• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.95-96
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• 2006

ITO thin film is generally fabricated by various methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) process is one of the suitable solutions which could solve the problems.

• Korea Science and Art Forum
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• v.20
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• pp.421-428
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• 2015

Electronic/hybrid car and electroplating rectifier should have switching devices such as SCR, MOSFET, IGBT. And those switching devices should be operated by gate driver. In this paper, we propose high power gate driver that contains H-Bridge using 4 BJTs. H-Bridge and transformer generate isolate power. And gate control signal is transferred to isolated one by photo coupler and operate real switching device. We designed H-Bridge and 555-Timer by PSpice simulation and manufactured real product. Finally we succeed to operate 27V 50,000A electroplating rectifier using proposed gate driver.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.123-127
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• 2009

In order to get more higher integration density of devices, it is getting to be used more and more micro via interconnection lines for interconnecting layers or devices. However, it is very important to enhance the electrical characteristic by reducing the electrical resistivity of micro via interconnection line because it affects the reliability of packaging. In this paper, Micro vias were patterned with a diameter from 10 to 100 um by increasing the step of 10 um and 100 um height and were fabricated by micromachining technology to investigate the electrical characteristic of micro via interconnection lines. These micro vias were filled with copper by electroplating process with appling pulse current mode. And the electrical characteristics of micro via interconnection lines were measured. The measured value of electrical resistivity shows with a range from 20 to $26\;m{\Omega}$. This value from micro via interconnection lines fabricated by pulse current mode electroplating process shows better result than the resistivity from than micro via interconnection lines fabricated by DC mode ($31\;m{\Omega}$).

• Journal of the Korean institute of surface engineering
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• v.36 no.3
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• pp.242-250
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• 2003

Electrodeposition of Ni was carried out on copper substrate from Ni Sulfamate bath by DC and high frequency pulse current. During the electroplating, bath temperature was steady $60^{\circ}C$ , agitation was applied. Morphology and surface roughness of electrodeposits was investigated with the AFM. Crystalline structure of electrodeposits was investigated with XRD. Also, surface electric resistivity was investigated with 4-point probe. The result of crystalline structure by X-ray diffractometer, in the case of DC, <200> direction was dominant growing direction. But in the case of PC, the ratio of <200> direction vs. other direction decreased. As the pulse frequency increased, the enhanced properties of deposits were shown. With increasing frequency, the degree of surface properties increased DC more than that of PC, eg surface morphology, roughness and the degree of compactness of grains. With increasing duty cycle, the surface properties such as the degree of the morphology, roughness and electroconductivity was deteriorated.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.249-249
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• 2015

Silver films have been of considerable interest for years due to their better performance relative to other metal films for engineering applications. A series of multi-layer silver coatings with different thickness (i.e. 0.3 um to 1.5 um) were prepared on Aluminium substrate containing copper undercoat by direct current (DC) magnetron sputtering method. For the comparative purpose, similar thickness silver coatings were prepared by electrolytic deposition method. Microstructural, morphological, and mechanical characteristics of the silver coatings were evaluated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), Surface roughness test, microhardness test and nano-scratch test. From the results, it has been elucidated that the silver films prepared by DC magnetron sputtering method has superior properties in comparison to the wet coating method. On the other hand, DC magnetron sputtering method is relatively easier, faster, eco-friendly and more productive than the electrolytic deposition method that uses several kinds of hazardous chemicals for bath formulation. Therefore, a New Work Item Proposal (NWIP) for the test methods standardization of DC magnetron sputtered silver coatings has recently been proposed via KATS, Korea and a NP ballot is being progressed within a technical committee "ISO/TC107-metallic and other inorganic coating".

• Journal of Sensor Science and Technology
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• v.29 no.4
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• pp.275-278
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• 2020

In this study, we evaluated the temperature-dependent characteristics of homojunction InGaAs vertical Fin-shaped Tunnel Field-Effect Transistors (Fin TFETs), which were fabricated using a novel nano-fin patterning technique in which the Au electroplating and the high-temperature InGaAs dry-etching processes were combined. The fabricated homojunction InGaAs vertical Fin TFETs, with a fin width and gate length of 60 nm and 100 nm, respectively, exhibited excellent device characteristics, such as a minimum subthreshold swing of 80 mV/decade for drain voltage (V_DS) = 0.3 V at 300 K. We also analyzed the temperature-dependent characteristics of the fabricated TFETs and confirmed that the on-state characteristics were insensitive to temperature variations. From 77 K to 300 K, the subthreshold swing at gate voltage (V_GS) = threshold voltage (V_T), and it was constant at 115 mV/decade, thereby indicating that the conduction mechanism through band-to-band tunneling influenced the on-state characteristics of the devices.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.7-9
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• 2008

ITO thin film is generally fabricated by various. methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) process is one of the suitable solutions which could solve the problems

• Korean Journal of Materials Research
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• v.12 no.1
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• pp.82-88
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• 2002

Chromium carbide films were deposited on high speed steels using a Cr_3C_2$ target by magnetron sputtering. Effects of the deposition parameters (power, Ar pressure and substrate temperature) on deposition rates and surface roughnesses of the films were investigated. The morphologies of those films were characterized by scanning electron microscopy and atomic force microscopy. The grain size of the samples deposited using dc-power is larger than that using equivalent rf-power. The hardness of the sample increases with increasing rf-power, whereas the elastic modulus nearly does not change with rf-power. The optimum sputter deposition conditions for chromium carbide on high speed steels in the corrosion resistance aspect were found to be the rf-power with small roughness.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3295-3297
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• 1999

This paper presents the fabrication of an electromagnetic micro actuator consisting of a Parylene diaphragm with a spiral copper coil and a permanent magnet. The copper coil is fabricated by electroplating and patterning. The frequency response of the actuator are obtained using a laser vibrometer. When the input voltage is 3 V, the DC deflection is 5 ${\mu}m$, and the resonance frequency is about 35 Hz. Also, the mechanical sensitivity of the actuator diaphragm is 69 ${\mu}m/V$.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1357-1358
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• 2006

Indium tin oxide (ITO) thin film is a transparent electrode, which is widely applied to solar battery, illuminators, optical switches, liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting displays (OLEDs) due to its easy formation on glass substrates, goof optical transmittance, and good conductivity. ITO thin film is generally fabricated by various methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) processis one of the suitable solutions which could solve the problems.