HSS STI-CMP적용을 위한이중 패드의 최적화

서용진,박성우,김철복,정소용,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

As the device geometry shrinks to the deep submicron region, chemical mechanical polishing(CMP) planarization become a more essential technique of advanced ULSI process. Also, CMP process was required for the global planarization of inter-metal dielectric(IMD), inter-level dielectric(ILD) layers and interconnections with free-defect. Especially, the complete global planarization of IMD, ILD and interconnections can be achieved only with the CMP process. However, as the IMD and ILD layer gets thinner, several problems were found in the CMP process. It does have various problems such as dishing effect, torn oxide defects and nitride residues in oxide. So, it leads to severe circuit failure, which affects yield. In this paper, we studied the characteristics of polishing pad, which can apply STI-CMP process for global planarization of multilevel interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was defected less than 2 on JR111 pad. Through the above result, we can select optimum polishing pad, so we can expect the improvement of throughput and device yield.

중소기업의 핵심역량, 대외협력관계, 경쟁우위와 기업성과간의 관계 : 대구ㆍ경북지역의 자동차부품업체를 중심으로

서영일,김경,김성권 계명대학교 산업경영연구소 2000 經營經濟 Vol.33 No.2

This study empirically investigates the determinants of competitive advantage of small and medium-sized firms in Korea, and the relationship between competitive advantage and corporate performance. The sample consists of 78 firms in the automotive parts industry, located in Daegu-Kyungpook area. Data for statistical analysis were collected through questionnaire method, and the regression analysis was utilized to test the hypotheses. The regression results revealed that organizational management capability as a sub-factor of core competence and commitment as a sub-factor of external cooperation have positive impacts on competitive advantage measured by technological advantage and price advantage. It was also revealed that competitive advantage as measured by technological advantage positively influences corporate performance as measured by sales growth rate and innovativeness.

제 7차 초등학교 수학 교육과정 내용 체계 분석 : Focusing on the Continuity, Sequence, and Integration of Mathematical Content

서경혜,유솔아,정진영 한국초등교육학회 2003 초등교육연구 Vol.16 No.2

교육과정 개정 때마다 수학 내용의 적정화가 중점 사항으로 제시되어 왔음에도 수학 내용의 양과 수준의 문제는 여전히 쟁점으로 남아있다. 이는 수학 내용의 적정화 문제를 내용의 양을 축소하고 수준을 하향 조정하는 기존의 방식으로 해결할 수 없음을 보여준다. 본 연구는 수학 내용의 적정화 문제를 내용 조직의 관점에서 접근해야 한다는 가정 하에 제 7차 초등학교 수학 교육과정의 수학 내용 조직에 관한 분석을 목적으로 하였다. 내용 조직에 대한 분석은 연속성, 계열성, 통합성의 원리에 근거하였다. 분석 결과 현행 초등학교 수학 교육과정의 내용 조직은 일회성, 단절성, 배타성의 특징을 띠고 있는 것으로 나타났다. 주요 수학내용이 대체로 한번 가르쳐지고 마는 편이었으며 현재 다루어지고 있는 내용이 전에 가르쳤던 내용과 그리고 앞으로 소개될 내용과 어떻게 연결되는지 내용의 위계를 찾기 어려운 경우가 많았다. 또한 여러 내용 영역들이 통합적으로 조작되어 내용 체계를 이루기보다는 서로 배타적으로 병립하고 있는 경향을 보였다. 수학 내용의 적정화를 위해서 수학 내용을 엄선하는 것 뿐 아니라 선정된 내용을 연속성, 계열성, 통합성의 원리에 근거하여 체계적으로 조직하는 작업이 요구된다. The present study examined the Korean elementary school mathematics curriculum focusing on the organization of mathematical content. The result showed a lack of continuity, sequence, and integration of mathematical content. Mathematical concepts and skills are usually introduced once with little relation to previously taught concepts and skills. In addition, six content domains - numbers and operations, geometry, measurement, patterns and functions, probability and statistics, and symbols - tend to be mutually exclusive, showing students little connections among six domains. Therefore, the present study suggests that important mathematical concepts are extended and deepened throughout the elementary school years so that students are provided with ample time and opportunities to learn important mathematical concepts and skills. Further, mathematical content domains need to be closely related and so important mathematical concepts are taught in several content domains from various perspectives. In doing so, the curriculum can help students develop an in-depth understanding of important mathematical concepts.

