教師著作
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Item Miniaturized multilayer dielectric coatings using metal masks fabricated by electroforming and photolithography technologies(SPIE, 2008-08-29) Jaing, Cheng-Chung; Yang, Chii-Rong; Chang, Chun-Ming; Chang, Yung-Hsin; Lee, Chao-Te; Hsiao, Chine-NanThe Ni films replacing photoresist serve as a mask to selectively deposit optical thin films at a substrate temperature of 300蚓 by an electron-beam gun evaporation. The photolithograph is used to define the growth of Ni films by an electroforming technique. Mosaic patterns with a width of 20&mgr;m are chosen as an arrangement of red color filters. The red filters are formed of alternate SiO2 and TiO2 layers and the average transmittance of red filters is larger than 90%. The experimental results successfully illustrate that the combinative uses of photolithography, electroforming and electron-beam gun evaporation can make miniaturized multilayer dielectric coatings with high light transmittance in a hot deposition.Item Comparison of Planar and 3D Electrode Designs for Cell Lysis by Electroporation(2006-01-15) Lu, Kuan-Ying; Lo, Ying-Jie; Chen, Ken-Chao; Lin, Chien-Ming; Wo, Andrew M.; Yang, Chii-RongItem Fabrication of nanoporous antireflection surfaces on silicon(Elsevier, 2008-11-01) Huang, Mao-Jung; Yang, Chii-Rong; Chiou, Yuang-Cherng; Lee, Rong-TsongAfter the surface of a silicon wafer has been texturized, the reflectance of the wafer surface can be reduced to increase the power generation efficiency of a silicon-based solar cell. This study presents the integration of self-assembled nanosphere lithography (SANSL) and photo-assisted electrochemical etching (PAECE) to fabricate a nanostructure array with a high aspect ratio on the surface of silicon wafer, to reduce its reflectance. The experimental results show that the etching depth of the fabricated nanopore array structure is about View the MathML source and its diameter is about 90 nm, such that the aspect ratio of the pore can reach about 68:1. The weighted mean reflectance of a blank silicon wafer is 40.2% in the wavelength range of 280–890 nm. Five-minute PAECE without SANSL reduces the weighted mean reflectance to 5.16%. Five-minute PAECE with SANSL reduces the weighted mean reflectance to 1.73%. Further coating of a 200 Å thick silicon nitride layer on the surface of a nanostructure array reduces the weighted mean reflectance even to 0.878%. The novel fabrication technology proposed in this study has the advantage of being low cost, and the fabricated nanostructure array can be employed as an antireflection structure in single crystalline silicon solar cells.Item Photoablation characteristics of novel polyimides synthesized for high-aspect-ratio excimer laser LIGA process(IOP, 2004-01-09) Yang, Chii-Rong; Hsieh, Yu-Sheng; Hwang, Guang-Yeu; Lee, Yu-DerThe photoablation properties of two soluble polyimides DMDB/6FDA and OT/6FDA with thicknesses of over 300 μm, synthesized by the polycondensation of a hexafluoropropyl group contained in a dianhydride with two kinds of diamines, are investigated using a 248 nm krypton fluoride (KrF) laser. The incorporation of the hexafluoropropyl group into the chemical structure gives these two polyimides higher etching rates than Kapton (a commercial polyimide film which is difficult to dissolve). The etching rates of synthesized polyimides are about 0.1–0.5 μm/pulse over a fluence range of 0.25–2.25 J cm-2. The photothermal mechanism for DMDB/6FDA contributes about 19% of etching depth at a laser fluence of 0.82 J cm-2. Moreover, the number of laser pulses seriously affects the taper angle of microstructures, especially at low fluence. Near-vertical side-wall structures can be built at high fluence (~2 J cm-2). Fresnel patterns with a thickness of 300 μm and a linewidth of 10 μm were fabricated, with an attainable aspect ratio of around 30. After photoablation, the complementary metallic microstructures were also fabricated by a sequential electroplating procedure. Then, those two new polyimides could be dissolved easily in most common solvents (such as THF, DMSO, NMP and DMF). These results indicate that these two soluble polyimides are highly suitable for use in the KrF laser LIGA process.Item Effects of various ion-typed surfactants on silicon anisotropic etching properties in KOH and TMAH solutions(Elsevier, 2005-03-28) Yang, Chii-Rong; Chen, Po-Ying; Yang, Cheng-Hao; Chiou, Yuang-Cherng; Lee, Rong-TsongThree ion-typed surfactants, including anionic SDSS, cationic ASPEG and non-ionic PEG, which are powerful wetting agents in electroforming, were added to 30 wt.% KOH and 10 wt.