• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.37-37
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• 2010

Silicate-silsesquioxane or siloxane-silsesquioxane hybrid thin films are strong candidates as matrix materials for ultra low dielectric constant (low-k) thin films. We synthesized the silicate-silsesquioxane hybrid resins from tetraethoxyorthosilicate (TEOS) and methyltrimethoxysilane (MTMS) through hydrolysis and condensation polymerization by changing their molar ratios ([TEOS]:[MTMS] = 7:3, 5:5, and 3:7), spin-coating on Si(100) wafers. In the case of [TEOS]:[MTMS] 7:3, the dielectric permittivity value of the resultant thin film was measured at 4.30, exceeding that of the thermal oxide (3.9). This high value was thought to be due to Si-OH groups inside the film and more extensive studies were performed in terms of electronic, ionic, and orientational polarizations using Debye equation. The relationship between the mechanical properties and the synthetic conditions of the silicate-silsesquioxane precursors was also investigated. The synthetic conditions of the low-k films have to be chosen to meet both the low orientational polarization and high mechanical properties requirements. In addition, we have investigated a new solution-based approach to the synthesis of semiconducting chalcogenide films for use in thin-film transistor (TFT) devices, in an attempt to develop a simple and robust solution process for the synthesis of inorganic semiconductors. Our material design strategy is to use a sol-gel reaction to carry out the deposition of a spin-coated CdS film, which can then be converted to a xerogel material. These devices were found to exhibit n-channel TFT characteristics with an excellent field-effect mobility (a saturation mobility of ${\sim}\;48\;cm^2V^{-1}s^{-1}$) and low voltage operation (< 5 V). These results show that these semiconducting thin film materials can be used in low-cost and high-performance printable electronics.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.67.1-67.1
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• 2012

Graphene has attracted much attention for future nanoelectronics due to its superior electrical properties. Owing to its extremely high carrier mobility and controllable carrier density, graphene is a promising material for practical applications, particularly as a channel layer of high-speed FET. Furthermore, the planar form of graphene is compatible with the conventional top-down CMOS fabrication processes and large-scale synthesis by chemical vapor deposition (CVD) process is also feasible. Despite these promising characteristics of graphene, much work must still be done in order to successfully develop graphene FET. One of the key issues is the process technique for gate dielectric formation because the channel mobility of graphene FET is drastically affected by the gate dielectric interface quality. Formation of high quality gate dielectric on graphene is still a challenging. Dirac voltage, the charge neutral point of the device, also strongly depends on gate dielectrics. Another performance killer in graphene FET is source/drain contact resistance, as the contact resistant between metal and graphene S/D is usually one order of magnitude higher than that between metal and silicon S/D. In this presentation, the key issues on graphene-based FET, including organic-inorganic hybrid gate dielectric formation, controlling of Dirac voltage, reduction of source/drain contact resistance, device structure optimization, graphene gate electrode for improvement of gate dielectric reliability, and CVD graphene transfer process issues are addressed.

• 마이크로전자및패키징학회지
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• 제27권1호
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• pp.17-24
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• 2020

As an interconnect scaling faces a technical bottleneck, the device stacking technologies have been developed for miniaturization, low cost and high performance. To manufacture a stacked device structure, a vertical interconnect becomes a key process to enable signal and power integrities. Most bonding materials used in stacked structures are currently solder or Cu pillar with Sn cap, but copper is emerging as the most important bonding material due to fine-pitch patternability and high electrical performance. Copper bonding has advantages such as CMOS compatible process, high electrical and thermal conductivities, and excellent mechanical integrity, but it has major disadvantages of high bonding temperature, quick oxidation, and planarization requirement. There are many copper bonding processes such as dielectric bonding, copper direct bonding, copper-oxide hybrid bonding, copper-polymer hybrid bonding, etc.. As copper bonding evolves, copper-oxide hybrid bonding is considered as the most promising bonding process for vertically stacked device structure. This paper reviews current research trends of copper bonding focusing on the key process of Cu-SiO₂ hybrid bonding.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.366-369
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• 2002

