• 제목/요약/키워드: MFIs

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유도 결합 플라즈마($Cl_2/Ar$)를 이용한 $CeO_2$ 박막의 식각 특성 연구 (A Study on the Etching Characteristics of $CeO_2$ Thin Films using inductively coulped $Cl_2/Ar$ Plasma)

  • 오창석;김창일;권광호
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 추계학술대회논문집
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    • pp.29-32
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    • 2000
  • Cerium oxide thin film has been proposed as a buffer layer between the ferroelectric film and the Si substrate in Metal-Ferroelectric-Insulator-Silicon (MFIS ) structures for ferroelectric random access memory (FRAM) applications. In this study, CeO$_2$thin films were etched with Cl$_2$/Ar gas combination in an inductively coupled plasma (ICP). The highest etch rate of CeO$_2$film is 230 $\AA$/min at Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2. This result confirms that CeO$_2$thin film is dominantly etched by Ar ions bombardment and is assisted by chemical reaction of Cl radicals. The selectivity of CeO$_2$to YMnO$_3$was 1.83. As a XPS analysis, the surface of etched CeO$_2$thin films was existed in Ce-Cl bond by chemical reaction between Ce and Cl. The results of XPS analysis were confirmed by SIMS analysis. The existence of Ce-Cl bonding was proven at 176.15 (a.m.u.).

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금속씨앗층과 $N_2$ 플라즈마 처리를 통한 Al/CeO$_2$/Si 커패시터의 유전 및 계면특성 개선 (Improvement of dielectric and interface properties of Al/CeO$_2$/Si capacitor by using the metal seed layer and $N_2$ plasma treatment)

  • 임동건;곽동주;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.326-329
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    • 2002
  • In this paper, we investigated a feasibility of cerium oxide(CeO$_2$) films as a buffer layer of MFIS(metal ferroelectric insulator semiconductor) type capacitor. CeO$_2$ layer were Prepared by two step process of a low temperature film growth and subsequent RTA (rapid thermal annealing) treatment. By app1ying an ultra thin Ce metal seed layer and N$_2$ Plasma treatment, dielectric and interface properties were improved. It means that unwanted SiO$_2$ layer generation was successfully suppressed at the interface between He buffer layer and Si substrate. The lowest lattice mismatch of CeO$_2$ film was as low as 1.76% and average surface roughness was less than 0.7 m. The Al/CeO$_2$/Si structure shows breakdown electric field of 1.2 MV/cm, dielectric constant of more than 15.1 and interface state densities as low as 1.84${\times}$10$\^$11/ cm$\^$-1/eV$\^$-1/. After N$_2$ plasma treatment, the leakage current was reduced with about 2-order.

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Device characterization and Fabrication Issues for Ferroelectric Gate Field Effect Transistor Device

  • Yu, Byoung-Gon;You, In-Kyu;Lee, Won-Jae;Ryu, Sang-Ouk;Kim, Kwi-Dong;Yoon, Sung-Min;Cho, Seong-Mok;Lee, Nam-Yeal;Shin, Woong-Chul
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제2권3호
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    • pp.213-225
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    • 2002
  • Metal-Ferroelectric- Insulator- Silicon (MFIS) structured field effect transistor (FET) device was fabricated and characterized. Important issues to realize ferroelectric gate field effect transistor device were summarized in three sections. The choice of interlayer dielectric was made in the consideration of device functionality and chemical reaction between ferroelectric materials and silicon surface during fabrication process. Also, various ferroelectric thin film materials were taken into account to meet desired memory window and process compatibility. Finally, MFIS structured FET device was fabricated and important characteristics were discussed. For feasible integration of current device as random access memory array cell address schemes were also suggested.

$Ar/CF_{4}/Cl_{2}$ 플라즈마에 의한 $CeO_2$ 박막의 식각 특성 연구 (A study on etch Characteristics of $CeO_2$ thin Film in an $Ar/CF_{4}/Cl_{2}$ Plasma)

  • 장윤성;장의구;김창일;이철인;김태형;엄준철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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    • pp.217-220
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    • 2001
  • The possibility of cerium dioxide $(CeO_2)$ thin films as insulators of metal erroelectric insulator semiconductor (MFIS) structures have been studied. The etching $CeO_2$ thin films have been perfonned in an inductively coupled $Cl_{2}/CF_{4}/Ar$ plasma. The high etch rate of the $CeO_2$ thin film was $250\AA /m$ at a 10 % addition of $Cl_2$ into the $Ar(80)/CF_{4}(20)$. The surface reaction of the etched $CeO_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS) analysis. There are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. These products can be removed by the physical bombardment of incident Ar ions.

