• Progress in Superconductivity and Cryogenics
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• v.10 no.2
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• pp.20-23
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• 2008

[ $La_2Zr_2O_7$] (LZO) buffer layers were deposited on biaxially textured Ni-W substrates by chemical solution deposition method (CSD). In this study, the effect of $B_2O_3$ addition on texture and surface roughness of LZO films was investigated. The alkoxide-based precursor solution was employed to synthesize the precursor solution of LZO and the solution was coated on biaxially textured Ni-W substrates and subsequently annealed at $900^{\circ}C$ for crystallization. The pure LZO film without $B_2O_3$ addition showed a (222) reflection in the X-ray diffraction (XRD) profile. The intensity of (222) reflection was enhanced and more rough surface was obtained after further repetition of coating. Contrary to this, the LZO film prepared by $B_2O_3$ added precursor solution shows well-developed (400) reflection peak in the XRD profile and excellent biaxial texture (${\Delta}{\theta}=4.3^{\circ}$, ${\Delta}{\phi}=6.8^{\circ}$). The surface roughness of LZO films were also improved by addition of $B_2O_3$ even after multicoating ($R_{rms}{\sim}3.1nm$). It was shown that the LZO film with smooth surface and biaxial texture was grown on the biaxially textured Ni-W substrates with addition of $B_2O_3$ in the precursor solution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.5
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• pp.382-386
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• 2019

The alignment characteristics of liquid crystal (LC) molecules on a solution-derived lanthanum zinc oxide (LZO) film under ion-beam irradiation were demonstrated. Using the solution process, an LZO film was fabricated on the glass substrate and cured at $100^{\circ}C$. Afterwards, ion-beam irradiation was performed following the LC alignment method. Using this film, an LC cell was fabricated and the characteristics of the LC alignment were verified. Cross polarizing microscopy and the crystal rotation method were used to investigate the alignment state of the LC molecules on the LZO films. Furthermore, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to explore the effect of the ion-beam irradiation on the LZO film. Through these, it was confirmed that the ion-beam irradiation induced surface modification, which demonstrated anisotropic physical and chemical surface characteristics. Due to this, uniform LC alignment was achieved. Finally, the residual DC and anchoring energy of the LC cell based on the LZO films were measured using a capacitance-voltage curve.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.174-174
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• 2008

Non-volatile memories using ferroelectric-gate field-effect transistors (Fe-FETs) with a metal/ferroelectric/semiconductor gate stack (MFS-FETs) make non-destructive read operation possible. In addition, they also have features such as high switching speed, non-volatility, radiation tolerance, and high density. However, the interface reaction between ferroelectric materials and Si substrates, i.e. generation of mobile ions and short retention, make it difficult to obtain a good ferroelectric/Si interface in an MFS-FET's gate. To overcome these difficulties, Fe-FETs with a metal/ferroelectric/insulator/semiconductor gate stack (MFIS-FETs) have been proposed, where insulator as a buffer layer is inserted between ferroelectric materials and Si substrates. We prepared $SrBi_2Ta_2O_9$ (SBT) film as a ferroelectric layer and $LaZrO_x$ (LZO) film as a buffer layer on p-type (100) silicon wafer for making the MFIS-FET devices. For definition of source and drain region, phosphosilicate glass (PSG) thin film was used as a doping source of phosphorus (P). Ultimately, the n-channel ferroelectric-gate FET using the SBT/LZO/Si Structure is fabricated. To examine the ferroelectric effect of the fabricated Fe-FETs, drain current ($I_d$) versus gate voltage ($V_g$) characteristics in logarithmic scale was measured. Also, drain current ($I_d$) versus drain voltage ($V_d$) characteristics of the fabricated SBT/LZO/Si MFIS-FETs was measured according to the gate voltage variation.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2002.02a
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• pp.340-340
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• 2002

In an effort to develop alternative single buffer layer technology for YBa$_2$Cu$_3$O$_{7-{\delta}}$ (YBCO) coated conductors, we have investigated both LaMnO$_3$, (LMO) and La$_2$Zr$_2$O$_{7}$ (LZO) as potential buffer layers. High-quality LMO films were grown directly on textured Ni and Ni-W (3%) substrates using rf magnetron sputtering. Highly textured LZO buffers were grown on textured Ni substrates using sol-gel alkoxide processing route. YBCO films were then grown on both LMO and LZO buffers using pulsed laser deposition. Detailed X-ray studies have shown that YBCO films were grown on both LMO and LZO layers with a single epitaxial orientation. A high J$_{c}$ of over 1 MA/cm$^2$ at 77 K and self-field was obtained on YBCO films grown on both LMO-buffered Ni or Ni-W substrates, and also on LZO-buffered Ni substrates. We have identified LaMnO$_3$ as a good diffusion barrier layer for Ni and it also provides a good template for growing high current density YBCO films. Similarly we have also demonstrated the growth of high J$_{c}$ YBCO films on all solution buffers. We will discuss in detail about our buffer deposition processes. processes.s.s.s.s.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.571-573
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• 2005