CMP 공정의 재현성 확보를 위한 공정제어 범위의 결정

서용진,정소영,김철복,박성우,이경진,김기욱,박창준 대불대학교 2002 大佛大學校大學院 硏究論文集 Vol.- No.1

To achieve the ULSI goals of higher density and greater performance, STI(shallow trench isolation)-CMP(chemical mechanical polishing) process has been attracted. Recently, the direct STI-CMP process without the conventional complex reverse moat etch process has established by using slurry additive with the high selectivity between SiO2 and Si3N4 films for the purpose of process simplification and in-situ EPD(end point detection). However, STI-CMP process has various defects such as nitride residue, torn oxide and demage of silicon active region. Also, it was difficult to assure the suitable process margin in the STI-CMP process. To solve these problems, in this paper, we discussed to determine the control limit of process, which can entirely remove the oxide on nitride film from the most area of high density as reducing the damage of dense moat area and minimizing dishing effect in the large field area. We, also, evaluated the wafer-to-wafer thickness variation and the day-by-day reproducibility of STI-CMP process after repeatable tests.

초등 수학 교육과정 내용 조직 비교 분석 : 제 7차 교육과정과 Everyday Mathematics The 7th Korean National Curriculum and Everyday Mathematics

서경혜,유솔아,정진영 이화여자대학교 사범대학 교육과학연구소 2002 교육과학연구 Vol.33 No.2

본 연구는 제 7차 초등 수학 교육과정의 내용 조직을 연속성, 계열성, 통합성의 관점에서 분석하였다. 분석 결과 수학 내용이 일회적이고 분절적으로 제시되고 있으며 내용 간의 통합성도 부족하다는 것이 가장 큰 문제점으로 드러났다. 이에 대한 개선 안 모색을 위해 외국의 초등 수학 교육과정 내용 체계를 살펴보았다. 그 중 시카고 대학의 수학 연구팀에 의해 개발된 「Everyday Mathematics」는 수학 내용 조직과 관련하여 유용한 시사점을 주었다. 첫째는 학생들에게 중요한 수학 내용을 배울 수 있는 충분한 활동과 시간을 제공해야 한다는 것이다. 현행 초등 수학 교육과정의 경우 내용이 일회적으로 다루어지고 있어 그 시점에서 제대로 학습하지 못하면 배울 기회를 잃게 되고 이러한 상황이 누적될 때 학생들은 결국 수학 학습 실패의 경험을 하게 되고 수학에 대한 관심과 흥미를 잃게 된다. 둘째는 수학 내용 간에 그리고 내용 영역들 간에 연관성이 필요하다는 것이다. 수학 내용을 한 내용 영역에서만 단편적으로 가르칠 것이 아니라 여러 내용 영역에서 통합적으로 다룸으로써 학생들이 중요한 수학 내용을 다양한 관점에서 접근할 수 있고 그리하여 수학 내용에 대한 깊은 이해를 할 수 있도록 도와주어야 할 것이다. The present study examined the Korean elementary school mathematics curriculum focusing on the scope and sequence of mathematical content. The results showed a lack of continuity, sequence, and integration of mathematical content. Mathematical concepts and skills are usually introduced once with little relation to previously taught concepts and skills. In addition, six content domains tend to be mutually exclusive, showing students little connections among six domains. In order to find out the alternatives, we reviewed elementary mathematics curricular in the United States and Canada. In particular, Everyday Mathematics curriculum provided useful suggestions. In Everyday Mathematics, important mathematical concepts and skills are introduced in the first grade and extended and deepened throughout the elementary school years. Thus the curriculum provides students with ample time and opportunities to learn important mathematical concepts and skills. Further, mathematical content domains are closely related and so a mathematical concept is taught in several content domains from various perspectives. In doing so, the curriculum helps students develop an in-depth understanding of important mathematical concepts. The purpose of this comparative analysis is not to argue that the Korean Curriculum should follow the way the mathematical content was selected and organized in the Everyday Mathematics. Instead, we hope that this comparative study promotes further research and discussion on the alternative approaches to curriculum development as well as the selection and organization of mathematical content.

