Browsing by Author "Wu, Shich-Chuan"

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Amorphous carbon coated silicon nanotips fabricated by MPCVD using anodic aluminum oxide as the template
(2007)
Chen, Te-Ming
;
Pan, Fu-Ming
;
Hung, Jui-Yi
;
Chang, L.
;
Wu, Shich-Chuan
We have used nanoporous anodic aluminum oxide (AAO) as a template to fabricate amorphous carbon (alpha-C) coated silicon nanotips by microwave plasma chemical vapor deposition (MPCVD). During the preparation of the well-ordered AAO pore channel array, an underlying TiN layer was anodically oxidized as well in the late stage of the AAO anodization, forming titanium oxide nanomasks for Si nanotip fabrication. The titanium oxide nanomasks were then used to transfer the arrangement pattern of the AAO pore channel array to the Si substrate by plasma etch in the MPCVD system and, therefore, a well-ordered Si nanotip array was produced. An alpha-C layer similar to 5 nm thick was in situ deposited on the Si nanotips during the MPCVD process. The alpha-C layer was rich in nanocrystalline graphitic carbons according to Raman and Auger electron spectroscopies. The nanocrystalline graphitic carbons in the coating and the sharp tip shape made the Si nanotip a good field emitter and a field enhancement factor of similar to 659 was obtained. (c) 2007 The Electrochemical Society.
Demonstration of multilayer titanium photonic crystals with 100-nm feature sizes
(2008-01-01)
Wu, Shich-Chuan
;
Lin, Chuan-Ding
;
Yang, Yu-Lin
;
Chen, Jing-Shian
;
Huang, Yang-Tung
Multilayer titanium photonic crystals are fabricated with the mature integrated circuit (IC) technology, which is similar to the Damascene interconnect process. The photonic crystals that we created have the face-centered-tetragonal lattice symmetry. In each layer, the feature size, height and the spacing of the titanium rods is 100 nm, 200 nm and 300 nm, respectively. To our knowledge, this is at the first time that the three-dimensional titanium photonic crystals are realized successfully with 100-nm line width. The reflectance spectra of three- and four-layer titanium photonic crystals are measured with the Fourier-transform infrared spectroscopy and simulated with the three-dimensional finite different time domain method. Through both the experimental observation and the calculation verification, the characterization of the photonic band gap is demonstrated at near-infrared wavelengths and the optical behavior of titanium photonic crystals is discussed for incident light waves of s- and p-polarization. Moreover, the absorption spectra are derived from the reflectance and transmittance spectra due to the law of conservation of energy. It is found that absorption near the photonic band edge is modified and enhanced in a narrow bandwidth because of the well-known recycling-energy mechanism. The large band gap can suppress black body radiation in the mid-infrared range and recycle energy into the near infrared. According to Kirchoff's law, the absorptance of a body equals its emissivity. Thus, the multilayer titanium photonic crystals would be applied as an efficient near-infrared light source with a narrow bandwidth, and produced on a mass scale with the standard IC technology.
Enhanced fight transmission for Si solar cells using anti-reflector of mesoporous silica with low refractive index
(2007)
Shieh, Jia-Min
;
Wang, Chao-Kei
;
Wu, Shich-Chuan
;
Ni, Wei-Xin
;
Kuo, Hao-Chung
Mesoporus silica dielectrics, which revealed low refractive index (n similar to 1.27), were introduced together with Si3N4 layers to be double-layer-based graded-refractive-index ant-reflectors for silicon solar-cells. Enhanced solar-light transmission increased conversion efficiency of Si solar panels by 20%.
Enhanced solar-light transmission by broadband anti-reflective structure with mesoporous silica of low refractive index
(2008)
Wang, Chao-Kei
;
Shieh, Jia-Min
;
Wu, Shich-Chuan
;
Yu, Wen-Chien
;
Kuo, Hao-Chung
Mesoporus silica dielectrics, which revealed low refractive index (n similar to 1.26), were introduced together with Si3N4 layers to be double-layer-based graded-refractive-index ant-reflectors for silicon solar-cells. Enhanced solar-light transmission increased conversion efficiency of Si solar panels by 4%.
Fabrication and characterization of three-dimensional all metallic photonic crystals for near infrared applications
(2009-01-26)
Yang, Yu-Lin
;
Hou, Fu-Ju
;
Wu, Shich-Chuan
;
Huang, Wen-Hsien
;
Lai, Ming-Chih
Three-dimensional all metallic photonic crystals with a feature size of 0.20 mu m were fabricated using electron-beam lithography with the photoresist of hydrogen silesquioxane. This process method has high compatibility with the fabrication of damascene copper interconnections and also simplifies the whole process flow. The dependence of the complete photonic band gaps on polarization was experimentally observed and compared with the simulation results. The band edge for the four-layer lattice was found at a wavelength of around 0.80 mu m in normal incidence.