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수정된 GMDH 알고리즘 기반 다층 퍼지 추론 시스템에 관한 연구 (A Study on Multi-layer Fuzzy Inference System based on a Modified GMDH Algorithm)

  • 박병준;박춘성;오성권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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    • pp.675-677
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    • 1998
  • In this paper, we propose the fuzzy inference algorithm with multi-layer structure. MFIS(Multi-layer Fuzzy Inference System) uses PNN(Polynomial Neural networks) structure and the fuzzy inference method. The PNN is the extended structure of the GMDH(Group Method of Data Hendling), and uses several types of polynomials such as linear, quadratic and cubic, as well as the biquadratic polynomial used in the GMDH. In the fuzzy inference method, the simplified and regression polynomial inference methods are used. Here, the regression polynomial inference is based on consequence of fuzzy rules with the polynomial equations such as linear, quadratic and cubic equation. Each node of the MFIS is defined as fuzzy rules and its structure is a kind of neuro-fuzzy structure. We use the training and testing data set to obtain a balance between the approximation and the generalization of process model. Several numerical examples are used to evaluate the performance of the our proposed model.

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Ar/CF$_4$/Cl$_2$ 플라즈마에 의한 CeO$_2$ 박막의 식각 특성 연구 (A study on etch Characteristics of CeO$_2$ thin Film in an Ar/CF/C1$_2$ Plasma)

  • 장윤성;장의구;김창일;이철인;김태형;엄준철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.217-220
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    • 2001
  • The possibility of cerium dioxide (CeO$_{7}$ ) thin films as insulators of metal erroelectric insulator semiconductor (MFIS) structures have been studied. The etching CeO$_2$ thin films have been performed in an inductively coupled C1$_2$/CF$_4$/Ar plasma. The high etch rate of the CeO$_2$ thin film was 250 ${\AA}$/m at a 10% addition of Cl$_2$ into the Ar(80)/CF$_4$(20). The surface reaction of the etched CeO$_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS) analysis. There are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. These products can be removed by the physical bombardment of incident Ar ions.

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유도 결합 플라즈마($Cl_2$/Ar)를 이용한 $CeO_2$ 박막의 식각 특성 연구 (A Study on the Etching Characteristics of $CeO_2$ Thin Films using inductively coupled $Cl_2$/Ar Plasma)

  • 오창석;김창일;권광호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.29-32
    • /
    • 2000
  • Cerium oxide thin film has been proposed as a buffer layer between the ferroelectric film and the Si substrate in Metal-Ferroelectric-Insulator-Silicon (MFIS ) structures for ferroelectric random access memory (FRAM) applications. In this study, CeO$_2$ thin films were etched with Cl$_2$/Ar gas combination in an inductively coupled plasma (ICP). The highest etch rate of CeO$_2$ film is 230 $\AA$/min at Cl$_2$/(Cl$_2$+Ar) gas mixing ratio of 0.2. This result confirms that CeO$_2$ thin film is dominantly etched by Ar ions bombardment and is assisted by chemical reaction of Cl radicals. The selectivity of CeO$_2$ to YMnO$_3$ was 1.83. As a XPS analysis, the surface of etched CeO$_2$ thin films was existed in Ce-Cl bond by chemical reaction between Ce and Cl. The results of XPS analysis were confirmed by SIMS analysis. The existence of Ce-Cl bonding was proven at 176.15 (a.m.u.).

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삼각전압소인법을 이용한 강유전체 박막내에서의 분극 및 유동이온에 대한 평가 (Evaluation of polarization and mobile charge in ferroelectric films using TVS(Triangular Voltage Sweep) method)

  • 김용성;이남열;정순원;김진규;정상현;김광호;유병곤;이원재;유인구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.86-89
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    • 2000
  • The detection technique both the polarization and the mobile charge density at the same time in ferroelectric films on Si using TVS method have been proposed. This method yields a polarizable and an ionic displacement current peaks whose areas are proportional to the total polarization reversal charge and the total moble ionic space charge, respectively. The calculated polarization and the mobile charge density were 0.42 [$\mu$C/$\textrm{cm}^2$] and 5.5$\times$10$^{11}$ (ions/$\textrm{cm}^2$) in the SBT film of MFIS structure measured at 25$0^{\circ}C$, and 1.4 [$\mu$C/$\textrm{cm}^2$] in the LiNbO$_3$ film of MFS structure measured at 30$0^{\circ}C$, respectively.

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An Overview of the Microfinance Sector in Bangladesh

  • Mia, Md Aslam
    • Asian Journal of Business Environment
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    • 제7권2호
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    • pp.31-38
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    • 2017
  • Purpose - While microfinance institutions(MFIs) from Bangladesh, such as Grameen Bank, received worldwide recognition and the Nobel Peace Prize in 2006, however, there is a paucity of research that provided a comprehensive discussion on the characteristics of the microfinance industry. Hence, the aim of this paper is to discuss some important aspects of the microfinance sector in Bangladesh. Research design, data, and methodology - This study used secondary sources of data, such as annual reports of the Microcredit Regulatory Authority (MRA) and the World Bank database in its descriptive analysis. Results - This study found that Bangladesh has made remarkable progress in her socio-economic and economic development in the last few decades. It is also generally perceived that microfinance has placed significant contribution on such socio-economic development. While microfinance observed unprecedented growth domestically, however, the regulatory framework is still rather weak, and a majority of the MFIs are found to be concentrated in the well-off areas (e.g., Dhaka, Chittagong etc.). Conclusions - The findings are significantly important for the parties who are interested to know the microfinance sector in Bangladesh. To some extent, the findings of this study will provide policy implications that may benefit the industry.