화학증착된 실리콘 카바이드 박막의 속도론적 모델 및 기계적 성질에 미치는 반응가스 분압의 영향

어경훈,소명기 한국세라믹학회 1991 한국세라믹학회지 Vol.28 No.6

Silicon carbide has been grown by a chemical vapor deposition (CVD) technique using CH3SiCl3 and H2 gaseous mixture onto a graphite substrate. Based on the thermodynamic equilibrium studies and the suggestion that the deposition rate of SiC is controlled by surface reaction theoretical kinetic equation for CVD of silicon carbide has been proposed. The proposed theoretical kinetic equation for CVD of silicon carbide agreed well with the experimental results for the variation of the deposition rate as a function of the partial pressure of reactant gases. The Vikers microhardness of the SiC layer was about 3000∼3400 kg/$\textrm{mm}^2$ at room temperature.

기상합성법에 의한 $\beta$-SiC 초미분말 합성 및 특성

어경훈,이승호,유용호,소명기 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.11

Ultrafine ${\beta}$-SiC powders were synthesized by the vapor phase reaction of TMS[Si(CH3)4] in hydrogen The reaction temperature and TMS concentration were varied from 1000 to 1400$^{\circ}C$ and from 1 to 10% respectively. The average particle size and phase of the powders were analyzed by TEM and XRD. Ultrafine ${\beta}$-SiC powders were synthesized above 1000$^{\circ}C$ and the crystallinity of the powders increased with increasing reaction temperature. Shape of the particles were spherical and had average size of about 20 nm which showed no difference as the reaction temperature and TMS concentration increased. From the FT-IR analysis the absorption bands of Si-C of the powders shifted to higher wavenumber as the reaction temperature increased,. Under the condition of total gas flow above 1500cc/min ${\beta}$-SiC and poly-Si powders were obtained simultaneously. The Si-O bond intensity was increased under the condition of total gas flow rate above 1000cc/min which might be due to oxidation formed on poly-Si.

Effects of Si incorporation on thermal stability and tribological properties of DLC films

어경훈,소명기 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.3

Pure and silicon (Si)-incorporated diamond-like carbon (Si-DLC) thin films were deposited onto Si wafers using a reactive sputtering method. By varying the SiH4 flow rate, DLC films of various Si contents were achieved. The effects of Si incorporation on the thermal stability and tribological properties of the DLC films were studied with reference to the modifications to their chemical bonding at elevated temperatures along with their friction mechanisms. Fourier transform infrared spectroscopy (FTIR), optical microscopy, field emission scanning electron microscopy (FESEM) with energydispersive X-ray spectroscopy (EDS), and micro-Raman spectroscopy were applied to determine the film’s thermal, friction, and wear behaviors. As the Si was incorporated, the Si-O bond intensity increased and the Si-C bond remained within the films, which presumably resulted in the good thermal stability. It was found that the lower friction coefficient of the Siincorporated films is correlated to the formation of a SiO2 transfer film on the surface of the wear scar.

도금조건에 따른 무전해 니켈 도금층에 대한 연구

어경훈(Kyoung-Hoon Er),오세희(Se-Hee Oh) 산업기술교육훈련학회 2010 산업기술연구논문지 (JITR) Vol.15 No.1

There are many plating methods already commercially employed in the surface technology. One of the plating methods is electroless plating, which is deposited by auto-catalytic reduction of metallic ion with the reducing agent in the plating bath. And it has many advantages compared with electrolytic plating in respect of properties of deposit, such as corrosion resistance, wear resistance, hardness, adhesion and so on. In electroless plating of nickel, studies on various factors affecting the plating operation were carrede out. The optimum bath composition and operating conditions were obtained. The structure and properties of the as deposits or deposits after heatment were investigated. T he m ost optimum conditions for the chem ical nickel. N iSO 4; 30g/ℓ N aH2PO 4; 10g/ℓ CH3COONa; 10g/ℓ pH5.0~5.5 temperature; 85~95℃. The plating of electroless nickel deposition showed the maximum on the condition of NiSO4; 30g/ℓ NaH2PO4; 10g/ℓ CH3COONa; 10g/ℓpH5.0 temperature; 95℃ and nickel hardness value followed by heat treatment temperature is maximium in temperature of 400℃. Corrosion resistance of chemical nickel deposits was improved according to increasing of heat treating temperature.

