Al 이온 주입된 p-type 4H-SiC에 형성된 Ni/Ti/Al Ohmic Contact의 전기적 특성

주성재,송재열,강인호,방욱,김상철,김남균,Joo, Sung-Jae,Song, Jae-Yeol,Kang, In-Ho,Bahng, Wook,Kim, Sang-Cheol,Kim, Nam-Kyun 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.11

Ni/Ti/Al multilayer system ('/'denotes the deposition sequence) was tested for low-resistance ohmic contact formation to Al-implanted p-type 4H-SiC. Ni 30 nm / Ti 50 nm / Al 300 nm layers were sequentially deposited by e-beam evaporation on the 4H-SiC samples which were implanted with Al (norminal doping concentration = $4\times10^{19}cm^{-3}$) and then annealed at $1700^{\circ}C$ for dopant activation. Rapid thermal anneal (RTA) temperature for ohmic contact formation was varied in the range of $840\sim930^{\circ}C$. Specific contact resistances were extracted from the measured current vs. voltage (I-V) data of linear- and circular transfer length method (TLM) patterns. In constrast to Ni contact, Ni/Ti/Al contact shows perfectly linear I-V characteristics, and possesses much lower contact resistance of about $2\sim3\times10^{-4}\Omega{\cdot}cm^2$ even after low-temperature RTA at $840^{\circ}C$, which is about 2 orders of magnitude smaller than that of Ni contact. Therefore, it was shown that RTA temperature for ohmic contact formation can be lowered to at least $840^{\circ}C$ without significant compromise of contact resistance. X-ray diffraction (XRD) analysis indicated the existence of intermetallic compounds of Ni and Al as well as $NiSi_{1-x}$, but characteristic peaks of $Ti_{3}SiC_2$, a probable narrow-gap interfacial alloy responsible for low-resistance Ti/Al ohmic contact formation, were not detected. Therefore, Al in-diffusion into SiC surface region is considered to be the dominant mechanism of improvement in conduction behavior of Ni/Ti/Al contact.

AI 이온 주입된 p-type 4H-SiC에 형성된 Ni/AI 오믹접촉의 전기 전도 특성

주성재,송재열,강인호,방욱,김상철,김남균,이용재,Joo, Seong-Jae,Song, Jae-Yeol,Kang, In-Ho,Bahng, Wook,Kim, Sang-Cheol,Kim, Nam-Kyun,Lee, Yong-Jae 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.9

Ni/Al ('/' denotes deposition sequence) contacts were deposited on Al-implanted 4H-SiC for ohmic contact formation, and the conduction properties were characterized and compared with those of Ni-only contacts. The thicknesses of the Ni and Al thin film were 30 nm and 300 nm, respectively, and the films were sequentially deposited bye-beam evaporation without vacuum breaking. Rapid thermal anneal (RTA) temperature was varied as follows : $840^{\circ}C$, $890^{\circ}C$, and $940^{\circ}C$. The specific contact resistivity of the Ni contact was about $^{\sim}2\;{\pm}\;10^{-2}\;{\Omega}{\cdot}cm^2$, However, with the addition of Al overlayer, the specific contact resistivity decreased to about $^{\sim}2\;{\pm}\;10^{-4}\;{\Omega}{\cdot}cm^2$, almost irrespective of RTA temperature. X-ray diffraction (XRD) analysis of the Ni contact confirmed the existence of various Ni silicide phases, while the results of Ni/Al contact samples revealed that Al-contaning phases such as $Al_3Ni$, $Al_3Ni_2$, $Al_4Ni_3$, and $Ab_{3.21}Si_{0.47}$ were additionally formed as well as the Ni silicide phases. Energy dispersive spectroscopy (EDS) spectrum showed interfacial reaction zone mainly consisting of Al and Si at the contact interface, and it was also shown that considerable amounts of Si and C have diffused toward the surface. This indicates that contact resistance lowering of the Ni/Al contacts is related with the formation of the formation of interfacial reaction zone containing Al and Si. From these results, possible mechanisms of contact resistance lowering by the addition of Al were discussed.

