scholarly journals Real-Time Double-Layer Thin Film Thickness Measurements Using Modified Sagnac Interferometer with Polarization Phase Shifting Approach

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 529
Author(s):  
Abdullahi Usman ◽  
Apichai Bhatranand ◽  
Yuttapong Jiraraksopakun ◽  
Rapeepan Kaewon ◽  
Chutchai Pawong

This paper describes a modified Sagnac interferometer with a self-referenced polarization and phase-shifting technique for real-time thickness measurement of single- and double-layer transparent thin films. The proposed interferometric setup generated outstanding rotating linearly polarized light with a degree of polarization (DOP) of 99.40%. A beam splitter placed at the interferometer output separated the beam into two identical linearly polarized beams. One of the beams served as a reference, while the other served as a sensing arm. The output linear polarizer set at 45° relative to a reference plane was positioned anterior to the photodetectors to get rotating light intensities for phase shift measurement; hence, the intensities at various polarizations of 0°, 45°, and 90° were automatically acquired without any polarizing device adjustments. These intensities were then transformed into a phase retardation introduced by a sample, and the resulting phase shift was eventually converted into film thickness. The samples were properly prepared, with pure BK7 substrate being deposited by WO3-, Ta2O5-, and WO3/Ta2O5 films of known thicknesses. The thickness measurement obtained from the proposed system yielded reading errors of 1.3%, 0.2%, and 1.3/2.5% for WO3-, Ta2O5-, and WO3/Ta2O5 films, respectively. The mathematical theory was effectively demonstrated and empirically confirmed. The experimental results show that the proposed setup has a lot of potential for real-time, non-destructive thickness assessment of transparent thin films without the need to modify polarizing device orientations.

Author(s):  
A.E. Shupenev ◽  
N.S. Pankova ◽  
I.S. Korshunov ◽  
A.G. Grigoriyants

The thickness of thin films determines the films’ unique properties, due to which they are widely used in optics and electronics. To measure the thickness of films in the range of 1 nm — 1 mcm during film deposition or on a finished product, it is important that non-destructive measurement methods should be used. An analysis of the most commonly used non-destructive methods for measuring and controlling the thickness of thin films is performed, with a possibility of in situ control of the technological process as well as for testing of finished products. This work describes theoretical and practical considerations of using reflection high-energy electron diffraction, piezoelectricity, interferometry and gravimetric methods for thin film thickness measurements. The results of the study can be used for selecting an optimal method of obtaining thin films when conducting theoretical and applied research.


Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 615 ◽  
Author(s):  
Hammad ◽  
Abdel-wahab ◽  
Vattamkandathil ◽  
Ansari

This study investigated nonstoichiometric nickel oxide thin films prepared via the DC-sputtering technique at different film thicknesses. The prepared films were characterized by a surface profiler for thickness measurement, X-ray diffraction (XRD) for film nature, atomic force microscopy (AFM) for film morphology and roughness, UV-visible-near infrared (UV-vis.-NIR) spectroscopy for optical transmittance spectra of the films, and the photoluminescence (PL) spectra of the prepared films were obtained. The measured film thickness increased from 150 to 503 nm as the deposition time increased. XRD detected the trigonal crystal system of NiO0.96. The crystallite sizes were mainly grown through (101) and (110) characteristic planes. NiO0.96 films have a spherical particle shape and their sizes decreases as the film thickness increased. The optical band gap values decrease from 3.817 to 3.663 eV when the film thickness increases. The refractive index was estimated from the Moss relation, while the high-frequency dielectric constant and the static dielectric constant were deduced from the empirical Adachi formula. The photoluminescence behavior of the studied films confirmed the photogeneration of an electron-hole in nickel and oxygen vacancies. Hence, this study confirms the presence of nickel oxide lattice in the hexagonal structure containing the defects originated from the nickel vacancies or the excess of oxygen.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Fabio Lopes ◽  
Luís Henrique Cardozo Amorin ◽  
Larissa da Silva Martins ◽  
Alexandre Urbano ◽  
Carlos Roberto Appoloni ◽  
...  

Nanometric thin films have always been chiefly used for decoration; however they are now being widely used as the basis of high technology. Among the various physical qualities that characterize them, the thickness strongly influences their properties. Thus, a new procedure is hereby proposed and developed for determining the thickness of V2O5nanometric thin films deposited on the glass surface using Portable X-Ray Fluorescence (PXRF) equipment and the attenuation of the radiation intensity Kαof calcium present in the glass. It is shown through the present paper that the radiation intensity of calcium Kαrays is proportional to film thickness in nanometric films of vanadium deposited on the glass surface.


2008 ◽  
Vol 19 (4) ◽  
pp. 047002 ◽  
Author(s):  
Sang-Heon Ye ◽  
Soo Hyun Kim ◽  
Yoon Keun Kwak ◽  
Hyun Mo Cho ◽  
Yong Jai Cho ◽  
...  

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