCD camera serving as the detector of imaging spectrophotometer constructed in our laboratory. To our experience the small areas corresponding to the pixels are sufficiently small so that the majority of the films can be considered uniform in all parameters within these areas. Boundary roughness is included into the reflectance formulas by means of the scalar diffraction theory (SDT) and the optical constant spectra of the ZnSe films were expressed by the dispersion model based on the parametrization of the joint density of electronic states (PJDOS). In general, there is a correlation between the searched parameters if the individual local reflectance spectra are fitted separately and, therefore, the local reflectance spectra measured for all the pixels are treated simultaneously using so called multi-pixel method in order to remove or reduce this correlation and determine the values of all the parameters with a sufficient accuracy. The results of the optical characterization of the same selected sample of the epitaxial ZnSe thin film obtained using the method presented here and combined method of variable-angle spectroscopic ellipsometry, spectroscopic reflectometry and single-pixel immersion spectroscopic reflectometry are introduced in the contribution as well.

Links

ED1.1.00/02.0068, research and development project

Name: CEITEC - central european institute of technology

ED2.1.00/03.0086, research and development project

Name: Regionální VaV centrum pro nízkonákladové plazmové a nanotechnologické povrchové úpravy

TA02010784, research and development project

Name: Optimalizace vrstevnatých systémů používaných v optickém průmyslu

Investor: Technology Agency of the Czech Republic

Citovat

NEČAS, David, Ivan OHLÍDAL, Jiří VODÁK, Miloslav OHLÍDAL and Daniel FRANTA. Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry. In Duparre, A; Geyl, R. Conference on Optical Systems Design - Optical Fabrication, Testing, and Metrology V. 9628th ed. BELLINGHAM, USA: SPIE-INT SOC OPTICAL ENGINEERING, 2015, p. "96280C-1"-"96280C-9", 9 pp. ISBN 978-1-62841-817-0. Available from: https://dx.doi.org/10.1117/12.2190091.

@inproceedings{1384153,
   author = {Nečas, David and Ohlídal, Ivan and Vodák, Jiří and Ohlídal, Miloslav and Franta, Daniel},
   address = {BELLINGHAM, USA},
   booktitle = {Conference on Optical Systems Design - Optical Fabrication, Testing, and Metrology V},
   doi = {http://dx.doi.org/10.1117/12.2190091},
   edition = {9628},
   editor = {Duparre, A; Geyl, R},
   keywords = {thin films; roughness; scalar diffraction theory; Rayleigh-Rice theory; spectrophotometry; ellipsometry; imaging techniques; zinc selenide},
   howpublished = {tištěná verze "print"},
   language = {eng},
   location = {BELLINGHAM, USA},
   isbn = {978-1-62841-817-0},
   pages = {"96280C-1"-"96280C-9"},
   publisher = {SPIE-INT SOC OPTICAL ENGINEERING},
   title = {Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry},
   year = {2015}
}

TY  - JOUR
ID  - 1384153
AU  - Nečas, David - Ohlídal, Ivan - Vodák, Jiří - Ohlídal, Miloslav - Franta, Daniel
PY  - 2015
TI  - Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry
PB  - SPIE-INT SOC OPTICAL ENGINEERING
CY  - BELLINGHAM, USA
SN  - 9781628418170
KW  - thin films
KW  - roughness
KW  - scalar diffraction theory
KW  - Rayleigh-Rice theory
KW  - spectrophotometry
KW  - ellipsometry
KW  - imaging techniques
KW  - zinc selenide
N2  - A new optical characterization method based on imaging spectroscopic reflectometry (ISR) is presented and illustrated on the characterization of rough non-uniform epitaxial ZnSe films prepared on GaAs substrates. The method allows the determination of all parameters describing the thin films exhibiting boundary roughness and non-uniformity in thickness, i.e. determination of the spectral dependencies of the optical constants, map of local thickness and map of local rms values of heights of the irregularities for the rough boundaries. The local normal reflectance spectra in ISR correspond to small areas (37x37 pm2) on the thin films measured within the spectral range 270-900 nm by pixels of a CCD camera serving as the detector of imaging spectrophotometer constructed in our laboratory. To our experience the small areas corresponding to the pixels are sufficiently small so that the majority of the films can be considered uniform in all parameters within these areas. Boundary roughness is included into the reflectance formulas by means of the scalar diffraction theory (SDT) and the optical constant spectra of the ZnSe films were expressed by the dispersion model based on the parametrization of the joint density of electronic states (PJDOS). In general, there is a correlation between the searched parameters if the individual local reflectance spectra are fitted separately and, therefore, the local reflectance spectra measured for all the pixels are treated simultaneously using so called multi-pixel method in order to remove or reduce this correlation and determine the values of all the parameters with a sufficient accuracy. The results of the optical characterization of the same selected sample of the epitaxial ZnSe thin film obtained using the method presented here and combined method of variable-angle spectroscopic ellipsometry, spectroscopic reflectometry and single-pixel immersion spectroscopic reflectometry are introduced in the contribution as well.
ER  -

NEČAS, David, Ivan OHLÍDAL, Jiří VODÁK, Miloslav OHLÍDAL and Daniel FRANTA. Simultaneous determination of optical constants, local thickness, and local roughness of thin films by imaging spectroscopic reflectometry. In Duparre, A; Geyl, R. \textit{Conference on Optical Systems Design - Optical Fabrication, Testing, and Metrology V}. 9628th ed. BELLINGHAM, USA: SPIE-INT SOC OPTICAL ENGINEERING, 2015, p.~''96280C-1''-''96280C-9'', 9 pp. ISBN~978-1-62841-817-0. Available from: https://dx.doi.org/10.1117/12.2190091.

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