• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.533-533
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• 2007

The stress effect of SiGe p-type metal oxide semiconductors field effect transistors(MOSFETs) has been investigated to compare device properties using Si bulk and partially depleted silicon on insulator(PD SOI). The electrical properties in SiGe PD SOI presented enhancements in subthreshold slope and drain induced barrier lowering in comparison to SiGe bulk. The reliability of gate oxides on bulk Si and PD SOI has been evaluated using constant voltage stressing to investigate their breakdown (~ 8.5 V) characteristics. Gate leakage was monitored as a function of voltage stressing time to understand the breakdown phenomena for both structures. Stress induced leakage currents are obtained from I-V measurements at specified stress intervals. The 1/f noise was observed to follow the typical $1/f^{\gamma}$ (${\gamma}\;=\;1$) in SiGe bulk devices, but the abnormal behavior ${\gamma}\;=\;2$ in SiGe PD SOI. The difference of noise frequency exponent is mainly attributed to traps at silicon oxide interfaces. We will discuss stress induced instability in conjunction with the 1/f noise characteristics in detail.

• 한국자기학회지
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• 제26권3호
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• pp.76-80
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• 2016

CoSiB은 비정질 구조를 갖는 강자성체 물질이며, CoSiB과 Pd을 포함한 다층박막은 수직자기이방성을 갖는다. 수직자기이방성은 수평자기이방성에 비해 STT-MRAM에 적용되기에 좋은 이점이 있으며, 특히 비정질 강자성체를 포함한 다층박막은 결정질강자성체를 포함한 다층박막과 비교하여 몇 가지 이점을 지니는데, 첫째는 grain boundary가 없다는 것이며 둘째는 결정질 재료에 비교하여 열적안정성이 보다 좋다는 것이다. 이러한 이유에 따라 우리는 비정질 강자성체 $Co_{75}Si_{15}B_{10}$을 포함하는 다층박막을 제작하여 그 자기적 특성을 연구하였다. 본 연구는 [CoSiB(3, 4, 5, 6) ${\AA}$/Pd(11, 13, 15, 17, 19, 24${\AA})]_5$ 다층박막을 제작하여 VSM 측정을 통해 두께에 따른 그 자기적 특성의 변화를 살펴보았으며, 이후 일부 다층박막의 열처리를 통해 온도에 따른 자기적 특성의 변화추이를 조사하였다. 포화자화값과 보자력은 CoSiB과 Pd 각 층의 두께 변화에 따라 증가와 감소를 반복하였으며, 열처리 온도의 범위는 상온에서 $500^{\circ}C$까지로 특정 온도에서 보자력의 증대를 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.78-79
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• 2008

In this paper, poly 3C-SiC thin films were grown on $SiO_2$/Si by atmospheric pressure chemical vapor deposition (APCVD) using HMDS, $H_2$, and Ar gas at $1100^{\circ}C$ for 30 min, respectively. And then, palladium films were deposited on poly 3C-SiC by RF magnetron sputter. Thickness, uniformity, and quality of these samples were performed by SEM. Crystallinity and preferred orientationsof palladium were analyzed by XRD. And Pd/poly 3C-SiC schottky diodes were fabricated and characterized by current-voltage measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$, 0.58 eV, respectively. And these devices operated about $350^{\circ}C$. From results, Pd/poly 3C-SiC devices are promising for high temperature hydrogen sensor and applications.

• 센서학회지
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• 제18권3호
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• pp.222-225
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• 2009

This paper describes the fabrication and characteristics of Schottky micro hydrogen sensors for high temperatures by using polycrystalline(poly) 3C-SiC thin films grown on Si substrates with thermal oxide layer using APCVD. Pd/poly 3C-SiC Schottky diodes were made and evaluated by I-V and C-V measurements. Electric current density and barrier height voltage were $2{\times}10^{-3}A/cm^2$ and 0.58 eV, respectively. These devices could operate stably at about 400 $^{\circ}$. The characteristics of implemented sensors have been investigated in terms of sensitivity, linearity of response, response rate, and response time. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature $H_2$ sensor applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.21-22
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• 2005

Partially-depleted Silicon on insulator metal-oxide-semiconductor field- effect transistors (PD-SOI MOSFETs) with Silicon-germanium (SiGe) layer is investigated. This structure uses SiGe layer to reduce the kink effect in the floating body region near the bottom channel/buried oxide interface. Among many design parameters influencing the performance of the device, Ge composition is presented most predominant effects, simulation results show that kink effect is reduced with increase the Ge composition. Because the bandgap of SiGe layer is reduced at higher Ge composition, the hole current between body and SiGe layer is enhanced.

