• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.163-166
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• 2002

We investigated structural and electrical properties of Metal-Oxide-Semiconductor(MOS) structure using Hafnium $oxide(HfO_{2})$ as high-k gate dielectric material. $HfO_{2}$ films are ultrathin gate dielectric material witch have a thickness less than 2.0nm， so it is spotlighted to be substituted $SiO_{2}$ as gate dielectric material. In this paper We have grown $HfO_{2}$ films with pt electrode on P-type Silicon substrate by RF magnetron sputtering system using $HfO_{2}$ target and oserved the property of semiconductor-oxide interface. Using pt electrode, it is necessary to be annealed at ${300^{\circ}C}$. This process is to increase an adhesion ratio between $HfO_{2}$ films with pt electrode. In film deposition process, the deposition time of $HfO_{2}$ films is an important parameter. Structura1 properties are invetigated by AES depth profile, and electrical properties by Capacitance-Voltage characteristic. Interface trap density are measured to observe the interface between $HfO_{2}$ with Si using High-frequency(1MHz) C-V and Quasi - static C-V characteristic.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2535-2541
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• 2009

Prebiotic isomaltooligosaccharide preparations contain $\alpha$-D-glucooligosaccharides comprising isomaltooligosaccharides (IMOs) and non-prebiotic maltooligosaccharides (MOs). They are both glucose oligosaccharides characterized by their degree of polymerization (DP) value (from 2 to $\sim$10), linkages types and positions (IMOs: $\alpha$-(1$\rightarrow$2, 3, 6 and in a lower proportion internal 1$\rightarrow$4) linkages, MOs: α-(1$\rightarrow$4) linkages). Their structure is the key factor for their prebiotic potential. In order to determine and elucidate the exact structure of unknown IMOs and MOs, unambiguous assignments of $^{13}C$ and $^1H$ chemical shifts of commercial standards, representative of IMOs and MOs diversity, have been determined using optimized standard one and two-dimensional experiments such as $^1H$ NMR, $^{13}C$ NMR, APT and ${^1}H-{^1}H$ COSY, TOCSY, NOESY and <$^1H-{^{13}}C$ heteronuclear HSQC, HSQC-TOCSY, and HMBC. Here we point out the differential effect of substitution by a glucose residue at different positions on chemical shifts of anomeric as well as ring carbons together with the effect of the reducing end configuration for low DP oligosaccharides and diasteroisotopic effect for H-6 protons. From this study, structural $^{13}C$ specific spectral features can be identified as tools for structural analysis of isomaltooligosaccharides.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.189-192
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• 1991

This paper presents a modular structure design of analog Hopfield neural network. Each multiplier consists of four MOS transistors which are connected to an op-amp at the front end of a neuron. A pair of MOS transistor is used in order to maintain linear operation of the synapse and can produce positive or negative synaptic weight. This architecture can be expandable to any size neural network by forming tree structure. By altering the connections, other nework paradigms can also be implemented using this basic modules. The stength of this approach is the expandability and the general applicability. The layout design of a four-neuron fully connected feedback neural network is presented and is simulated using SPICE. The network shows correct retrival of distorted patterns.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(3)
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• pp.149-152
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• 2000

We propose simple analog MOS circuits producing the one-dimensional compact motion-sensing circuits. In the proposed circuit, the optical flow is computed by a number of local motion sensors which are based on biological motion detectors. Mimicking the structure of biological motion detectors made the circuit structure quite simple, compared with conventional velocity sensing circuits. Extensive simulation results by a simulation program of integrated circuit emphasis (SPICE) indicated that the proposed circuits could compute local velocities of a moving light spot and showed direction selectivity for the moving spot

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.735-736
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• 1998

Reduction of hot carrier degradation in MOS devices has been one of the most serious concerns for MOS-ULSIs. In this paper, three types of LDD structure for suppression of hot carrier degradation, such as spacer-induced degradation and decrease of performance due to increase of series resistance will be investigated. LDD-nMOSFETs used in this study had three different drain structure. (1) conventional ${\underline{S}}urface$ type ${\underline{L}}DD$(SL), (2) ${\underline{B}}uried$ type ${\underline{L}}DD$(BL), (3) ${\underline{S}}urface$urface ${\underline{I}}mplantation$ type LDD(SI). As a result, the surface implantation type LDD structure showed that improved hot carrier lifetime to comparison with conventional surface and buried type LDD structure.

