• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.167-171
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• 2003

We report the material and electrical properties of $CoSi_2$ and $NiSi_2$contacts to n-type 4H-SiC depending on the post-annealing and the metal covering conditions. The Ni and Co silicides are deposited by RF sputtering with Ni/Si/Ni and Co/Si/Co films separately deposited on 4H-SiC substrates. The deposited films are annealed at $800\;^{\circ}C$ in $Ar:H_2$ (9:1) gas ambient. Results of the specific surface resistivity measurements show that the resistivity of the Co-based metal contact was the one order lower than that of the Ni-based contact. The specific contact resistance was measured by a transmission line technique, and the specific contact resistivity of $1.5{\times}10^{-6}\;{\Omega}\;cm^2$ is obtained for Co/Si/Co metal structures after a two-step annealing; at $550\;^{\circ}C$ for 10 min and $800\;^{\circ}C$ for 3min. The physical properties of the contacts were examined by using XRD and AES, and the results indicate that the Co-based metal contacts have better structural stability of silicide phases formed after the high temperature annealing.

• 전기전자학회논문지
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• 제25권3호
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• pp.467-472
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• 2021

고온에서도 반도체 소자의 안정적인 동작이 필요하다. 반도체 소자의 구조중에서 고온에서 불안정한 전기적 응답을 야기할 수 있는 영역은 금속과 반도체가 접합하는 콘택층이다. 본 연구에서는 p형 SiC 층위에 니켈-실리사이드(NiSix)의 콘택층을 형성하는 공정과정에 포함되는 어닐링 공정 조건이 콘택 저항의 비저항과 전체 저항에 미치는 효과를 고찰하였다. 이를 위해, 4인치 p형 SiC층 위에 전송길이 이론(transfer length method: TLM) 측정을 위한 알련의 전극 패턴들을 형성하였고, 어닐링 온도(1700와 1800℃)와 어닐링 시간(30와 60분)을 달리하여 4종의 시료를 제조하였으며, TLM을 이용한 저항을 측정하였다. 그 결과, 어닐링 조건이 콘택층의 저항과 소자의 전기적 안정성에 영향을 미치는 사실을 확인하였다.

• 한국생산제조학회지
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• 제23권3호
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• pp.259-265
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• 2014

When the brakes of a vehicle are applied, large amounts of heat are generated on the surfaces of the brake discs owing to friction between the discs and the brake pads. A high temperature gradient on the disc surfaces leads to thermal deformation and severe disc abrasion. Ultimately, the thermal deformation and disc wear give rise to a thermal judder phenomenon, which has a major effect on the stability of the vehicle. To investigate and propose a solution to these problems, thermoelastic instabilities under applied thermal and mechanical loads were analyzed using the commercial finite element package ANSYS by considering the contact surfaces between the discs and pads. Direct-contact three-dimensional finite elements between the discs and pads were applied to investigate the disc friction temperature, thermal deformation, and contact stress so that the thermal judder phenomenon on the surface of the disc could be predicted.

• Transactions on Electrical and Electronic Materials
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• 제9권4호
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• pp.137-142
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• 2008

The parasitic resistance is studied to silicon/metal contact junction for improving device performance and to lower contact/serial resistance silicide in natural sequence. In this paper constructs the stepwise Ni silicide process for parasitic resistance reduction for silicon/metal contact junction. We have investigated multi-step Ni silicide on SiGe substrate with stepwise annealing method as an alternative to compose more thermally reliable Ni silicide layer. Stepwise annealing for silicide formation is exposed to heating environment with $5^{\circ}C/sec$ for 10 seconds and a dwelling for both 10 and 30 seconds, and ramping-up and the dwelling was repeated until the final annealing temperature of $700\;^{\circ}C$ is achieved. Finally a direct comparison for single step and stepwise annealing process is obtained for 20 nm nickel silicide through stepwise annealing is $5.64\;{\Omega}/square$ at $600\;^{\circ}C$, and it is 42 % lower than that of as nickel sputtered. The proposed stepwise annealing for Ni silicidation can provide the least amount of NiSi at the interface of nickel silicide and silicon, and it provides lower resistance, higher thermal-stability, and superior morphology than other thermal treatment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.609-612
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• 2007

The HDD (hard disk drive) using Load/Unload (L/UL) technology includes the benefits which are increased areal density, reduced power consumption and improved shock resistance than those of contact-start-stop (CSS). Dynamic L/UL has been widely used in portable hard disk drive and will become the key technology for developing the small form factor hard disk drive. The main design objectives of the L/UL mechanisms are no slider-disk contact or no media damage even with contact during L/UL, and a smooth and short unloading process. In this paper, we focus on lift-off force, pitch static attitude (PSA), roll static attitude (RSA) and dimple point. The "lift-off" force, defined as the minimum air bearing force, is another very important indicator of unloading performance. A large amplitude of lift-off force increases the ramp force, the unloading time, the slider oscillation and contact-possibility. PSA and RSA are also very important parameters in L/UL system and stability of slider is mainly determined by PSA and RSA. Dimple point by PSA and RSA is also important indicator. Therefore we find the optimal dimple point of SFF HDD suspension for improving the unloading performance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.377-378
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• 2006