효과적인 초등영어 어휘 학습 자료 및 지도법

주성재(Joo Sung Jae),홍선호(Hong Sun Ho),배한숙(Bae Han Suk) 한국초등영어교육학회 2016 초등영어교육 Vol.22 No.4

The present meta-analysis investigated the overall effect sizes of implementing teaching materials and methods in vocabulary instruction; and examined the mediating variables which influence the size of the overall effects. Nineteen experimental studies were selected based on the specific inclusion and exclusion criteria, and 79 mean-difference effect sizes were calculated. Results showed that the overall effect size of implementing teaching materials and methods in vocabulary instruction was .75. The most effective teaching materials in vocabulary instruction was using English books (g = 1.16), followed by using web-based English materials (g = .984), English newspapers for children (g = .978), and English movies for children (g = .77). In addition, the lexical approach was the most effective teaching method in vocabulary instruction (g = .49) compared to the way of teaching individual words (g = .11). Participants grade level, their English proficiency, and the total instructional time mediated the overall effects of implementing teaching materials and methods in vocabulary instruction. Educational implications and future research recommendations were discussed.

초등학생 영어 글쓰기에 나타난 어휘 사용 양상 분석

주성재(Sung Jae Joo) 한국초등영어교육학회 2023 초등영어교육 Vol.29 No.4

어휘 주석 유형과 초등영어 어휘학습의 연관성

주성재(Joo Sung jae),홍선호(Hong Sun ho) 한국초등영어교육학회 2015 초등영어교육 Vol.21 No.1

This study aims to investigate the effects of vocabulary gloss types on elementary English learners' vocabulary learning in an effort to find which type of vocabulary gloss is more effective for vocabulary retention. The types of vocabulary glosses used in this study include texts and pictures, and students were taught vocabulary using reading texts containing vocabulary glosses. The participants were 123 elementary students, including 60 fourth grade students and 63 sixth grade students. The participating students were divided into two groups according to gloss type, and taught vocabulary while reading text-or-picture glossed material during the experiment class. The results showed a positive effect of the glosses on vocabulary learning, and pictorial glosses were more effective than textual glosses. Particularly, pictorial glosses were more effective for lower level students' vocabulary learning than textual glosses in fourth grade. The results of the present study suggest that vocabulary glosses could be an effective method in vocabulary teaching for elementary English learners, especially in the case of the pictorial glosses. In addition, vocabulary glosses should be provided for elementary students according to their language proficiency and learning environment.

한국 초등학교 원어민 영어교사의 이야기

주성재 ( Sung Jae Joo ),홍선호 ( Sun Ho Hong ) 서울敎育大學校 初等敎育硏究所 2016 한국초등교육 Vol.27 No.2

외국어로서 영어를 가르치고 있는 우리나라의 EFL 상황에서 원어민 영어교사를 활용한 영어 수업은 학생들로 하여금 실제와 유사한 의사소통 상황에서 영어에 대한 노출의 기회를 최대한 많이 제공해줄 수 있다는 장점을 가지고 있다. 원어민 영어교사는 이제 우리나라 초등학교의 한 구성원으로서 중요한 역할을 담당하고 있음에도 불구하고, 그들과 관련한 연구는 대부분 협력 수업에 초점을 맞추고 있다. 이에 본 연구는 우리나라의 초등학교에서 근무하고 있는 한 원어민 영어교사의 개인적인 경험에 관한 이야기를 질적 연구의 한 방법인 내러티브 분석을 통해 그들이 어떠한 생각을 가지고 학교생활과 영어교육에 임하고 있는지에 대해 심층적으로 알아보고자 하였다. 본 연구는 경기도의 한 중소도시의 농촌 지역에 위치하고 있는 공립 초등학교에 2년간 근무한 원어민 영어교사 한 명에 초점을 맞추어 그의 경험과 관련된 이야기들을 심층 면담을 통해 데이터로 수집하여 기술하였으며, 이러한 경험들을 연대기순으로 배열하는 내러티브 연구의 과정을 적용하였다. 연구 결과, 먼저 영어 교육의 발전에 기여할 수 있는 양질의 원어민 영어교사들이 우리나라로 많이 올 수 있도록 하기 위해 다양한 정책적 지원이 필요함을 알 수 있었다. 또한 원어민 영어교사들이 한국 학교의 특수한 문화에 적응하고 학교의 구성원들과 긍정적인 인간관계를 형성할 수 있도록 동료 교사 들이 먼저 도움을 주고자 노력해야 하며, 더욱 세부적이고 체계적인 원어민 영어교사의 선발 및 지속적인 관리를 통해 우리나라의 원어민 영어교사 제도가 더욱 발전적인 방향으로 나아 갈 수 있도록 해야 할 것이다. The Native English Speaking Teacher (NEST) program has been in placed for over 20 years in Korean education system. However, relatively not enough qualitative research on the effects of the program has been conducted from diverse perspectives. The present study sought to describe a NEST, Steve’s life and experience in Korean elementary school. The data were collected through semi-structured in-depth interviews with a NEST teaching at a small elementary school located in rural area in Korea. Narrative data analysis was conducted, and main themes that emerged from interview transcripts were categorized. Results revealed that the NEST’s different experiences and perceptions in Korean private school (Hagwon) and public elementary school, the relationship with his students and colleague teachers, and his educational values as a teacher. The findings of this study also suggest that more supportive efforts are necessary so that NESTs can do their best in teaching as well as in adjusting themselves to Korean culture easily. In addition, Korean colleague teachers should help NESTs in adjusting to Korean school culture and making positive relationship with school members. Finally, various opinions from NESTs should be reflected as a significant source for the improvement of English education policy. The NEST program has plenty of positive effects in Korean elementary English education.

