Browsing by Author "Chao, Yu-Faye"

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Assessment of interface roughness during plasma etching through the use of real-time ellipsometry
(2011-01-15)
Han, Chien-Yuan
;
Lai, Chien-Wen
;
Chao, Yu-Faye
;
Leou, Ke-Ciang
;
Lin, Tsang-Lang
Real-time in situ ellipsometry was used to investigate the etching of SiO(2)/silicon wafers with a high concentration of Cl(2). We monitored the temporal trajectory of the ellipsometric parameter Delta and then selected several points for ex situ study using atomic force microscopy (AFM). There was a clearly observable transition period in the trajectory near the endpoint of the SiO(2)/Si interface. We studied the relationship between the ellipsometric parameter Delta and the same point in the AFM ex situ measurements. Three stages, thin film, the interface layer, and the substrate, were analyzed in this work. (C) 2010 Elsevier B.V. All rights reserved.
Deassociate the initial temporal phase deviation provided by photoelastic modulator for stroboscopic illumination polarization modulated ellipsometry
(2011-03-01)
Tsai, Hsiu-Ming
;
Chen, Chih-Wei
;
Tsai, Tsung-Han
;
Chao, Yu-Faye
;
光電工程學系
In addition to operating the imaging ellipsometric measurements by four-specific temporal phases in the photoelastic modulated ellipsometry, we added the fifth one to solve the initial phase of the photoelastic modulator. This methodology has been developed to conquer the slow imaging processing of charge-coupled device camera for the stroboscopic illumination in the polarization modulated imaging ellipsometry. Without any calibration in its initial phase, we can perform the ellipsometric measurement by the measurements of intensity at five-specific temporal phases. The intensities of a full cycle for a point on SiO(2)/Si thin film were measured and analyzed for verifying this algorithm. The five stroboscopic illuminations were performed to measure the two-dimensional distribution of the same SiO(2)/Si thin film. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3568745]
Determining thickness of films on a curved substrate by use of ellipsometric measurement
(2008-01-01)
Han, Chien-Yuan
;
Lee, Zhen-You
;
Chao, Yu-Faye
;
光電工程學系
;
Department of Photonics
The three intensity polarizer-sample-analyzer imaging ellipsometry is used to measure the ellipsometric parameters (Psi, Delta). In addition to the ellipsometric parameters, we introduce an extra angle alpha to measure the of the azimuth deviation of polarizer. After careful calibration, we found this deviation can indicate how much the surface normal slanted from the plane; then it can be used to deduce the thickness profile coated on a cylindrical lens. Using this technique, we. not only can determine the radius curvature of the curved surface, we also can calculate the thickness of the thin film coated on a curved surface.
Determining thickness of films on a curved substrate by use of ellipsometric measurements
(2009-06-10)
Han, Chien-Yuan
;
Lee, Zhen-You
;
Chao, Yu-Faye
;
光電工程學系
;
Department of Photonics
A three-intensity measurement technique has been employed in polarizer-sample-analyzer imaging ellipsometry to measure the two-dimensional ellipsometric parameters of a coated cylindrical lens. Since azimuth deviation a of a polarizer can also be measured with this three-intensity measurement technique, we tilted a well-calibrated thin-film wafer to identify the orientation of the measured a with respect to the incident plane. Using the analytic property of this measurement technique, we can correct the deviation and determine the thickness profile of the thin film coated on a cylindrical lens. (C) 2009 Optical Society of America
Developing a Phase and Intensity Measurement Technique with Multiple Incident Angles under Surface Plasmon Resonance Condition
(2013-01-01)
Han, Chien-Yuan
;
You, Du Cheng
;
Chen, Yi-Ren
;
Chao, Yu-Faye
;
光電工程學系
This work presents the application of a focused beam polarizer-sample-analyzer imaging ellipsometer in measuring the ellipsometric parameters under the surface plasmon resonance condition. By using a cylindrical lens to produce fan shaped beam with multiple incident angles, three-intensity measurement technique can measure the ellipsometric parameters against each incidence but without the need of calibrating the azimuth errors of polarizer and analyzer. As a result of multiple incident angles approach, the whole SPR curve can be obtained without rotating the sensor chip. The intensity and phase response in the air and water interface of the sensor chip were demonstrated, and almost all measured results are close to the theoretical model.
Dynamic characterization of photo-alignment of azo-dye-doped polymer using phase modulated polarimetry
(2013-01-01)
Chuang, Chun-I
;
Lin, Shivan-Huei
;
Chao, Yu-Faye
;
電子物理學系
;
光電工程學系
Using a combination of two-probe-beam phase modulated polarimetry and a waveform extraction technique, we show it is possible to determine all the optical parameters of an anisotropic medium. Particularly, we have measured the dynamic changes of refractive index ellipsoid of the disperse red 19-doped poly(methyl methacrylate) under the irradiation of linear polarized lights. The long axis of the trans molecule can be aligned to the propagation direction of P-polarized light while it is irritated by two crossed polarized lights. The refractive indices and orientation angles can be determined in one cycle of modulation (20 mu s) with sufficient precision of 10(-6) and 0.1 degrees, respectively. This work shows a new way to simultaneously monitor and control the photo-alignment process of azobenzene molecules in a polymer matrix. (c) 2012 Elsevier B.V. All rights reserved.