• 한국음향학회지
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• 제22권7호
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• pp.612-621
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• 2003

MP3의 사용이 늘어나면서 저작권 보호나 음악 콘텐츠 정보의 삽입을 위한 방법에 대한 요구가 증가하고 있으며 관련된 연구가 활발히 진행 중에 있다. 이때 부가적인 정보가 삽입되어도 MP3의 비트스트림 구조가 크게 변형되어 음질의 열화나 파일 크기의 변화가 발생하여서는 안 된다. 본 연구에서는 위의 조건을 만족할 수 있도록 MP3 부호화 과정 중에서 양자화 된 정수 형태의 계수가 허프만 부호화 될 때, 값이 큰 샘플들의 특징을 이용하여 linbits 중 몇 개의 비트를 변형하여 부가적인 정보를 삽입하고, 그 음질의 열화 정도를 테스트하였다. 일련의 실험 과정을 통하여 평균 60 bytes/sec의 정보 삽입률에서 MOS 4.6 정도의 음질을 얻을 수 있음을 확인하였다. 제안된 방법을 이용하면 저작권에 대한 정보 또는 미디어 자체에 대한 정보들을 효과적으로 삽입할 수 있어 음악 데이터베이스의 운용과 같은 다양한 분야에 적용될 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.644-647
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• 2001

이 연구에서는 P-MOS 커패시터에 Co $u^{60}$-${\gamma}$선을 조사한 후 조사선량 및 산화막 두께에 따른 전하의 거동을 고찰하고자 1[MHz]의 고주파 신호에서 정전용량-전압(C-V) 특성 및 유전손실계수-전압(D-V)특성을 측정하였다. C-V 특성에서 플랫밴드 전압과 문턱전압을 구하여 이들 파라메타와 D-V 특성의 피크와의 관련성을 검토하였다. C-V 특성이 P-MOS 커패시터의 정상상태의 전하의 거동 및 계면 상태특성을 해석하기가 편리하고 D-V 특성은 C-V 특성보다 산화막 내부의 공간전하분포와 계면상태의 밑도 등을 더 명확하게 파악할 수 있으며 산화막내 캐리어의 전도철상에 관한 미시적 전하 거동의 고찰에도 편리함이 확인되었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.8-9
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• 2006

Hafnium oxide ($HfO_2$) thin films were deposited on p-type (100) silicon wafers by atomic layer deposition (ALD) using TEMAHf and $O_3$. Prior to the deposition of $HfO_2$ films, a thin Hf ($10\;{\AA}$) metal layer was deposited. Deposition temperature of $HfO_2$ thin film was $350^{\circ}C$ and its thickness was $150\;{\AA}$. Samples were then annealed using furnace heating to temperature ranges from 500 to $900^{\circ}C$. The MOS capacitor of round-type was fabricated on Si substrates. Thermally evaporated $3000\;{\AA}$-thick AI was used as top electrode. In this work, We study the interface characterization of $HfO_2$/Hf/Si MOS capacitor depending on annealing temperature. Through AES(Auger Electron Spectroscopy), capacitance-voltage (C-V) and current-voltage (I-V) analysis, the role of Hf layer for the better $HfO_2$/Si interface property was investigated. We found that Hf meta1 layer in our structure effective1y suppressed the generation of interfacial $SiO_2$ layer between $HfO_2$ film and silicon substrate.

• 한국전기전자재료학회논문지
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• 제22권2호
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• pp.101-106
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• 2009

In this paper, Thin films of $HfO_2$/Hf were deposited on p-type wafer by Atomic Layer Deposition (ALD). We studied the electrical and material characteristics of $HfO_2$/Hf/Si MOS capacitor depending on thickness of Hf metal layer. $HfO_2$ films were deposited using TEMAH and $O_3$ at $350^{\circ}C$. Samples were then annealed using furnace heating to $500^{\circ}C$. Round-type MOS capacitors have been fabricated on Si substrates with $2000\;{\AA}$-thick Pt top electrodes. The composition rate of the dielectric material was analyzed using TEM (Transmission Electron Microscopy), XRD (X-ray Diffraction) and XPS (X-ray Photoelectron Spectroscopy). Also the capacitance-voltage (C-V), conductance-voltage (G-V), and current-voltage (I-V) characteristics were measured. We calculated the density of oxide trap charges and interface trap charges in our MOS device. At the interface between $HfO_2$ and Si, both Hf-Si and Hf-Si-O bonds were observed, instead of Si-O bond. The sandwiched Hf metal layer suppressed the growing of $SiO_x$ layer so that $HfSi_xO_y$ layer was achieved. And finally, the generation of both oxide trap charge and interface trap charge in $HfO_2$ film was reduced effectively by using Hf metal layer.

• 천문학회보
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• 제46권2호
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• pp.68.1-68.1
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• 2021

We study galaxy evolution with the large-scale environment with confirmed galaxy clusters from multi-object spectroscopy (MOS) observation. The observation was performed with Inamori Magellan Areal Camera and Spectrograph (IMACS) mounted on the 6.5 m Magellan/Baade telescope in Las Campanas Observatory. With the MOS observation, we spectroscopically confirm 34 galaxy clusters, including three galaxy clusters discovered in Kim et al. (2016) and 11 of them have halo mass of > 10^14.5 M_◉. Among the confirmed clusters, 12 galaxy clusters are part of large-scale structure at z ~ 0.9, and their size stretches to 40 Mpc co-moving scale. In this study, we checked the 'web feeding model,' which postulates that more linked (with their environment) galaxy clusters have less quenched populations by investigating the correlation between properties of confirmed galaxy clusters and the large-scale structure environment. Lastly, we found that galaxy clusters that make up the large-scale structure have larger and widely spread values of total star formation density (ΣSFR/M_halo) than typical clusters at similar redshifts.