Papers by Author: Chia Jen Ting

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Authors: Cheng Huan Chen, Po Chou Chen, Chin Ju Hsu, Chia Jen Ting
Abstract: A diffractive laser beam shaper has been proposed as a lossless approach to transfer a Gaussian laser beam into a thin line beam with a uniform distribution along the line direction for scanning material processing or illumination application. With the consideration for the feasibility of fabrication, the optical performance of the diffractive beam shaper with its surface relief quantized at different levels has been analyzed with scalar diffraction theory, which shows that an 8 level solution is sufficient for keeping the uniformity in the line direction while the focusing function in the orthogonal dimension needs to be performed by an extra cylindrical lens.
Authors: Hung Yin Tsai, Ching Wen Liu, Chia Jen Ting
Abstract: Owning to the robust characteristics of diamonds, a nano-tip array structured mold was fabricated with diamond, we can then use this mold to produce anti-reflection (AR) films with nanoimprint lithography. Taking advantage of the self-ordered characteristic of anodic aluminum oxide (AAO), we can obtain the diamond mold by depositing a layer of diamond on the AAO using hot filament chemical vapor deposition (HFCVD). Then taking advantage of the high through-put characteristics of nanoimprint lithography, AR films can be mass produced. The AR films were subjected to reflectivity inspections, a 5.5% reduction in reflectivity was obtained.
Authors: Chia Jen Ting, Hung Yin Tsai, Chang Pin Chou
Abstract: Many research works have been focusing on nanoimprint technology due to the recent potential mass production for the nanostructure applications. For optical or display application, a nanoimprint mold of large area becomes one of the thorniest techniques since it takes much time to fabricate the whole mold with nanostructure and it may make the beginning nanostructures inconsistent with the final ones. In order to fabricate the nanostructure mold of large area in a short time, the plasma process forming nanostructures on silicon substrate and the electroforming process are explored in the current study. Well-aligned nanotip arrays of 4 inch silicon were fabricated by electron cyclotron resonance (ECR) plasma process using gas mixtures of silane, methane, argon, and hydrogen. The resultant tips have nano-scale apexes, approximately ~1 nm, with high aspect ratios, nearly ~15, which were achieved by simultaneous SiC nano-mask formation and dry etching during ECR plasma process. Next, the nickel mold of nanostructures is made from silicon nanostructures through the electroforming process by using Nickel Sulfamate. The total thickness of the nickel mold is 120 μm after a 10-hour-long electroforming process. The nanostructures of 100 nm diameter holes are successfully obtained. Nanoimprint process is proceeded by the nickel mold and the reflectance of the PMMA after imprinting at 160 °C has the lowest value, 0.2 %, compared with the other results for the incident optical wavelength of 550 nm. The large-area imprint mold with high-aspect-ratio nanotip arrays of sub-micron diameter is fabricated and is proofed by the optical application.
Authors: Hung Yin Tsai, Chia Jen Ting, Kei Lin Kuo, Chang Pin Chou
Abstract: The laser ablation technique is one option for micro-machining and patterning of diamond film. A UV YAG laser with higher energy density can remove or destroy the diamond film more efficiently than the excimer laser. That is, the UV YAG laser not only provides faster etching rate on the diamond film, but also requires less processing and maintenance cost. In the current study, synthetic diamond films with grain size of 30 μm were deposited on silicon substrate by microwave plasma enhanced chemical vapor deposition (MPCVD) in the CH4/H2 mixture atmosphere. A pulsed UV YAG laser (λ = 355 nm, 10 kHz) was employed to machine and remove the diamond film. The diamond film surface was analyzed by SEM and Raman spectroscopy after the laser machining. The beam size of YAG laser was adjusted to between 0.1 mm and 1.5 mm by the trepan mechanism to approach the following defined scanning width. In order to shape a 4-inch diamond wafer into a microstructure, the scanning width of the UV YAG laser was defined to 0.1 mm, 0.75 mm and to 1.5 mm in several loops. The results show that the laser-polishing effect can be applied to the pretreatment of mechanical polishing of diamond wafer in the condition of 0.75 mm scanning width in 3 loops. From Raman spectrum, it could prove the mechanism of carbon burning reaction during the laser processing and the residual carbon existing in the laser-patterned area. The surface of diamond film is strongly affected by the laser processing and a better result from the parameter of 0.75 mm scanning width in 3 loops is shown in the current study.
Authors: Chia Jen Ting, Chi Feng Chen, Ta Hsin Chou, Tsung Cho Wu, Tsung Hsin Lin
Abstract: The machining technology of ultrasonic assisted ductile mode grinding for the silicon carbide (SiC) wafer carrier. The machining tool is designed and analyzed by ANASYS 14.0 and the machining technology is studied for the 6-inch SiC wafer carrier. The ultrasonic tool holder with the resonance frequency 26 kHz is designed and fabricated. The advantageous machining parameters are proposed that spindle rotation rate is 3000 rpm, feed speed is 200 mm/min, and ultrasonic output power is 250 W. The measurement results show that the average roughness (Ra) of the SiC is 0.18 μm, the MRR is over 2.4 mm3/min, the tool tips are only minor abrasion, and the cutting temperature are reduced. Obvious, the machining technology has the advantage of high surface quality, high machining efficiency and long tool life.
Authors: Cho Wei Chang, Tien Li Chang, Ting Kai Tsai, Chia Jen Ting, Chien Ping Wang, Chang Pin Chou
Abstract: Femtosecond laser (FS-laser) microstructuring of metals has become a promising tool because of its non-contact nature, which allows the micromachining and direct processing of materials with a minimized volume of heat-affected zone for electro-optics applications such as light emitting diodes (LED) and solar photovoltaic (PV) lighting. This study presents ultra-short pulse (10-15 sec) FS-laser processing. Through integrating the laser source, optical system and dynamic control modules, the materials of metals with micro-scale or nanoscale structures can be fabricated. In traditional processing such as semiconductor processing, development, exposure and etching necessitate expensive equipment and time-consuming tasks. With FS-laser processing, high-precision patterns are obtained, which will be a great benefit to keeping costs down. In this study, the wavelengths of FS-laser ablation are employed using visible and infrared light. To make a breakthrough in electro-optics processes, the CIGS thin-film of solar cells in metal process can be easily produced by the FS-laser. The ablation speed of the FS-laser for thin film layer CIGS solar cells can reach 2000 mm/s which is faster than the current Nd:YAG laser machine (~1000 mm/s). On the other hand, the minimum size of metal lines can be controlled to a value that is lower than 40 µm. Furthermore, green energy can be effectively developed for the future.
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