SF₆/O₂ 혼합가스에 의한 실리콘 웨이퍼의 표면 텍스쳐링 특성

강민석,주성재,구상모,Kang, Min-Seok,Joo, Sung-Jae,Koo, Sang-Mo 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.5

The optical losses associated with the reflectance of incident radiation are among the most important factors limiting the efficiency of a solar cell. Therefore, photovoltaic cells normally require special surface structures or materials, which can reduce reflectance. In this study, nano-scale textured structures with anti-reflection properties were successfully formed on silicon. The surface of sicon wafer was etched by the inductively coupled plasma process using the gaseous mixture of $SF_6+O_2$. We demonstrate that the reflection characteristic has significantly reduced by ~0% compared with the flat surface. As a result, the power efficiency $P_{max}$ of the nano-scale textured silicon solar cell were enhanced up to 20%, which can be ascribed primarily to the improved light trapping in the proposed nano-scale texturing.

지식기반산업의 입지행태와 정책방향

김갑성(Kab Sung Kim),김경환(Kyung Hwan Kim),남기범(Kee Bom Nahm),주성재(Sung Jae Choo),황주성(Joo Seong Hwang) 한국지역학회 2002 지역연구 Vol.18 No.1

This paper seeks to derive policy recommendations towards promoting the development of knowledge-based industries by facilitating the formation of clusters that meet the locational needs of firms. For this purpose, theories on the formation of knowledge-based industrial clusters were reviewed with a special attention to the role played by government in facilitating the establishments and nurturing of such clusters. An analysis of the locational behavior of knowledge-based industry was conducted to identify key factors behind their locational choice at different stages of development, using data taken from a firm-level survey. The paper then evaluates the existing policy instruments aimed at meeting the industry`s spacial requirements. Despite the various forms of policy intervention, a serious gap appears to exist. The problems include. 1) policy instruments are predominantly geared towards the firms at the incubating stage and the spatial needs of growing and maturing firms are not adequately supported: 2) clusters are not allowed in. the Seoul Capital Region, which is the most preferred location of firms; 3) the administration of intervention is scattered over responsible line ministries rather than being responsive to the needs of firms. In order to address these problems, it is suggested that policy reform be directed towards : 1) promoting the development of the knowledge-based industry : 2) supporting knowledge-based industrial clusters by integrating industrial policy and spatial policy in a coherent manner: 3) offering policy instruments catering differential needs of firms at various stages of development : 4) accommodating clusters in locations preferred by firms.

EBS 영어교육방송(EBSe) 활용에 대한 인식 및 효과

홍선호(Hong, Sun-Ho),주성재(Joo, Sung Jae),전재호(Jeon, Jaeho),유지혜(Yu, Jihye) 한국초등영어교육학회 2021 초등영어교육 Vol.27 No.2

The present study aims to analyze the effects and perception whilst using EBSe (EBS English) broadcasting programs in order to seek the improvement and development plans of EBSe. The survey was comprised of three main categories targeting students, parents, teachers, and the general public who have used EBSe programs. A total of 3,971 cases were collected as valid examples of the survey. The analysis of the survey data revealed that the learners mostly used EBSe programs as an addition to their classroom-based English education. In addition, most of the participants were highly satisfied with the use of EBSe programs. Lastly, the participants’ perception with regard to goal achievement and social effectiveness of EBSe programs were shown to be positive in the following four major objectives: enhancement of public English education, reducing the cost of private education, narrowing the gap of English education between different social classes and regions, and creating an environment of English education that has no time and space restrictions. In consideration of the current lack of English learning hours in the public English education system, proper change of the English education seems to be necessary using EBS English broadcasting programs for balanced improvement of the learners’ English ability.

