• Transactions on Electrical and Electronic Materials
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• v.18 no.1
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• pp.25-29
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• 2017

This paper presents a unique pressure sensor design for environmental applications. The design uses a new geometry for a multi bossed beam-membrane structure with a SOI (silicon-on-insulator) substrate and a mechanical transducer. The Intellisuite MEMS CAD design tool was used to build and analyze the structure with FEM (finite element modeling). The working principle of the multi bossed beam structure is explained. FEM calculations show that a sensing diaphragm with Mises stress can provide superior linear response compared to a stress-free diaphragm. These simulation results are validated by comparing the estimated deflection response. The results show that, the sensitivity is enhanced by using both the novel geometry and the SOI substrate.

• Journal of Magnetics
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• v.18 no.2
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• pp.163-167
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• 2013

We fabricated prototype cantilevers for mechanically detected high-frequency ESR measurement. Cantilevers are fabricated from silicon-on-insulator (SOI) wafers using standard MEMS techniques such as lithography, wet etching, and plasma etching. Using commercial SOI wafers, fabrication cost and the number of processes can be substantially reduced. In this study, three types of cantilevers, designed for capacitive and optical detection, are shown. Capacitive type with lateral dimensions of $3.5{\times}1.6mm^2$ is aimed for low spin concentration sample. On the other hand, optical detection type with lateral dimensions of $50{\times}200{\mu}m^2$ is developed for high-sensitive detection of tiny samples such as newly synthesized microcrystals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.187-190
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• 1996

Conducting polymers have band structures similar to those of inorganic semiconductors such as silicon. Several electronic devices have been constructed with conjugated polymers, mainly Schottky diodes and Metal-Insulator-Semiconductor Field-Effect Transistors (MISFET's). Organic semiconductor has been reported as active materials in MISFET's.$^{1.4}$ In our laboratory, $\alpha$-Sexithiencyl ($\alpha$-6T) has been synthesized and purified by sublimation method. In this study, thin films of $\alpha$-Sexithienyl were prepared on various substrates in ultra-high vacuum chamber by vacuum evaporation method, so called OMBD(Organic Molocular Beam Deposition).$^{7.9}$ The $\alpha$-Sexithienyl thin films were deposited with various deposition conditions. The crystalline structure, and molecular orientation of these films have being studied by using UV/Vis. spectroscopy and X-Ray Diffractometry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.170-173
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• 2003

In this paper, we proposed a new bulk LDMOS structure which can be used for RF application, and its fabrication steps were introduced. The simulated devices consist of three types: Bulk device, SLB(SOI Like Bulk), and SOI device. As a result of process and device simulation, we showed electrical characteristics, such as threshold voltage, subthreshold slope, DIBL(Drain Induced Barrier Lowering), off-state current, and breakdown voltage. In this simulation study, the lattice temperature model was adopted to see the device characteristics with lattice temperature during the operation. SLB device structure showed the best breakdown characteristics among the other structures. The breakdown voltage of SLB structure is about 9V, that of bulk is 7V, and that of SOI is 8V.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.425-427
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• 1994

A manipulator which can separate dielectric particles (biological cells) was fabricated on a silicon wafer using polyimide and n-type electroplating. It consists of 1024 electrode arrays ($60{\mu}m{\times}60{\mu}m$) and spacing insulator. Positive dielectrophoresis is used for attracting particles. We have the solution of 3-D laplace equation about this device and calculate the force acting on the particles. The solution has spatial periodicity in the x, y directions and decays exponentially in the z direction.

• Current Optics and Photonics
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• v.3 no.5
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• pp.438-444
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• 2019

In this theoretical study, a line-defect photonic-crystal waveguide hosted in an annular photonic crystal was demonstrated to provide high-performance slow light with a wide band, low group-velocity dispersion, and a large normalized delay-bandwidth product. Combined with structural-parameter optimization and selective optofluid injection, the normalized delay-bandwidth product could be enhanced to a large value of 0.502 with a wide bandwidth of 58.4 nm in the optical-communication window, for a silicon-on-insulator structure. In addition, the group-velocity dispersion is on the order of $10^5$ ($ps^2/km$) in the slow-light region, which could be neglected while keeping the signal transmission unchanged.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.131-138
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• 2021

The optimization of the specifications of vertical silicon on insulator (SOI) slot optical waveguides suitable for integrated-optical biochemical sensors was performed through computational analysis of the confinement factor of the guided mode distributed in the slot in addition to analytical examination of the TE mode. The optimized specifications were confirmed based on sensitivity in terms of the change in the refractive index of the biochemical analyte. When the slot width, rail width, and height were set to 120 nm, 200 nm, and 320 nm, respectively, the confinement factor was evaluated to be about 56% and the sensitivity was at least 0.9 [RIU/nm].

• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.107-114
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• 2022

The effects of ring radius and coupling spacing on the free spectral range (FSR), full width at half maximum (FWHM), quality factor, and sensitivity of single-channel and add-drop channel slot ring resonators were systematically investigated using FIMMPROP and PICWAVE numerical software. The single-channel ring resonator exhibited better characteristics, namely, a wider FSR and narrower FWHM compared with the add-drop structure; thus, it was evaluated to be more suitable for biochemical sensors. The FSR, FWHM, quality factor, and sensitivity for a single channel ring resonator with a radius of 59.4 ㎛ and coupling gap of 0.5 ㎛ were 2.4 nm, 0.087 nm, 17677, and 550 [nm/RIU], respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.159-162
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• 2002

This paper reviews an advanced excimer-laser crystallization technique enabling precise location-control of the individual grains. With the developed ${\mu}$-Czochralski (grain-filter) process, the large grains having a diameter of 6 ${\mu}m$ can be set precisely at predetermined positions. We will also discuss the performance of the single-crystalline Si TFTs that are formed within the location-controlled Si grains. The field-effect mobility for electrons is 430 $cm^2/Vs$ on average, which is well comparable to that of TFTs made with silicon-on-insulator wafers.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.31-32
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• 2010

In our previous reports [1-3], electron transport for the switching and memory devices using alkyl thiol-tethered Ru-terpyridine complex compounds with metal-insulator-metal crossbar structure has been presented. On the other hand, among organic memory devices, a memory based on the OFET is attractive because of its nondestructive readout and single transistor applications. Several attempts at nonvolatile organic memories involve electrets, which are chargeable dielectrics. However, these devices still do not sufficiently satisfy the criteria demanded in order to compete with other types of memory devices, and the electrets are generally limited to polymer materials. Until now, there is no report on nonvolatile organic electrets using nano-interfaced organic monomer layer as a dielectric material even though the use of organic monomer materials become important for the development of molecularly interfaced memory and logic elements. Furthermore, to increase a retention time for the nonvolatile organic memory device as well as to understand an intrinsic memory property, a molecular design of the organic materials is also getting important issue. In this presentation, we report on the OFET memory device built on a silicon wafer and based on films of pentacene and a SiO2 gate insulator that are separated by organic molecules which act as a gate dielectric. We proposed push-pull organic molecules (PPOM) containing triarylamine asan electron donating group (EDG), thiophene as a spacer, and malononitrile as an electron withdrawing group (EWG). The PPOM were designed to control charge transport by differences of the dihedral angles induced by a steric hindrance effect of side chainswithin the molecules. Therefore, we expect that these PPOM with potential energy barrier can save the charges which are transported to the nano-interface between the semiconductor and organic molecules used as the dielectrics. Finally, we also expect that the charges can be contributed to the memory capacity of the memory OFET device.[4]