Optimization of a four-temporal phase lock for photoelastic-modulated polarimetry
(2009-08-01)
Tsai, Hsiu-Ming
;
Chao, Yu-Faye
;
光電工程學系
;
Department of Photonics
A set of four-temporal phases in photoelastic-modulated polarimetry is proposed to measure the Stokes parameters. In comparison with the conventional polarimetry, which uses a set of four-spatial angles by rotating a quarter-wave plate to obtain the polarimetric parameters, this temporal type polarimetry not only can reduce the time consumption but also can avoid the measurement error from the beam deviation. In addition, based on singular value decomposition, the figure of merit of this temporal phase technique can improve its signal-to-noise ratio by a factor of 2 in comparison with the rotating quarter-wave plate. (C) 2009 Optical Society of America
Phase-modulated ellipsometry for probing the temperature-induced phase transition in ruthenium-doped lead zinc niobate-lead titanate single crystal
(2011-02-28)
Chuang, Chun-I
;
Marinova, Vera
;
Lin, Shiuan-Huei
;
Chao, Yu-Faye
;
電子物理學系
Phase-modulated ellipsometry was applied to measure changes in the refractive index of pure and ruthenium (Ru)-doped 0.9Pb (Zn(1/3)Nb(2/3))O(3)(PZN)-0.1 PbTiO(3) (PT) during the heating process in real time. Both samples were heated from room temperature to 200 degrees C in a thermally insulated chamber. In both samples, the phase transitions were observed to change from tetragonal to cubic. The temperature region at which the phase transition (Curie region) of Ru-doped 0.9PZN-0.1PT occurred not only broadened but also shifted to a lower temperature. The refractive indices were extremely stable in this region, meaning that Ru-doped 0.9PZN-0.117 is a more favorable medium for the fabrication of optical memories. (C) 2011 Elsevier B.V. All rights reserved.
Post flight analysis of the surface plasmon resonance enhanced photoelastic modulated ellipsometry
(2007-02-20)
Chao, Yu-Faye
;
Han, Chien-Yuan
;
光電工程學系
;
Department of Photonics
A total internal reflection ellipsometer equipped with a photoelastic modulator (PEM) is installed to investigate the chemical activation and antibody immobilization process on thin gold films. We set up two detection channels in this configuration: one for real-time monitoring with a data rate of 1 set per second, and the other for post flight analysis with a data rate of 25,000 sets per second. More detailed information has been obtained through the post flight analysis technique during the chemical activation process. This surface plasmon resonance enhanced PEM ellipsometry provides higher sensitivity and temporal resolution. It is feasible to resolve a faster reaction such as chemical reaction or protein folding by the post flight analysis technique. (c) 2006 Elsevier B.V. All rights reserved.
Rapid and accurate extraction of optical parameters for uniaxial bulk media by phase modulated ellipsometry
(2013-07-01)
Chuang, Chun-I
;
Lin, Shiuan-Huei
;
Chao, Yu-Faye
;
電子物理學系
;
光電工程學系
An improved phase modulated technique has been implemented to increase the speed and accuracy of optical parameters extraction for a uniaxial bulk media. In combination of the genetic algorithm, we show that not only the complex refractive indices, the inclination and azimuth angles of optical axis can also be extracted. Furthermore, by using a two-probe-beam configuration, the speed of convergence can be improved by 5-times. Such a high speed and accurate method can be applied for the in-situ measurement of dynamic materials. (C) 2013 Elsevier Ltd. All rights reserved.
Real-time measurement of photo-induced effects in 9,10-phenanthrenequinone-doped poly(methyl methacrylate) photopolymer by phase-modulated ellipsometry
(2010-09-01)
Chuang, Chun-I.
;
Hsiao, Yi-Nan
;
Lin, Shivan-Huei
;
Chao, Yu-Faye
;
電子物理學系
The photo-induced effects in 9,10-phenanthrenequinone-doped (PQ-doped) poly(methyl methacrylate) (PMMA) photopolymer were studied by phase-modulated ellipsometry and polarimetry in real time. The PQ-doped PMMA was exposed to an Ar/Kr tunable laser at the wavelength of 488 nm and measured by a HeNe laser (632.8 nm). We measured the induced birefringence and the variation of the refractive index separately during exposure; there was a difference of three orders of magnitude between these two effects. This suggested that the physical mechanism of holographic recording in PQ-doped PMMA is mainly due to the photo-induced variation in the refractive index. (C) 2010 Elsevier B.V. All rights reserved.
Ultra fast self-corrected polarization modulated ellipsometer
(2011-02-28)
Tsai, Hsiu-Ming
;
Chen, Leng-Chun
;
Chao, Yu-Faye
;
光電工程學系
;
Department of Photonics
A high speed self-corrected algorithm is proposed for the polarization modulated ellipsometry (PME). In this post-flight analysis, we prove that a set of optimized ellipsometric parameters (EPs) can be obtained by using the intensities at 4 specific temporal phases. The correction ability to its initial phase by this technique has been demonstrated through a twisted nematic liquid crystals (TN-LC) cell under the driving of a square wave. Furthermore, the optimal modulation amplitude in obtaining the accurate and precise set of EPs will be discussed in this work. (C) 2011 Elsevier B.V. All rights reserved.
Volume polarization holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer
(2011-08-15)
Lin, Shiuan Huei
;
Chen, Po-Lin
;
Chuang, Chun-I
;
Chao, Yu-Faye
;
Hsu, Ken Y.
Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514nm reaches 1.2 x 10(-5). In addition, ability for recording volume polarization grating using two different polarization configurations is demonstrated and compared. The experimental results show that the diffraction efficiency of the hologram reaches to similar to 40% by using two orthogonal circularly polarized beams. (C) 2011 Optical Society of America