• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1593-1597
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• 2009

A biosensor has been developed based on induced wavelength shifts in the Fabry-Perot fringes in the visible reflection spectrum of appropriately derivatized thin films of porous silicon semiconductors. Porous silicon (PSi) was generated by an electrochemical etching of silicon wafer using two electrode configurations in aqueous ethanolic HF solution. Porous silicon displayed Fabry-Perot fringe patterns whose reflection maxima varied spatially across the porous silicon. The sensor system studied consisted of a mono layer of porous silicon modified with Protein A. The system was probed with various fragments of an aqueous Human Immunoglobin G (Ig G) analyte. The sensor operated by measurement of the Fabry-Perot fringes in the white light reflection spectrum from the porous silicon layer. Molecular binding was detected as a shift in wavelength of these fringes.

• Journal of the Korean Graphic Arts Communication Society
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• v.28 no.1
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• pp.15-24
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• 2010

Photovoltaic solar cells are all in the incident because they are not converted into electrical energy, high-efficiency solar cells in order to reduce the loss of elements must be. Significant factor in the loss of solar cells, optical loss and electrical loss can be divided into. Optical losses occur when the sun will be joined on the surface of the reflection, the shadow loss due to electrodes, and the losses are in the solar wavelengths. Commercialization is currently the most common solar cells on the front of the light incident on the electrode is formed. Therefore, the shadow caused by the electrode to cover the dead area of the sun, due to factors that hinder the absorption of sunlight which is shadowing them and conversion efficiency of solar cells is the inhibition factor. These barriers to eliminate the electrode linewidth reduces the shadowing to reduce, but simply of the electrode line width is reduced electrode area by reducing the series resistance elevates this because to improve the electrode Aspect ratio(height/width) to increase Ag development of paste is required. In this study, aspect ratio of screen-printing method to increase the electrode Ag paste composition of the binder for the characterization of rheology in the shadow of the electrode by reducing the optical loss of the photoelectric conversion efficiency of solar cells to boost the performance measures was. Properties and printability of the paste, the binder resin sintered characteristics that affect the thermal properties are excellent with a good screen printability acrylic resin, ethyl cellulose, using a resin were evaluated. Prepared paste rheology properties, was formed to evaluate the electrode conductivity and aspect ratio.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.433-439
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• 2011

Poly Si TFTs (poly silicon thin film transistors) with p channel those are annealed HT (high temperature) with gate poly crystalline silicon and LT (low temperature) with metal gate electrode were fabricated on quartz substrate using the analyzed data and compared according to the activated grade silicon thin films and the size of device channel. The electrical characteristics of HT poly-Si TFTs increased those are the on current, electron mobility and decrease threshold voltage by the quality of particles of active thin films annealed at high temperature. But the on/off current ratio reduced by increase of the off current depend on the hot carrier applied to high gate voltage. Even though the size of the particles annealed at low temperature are bigger than HT poly-Si TFTs due to defect in the activated grade poly crystal silicon and the grain boundary, the characteristics of LT poly-Si TFTs were investigated deterioration phenomena those are decrease the electric off current, electron mobility and increase threshold voltage. The results of transconductance show that slope depend on the quality of particles and the amplitude depend on the size of the active silicon particles.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.6 s.336
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• pp.23-30
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• 2005

In this paper, OPPS(oxidized porous poly-silicon) field emitters were fabricated by using various emitter-electrode metal and these electron emission characteristics were investigated for different thermal annealing effects. The addressed OPPS field emitter with Pt/Ti emitter electrode annealed at $300^{\circ}C$-1hr showed the efficiency of $2.98\%$ at $V_{ps}$=12 V and one annealed at $350^{\circ}C$-1hr showed the highest efficiency of $3.37\%$at $V_{ps}$=16V. They are resulted from the improvement of interfacial contact characteristics of thin emitter metal to an oxidized porous poly-silicon and the decrease of electrical resistance of emitter metal. The brightness of the OPPS field emitter increases linearly in $V_{ps}$ and after oxidation process for $900^{\circ}C$-50min, the brightness of the OPPS field emitter with the as-deposited Pt/Ti emitter electrode was 3600 cd/$m^2$ at the $V_{ps}$=15 V, 6260 cd/$m^2$ at the $V_{ps}$=20 V. Thermal treatment improved the adhesion between the Ti buffer layer and the oxidized porous poly-silicon and also played an important role in the uniform distribution of electric field to the emitter electrode.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.1-5
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• 2019