% TMAH solutions to evaluate the silicon anisotropic etching properties of the (1 0 0) silicon plane without agitation and no IPA additive. The results indicate that the surfactant ion-types are not the main determinants of the silicon anisotropic etching properties in KOH and TMAH solutions. The wetting capacity of the etchants causes the efficacies of the etchants on the roughness to follow the order anionic SDSS, cationic ASPEG, non-ionic PEG and pure solution in KOH solutions, and the order cationic ASPEG, non-ionic PEG, pure solution and anionic SDSS in TMAH solutions, especially at higher etching temperatures. Moreover, the chemical activities of etchants differ so that the etching rates follow the order anionic SDSS, pure solution, non-ionic PEG and cationic ASPEG in KOH solutions, and the order anionic SDSS, pure solution, cationic ASPEG and non-ionic PEG in TMAH solutions at a given etching temperature. Anionic SDSS has the highest etching rate of 5.4 μm/min and the lowest surface roughness of 7.5 nm, which are about 1.69 times higher and 7.87 times lower, respectively, than those obtained in pure KOH solution. The cationic ASPEG has a reasonable etching rate of 0.7 μm/min and the lowest surface roughness of 4 nm in TMAH solutions for etching temperature of 100 °C. Furthermore, the surfactants used here were demonstrated to allow the utilization of usual mask materials and anionic SDSS can even increase the selectivity of silicon dissolution toward silicon dioxide in KOH solutions. A drastic reduction of the undercutting of the convex corners is obtained in TMAH solutions with non-ionic PEG surfactant. This finding reveals that the addition of non-ionic PEG to TMAH solutions is ideal when accurate profiles are required without extremely deep etching.Item Microstructuring characteristics of a chemically amplified photoresist synthesized for ultra-thick UV-LIGA applications(IOP, 2004-01-09) Yang, Chii-Rong; Hsieh, Gen-Wen; Hsieh, Yu-Sheng; Lee, Yu-DerThe thick-film photoresists are essential to fabricate high-aspect-ratio microstructures by the UV-LIGA process. However, current thick-film photoresists have some weaknesses including a thickness of only up to 100 µm, a poor line-width resolution and difficulty in being stripped. Consequently, a new type of thick-film photoresist is required. This work presents a novel positive-tone MMA/TBMA photoresist, formed by combining copolymerization and chemically amplification (CA) for use in the ultra-thick UV-LIGA process. An MMA/TBMA photoresist film with a thickness of 500 µm is easily achieved. For MMA/TBMA photoresist layers with thicknesses from 100 µm to 500 µm, an exposure dose from 80 to 100 mJ cm−2 per micron is required to remove all of the exposed photoresist, revealing that the selectivity between radiated and non-radiated zones during a long development process is sufficiently high; the sidewall verticality and aspect ratio of the microstructure are excellent; stress-induced cracks are not observed in the non-radiated zones after development. MMA/TBMA photoresist is demonstrated to fabricate open microstructures with aspect ratios of at least 10 and close microstructures with aspect ratios of not more than 10, such values of aspect ratio are still sufficient for most ultra-thick mold applications. Moreover, MMA/TBMA photoresist can undergo erosion by acidic electrolyte and easily be stripped using usual organic solvents. These findings demonstrate that MMA/TBMA photoresist has the potential to replace SU-8 resist in the ultra-thick UV-LIGA process.Item Study on anisotropic silicon etching characteristics in various surfactant-added tetramethyl ammonium hydroxide water solutions(IOP, 2005-09-20) Yang, Chii-Rong; Yang, Cheng-Hao; Chen, Po-YingThree ion-typed surfactants, including anionic sodium dihexyl sulfosuccinate (SDSS), cationic ammonium salt of poly(ethylene glycol) (ASPEG) and non-ionic poly(ethylene glycol) (PEG), were added to 10 wt% tetramethyl ammonium hydroxide water (TMAHW) solutions to evaluate the silicon anisotropic etching properties of the (1 0 0) silicon plane without agitation and no isopropyl alcohol (IPA) additive. The results indicate that the wetting capacity of the etchants cause the efficacies of the etchants on the roughness reduction to follow the order cationic ASPEG, non-ionic PEG, pure solution and anionic SDSS in TMAHW solutions, especially at high etching temperatures. Moreover, the chemical activities of the etchants cause the efficacies of the etchants on the etching rates to follow the order anionic SDSS, pure solution, cationic ASPEG and non-ionic PEG in TMAHW solutions at a given etching temperature. The cationic ASPEG has a reasonable etching rate of 0.7 µm min−1 and the lowest surface roughness of 4 nm in TMAHW solutions at an etching temperature of 100 °C. ASPEG and PEG in TMAHW solutions markedly affect aluminum passivation. The undercutting of the convex corners in PEG-added TMAHW solutions can be drastically reduced without using corner compensation; the undercutting ratio obtained using a PEG surfactant is about 45% lower than that obtained in pure TMAHW solution. This finding reveals that non-ionic PEG should be added to TMAHW solutions when accurate