기상반응에 의한 $Si_3N_4$ 미세분말의 합성

유용호,어경훈,소명기 한국세라믹학회 2000 한국세라믹학회지 Vol.37 No.1

Silicon nitride powders, were synthesized by the vapor phase reaction using SiH4-NH3 gaseous mixture. The reaction temperature, ratio of NH3 to SiH4 gas and the overall gas quantity were varied. The synthesized powders were characterized using X-ray, TEM, FT-IR and EA. The synthesized silicon nitride powders were in amorphous state, and the average particle size was about 100nm. TEM analysis revealed that the particle size decreased with increasing reaction temperature and gas flow quantity. As-received amorphous powders were annealed in nitrogen atmosphere at 140$0^{\circ}C$ for 2h, then the powders were completely crystallized at 0.2 ratio of NH3 to SiH4.

다결정 $Si_{1-x}Ge_x$박막 증착에 관한 연구(II) 증착변수에 따른 표면거칠기, 결정립크기 및 전기적성질 변화

이승호,어경훈,소명기 한국결정성장학회 1998 韓國結晶成長學會誌 Vol.8 No.1

증착변수(온도, 압력, Ge조성) 변화에 따라 증착된 다결정 $Si_{1-x}Ge_x$박막의 결정성 및 결정립크기 그리고 표면거칠기 변화와 이러한 결과들이 비저항에 미치는 영향에 대해 살펴보았다. 증착온도와 Ge조성이 증가함에 따라 결정화도와 결정립크기가 증가하였으며 증가된 결정립에 의해 비저항값은 감소하였으나 표면거칠기가 증가하였다. 한편 증착압력 증가에 따라 결정화도는 증가했으나 결정립크기와 cluster 크기가 감소하였는데 이러한 결정립과 cluster 크기 감소에 의해 표면거칠기가 감소하였다. 또한 증착압력 증가에 따라 결정화도와 비저항은 증가하였으나 결정립크기와 cluster 크기가 작아져 표면거칠기가 감소하였다. 결정화도와 결정립크기가 비저항에 미치는 영향을 볼 때, 결정화도 보다는 결정립크기가 비저항에 더욱 영향을 줌을 알 수 있었다. In this work, we have investigated the change of surface roughness, grain size and crystallinity of Poly-$Si_{1-x}Ge_x$ films deposited with the variation of deposition parameters (temperature, pressure, Ge composition ) and the effect of these results on the electrical resistivity. The crystallinity and the grain size were increased with increasing deposition temperature and Ge composition. Also, the electrical resistivity was decreased by enhanced grain size, while the surface roughness was increased. With increasing deposition pressure, the crystallinity was increased, but the grain size and the cluster size were decreased, by which the surface roughness was decreased. And the electrical resistivity was increased. Based on the effect of the crystallinity and the grain size on the electrical resistivity, it was founded that the electrical resistivity was depend on the grain size rather than the crystallinity.

기상반응을 이용한 SiC 초미분말 합성에 관한 수치모사

유용호,어경훈,송은석,이성철,소명기 한국결정성장학회 1999 韓國結晶成長學會誌 Vol.9 No.6

수평형 반응로에서 $TMS[Si(CH_3)_4]-H_2$ 와 H$_2$가스를 이용하여 SiC 초미분말 합성시 최적 공정 조건을 알아보기 위하여 수치모사방법을 이용하였다. 이론적인 해석 결과, 반응온도가 증가함에 따라 TMS의 전환률은 증가하였지만, 수소유량이 증가함에 따라서는 TMS 전환률이 감소하였다. 또한 반응온도가 높을수록 기상의 충돌확률이 증가하여 최종 생성된 SiC 입자농도는 감소하였지만, 수소유량과 TMS 농도가 증가하는 경우에서는 생성된 입자농도가 증가하였다. 한편 입자크기는 반응온도와 초기 TMS 농도가 증가함에 따라 증가하였지만 수소유량이 증가하는 결향을 나타내었다. 이러한 반응온도, 수소유량 및 TMS 농도에 따른 입자크기 변화는 실제 실한 결과와 이론적으로 고찰한 결과가 일치하였다. The numerical simulation method was utilized to investigate the optimal condition for synthesizing ultrafine SiC powders by using $TMS[Si(CH_3)_4]-H_2$ gaseous mixtures in the horizontal reactor. As a result of the theoretical analysis, the conversion percentage of TMS source was increased with increasing reaction temperature, however, which was decreased with increasing H$_2$flow rate. Though the SiC particles concentration synthesized was decreased with increasing the reaction temperature due to the higher collision rate in the gas phase, they were increased with increasing the H$_2$flow rate and TMS concentration. The SiC particle size showed a tendency to become larger as the reaction temperature and the initial TMS concentration were increased and smaller as the H$_2$ flow rate was increased. The variation of experimental particle size with the reaction temperature, H$_2$flow rate and TMS concentration was agreed with the theoretical results.