EBS English 방과 후 영어 프로그램의 효과 및 개선방안 연구

홍선호 ( Hong Sun-ho ),주성재 ( Joo Sung Jae ),전재호 ( Jeon Jaeho ),유지혜 ( Yu Jihye ) 서울교육대학교 초등교육연구원 2021 한국초등교육 Vol.32 No.2

이 연구는 EBS English(이후 EBSe) 방과 후 영어 프로그램의 효과 분석과 개선방안 제안을 목표로 한다. EBSe 방과 후 영어 프로그램은 블렌디드 학습 환경 및 게임형 콘텐츠 제공 등 영어과 방과 후 프로그램의 다양성 제고에 기여한다. 그러나 EBSe 방과 후 영어 관련 선행연구는 주로 프로그램에 참여한 학생을 대상으로 한 연구에 국한되며, 그 수 또한 제한적이다. 연구목표 달성을 위해 프로그램의 효과 및 개선점에 대한 설문조사를 실시하였으며, EBSe 웹사이트 이용자(학생, 교사, 학부모, 일반인) 3,971명이 응답에 참여했다. 설문 결과를 통해 이용자의 전반적인 인식뿐만 아니라 EBSe 방과 후 영어 프로그램에 대한 집단 간 인식의 차이점을 논의하였다. 설문 결과를 분석한 결과에 따르면 프로그램 사용자들은 공교육 보완, 듣기/읽기 능력 향상 등 EBSe 방과 후 영어 프로그램의 효과에 대해 긍정적으로 인식하고 있었다. 그러나 다수의 웹사이트 사용자가 EBSe 방과 후 영어 프로그램을 사용해본 경험이 없다고 밝혔으며, 홍보 부족이나 타 콘텐츠 이용을 주요 이유로 제시하였다. 한편, 학부모와 교사의 프로그램에 대한 적극적인 활용 의지 또한 분석되었다. 더불어, 향후 ‘EBSe 방과후 영어’ 관련 콘텐츠가 어떤 형식으로 개발되었으면 하는지에 대해 EBSe 사용자 의견을 조사하였다. 이 조사는 단답형 문항으로 진행되었으며, 사용자들은 제시된 질문에 대해 자유롭게 본인의 의견을 개진하였다. 연구자는 조사된 의견을 여러 차례 읽는 과정을 통해 반복되는 제안 내용을 발견하고 이를 집단별로 나누어 분석하였다. 전반적인 의견과 집단별로 제안한 내용의 차이를 정리하여 제시하였다. 설문 결과를 바탕으로 적극적인 홍보의 필요성, 콘텐츠 다양화, 학부모, 교사를 위한 프로그램 활용법 개발을 EBSe 방과 후 영어 프로그램의 개선방안으로 제안하고자 한다. The purpose of this study is to examine the effects of the EBS English (EBSe) after-school program and suggest future directions for the program. Previous literature on after-school programs has revealed that these programs should utilize diverse content and further development should reflect various user perspectives. The EBSe after-school program contributes to the diversity of after-school programs in that it provides different types of content such as blended learning environments and gamified activities. However, previous studies on this program are limited in number and have focused only on students and teachers who participated in the program. To accomplish the purpose of this study, we administered user surveys regarding program effects and improvements to a total of 3,971 general EBSe website users who consisted of students, teachers, parents, and others. Results indicated overall positive perceptions on the effects of the program. However, more than half of the general users had not utilized the EBSe after-school program and the main reasons for this were a lack of promotion and the use of other content. The results also indicated that parents and teachers were more willing to use the program than students or others. Based on these findings, we suggested implementing active promotion, content diversification, and the development of guidelines for parents and teachers as future directions for the program. We also expect that the EBSe after-school program will contribute to the improvement of students' self-directed learning and reduction of private education expenses.