• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.195-195
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• 2015

반도체 제조 시 ohmic contact을 형성하고, barrier metal layer형성을 위해 NH3 기체를 사용하는 rapid thermal nitridation (RTN)은 반도체 공정에 있어 매우 중요한 핵심 기술이다. 그러나 공정 진행 시 발생하는 공정 부산물에 의한 chamber오염으로 인해 매우 정확히 입사 되어야 할 thermal energy의 controllability가 저하되고 있어, 미세 공정능력 구현의 한계에 부닥치고 있다. 본 연구에서는 quartz plate liner를 적용하여 RTN 공정에서 발생하는 공정 부산물인 ammonium chloride (NH4Cl)의 chamber 표면 증착을 최소화하였고, 공정 진행 온도의 controllability를 확보하였다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.111-115
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• 2001

Thermo-acoustic emission (AE) from composite laminates under the repetitive thermal cyclic loads have been quantitatively analyzed in consideration of AE source mechanisms. The repetitive thermal load brought about a large reduction, i.e. an exponential decrease in AE total ringdown counts and AE amplitudes. It was thought that generation of thermo-AE during the first thermal cycle was not caused by crack propagation but by secondary microfracturing due to abrasive contact between crack surfaces.

• Tribology and Lubricants
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• v.14 no.1
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• pp.28-36
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• 1998

This paper presents the thermal behaviours of a solid type disk brake for a high-speed train. The thermal behaviours of a brake disk with 50mm thickness shows good performance compared with 45mm thickness of a disk because of a high specific heat capacity. The FEM results show that the thickness of the disk with a same weight of the brake disk should be increased for a good flexibility of the contact thermal problems. Therefore, the ratio between the pad and disk in diameter may be reduced and the thickness of a disk increased.

• Transactions on Electrical and Electronic Materials
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• v.9 no.4
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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.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.244-246
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• 1997

This paper is to analyze the Premature Quench characteristics of a rotating magnet type superconducting fluxpump and consider the method of detecting and protecting this premature quench. Practically, there is contact resistance between the fluxpump and the load, namely the S.C. magnet. The thermal increase due to the contact resistance cause the premature quench before the charging current amounts to the critical current of S.C magnet. Therefore, this paper is devoted to solving the heat equation on contact region using cylindrical coordinates and to calculating the rate of thermal increase during the current is pumped up. Doing so, the predictive value of the maximum pumping current is obtained. It has been verified that the results of simulation are coincident with those of experiment. It must be considered essentially to minimize the contact resistance in designing the S.C fluxpump system in order to protect the premature quench and improve the maximum pumping current.

• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.131-135
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• 2005

This paper describes the ohmic contact formation of single crystalline 3C-SiC thin films heteroepitaxially grown on Si(001) wafers. In this work, a TiW (Titanium-tungsten) film as a contact matieral was deposited by RF magnetron sputter and annealed with the vacuum and RTA (rapid thermal anneal) process respectively. Contact resistivities between the TiW film and the n-type 3C-SiC substrate were measured by the C-TLM (circular transmission line model) method. The contact phases and interface the TiW/3C-SiC were evaulated with XRD (X-ray diffraction), SEM (scanning electron microscope) and AES (Auger electron spectroscopy) depth-profiles, respectively. The TiW film annealed at $1000^{\circ}C$ for 45 sec with the RTA play am important role in formation of ohmic contact with the 3C-SiC substrate and the contact resistance is less than $4.62{\times}10^{-4}{\Omega}{\cdot}cm^{2}$. Moreover, the inter-diffusion at TiW/3C-SiC interface was not generated during before and after annealing, and kept stable state. Therefore, the ohmic contact formation technology of single crystalline 3C-SiC using the TiW film is very suitable for high temperature MEMS applications.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.2
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• pp.25-33
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• 2016

The thermal stratification phenomenon in the nuclear power plant can cause abnormal deformation of the piping, contact with the support, damage to the support system. Repetition of the thermal stratification phenomenon or variation of the thermal boundary layer can cause thermal fatigue. Thermal stratification phenomenon in nuclear power plants is still an ongoing issue and active research has been carried out. In this paper, the current situation in Korean nuclear power plants is described, followed by the status of research and the future problems on the thermal stratification phenomenon in Korea.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.114-117
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• 2004

The purpose of this study is to investigate geometric effect on the contact stress at a lip seal. The geometries of interest were angle, thickness of lip seal and width of contact surface. The contact stress was calculated by using a coupled thermo-mechanical analysis method. The friction thermal load between lip seal and sleeve was adopted to design load. Based on the FEA results, design variables for controlling the maximum contact stress at the lip seal were identified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.603-606
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• 2000

This dissertation is concerned with ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a leaf spring mechanism and a capacitive-type sensor. The contact probe is attached on the z-axis during measurement while aspheric objects are supported on an precision xy-stage whose lateral motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed in this investigation is capable of providing a repeatability of 50 nanometers with a $\pm$3$\sigma$ uncertainty of 300 nanometers. Thermal disturbance is found the most significant factor that should be precisely controlled for accurate measurement.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.25.2-25.2
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• 2005