Fabrication and field-emission characteristics of TiN nanorods with a concave top surface
(2008)
Chen, Te-Ming
;
Hung, Jui-Yi
;
Pan, Fu-Ming
;
Chang, L.
;
Sheu, J. -T.
Well-ordered titanium nitride nanorods were fabricated by reactive ion etch using titanium oxide nanodots as the mask, which were prepared using the anodic aluminum oxide templation method. The TiN nanorods exhibited a concave top surface with a protruding edge. Due to the protruding top edge and a high aspect ratio, the TiN nanorods showed a low turn-on voltage of 1.6 V/mu m. The ellipsoidal cylinder model was used to evaluate the field-enhancement effect of the protruding edge, and an underestimation by similar to 26% was found as compared with the enhancement factor derived from the Fowler-Nordheim plot. (C) 2008 The Electrochemical Society.
Fabrication and properties of Cu-Ni mixed-metal periodical array for midinfrared filtering and hydrophobic application
(2008-09-01)
Huang, Wen-Hsien
;
Yang, Yu-Lin
;
Wu, Shich-Chuan
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Cu was grown successfully on Ni film as a conductive layer that demonstrated a stronger Cu (111) preferred crystallographic orientation. Furthermore, we studied the scale effect of various periods of patterned Ni lines separated by variable widths of SiO2. When Cu was electroplated onto this patterned Ni, it preferentially deposited on the Ni edges adjacent to the SiO2 stripes, resulting in a Cu-Ni-Cu-SiO2, Cu-SiO2-Cu, or Cu-Cu structure, depending on the dimensions of the starting Ni pattern and the deposition time. There are two reflective dips at 2.2 and 8 mu m wavelengths using Fourier transform infrared spectroscopy, which revealed a trend of narrower bandwidth in reflective spectra and a redshift effect with increasing deposition time. Interestingly, a hydrophobic surface was also observed due to its particular surface-roughness structures that could be controlled by the deposition time and altered the contact angle from 72 degrees to 110 degrees without coating any extra low free-energy materials. (C) 2008 American Vacuum Society.
Layer-by-Layer Copper Photonic Crystals for Near Infrared Spectral Region
(2010)
Wu, Shich-Chuan
;
Yang, Yu-Lin
;
Huang, Wen-Hsien
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
We selected copper as the material to form the 3D structures with feature sizes of 0.4 mu m to study its desirable optical properties at near infrared wavelengths from using the high compatible process of damascene copper interconnections technique. The reflectance and transmittance spectra of the 3D copper photonic crystals were measured with the Fourier-transform infrared (FTIR) spectroscopy and simulated with the 3D FDTD method. Through both the experimental observation and the calculation verification, the characterization of the PBG is right at near infrared wavelengths. It is worth noted that some interesting behavior were observed in the spectra and transmitting ratio under different polarization incident conditions.
Pulse Electrodeposition of Iridium Oxide on Silicon Nanotips for Field Emission study
(2009-05-01)
Chen, Te-Ming
;
Hung, Jui-Yi
;
Pan, Fu-Ming
;
Chang, L.
;
Wu, Shich-Chuan
To improve electron field emission properties of anodic aluminum oxide (AAO) templated Si nanotips, IrO(2) nanoparticles were deposited on the nanotips using bipolar pulse electrodeposition method. The IrO(2) nanoparticles had a uniform size distribution with an average value of similar to 4 nm, and well dispersed on the ordered Si nanotips. Due to the small radius and a lower work function, the IrO(2)/Si nanotip exhibited field emission properties better than the bare Si nanotip with a field enhancement factor of similar to 128. The SEM and TEM were utilized to investigate the structure and morphology. The physical and chemical properties were evaluated XRD and X-ray photoelectron spectroscopy (XPS).
Thermal emission at near-infrared wavelengths from three-dimensional copper photonic crystals
(2011-08-15)
Wu, Shich-Chuan
;
Yang, Yu-Lin
;
Huang, Wen-Hsien
;
Huang, Yang-Tung
;
電子工程學系及電子研究所
A three-dimensional copper photonic crystal was fabricated with the high compatibility process, damascene copper interconnections technique. The reflectance and transmittance spectra of this structure were measured with the Fourier-transform infrared spectroscopy and simulated with the 3 D finite-difference time-domain method. From the experiment data, it is shown that this structure exhibits a large photonic bandgap from mid-infrared regime to lambda = 1.95 mu m. At a heating temperature of 420 degrees C, it is observed that thermal emission is enhanced near the bandedge lambda = 1.71 mu m and suppressed in the bandgap region. This is attributed to the enhancement of photonic density of states near the bandedge. (C) 2011 American Institute of Physics. [doi:10.1063/1.3625263]