• 한국결정학회지
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• 제18권1_2호
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• pp.1-6
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• 2007

유기금속 화합물 $C_{16}H_{35}B_{10}IrS_2Si$를 o-carborane으로 출발하여 $Cp^*Ir(S_2C_2B{10}H_{10})$을 합성하고, $Me_3SiCHN_2$를 가하여 합성하였다. X-선 회절법을 이용하여 $C_{16}H_{35}B_{10}IrS_2Si$ 화합물의 분자구조를 규명하였다. 이 화합물의 결정학적 자료는 monoclinic, space group $P2_1/n$, $a=10.1986(12)\;{\AA}$, $b=14.834(5)\;{\AA}$, $c=17.139\;{\AA}$, ${\beta}=92.24(2)^{\circ}$, Z=4, $V=2591.0(14)\;{\AA}^3$이다. 결정 구조는 직접법으로 해석하였으며, 완전행렬최소자승법을 정밀화 하였으며 5080개의 회절 반점에 대하여 최종 신뢰도 인자 R=0.053인 분자모형을 구하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.352-352
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• 2010

Silicon Carbide (SiC) power device possesses attractive features, such as high breakdown voltage, high-speed switching capability, and high temperature operation. In general, device design has a significant effect on the switching characteristics. In this paper, we report the effect of the P-base doping concentration ($N_{PBASE}$) on the transient characteristics of 4H-SiC DMOSFETs. By reducing $N_{PBASE}$, switching time also decreases, primarily due to the lowered channel resistance. It is found that improvement of switching speed in 4H-SiC DMOSFETs is essential to reduce the and channel resistance. Therefore, accurate modeling of the operating conditions are essential for the optimization of superior switching performance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.521-524
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• 2001

In this letter, we report on the investigation of Ti, Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at 500$^{\circ}C$ for 1h, 950$^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method, which resulted in specific contact resistivities in the 3.5x10$\^$-3/ and 6.2x10$\^$-4/ ohm/$\textrm{cm}^2$, and the physical properties of the contacts were examined using x-ray diffraction, microscopy, AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si, migration of into SiC. Overlayer of Pt had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• 한국재료학회지
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• 제4권8호
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• pp.877-887
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• 1994

강도, 소전율, 스프링성, 내열성 및 굽힘 가공성등의 적절한 조화를 갖는 콘넥팅재료를 개발하기 위하여 Cu-Ni-Si-P합금에 대하여 연구하였다. Ni와 Si의 조성을 달리한 3종류의 합금을 용해, 주조하여 약 $900^{\circ}C$에 열간압연 후 수냉하고, 그 후 냉간압연하여 $450^{\circ}C$. $500^{\circ}C$ 및 $550^{\circ}C$에서 시효처리한 후 기계적 성질 변화와 도전율 등을 조사하였다. 고강도와 고존도율의 적절한 조화를 나타내는 Cu-2.7%Ni-0.53% Si-0.029%P 합금을 만들었다. 합금 1을 0.5mm두께의 콘넥팅재료로 가공한 후 여러가지 특성은 인청동(C 5210R-H)과 황동(C2600R-EH)에 비해 우수한 것으로 평가되었다.

• 한국전기전자재료학회논문지
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• 제22권8호
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• pp.637-640
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• 2009

In this work, we demonstrate 800 V 4H-SiC power DMOSFETs with several structural alterations to obtain a low threshold voltage ($V_{TH}$) and a high figure of merit ($V_B\;^2/R_{SP,ON}$), To optimize the device performance, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. These parameters are optimized using 2D numerical simulation and the 4H-SiC DMOSFET structure results in a threshold voltage ($V_{TH}$) below $^{\sim}$3.8 V, and high figure of merit ($V_B\;^2/R_{SP,ON}$>$^{\sim}$200 $MW/cm^2$) for a power MOSFET in $V_B\;^{\sim}$800 V range.

• 대한화학회지
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• 제25권5호
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• pp.311-317
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• 1981

새로운 니켈(II) 화합물, 비스(트리메틸실릴메틸)1,2-(비스디페닐포스피노) 에탄니켈(II)(1)이 디클로로-1,2-비스(디페닐포스피노)에탄니켈(Ⅱ)와 트리메틸실릴메틸리튬의 반응으로부터 합성되었다. 화합물 1은 질소하, 상온에서 안정하다. 화합물 1은 열분해하여 환원성짝지음 생성물, 1,2-비스(트리메틸실릴)에탄을 생성한다. 화합물 1은 상온에서 일산화탄소 및 산소와, 그리고 80${\circ}$C에서 1,2-비스(디페닐포스피노)에탄과 반응하여 역시 1,2-비스(트리메틸실릴)에탄을 생성한다.