At present, the study of direct digital X-ray detector and indirect digital X-ray detector proceed actively. But it needs high thickness and high voltage in selenium for high ionization rate. Therefore, we carried out the study of electric characteristics of a-Se with additive ratio of Iodine in drafting study for developing Hybrid X -ray Sensor for complementing direct digital X -ray detector and indirect digital X-ray detector in this paper. On this, there are formed Amorphous selenium multi-layers by sticking phosphor layer$(Gd_{2}O_{2}S(Eu^{2+}))$ using optical adhesives of EFIRON Co. Amorphous selenium multi-layers having dielectric layer(parylene) has characteristics of low dark-current, high X-ray sensitivity. So we can acquired a enhanced signal to noise ratio. We make Amorphous selenium multi-layers with $30{\mu}m$ thickness on glass.

• 한국레이저가공학회지
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• 제15권4호
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• pp.6-11
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• 2012

Laser beam can be either absorbed or scattered in porous ceramic material and its optical characteristics need to be understood. Electro-magnetic multiphysics software was used to simulate and understand the actual scattering phenomena in porous materials. 785nm femtosecond laser was irradiated on the surface of ceramic material and strong scattering occurred in drilling process. The computer results showed the scattering and absorption phenomena of Aluminum oxide were a mixture of dielectric and metallic material. The computer simulation showed the laser beam was almost extinct at the aspect rate of 5 approximately.

• 마이크로전자및패키징학회지
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• 제25권4호
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• pp.53-58
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• 2018

집적회로 소자의 축소가 물리적 한계에 도달 한 이후 3D 패키징, 임베디드 패키징 및 팬 아웃 웨이퍼 레벨 패키징(FOWLP, fan-out wafer level packaging)과 같은 혁신적인 패키징 기술들이 활발히 연구되고 있다. 본 연구에서는 FOWLP의 다층 재배선(redistribution layer)에 사용하기 위한 유무기 하이브리드 유전체 소재의 공정을 평가하였다. 폴리이미드(PI) 또는 폴리파라페닐렌벤조비스옥사졸(PBO)과 같은 현 유기 유전체와 비교하여 폴리실세스키옥산(polysilsesquioxane, PSSQ)라고 불리는 유무기 하이브리드 유전체는 기계적, 열적 및 전기적 안정성을 향상시킬 수 있고, UV 노광을 통하여 경화 공정과 패턴 공정을 동시에 할 수 있는 장점이 있다. 폴리실세스키옥산 용액을 6 인치 Si 웨이퍼에 스핀 코팅한 후 pre-baking과 UV 노광 공정을 이용하여 패턴 및 경화를 진행하였다. 10분의 UV 노광 시간으로 경화와 $2{\mu}m$ 라인 패턴 형성이 동시에 진행됨을 확인하였고, 경화된 폴리실세스키옥산 유전체의 유전상수는 2.0에서 2.4 로 측정되었다. 폴리실세스키옥산 소재를 이용하여 고온 경화 공정없이 UV 노광 공정만으로 경화와 패턴을 할 수 있는 공정 가능성을 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.160-160
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• 2009

In recent years, the merging of nanomaterials and nano-technology into electro-optic (EO) device technology such as liquid crystal displays (LCDs) has attracted much attention because of their unique electro- and magneto-optic properties and novel display applications. One example of hybrid LC-inorganic systems is semiconductor nanorods added to LC for their strong reorientation effect and tunable refractive index. Doping of nanoparticles in LC or polymers can lead to changes in performance characteristics such as electro-optical, dielectric, memory effect, phase behavior, etc. Due to the tunability of LCDs with mixed inorganic materials, low voltage operation of a LC system can also be achieved using the significant electro-optical effect achieved through suspension of ferroelectric nanoparticles in NLC.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.578-581
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• 2004