This study has been focused on properties of surface technology for large diameter upper electrode using in high density plasma process as like semi-conductor manufacturing process. The experimental studies have been carried out to get mirror surface for upper electrode. For a formation of high surface quality upper electrode, single crystal silicon upper electrode has been mechanical and chemical machining worked. Mechanical machining work of the upper electrode is carried out with varying mesh type using diamond wheel. In case of chemical machining work, upper electrode surface roughness was observed to be strongly dependent upon the etchant. The different surface roughness characteristics were observed according to etchant. The machining result of the surface roughness and surface morphology have been analyzed by use of surface roughness tester, laser microscope and ICP-MS.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.4
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• pp.252-256
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• 2003

In this paper we describe the status of a silicon-based microelectrode for neural recording and an advanced neural interface. We have developed a silicon neural probe, using a combination of plasma and wet etching techniques. This process enables the probe thickness to be controlled precisely. To enhance the CMOS compatibility in the fabrication process, we investigated the feasibility of the site material of the doped polycrystalline silicon with small grains of around 50 nm in size. This silicon electrode demonstrated a favorable performance with respect to impedance spectra, surface topography and acute neural recording. These results showed that the silicon neural probe can be used as an advanced microelectrode for neurological applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.4
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• pp.209-216
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• 2014

The screen printed technique is one of the electrode forming technologies for crystalline silicon solar cell. It has the advantage that can raise the production efficiency due to simple process. The electrode technology is the core process because the electrode feature is given a substantial factor (for solar cell efficiency). In this paper, we tried to change conditions such as squeegee angle $55{\sim}75^{\circ}$, snap off 0.5~1.75 mm, printing pressure 0.6~0.3 MPa and 1.6~2.0 mm finger spacing. As a result, the screen printing process showed an improved performance with an increased height higher finger height. Optimization of fabrication process has achieved 17.48% efficiency at screen mesh of 1.6 mm finger spacing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.349-349
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• 2010

Great performance of many semiconductor devices requirs the use of low-resistance ohmic contact. Typically, transmission line method (TLM) patterns are used to measure the specific contact resistance between silicon and metal. In this works, we investigate contact resistance for metal dependent (Cr/Ag, Ni) using TLM pattern based on silicon-on-insulator (SOI) wafer. The electrode with Ni linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in accumulation part, but non-linearly increase in inversion part. In additional, the electrode with Cr/Ag linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in inversion part, but non-linearly increase in accumulation part.

• Current Photovoltaic Research
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• v.4 no.4
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• pp.145-149
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• 2016

Characteristic of aluminum-silicon alloy paste which is applied on the rear side of PERC cell was investigated. The paste was made by aluminum-silicon alloy with eutectic composition to avoid the formation of void which is responsible for the degradation of the open-circuit voltage. Also, the glass frit component of the paste was changed to improve the adhesion of aluminum-silicon paste. We observed the formation of void and local back surface field between aluminum electrode and silicon base by SEM. The light IV, quantum efficiency and reflectance of the solar cells were characterized and compared for each paste.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.11
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• pp.575-580
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• 2001

In this paper, using $500\mum-thickness\; (100)\; silicon\; wafer,\; flat\; 65\mum-thickness$ silicon mirror plates were fabricated through dry etching and wet etching, and $45\mum-depth$ grooved driving electrodes were fabricated through UV-LIGA process. Four shapes of the driving electrode were fabricated: twenty four grooves of the $50\mum-width$, twelve grooves of the $100\mum-width$, six grooves of the $200\mum-width$, and no grooves on the driving electrode. Fabricated mirror plate size and spring size are $2400\times2400\times65\mum3\; and \;500\times10\times65\mum3,$ respectively. Mirror plate parts and driving electrodes were assembled into the scanning mirrors. Measured natural resonance frequencies were about 600Hz which have error within $\pm 2%$ to calculated value. Due to the squeeze effect in the narrow gap between the mirror plate and the driving electrode, measured resonance frequencies were reduced as raising the amplitude of the mirror plate. In a case of driving electrode without grooves, the resonance frequency was reduced largely, compared with a case of driving electrode with grooves. According to the experimental results, squeeze effect was smaller in the driving electrode with smaller-width and many grooves. Therefore, the driving electrode with smaller-width and many grooves was effective in low voltage and high speed operation.