The knuckle crane mainly consists of six parts such as swing, main boom, outer boom, extension boom, hydraulic rotor and knuckle. And the hydraulic rotor is connected at the end of extension boom has rotor block, rotor body, rotor vane. In this study, we carried out kinematics analysis of the hydraulic rotor block curvature for a knuckle crane. Then, we showed the formula to establish the radius of a circumscribed circle to form the rotor block curvature. Third, we analyzed the stress at each point of the rotor block curvature according to the contact angle. From the result of this study, we designed the rotor block curvature with a proper contact angle for a knuckle crane to guarantee the stability of hydraulic rotor.

• Physical Therapy Rehabilitation Science
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• 제10권4호
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• pp.406-413
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• 2021

Objective: The purpose of this study was to investigate effects of taping technique applied to knee instability. Design: Cross sectional study. Methods: Twenty-six participants with knee instabilityparticipated in this study. They were randomly assigned to the Kinesio taping (KT) group (n=13) and the dynamic taping (DT) group (n=13). Both groups applied knee stabilization taping techniques. In order to compare the effects of each taping technique, the change in the landing error scoring system (LESS) and lower extremity joint angle wasrecorded before and after the intervention. Results: Both groups significantly decreased in the change before and after the LESS (p<0.05). At the joint angle of the lower extremities, KT group significantly reduced the valgus angle at the max knee flexion (p<0.05). In DT group knee joint flexion and hip joint flexion angles were significantly increased at foot contact (p<0.05). In max knee flexion, the knee joint flexion angle was significantly increased (p<0.05). In foot contact, max knee flexion, the knee joint valgus angle was significantly increased (p<0.05). DT group showed more significant changes in knee joint flexion angle at foot contact and hip joint flexion angle at max knee flexion. Conclusions: Dynamic taping is a clinically applicable intervention method for lowering the risk of non-contact injury in participants with knee instability and for knee stability during rehabilitation exercises.

• 비파괴검사학회지
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• 제36권5호
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• pp.399-405
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• 2016

최근 많은 장점으로 기존 전기식 센서를 대체하여 그 적용 영역을 빠르게 넓혀가고 있는 광섬유 센서는 센서부에서 계측기 사이의 신호 전달을 위해 광 어댑터와 광 점퍼 코드와 같은 광소자를 사용하게 된다. 광 어댑터를 이용하여 신호 전달을 하는 경우 단면이 서로 맞닿게 되어 이물질에 의해 코어 부분에 손상이 발생할 수 있으며, 이는 광 손실 및 광 접속 불능을 유발할 수 있다. 따라서, 본 연구에서는 지속적인 유지보수를 필요로 하는 문제들을 근원적으로 해결할 수 있는 대안으로 비접촉식 광섬유 점퍼 코드를 개발하였으며 그 전송 성능을 평가하였다. 시험 결과, 기존의 접촉식 광 점퍼 코드는 2 mm의 간극에서 광 신호 전송이 불가능한데 반해 비접촉식 광 점퍼 코드의 경우 초기 광 손실은 상대적으로 크지만 간극이 증가하더라도 약 7 mm 정도까지 안정적으로 신호 전송이 가능하였다. 따라서, 패치 코드가 광센서 간 신호 전송을 위한 케이블임을 고려할 때 외부의 환경적 요인에 대해 더 우수한 신호 안정성을 가진 비접촉식 패치 코드가 접촉식 패치 코드에 비해 현장 적용성이 더 뛰어남을 확인하였다.

• Journal of Periodontal and Implant Science
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• 제29권2호
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• pp.415-433
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• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• Geomechanics and Engineering
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• 제16권4호
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• pp.415-421
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• 2018

A location determining method is proposed for critical sliding surface in the stability analysis of the filling materials in karst caves. First, a preliminary location of the sliding surface is determined based on simulation results which includes displacement contour and plastic zone. The sliding surface will locate on the bottom contact interface when the friction angle is relative small. However, a weakened contact interface always becomes the critical sliding surface no matter what the friction angle is. Then when the friction angle becomes larger, the critical sliding surface inside fillings can be determined by a parabola, the coefficient of which increases linearly with the friction angle under the same cohesion. Finally, the critical sliding surface approximately remains unchanged with friction angle. The influence of cohesion is similar to that of friction angle. Although affected by shape, size or position of the karst cave, the critical sliding surface mainly depends on both friction angle and cohesion. Thus, this method is always useful in determining the critical sliding surface.