• 한국산학기술학회논문지
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• 제20권4호
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• pp.458-463
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• 2019

팔라듐 (Pd)은 촉매 또는 유해 가스 감지물질로서 널리 활용되고 있다. 특히 자체 부피의 900배까지 수소를 흡착할 수 있는 특성 때문에 수소가스 센서로서의 다양한 연구가 이루어졌다. 본 연구에서는 팔라듐 옥사이드 (PdO) 나노구조물을 실리콘 기판 ($SiO_2(300nm)/Si$) 위에 열화학기상증착 장비를 이용하여 $230^{\circ}C{\sim}440^{\circ}C$ 영역에서 3시간 ~ 5시간 동안 성장시켰다. 원료물질인 Pd 파우더는 $950^{\circ}C$에서 기상화시켰고, 이송가스인 고순도 아르곤 가스를 200 sccm으로 흘려주었다. 성장된 팔라듐 옥사이드 나노구조물의 형상을 전계방출 주사전자현미경으로 조사하였고, 결정학적 특성을 Raman 분광학으로 분석하였다. 그 결과 성장된 나노구조물은 PdO 상을 가지고 있었으며, 특정한 기판 온도와 성장 시간에서 나노큐브 형태의 PdO 나노구조물이 성장되었다. 특히 5시간 동안 성장된 $370^{\circ}C$ 영역에서 균일한 형태의 나노큐브 PdO 나노구조물이 성장되었다. 이러한 PdO 나노큐브는 기상-액상-고상 공정으로 성장된 것으로 판단되며, 그래핀 위에 성장되는 PdO 나노큐브 구조는 고감도 수소가스 감지 센서로 활용될 수 있을 것으로 기대된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권7호
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• pp.388-393
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• 2000

Hydrogen-sensing behaviors of Pd- and Pt-SiC Schottky diodes, fabricated on the same SiC substrate, have been systematically compared and analyzed as a function of hydrogen concentration and temperature by I-V and$\DeltaI-t$ methods under steady-state and transient conditions. The effects of hydrogen adsorption on the device parameters such as the barrier height are investigated. The significant differences in their hydrogen sensing characteristics have been examined in terms of sensitivity limit, linearity of response, response rate, and response time. For the investigated temperature range, Pd-SiC Schottky diode shows better performance for H2 detection than Pt-SiC Schottky diode under the same testing conditions. The physical and chemical mechanisms responsible for hydrogen detection are discussed. Analysis of the steady-state reaction kinetics using I-V method confirmed that the atomistic hydrogen process is responsible for the barrier height change in the diodes.

• 한국재료학회지
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• 제7권8호
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• pp.640-645
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• 1997

Pd게이트 MOS센서의 수소검지특성에 Pd 박막의 증착조건이 미치는 영향에 대해서 조사였다. rf power의 증가와 증착온도의 증가는 모두 센서의 감도와 초기반응속도를 감소시켰으며 rf power의 변화보다는 증착온도의 변화에 의한 효과가 현저하였다. 절연막을 Si$_{x}$N$_{y}$ /SiO$_{2}$로 대신한 결과 SiO$_{2}$에서돠는 달리 시간이 지남에 따라 평탄대역전압이 여러 단계로 변화하는 양상을 보였다. rf power, 증착온도, 기판의 변화가 MOS 센서의 감도나 초기반응속도등의 센서특성에 영향을 미친다는 사실을 확인할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.902-910
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• 2018

In recent times, development of nanofluid insulation for power transformers is a hot research topic. Many researchers reported the enhancement in dielectric characteristics of nano modified mineral oils. Considering the drawbacks of petroleum based mineral oil, it is necessary to understand the dielectric characteristics of nanofluids developed with natural ester based oils. Palm oil has better insulation characteristics comparable to mineral oil. However very few research reports is available in the area of nanofluids based on palm oil. Partial discharge (PD) is one of the major sources of insulation performance degradation of transformer oil. It is essential to understand the partial discharge(PD) characteristics by collecting huge data base of PD performance of nano modified palm oil which will increase its confidence level for power transformer application. Knowing these facts, in the present work, certain laboratory experiments have been performed on PD characteristics of nano $SiO_2$ modified palm oil at different electrode configurations. Influence of concentration of nano filler material on the PD characteristics is also studied. Partial discharge inception voltage, Phase resolved partial discharge (PRPD) pattern, PD signal time-frequency domain characteristics, PD signal equivalent timelength-bandwidth mapping, Weibull distribution statistical parameters of PRPD pattern, skewness, repetition rate and phase angle variations are evaluated at different test conditions. From the results of the experiments conducted, we came to understand that PD performance of palm oil is considerably enhanced with the addition of $nano-SiO_2$ filler at 0.01%wt and 0.05%wt concentration. Significant reduction in PD inception voltage, repetition rate, Weibull shape parameter and PD magnitude are noticed with addition of $SiO_2$ nanofillers in palm oil. These results will be useful for recommending nano modified palm oil for power transformer applications.

• 대한의용생체공학회:의공학회지
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• 제25권5호
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• pp.383-389
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• 2004

본 연구에서는 치과용 티타늄(CP-Ti)과 Ti-25wt%Pd를 인산염계 실리카$.$알루미나 주형재로 주조 후 SEM/EDS, XRD, XPS를 이용하여 주조시 생성되는 표면반응생성물을 조사하였다. Ti-25wt%Pd는 CP-Ti에 비하여 융점이 현저이 감소하여 주조체의 표면반응이 상대적으로 적게 발생하였다. 또한 인산염계 실리카$.$알루미나 주형재를 소성한 결과 주형재는 $SiO_2$, $Al_2$ $O_3$, P$_2$ $O_{5}$, $Mg_3$(P $O_4$)$_2$, AlP $O_4$, $Mg_2$ $SiO_4$, MgAl$_2$ $O_4$의 성분들로 구성되어 있었으며, 표면반응생성물은 CP-Ti 주조체의 경우 $Ti_{5}$Si$_3$ 와 Ti $O_2$로, Ti-25wt%Pd 주조체의 경우 Ti $O_2$ 와 $SiO_{x}$ 로 구성되어 있었다.