다결정 $Si_{1-x}Ge_x$박막 증착에 관한 연구(I) 증착변수에 따른 증착속도 및 Ge조성 변화

이승호,어경훈,소명기 한국결정성장학회 1997 韓國結晶成長學會誌 Vol.7 No.4

RTCVD법으로 $SiH_4$과 $GeH_4$ 가스를 이용하여 oxidized Si 위에 SiH$_4$: $GeH_4$ flow ratio(1 : 0.1~2 : 1), 증착온도(400~$600^{\circ}C$) 그리고 증착압력(1~50 torr)인 조건에서 다결정 $Si_{1-x}Ge_x$박막을 증착하여, 증착변수 변화에따른 $Si_{1-x}Ge_x$ 박막의 Ge 조성 변화와, Ge 조성이 증착속도에 미치는 영향 등에 대해 살펴보았다. 실험결과, 증착온도와 Ge 조성 증가에따라 증착속도는 증가하였으나 증착온도 증가에따라 Ge 조성이 감소하였다. 또한 증착압력 변화에따른 증착속도와 Ge조성 변화는, 증착압력 10 torr까지는 거의 직선적으로 증가하였으나 그이상에서는 서서히 증가함을 알 수 있었다. 이와같이 10 torr 이상의 증착압력에서 증착속도가 서서히 증가하는것은 물질전달 속도에 비해 표면반응 속도가 늦어져 나타난 현상으로 생각된다. Poly-$Si_{1-x}Ge_x$ films on oxidized Si wafer were prepared by rapid thermal chemical vapor deposition using the $SiH_4$ and $GeH_4$ gaseous mixture at various deposition conditions. The deposition temperature, $SiH_4\;: GeH_4$ flow ratio and pressure were varied from 400 to $600^{\circ}C$, 1 : 0.1-2 : 1 and 1 to 50 torr, respectively. In this work, we have investigated the change of Ge composition of poly-$Si_{1-x}Ge_x$ films deposited with the variation of deposition parameters and the effect of Ge composition on the deposition rate. From the experimental results, it was observed that the deposition rate increased with increasing deposition temperature and Ge composition. On the other hand, the Ge composition decreased with increasing temperature. As the deposition pressure increased, the deposition rate and Ge composition were increased linearly to 10 torr but increased slowly above it, which has been attributed to the slower rate of surface reaction than mass transfer.

기상반응에 의한 $\beta$-SiC 초미분말 합성시 수소 가스유량과 TMS 농도의 영향

유용호,어경훈,소명기 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.8

To investigate the effect of H2 flow rate and TMS[Si(CH3)4] concentration on synthesizing ultrafine ${\beta}$-SiC powder by vapor phase reaction the experiment was performed at 1100$^{\circ}C$ of the reaction temperature under the condition of 200-2000 cc/min of H2 gas flow rate and 1-10% of TMS concentration respectively. The shape of ${\beta}$-SiC particles synthesized was spherical and the size of particles decreased and the distribution of particles was more uniform with increasing H2 gas flow rate. In this case Si powders were coexisted with ${\beta}$-SiC Pure and ultrafine ${\beta}$-SiC powders without Si were obtained under the condition of above 2% of TMS concentration and below 1500 cc/min of H2 gas flow rate.

Crash Signal 분석 및 전자식 Airbag System에 관한 연구

고성제,어경훈,강의성 한국자동차공학회 1993 한국자동차공학회 학술강연초록집 Vol.- No.-

에어백 시스템의 입력으로 주어지는 가속도 신호를 바탕으로 충돌 순간의 차체와 탑승자의 운동을 해석하고, 이 결과를 바탕으로 호율적인 에어백 전개 알고리즘을 연구하엿다.DSP chip를 사용하여 에어백 시스템의 하드웨어를 설계하여, 전개 알고리즘을 실시간으로 처리할 수 있음을 보였다.