유화 Chlorosulfonated Polyethylene Rubber (CSM)의 제조 및 특성 연구

이은경,최교창,최세영 한국고무학회 2005 엘라스토머 및 콤포지트 Vol.40 No.1

본 연구에서는 CSM 에멀젼의 물성을 향상시키고자 금속성 가교제인 magnesium carbonate 및 calcium hydroxide를 첨가하여 가교밀도, 열적특성, 표면자유에너지 그리고 인장강도, 파단신율 및 인열강도 특성을 고찰하였다, 금속성 가교제인 magnesium carbonate 및 calcium hydroxide 양이 증가함에 따라 CSM 에멀젼 필름은 가교밀도는 증가하였고, 이에 내수성과 T_(g) 값도 증가하였다. 금속성 가교제로 magnesium carbonate를 첨가하였을 때 calcium hydroxide에 비해서 다소 높은 가교밀도와 T_(g) 값을 보였다. 하지만 CSM 에멀젼 필름의 표면에너지 및 기계적 특성들은 다소 다른거동을 보였다 Magnesium carbonate 0.75% 그리고 calcium hydroxide 1.0% 첨가한 경우가 가장 높은 표면 자유에너지 값과 인장강도 및 인열강도를 보였으나, 그 이상의 양을 첨가하였을 경우에는 오히려 감소함을 확인하였다. 그러므로 본 연구에서 CSM 에멀젼의 물성을 향상시키는데 적용되는 금속성 가교제로서 calcium hydroxide 보다 magnesium carbonate가 더 적당하며, 0.75% 첨가하였을 때 보다 향상된 물성을 얻을 수 있었다. In this work. magnesium carbonate and calcium hydroxide as metallic crosslinking agent were added to chlorosulfonated polyethylene rubber (CSM) emulsion to enhance the mechanical properties of emulsion film such as tensile strength. elongation at break, and tear strength and crosslinking density. thermal features, and surface energy were also investigated. Crosslinking density of the CSM emulsion film with increasing the amount of magnesium carbonate and calcium hydroxide increased. leading to the enhancement of water resistance. It was shown that compared with calcium hydroxide, magnesium carbonate had a little higher crosslinking density and To value. The surface energy and mechanical characteristics of the CSM emulsion film, however, showed somewhat different behaviors. The highest surface energy. tensile strength. and tear strength were observed when 0.75° o for magnesium carbonate and 1.0° o for calcium hydroxide were added respectively. Therefore. it can be concluded that as metallic crosslinking agent to improve water resistance and mechanical properties of the CSM emulsion, magnesium carbonate is more preferable to calcium hydroxide

Unaccusative Constructions in English

임은경,서영미 대전대학교 인문과학연구소 2002 人文科學論文集 Vol.33 No.-

제어기를 이용한 원통박육부재의 에너지흡수특성

기경서,김선규,양인영 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.1

In this paper, collapse test of thin-walled circular tube member is performed under axially static in consideration of the collapse characteristics to develop the optimum structural members. Furthermore, the energy absorption characteristics is observed according to the controller, height of the controller, clearance between specimen and controller. thickness of the controller. As a result, it was clear that the energy absorption characteristics of circular tubes were influence by the controller, height, clearance, thickness in this study.

뇌성마비 환아의 발달 평가와 유발 전위, 뇌파,뇌 자기 공명 영상의 비교연구

서정수,김태민,채진목,김영경,김봉옥 大韓再活醫學會 2000 Annals of Rehabilitation Medicine Vol.24 No.4

동합금의 생물학적 친화성에 대한 연구

김경남,박경준,이서영 大韓齒科器材學會 1991 대한치과재료학회지 Vol.18 No.2

The rise in the cost of gold was lead to use base metal alloy instead of using gold alloy which was known to be most biocompatible. But these base metal alloys are too hard and have low biocompatibility compared to gold alloy. Especially, nickel allergy & hypersensitivity came to be a problem, so use of these alloys is needed to take a careful consideration. In addition, copper alloy has been used in dentistry until now because of giving a golden color but it has lower castability and higher solubility in the oral environment compared to gold alloy. Many reports also have been made on the high toxicity of copper alloy, which revealed the inadequate dental uses of copper alloy. Recently, NPG copper alloy (Alba Dent Co., U.S.A.) have been introduced in Korea. This study was done cell toxicity test (Agar overlay test) and tarnish test in artificial saliva for 30 days and in 5% Na₂S solution for 13 days for 3 gold alloys, a Ag-Pd alloy, and NPG copper alloy. The results were as followed; 1. NPG copper alloy indicated zone index 3 and lysis index 5 in agar overlay test, which revealed high toxicity compared to gold or silver alloys. 2. In tarnish test, contrast to a small color change of gold and silver alloys, NPG copper alloy had a striking color change, 1st day in artificial saliva indicated 2 degree, 30th day in artificial saliva indicated 4 degree and in 5% Na₂S solution, extreme color change of 5 degree showed even on the 1st day.