• 한국전기전자재료학회논문지
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• 제21권11호
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• pp.968-972
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• 2008

Ni/Ti/Al multilayer system ('/'denotes the deposition sequence) was tested for low-resistance ohmic contact formation to Al-implanted p-type 4H-SiC. Ni 30 nm / Ti 50 nm / Al 300 nm layers were sequentially deposited by e-beam evaporation on the 4H-SiC samples which were implanted with Al (norminal doping concentration = $4\times10^{19}cm^{-3}$) and then annealed at $1700^{\circ}C$ for dopant activation. Rapid thermal anneal (RTA) temperature for ohmic contact formation was varied in the range of $840\sim930^{\circ}C$. Specific contact resistances were extracted from the measured current vs. voltage (I-V) data of linear- and circular transfer length method (TLM) patterns. In constrast to Ni contact, Ni/Ti/Al contact shows perfectly linear I-V characteristics, and possesses much lower contact resistance of about $2\sim3\times10^{-4}\Omega{\cdot}cm^2$ even after low-temperature RTA at $840^{\circ}C$, which is about 2 orders of magnitude smaller than that of Ni contact. Therefore, it was shown that RTA temperature for ohmic contact formation can be lowered to at least $840^{\circ}C$ without significant compromise of contact resistance. X-ray diffraction (XRD) analysis indicated the existence of intermetallic compounds of Ni and Al as well as $NiSi_{1-x}$, but characteristic peaks of $Ti_{3}SiC_2$, a probable narrow-gap interfacial alloy responsible for low-resistance Ti/Al ohmic contact formation, were not detected. Therefore, Al in-diffusion into SiC surface region is considered to be the dominant mechanism of improvement in conduction behavior of Ni/Ti/Al contact.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.63-63
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• 2009

In this work, we demonstrate 800V 4H-SiC power DMOSFETs with several structural alterations to observe static DC characteristics, such as a threshold voltage ($V_{TH}$) and a figure of merit ($V_B^2/R_{SP,ON}$). To optimize the static DC characteristics, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. Design parameters are optimized using 2D numerical simulations and the 4H-SiC DMOSFET structure results in high figure of merit ($V_B^2/R_{SP,ON}$>~$340MW/cm^2$) for a power MOSFET in $V_B{\sim}1200V$ range.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.345-348
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• 2017

In this work, static characteristics of 4H-SiC SJ-ACCUFETs were obtained by adjusting the p-pillar region. The structure of this SJ-ACCUFET was designed by using a two-dimensional simulator. The static characteristics of SJ-ACCUFET, such as the breakdown voltages, on-resistance, and figure of merits, were obtained by varying the p-pillar doping concentration from $1{\times}10^{15}cm^{-3}$ to $5{\times}10^{16}cm^{-3}$ and the thickness from $0{\mu}m$ to $9{\mu}m$. The doping concentration and the thickness of p-pillar region are closely related to the break down voltage and on-resistance and threshold voltages. Hence a silicon carbide SJ-ACCUFET structure with highly intensified breakdown voltages and low on-resistances with good figure of merits can be achieved by optimizing the p-pillar thickness and doping concentration.

• 한국자기학회지
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• 제4권1호
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• pp.7-11
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• 1994

비정질 $Fe_{76}Cu_{1}Nb_{3}Si_{14}B_{6}$ 합금을 $400\;-\;700^{\circ}C$사이에서 $50^{\circ}C$ 간격으로 1시간 열처리하여 미세자기구조를 알아 보기 위해서 강자성공명 실험을 하였다. 열 처리온도에 따른 미세자기구조 변화를 강자성공명 실험을 통해 얻어진 미분흡수선의 선폭 ${\Delta}H_{p.p}$와 공명자기장의 변화와 관련시켜 정성적으로 고찰한 후 다음을 알 수 있었다. 열처리 온 명자기장은 증가한다. 열처리 온도가 $400^{\circ}C$에서 $500^{\circ}C$로 증가하면 비정질상 내에 미세결정이 불균일하게 나타남으로서 자기이방성 증가하기 때문에, 선폭은 증가하고 공명자기장은 감소한다. 열처리 온도가 $500^{\circ}C$에서 $550^{\circ}C$로 증가하면 균일한 미세결정구조가 형성됨으로서 자기이방성이 감소하기 때문에, 선폭은 감소하고 공명자기장은 증가한다. 열처리 온도가 $550^{\circ}C$이상으로 증가하면 여러가지 결정상들이 혼재한 불균한 조직에 의해 자기이방성이 증가함으로서 선폭은 증가하고 공명자기장은 감소한다.