유전체가 삽입된 공동 공진기는 유전체에 대부분의 전자계가 집속되어 있기 때문에, 도체 손실이 매우 적고 높은 Q값과 온도 안정성이 뛰어나다. 동일한 주파수에서 동작하는 다른 필터에 비해 상대적으로 작기 때문에 소형화에도 적합하다. 본 논문에서는 유전체가 삽입된 공동 공진기의 전자기 분포와 특성을 수치해석과 HFSS(High Frequency Structure Simulator)를 이용하여 분석하였고 이 결과를 토대로 HFSS를 이용한 순차적 방법을 도입하여 4-pole 이중모드 대역통과 필터를 설계, 제작하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.477-480
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• 2002

ULSI(ultra large scaled integrated circuits)의 고집적화와 고속화를 위한 다층 배선 기술 중에서 층간 절연막의 특성을 향상시켜주는 것은 매우 중요한 요소이다. 소자의 소형화에 따른 절연층의 용량에 의한 신호의 지연을 방지하고 금속배선간의 상호간섭을 막아주기 위해서 현재 요구되는 0.13$\mu\textrm{m}$급 소자의 경우에서는 유전율이 매우 낮은 k$\leq$2.0인 층간 절연막이 필요하게 된다. 이러한 차세대 반도체 소자의 층간 절연물질로서 사용될 유력한 저유전 물질로 Nanoporous silica(k=1.3~2.5)를 적용하려는 연구가 진행되고 있다(1)-(3). 그러한 물질 중에 하나가 organosilicate films이 있는데 carbon-doped oxides, silicon-oxicarbides, carbon-incorporated silicon oxide film, organic-inorganic hybrid type Si-O-C thin films 혹은 organic-inorganic hybrid silica materials 등으로 불린다. 이에 본 연구에서는 nano-pore를 갖는 유무기 하이브리드 구조의 저유전 박막을 BTMSM/O$_2$의 혼합된 precursor를 사용하여 ICPCVD 방법에 의해 형성하였다. 총 유량을 20sccm이 되도록 하여 $O_2$:BTMSM(Ar)의 유량비를 변화시키며, 작업진공도는 300mTorr였다. 기판은 가열하지 않고, p-type Si(100) 위에 Si-O-C-H 박막을 형성하였다. 열적안정성을 조사하기 위하여 30$0^{\circ}C$, 40$0^{\circ}C$, 50$0^{\circ}C$에서 30분간 열처리하여 비교 분석하였다. 형성된 박막의 특성은 XPS로 분석하여 유전상수와의 상관관계를 조사하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.132-132
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• 2003

Second-order nonlinear optical(NLO) materials have been extensively studied for applications in photonic devices, such as frequency doubling and electro-optical(EO) modulation, because of their large optical nonlinearity, excellent processibility, low dielectric constant, and high laser damage thresholds. The poling behaviour of NLO chromophore in organic/inorganic matrixes showed the randomization of poled NLO chromophore in the absence of poling Held. The liquid crystal molecules in a droplet showed a long-range orientational order along a director. Therefore, liquid crystal effects on poling behaviour of NLO chromophore dispersed in organically modified inorganic sol-gel materials were investigated. Using sol-gel process for the development of NLO material has received increasing attention, Organically modifked inorganic NLO sol-Eel materials are obtained via incorporation of the organic NLO active chromophore into an alkoxysilane based inorganic network. One of the most important thing in this works was that tetraethoxysilane(TEOS) and methyltrimathoxysilane(HTMS) were used as precursor followed by hydrolysis and condensation without using any acidic catalyst during the process. The NLO chromophores in the liquid crystal nanodomains were well mixed with I/O hybrid matrix, deposited on transparent ITO-coated glasses. The poling behaviour of liquid crystal effects of NLO chromophore dispersed in I/O hybrid matrix were investigated by UV-vis spectroscopy. Size distribution and morphology of the NLO chromophores doped in the liquid crystal nanodomains dispersed in I/O hybrid matrix were investigated by SEM.