• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.97-97
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• 1996

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.990-995
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• 2005

This paper reports the fabrication and characterization of $5\;\times\;5$ thermal cantilever array for nano-scaled memory device application. The $5\;\times\;5$ thermal cantilever array with integrated tip heater has been fabricated with MEMS technology on SOI wafer using 7 photo masking steps. All single-level cantilevers have a diode in order to eliminate any electrical cross-talk between adjacent tips. Electrical measurements of fabricated thermal cantilever away show its own thermal heating mechanism. Thermal heating is demonstrated by the reflow of coated photoresist on the cantilever array surface.

• Analytical Science and Technology
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• v.19 no.6
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• pp.519-528
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• 2006

An analytical method for the determination of thyroid hormones in urine samples has been studied by using solid-phase extraction and high-performance liquid chromatography/diode array detector/electro-spray mass spectrometry. Seven thyroid hormones were successfully separated by gradient elution on the reverse phase Hypersil ODS column (4.6 mm I.D., 100 mm length, particle size $5{\mu}m$) with ammonium formate buffer and acetonitrile, and UV spectra and mass fragment could be confirmed. The extraction recoveries of thyroid hormones in the urine samples (pH 3) were in the range of 89.0-113.1% with solid-phase extraction by C18, followed by elution with 4 ml of methanol/ammonium hydroxide (9 : 1). The calibration curves showed good linearity with the correlation coefficients ($r^2$) varying from 0.992 to 0.998 and the detection limits of all analytes were obtained in the range of 2-4 ng/ml (3.8-13.0 pmol/ml).

• Progress in Medical Physics
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• v.19 no.3
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• pp.164-171
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• 2008

One of the most important task in commissioning intensity modulated radiotherapy (IMRT) into a clinic is the characterization of dosimetry performance under small monitor unit delivery conditions. In this study, method of evaluating dose monitor linearity, beam flatness and symmetry, and MLC positioning accuracy using a diode array is investigated. Siemens Primus linear accelerator (LA) with 6 and 10 MV x-rays was used to deliver radiation and the characteristics were measured using a multi array diodes. Monitor unit stabilities were measured for both x-ray energies. The dose linearity errors for the 6 MV x-ray were 2.1, 3.4, 6.9, 8.6, and 15.4 % when 20 MU, 10 MU, 5 MU, 4 MU, and 2 MU was delivered, respectively. Greater errors were observed for 10 MV x-rays with a maximum of 22% when 2 MU was delivered. These errors were corrected by adjusting D1_C0 values and reduced to less than 2% in all cases. The beam flatness and symmetry were appropriate without any correction. The picket fence test performed using diode array and film measurement showed similar results. The use of diode array is a convenient method in characterizing beam stability, symmetry and flatness, and positioning accuracy of MLC for IMRT commissioning. In addition, adjustment of D1-C0 value must be performed when a Siemens LA is used for IMRT because factory value usually gives unacceptable beam stability error when the MU/segment is smaller than 20.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.894-900
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• 2006

This paper reports the fabrication and characterization of $32{\times}32$ thermal cantilever array for nano-scaled memory device applications. The $32{\times}32$ thermal cantilever array with integrated tip heater has been fabricated with micro-electro-mechanical systems(MEMS) technology on silicon on insulator(SOI) wafer using 9 photo masking steps. All of single-level cantilevers(1,024 bits) have a p-n junction diode in order to eliminate any electrical cross-talk between adjacent cantilevers. Nonlinear electrical characteristic of fabricated thermal cantilever shows its own thermal heating mechanism. In addition, n-channel high-voltage MOSFET device is integrated on a wafer for embedding driver circuitry.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.12
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• pp.13-18
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• 2005

In this paper, we fabricated a pixel array in which each pixel was consisted of Organic Thin Film Transistor (OTFT) serially connected with Organic Light Emitting Diode (OLED) on Poly-ethylene-terephthalate (PET) substrate and the number of pixels was 64 x 64. As a gate insulator of OTFT, the thermally cross-linked PVP was used and the organic semiconductor, Pentacene, is deposited for an active layer of OTFT considering the compatibility with PET substrate. The mobility of OTFT is $1.0\;cm^2/V{\cdot}sec$ as a discrete device, but it was reduced to $0.1\~0.2\;cm^2/V{\codt}sec$ in the array. We analyzed the operation of the array and confirmed the current driving ability of OTFTs for the OLEDs.

• Biomedical Science Letters
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• v.14 no.2
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• pp.91-96
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• 2008

Light Emitting Diode (LED) of 880 nm was used as a function of luminosity in culture of the photosynthetic bacteria including Rhodobacter sp.. An array of 880 run LED was driven with an energy density of $6.0mW/cm^2$. In processing time, we were able to show that the cell growth were gained of significant changes in the pigment and in the dry weight. And we also showed that photosynthetic bacteria had the resonable relativity of optical density to dry weight. LED-880nm is of great significance for the potential use of photo-bioreactor construction.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.591-592
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• 2006

Schottky diodes for Radio-frequency identification (RFID) tag integration on chip were designed and fabricated using Samsung electronics System LSI standard $0.18{\mu}m$ CMOS process. Schottky diodes were designed as interdigitated fingers array by CMOS layout design rule. 64 types of Schottky diode were designed and fabricated with the variation of finger width, length and numbers with a $0.6{\mu}m$ guard ring enclosing n-well. Titanium was used as Schottky contact metal to lower the Schottky barrier height. Barrier height of the fabricated Schottky diode was 0.57eV. DC current - voltage measurements showed that the fabricated Schottky diode had a good rectifying properties with a breakdown voltage of -9.15 V and a threshold voltage of 0.25 V.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.577-584
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• 2015

A photovoltaic (PV) system generates electricity by installing a solar energy array; therefore, the photovoltaic system can be easily exposed to external factors, which include environmental factors such as temperature, humidity, and radiation. These factors-as well as shading, in particular-lead to power degradation. When there is an output loss in the solar cell of a PV module package, the output loss is partly controlled by the bypass diode. As solar cells become highly efficient, the characteristics of series resistance and parallel resistance improve, and the characteristics of reverse voltage change. A bypass diode is connected in parallel to the string that is connected in series to the PV module. Ideally, the bypass diode operates when the voltage is -0.6[V] around. This study examines the bypass diode operating time for different types of crystalline solar cells. It compares the reverse voltage characteristics between the single solar cell and polycrystalline solar cell. Special modules were produced for the experiment. The shading rate of the solar cell in the specially made solar energy module was raised by 5% each time to confirm that the bypass diode was operating. The operation of the bypass diode is affected not only by the reverse voltage but also by the forward bias. This tendency was verified as the number of strings increased.

• Proceedings of the Optical Society of Korea Conference
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• 1991.07a
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• pp.77-82
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• 1991

여러개의 레이저 빔을 결합하여 대표적인 방법의 장단점을 비교 분석하였다. incoherent 방법으로는 wavelength multiplexing, spatial multiplexing, polarization multiplexing을 분석하였고 coherent 방법으로는 binary phase grating과 travelng-were amplification을 고려하였다. 특히 고출력 laser diode array를 이용한 대출력 증폭기 시스템을 분석하였다.