profiles are required without extremely deep etching. This study also demonstrated that non-ionic PEG is more appropriate than IPA for anisotropic silicon TMAHW etching.Item Three dimensional electrode array for cell lysis via electroporation(Elsevier, 2006-10-15) Lu, Kuan-Ying; Wo, Andrew M.; Lo, Ying-Jie; Chen, Ken-Chao; Lin, Cheng-Ming; Yang, Chii-RongMicrofabricated devices for cell lysis have demonstrated many advantages over conventional approaches. Among various design of microdevices that employ electroporation for cytolysis, most utilize Ag/AgCl wires or 2D planar electrodes. Although, simple in fabrication the electric field generated by 2D electrodes decays exponentially, resulting in rather non-uniform forcing on the cell membrane. This paper investigates the effect of electric field generated by 3D cylindrical electrodes to perform cell lysis via electroporation in a microfluidic platform, and compared with that by 2D design. Computational results of the electric field for both 2D and 3D electrode geometries showed that the 3D configuration demonstrated a significantly higher effective volume ratio—volume which electric field is sufficient for cell lysis to that of net throughflow volume. Hence, the efficacy of performing cell lysis is substantially greater for cells passing through 3D than 2D electrodes. Experimentally, simultaneous multi-pores were observed on leukocytes lysed with 3D electrodes, which is indicative of enhanced uniformity of the electric field generated by 3D design. Additionally, a single row of 3D electrode demonstrated a substantially higher lysing percentage (30%) than that of 2D (8%) under that same flow condition. This work should aid in the design of electrodes in performing cell lysis via electroporation.Item Effects of mechanical agitation and surfactant additive on silicon anisotropic etching in alkaline KOH solution(Elsevier, 2005-03-28) Yang, Chii-Rong; Chen, Po-Ying; Chiou, Yuang-Cherng; Lee, Rong-TsongAgitation is a key method that significantly affects silicon wet anisotropic etching quality including the etching rate and surface roughness. This study introduced the ultrasonic agitation to improve the roughness quality of etched (1 0 0) silicon plane in 30 wt.% KOH solution. These etching characteristics have been compared with those using magnetic stirring and no agitation. In ultrasonic agitation condition, the etching rate increases linearly with agitating power, but the surface roughness worsens. Although the etching rate always exceeds 1.2 μm/min and the average roughness, Ra is below 15 nm, the membrane microstructures are damaged easily by ultrasonic agitation. Moreover, the KOH solution with added anionic surfactant, dihexyl ester of sodium sulfosuccinic acid, is also used to evaluate the etching properties of (1 0 0) silicon under without agitation. Owing to increasing hydrophilic ability between the hydrogen bubble and silicon surface and the effect of silicon wettability, the etching properties are promoted drastically. Experimental results show that the average roughness, Ra can be reduced to 7.5 nm in aqueous KOH with anionic surfactant, which is about eight times better than achieved by the pure KOH solution without agitation for etching temperature of 100 °C. Meanwhile, the etching rate can be enhanced to 4.9 μm/min, which is 1.44 times better than that is obtainable in a pure KOH solution with ultrasonic agitation. The etching rate of the KOH solution with added surfactant is about twice that in the KOH solution with isopropyl alcohol (IPA) for etching temperature of 80 °C. Furthermore, this study also illustrates the reflectivity of etched surface for visible wavelength and the fabrication of thin film microstructures.Item DNA detection using a radio frequency biosensor with gold nanoparticles(Frontiers in Bioscience, 2008-05-01) Chien, Jui-Hung; Yang, Ching-Hao; Chen, Ping-Hei; Yang, Chii-Rong; Lin, Chin-Shen; Wang, HueiThis study presents a novel method for DNA detection with multi-layer AuNPs to enhance overall detection sensitivity. This essay achieves not only an innovative radio-frequency biosensor but also a critical signal amplification methodology. Results show that bandwidth change for multi-layer AuNP with hybridization of DNA exceeds that for the double-layer AuNP up to 0.5 GHz. Furthermore, the developed biosensor detection limit for the DNA set employed in this essay is currently 10 pM. A single base-pair mutation of the wild-type target DNA could be distinguished from the perfect match target DNA at the melting temperature of 47 degrees C with a temperature controlling system. Experimental results in this study indicate that the proposed biosensor and the developed amplification methodology are successful. As health care becomes much more essential in modern life, this biosensor has potential applications in a screening kit for recognizing, sensing, and quantifying biomolecules in real samples.