최근 모바일 폰, 휴대형 MP3 재생기, 휴대형 미디어 재생기, 휴대형 게임기 등 휴대형 디지털 가전 제품이 일반화되고 있으며 이들의 컴퓨팅 환경이 향상됨에 따라 휴대 가전의 사용 편의성 및 부가가치를 향상시키기 위해 UI가 하나의 큰 경쟁력 요소로 대두되고 있다. 그러나 현재까지는 휴대 단말기를 중심으로 사용자의 개인성을 강조하는 UI가 일부 채택되고 있으며 타 휴대 가전 분야에서는 최근에야 UI의 중요성이 부각되어 UI용 엔진들이 개발되고 있는 실정이다. 본 논문에서는 낮은 사양의 프로세서를 가지는 휴대형 가전에서 UI로 활용할 수 있는 비손실 영상 압축 시스템 개발에 대한 내용을 기술한다. 본 논문에서 제안된 기법은 현재 메모리 사용량 및 디코딩 속도에서 우수한 성능을 보이는 LZO 기법을 수정한 것으로 휴대 단말기의 프로세서에서 압축율 보다는 디코딩 속도에 최적화되었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.140-141
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• 2007

To fabricate the metal-ferroelectric-insulator-semiconductor (MFIS) structure for the ferroelectric random access memory (FRAM) application, we prepared the ferroelectric $Sr_{0.9}Bi_{2.1}Ta_2O_9$ (SBT) and the insulator LaZrOx (LZO) thin films on the silicon substrate using a sol-gel method. In this study, we will investigate the feasibility of the SBT/LZO/Si structure as one of the promising gate configuration for the 1-transistor (1-T) type FRAM, by measurements of the electrical properties and the physical properties.

• Progress in Superconductivity and Cryogenics
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• v.8 no.3
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• pp.37-40
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• 2006

Oxide buffer layers for YBCO coated conductors were fabricated using MOD processing and development of microstructure and texture were investigated. A $CeO_2$ buffer layers were formed on RABiTS tape. Acetate-based precursor solution was employed to synthesize the precursor solution. Subsequently, the precursor solution was stabilized and modified with triethanolamine. $CeO_2$ precursor gel film was coated and annealed in $Ar/H_2$ atmosphere at high temperature. An annealed $CeO_2$ film shows mixed orientation with high (001) texturing. It was shown that (111) texture of $CeO_2$ layers were enhanced by multiple coating. This degradation was attributed to development of microcracks in the multiply coated $CeO_2$ films. Also discussed are the synthesis and the characterization of $La_2Zr_2O_7$ (LZO) buffer layers on RABiTS tape. A biaxially textured LZO buffer layer was fabricated with MOD processing method using metal alkoxide based precursor solution. It was shown that the LZO film were epitaxially grown on RABiTS tape and crack-free & uniform surface was obtained after annealing in $Ar/H_2$ atmosphere.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.128-129
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• 2007

We fabricated seeded $SrBi_2Ta_2O_9$(SBT) thin films using seeding technique on the $LaZrO_x$ (LZO)/Si structure. To evaluate the ferroelectric properties of seeded SBT thin films, we investigated the crystalline phase, the surface morphology, the capacitance-voltage (C-V) curve and the current density-voltage (J-V) curve of seeded films and then compared with the physical and electrical properties of unseeded films. As the result of that, the characteristics of seeded and unseeded films have a slight difference. Therefore, the ferroelectric properties of seeded SBT thin films are not necessarily superior than unseeded films.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.252-255
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• 2012

가상화 기술은 각종 장비들을 편리하게 이용하게끔 하고 있으며, 특히 데스크탑 가상화 기술의 경우 클라우드 컴퓨팅에 의한 유저의 요구가 많아져 상당한 연구가 진행되고 있다. 데스크탑 가상화의 경우 사용자에게도 큰 이점이 있지만 관리 측면에서 Cost를 줄이는 데 일조하고 있다. 데스크탑 가상화는 관리자 측면에서 보았을 때 사용자의 요청에 따라 가상 데스크탑을 빠르게 제공하여야 하는 의무가 있다. 관리자가 가상 데스크탑을 빠르게 제공하기 위해서 미리 구축해 둔 가상 머신의 상태를 저장하는 데, 본 논문에서는 가상 데스크탑의 상태를 저장하고 제공하는 데 있어서의 효율을 위해 압축 알고리즘을 사용하는 방법을 제안한다. 가상 데스크탑의 상태가 메모리 명령어의 집합이라는 특성에 따라 무손실 압축 알고리즘을 사용하고, 그들 중 빠르고 압축률이 높기로 알려진 네 가지 알고리즘을 찾아 비교하였다. 비교 결과 가장 효율이 좋았던 LZO lgorithm을 메모리 상태 저장/복원의 중간 과정에 삽입하였다. 실험 결과 기존의 압축하지 않았던 방법보다 최대 1.7배의 성능 향상을 보였으며 가상 머신의 상태를 저장했을 때의 평균 54%의 용량 절감이 있었다.

• Progress in Superconductivity and Cryogenics
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• v.10 no.3
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• pp.5-8
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• 2008

On highly-textured IBAD-MgO templates, we have tried to find proper buffer layers among various candidate materials, including $LaMnO_3$ (LMO), $La_2Zr_2O_7$ (LAO), $LaAlO_3$ (LAO), $LaGaO_3$ (LGO), $NdGaO_3$ (NGO), and $BaZrO_3$ (BZO). All buffer layers were deposited on the IBAD-MgO templates by KrF pulsed laser deposition(PLD). LAO layer showed an armorphous phase. LZO, LGO, and NGO layers showed polycrystalline growth. Only LMO and BZO layers exhibited c-axis oriented biaxially textured films. Optimally processed LMO buffer layer at deposition temperature of $750^{\circ}C$ and $PO_2$ of 100mTorr exhibited ${\triangle}{\phi}$ value of ${\sim}-5.2^{\circ}$ and RMS roughness of 5.6nm. Interestingly, BZO buffer layers with ${\triangle}{\phi}$ values of ${\sim}-6^{\circ}$ could be routinely produced over a wide PLD processing condition.