• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1006-1009
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• 2006

The chemical structure of the interface between Ag with $Li_2O$ and tri (8-hydroxyquinoline) aluminum (Alq) was investigated by using in-situ characterization of x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). $Li_2O$ on Ag had lower barrier height than LiF on Ag. XPS and UPS results show the interaction between $Li_2O$ and Alq leads to gap state formation in HOMO of Alq.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1429-1431
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• 2005

Organic molecular-beam deposition of Mg:Ag thin films with a low Mg concentration on tris (8-hydroxyquinolino) aluminum $(Alq_3)$ layers at room temperature was performed to investigate the feasibility of using Mg:Ag thin films as cathode electrodes in organic light-emitting devices (OLEDs). The effective barrier height of the $Mg:Ag/Alq_3$ heterointerface, determined from current-voltage measurements, was as low as 0.23 eV. These results help improve understanding the electrical properties of the $Mg:Ag/Alq_3$ heterointerfaces in OLEDs.

• The Korean Journal of Ceramics
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• v.4 no.1
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• pp.43-46
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• 1998

We have investigated the formation and thermal stability of cobalt aluminide(CoAl) thin films on GaAs. In order to obtain cobalt-aluminide thin films, we deposited a multilayer of Co/Al on GaAs, and subsequently annealed the samples at 80$0^{\circ}C$ for 30 min. After annealing, single-phase cobalt aluminide was produced showing a flat and uniform interface with GaAs. which indicates that cobalt aluminide (CoAl) is thermally stable with GaAs. In addition, the adherence and mechanical properties of the as-deposited, and annealed Co/Al multilayer structure on GaAs are compatible with those required for device fabrication processes. The electrical property of the CoAl/GaAs contact shows rectifying characteristics, indicating that the diodes were usable as rectifying gate electrodes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.275-275
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• 2008

This paper describe the fabrication of a Pd/polycrystalline 3C-SiC schottky diode and its characteristics, in which the polycrystalline 3C-SiC layer and Pd Schottky contact were deposited by using APCVD and sputter, respectively. Crystalline quality, uniformity, and preferred orientations of the Pd thin film were evaluated by SEM and XRD, respectively. Pd/poly 3C-SiC Schottky diodes were fabricated and characterized by I-V and C-V measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$ and 0.58 eV, respectively. These devices were operated until about $400^{\circ}C$. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature chemical sensor applications.

• ETRI Journal
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• v.10 no.4
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• pp.118-126
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• 1988

A numerical analysis was performed for the flow field in the vertical channels consist of dummy cards and active cards to define the hydrodynamic role of dummy card which is often installed in electronic equipment between active cards to control the cooling air distribution. For a given velocity profile at the inlet and a pressure-based boundary condition at the outlet of the computation domain, the percentage of the flow rate distribution through active channel and dummy channel formed by an active card and dummy card, respectively, were investigated. As a result of present analysis, the pecentage of flow rate through active channel increases quadraticaly with the increase of the ratio of the height of barrier to the width of the dummy channel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1061-1064
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• 1997

Micro injection molding technology is very important fiw mass product of micro structures or micro parts. And, it is so difficult that the molding technology of micro pole or thin wall(barrier rib) structures with high aspect ratio. In this stud). \vc intend to research on the basic technology of micro wall structure part:< with high aspect ratio by the inject~on moldins method. The mold for esperimenrs with micro multi-square structures was made by L, I(;A process. One square polc's size is 157 157pm. height 50011111. And the distance of each poles is 5011n1. 7'hus. molding products will be for~nctl like as the net structure with thin wall of about 50pn thickness.(aspect ratio 10) Ihrough the e~lxriment. \be obtained the prociuctr of micro multi-square slructure with bout 37.000 cell per a piece. 'Ihe micro injection molding process technolog for thin wall by multi-square structure mold was analy~cd.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.238-242
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• 2001

In this paper, the current-voltage characteristics of a 4H-SiC MESFET is simulated by using the Atlas Simulation tool. we are able to use the simulator to extract more information about the new material 4H-SiC, including the mobility, velocity-field Curve and the Schottky barrier height. We have enabled and used the new simulator to investigate breakdown Voltage and thus predict operation limitiations of 4H-SiC device. Modeling results indicate that the Breakdown Voltage is 197 V and Current is 100 mA

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.1027-1031
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• 2001

A new constant growth technique to conserve an initial grating height of V-groove AlGaAs/InGaAs quantum nanostructures above 1.0 $\mu\textrm{m}$ thickness has been successfully embodied on submicron gratings using low pressure metalorganic chemical vapor deposition. A GaAs buffer prior to an AlGaAs barrier layer on submicron gratings plays an important role in overcoming mass transport effects and improving the uniformity of gratings. Transmission electron microscopy (TEM) image shows that high-density V-groove InGaAs quantum wires (QWRs) are well confined at the bottom of gratings. The photoluminescence (PL) peak of the InGaAs QWRs is observed in the temperature range from 10 to 280 K with a relatively narrow full width at half maximum less than 40 meV at room temperature PL. The constant growth technique is an important step to realize complex optoelectronic devices such as one-step grown distributed feedback lasers and two-dimensional photonic crystal.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.240-241
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• 2005

비 직선적 정(+) 저항온도계수 특성을 갖는 PTC thermistor는 전이온도(큐리점) 부근에서 온도변화에 대하여 극히 큰 저항 값의 변화를 나타내는 산화물계반도체 저항기(또는 발열체)로써, 일반적으로 반도체의 온도-저항 특성과 같이 상온영역에서 온도의 상승과 함께 부성저항 특성을 나타내다가 온도가 점점 증가하여 큐리점 부근에 도달하면 저항이 급격히 증가하는 독특한 특성을 갖는다. Perovskite 구조의 $BaTiO_3$를 주성분으로 미량의 Dopant를 첨가하여 도전성을 갖게 한 N형 반도체의 일종으로 저항-온도 특성 전류-전압 특성, 전류감쇄 특성 등을 이용하여 과전류 보호회로, 히터, TV 소자회로(degausser), 모터기동회로, 온도센서, 정온발열기기 등으로 널리 사용된다. 본 연구는 큐리점 부근의 급격한 저항변화 현상과 결정입계의 전위장벽 형성 및 그에 따른 정온발열 기능의 상관성으로부터 그 응용성을 조사하였다.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.938-940
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• 1999

We have fabricated SiC Schottky diode for high temperature applications. SiC thin film for drift region has been deposited by ICP-CVD. In order to establish metallization conditions, we have extracted the device parameters of the Schottky diode from the forward I-V characteristics and the C-V characteristics as a function of temperature. The ideality factor was varied from 2.07 to 1.15 and the barrier height was also varied from 1.26eV to 1.92eV with increase of temperature. The reverse blocking voltage was 183 V.