• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.21-23
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• 2011

Uniformity of plasma etching processes critically depends on the wafer temperature and its distribution. The wafer temperature is affected by plasma, chucking force, He back side pressure and the surface temperature of ESC(electrostatic chuck). In this work, 3D mathematical modeling is used to investigate the influence of the geometry of coolant path and the temperature distribution of the ESC surface. The model that has the coolant path with less change of the cross-sectional area and the curvature shows low standard deviation of the ESC surface temperature distribution than the model with the coolant path of the larger surface area and more geometric change.

• 한국전기전자재료학회논문지
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• 제17권4호
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• pp.448-452
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• 2004

The micromachined variable optical attenuator(VOA) was presented in the paper. The VOA has two single mode fiber(SMF) aligned with free space and symmetric parallel plate actuator with microshutter, which can control a amount of light by driving the actuator. In the paper, analysis on driving performances of the VOA was performed and can be reduced threshold voltage through the decreasing displacement actuating range. This paper presents a VOA that is fabricated using bosch deep silicon etching process with silicon on insulator(SOD wafer. The VOA consists of driving electrode, ground electrode, actuating microshutter, and mechanical stopper. In this VOA, actuating shutter is driven by electrostatic force and the threshold voltage is close to 28V, 46V come along with the spring width of 5${\mu}{\textrm}{m}$, 7${\mu}{\textrm}{m}$ respectively. Attenuation range is measured from 2.4㏈ to 16.7㏈.

• Transactions on Electrical and Electronic Materials
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• 제10권6호
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• pp.189-192
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• 2009

The leakage current in a CMOS image sensor (CIS) can have various origins. Leakage current investigations have focused on such things as cobalt-salicide, source and drain scheme, and shallow trench isolation (STI) profile. However, there have been few papers examining the effects on leakage current of nitride stringers that are formed by gate sidewall etching. So this study reports the results of a series of experiments on the effects of a nitride stringer on real display images. Different step heights were fabricated during a STI chemical mechanical polishing process to form different nitride stringer sizes, arsenic and boron were implanted in each fabricated photodiode, and the doping density profiles were analyzed. Electrons that moved onto the silicon surface caused the dark leakage current, which in turn brought up the speckle defect on the display image in the CIS.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1126-1129
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• 2004

Because of the various length condition of carbon nanotube, it is very confined the application area of the single CNT tip. In this paper, it was proposed the cutting technique of single CNT tip and the relationship between the etched volume and the amount of the applied charge. It is possible to control the length of single CNT tip arbitrary using this technique. The etched volume and length in the single CNT tip can be predicted with the amount of the applied charge. It is very easy to make a single CNT tip with proper length using this technique and to make nanotweezer that was composed two single CNT tips.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1136-1141
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• 2004

In recent years, demands on microelectrode have been greatly enhanced because of its potential applications and mass production of microelectrodes is needed. An electrochemical fabrication is used as an method for the simple and cheap fabrication of multi microelectrodes. In this paper, one dimensional microelectrode array is used for fabricating of multi electrodes. A diffusion layer which is formed near the electrode surface has an effect on the shape error of multi microelectrodes. The optimal distance between electrodes to minimize shape errors of multi electrodes is investigated. Multi microelectrodes which has several tens of and hundreds of micrometer in diameter are fabricated at a time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1364-1369
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• 2004

New method for the design, fabrication, and calibration of micro-machined heat flux sensor has been developed. Two types of micro-machined heat flux sensor having different thicknesses of the thermal-resistance layer are fabricated using the MEMS technique. Photo-resist patterning using a chrome mask, bulk-etching and copper-nickel sputtering using a shadow mask are applied to make heat flux sensors, which are calibrated in the convection-type heat flux calibration facility. The sensitivity of the device varies with thermal-resistance layer, and hence can be used to measure the heat flux in heat-transfer phenomena.

• 한국생산제조학회지
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• 제18권6호
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• pp.636-641
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• 2009

Recently, expansion of micro-technology parts requires micro-precision machining technology. Micro-groove machining is important to fabricate micro-grating lens and many micro-parts such as microscope lens, fluidic graphite channel etc. Conventional groove fabrication methods such as etching and lithography have some problems in efficiency and surface integrity. But, mechanical micromachining methods using single crystal diamond tools can reduce these problems in chemical process. For this reason, microfabrication methods are expected to be very efficient, and widely studied. This study deals with machinability in micro-precision V-grooves machining of nickel plated layer using non-rotational single crystal diamond tool and 3-axis micro stages. Micro V-groove shape, chip formation and tool wear were investigated for the analysis of machinability of Ni plated layer.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.71-74
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• 2012

Uniformity of the wafer temperature is one of the important factors in etching process. Plasma, chucking force, backside helium pressure and the surface temperature of ESC(electrostatic chuck) affect the wafer temperature. ESC consists of several layers of structure. Each layer has own thermal resistance and the Si-adhesive layer has highest thermal resistance among them. In this work, the temperature distribution of ESC was analyzed by 3-D FEM with various defects and the thickness deviation of the Si-adhesive layer. The result with Si-adhesive layer with the low center thickness deviation shows modified temperature distribution of ESC surface.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2002년도 춘계 기술심포지움 논문집
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• pp.274-278
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• 2002

The purpose of this study was to characterize the reaction of Cu surface with Cu slurry and CMP performance as a function of additives in CMP slurry. The polish rate of Cu was dependent on the kind of organic acids added in slurry. It was considered that polish rate of Cu was dependent on the concentration of carboxylates and mean particle size. When the etchant and oxidant were added in slurry, the highest removal rate and lower etch rate were measured at neutral pH. The addition of etchant, oxidant and pH adjustor played key roles of CMP ability in slurry. As the pH increased, polish rate of Cu was increased by the enhanced the mechanical effects due to effective dispersion of slurry particles. Alumina abrasives was more desirable for 1st step slurry because of high removal rate of Cu and high selectivity ratio among TaN and Cu.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1912-1913
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• 2003

This paper presents a variable optical attenuator (VOA) that is fabricated using bosch deep silicon etching process [1] with silicon-on- insulator (SOI) wafer. The VOA consists of driving electrode, ground electrode, actuating mirror, and mechanical slower. In this VOA, actuating mirror is driven by electrostatic force [2] and the pull-in voltage is close to 13V, 28 V, 46V come along with the spring width of $3{\mu}m,\;5{\mu}m,\;7{\mu}m$ respectively.