Liquid crystal alignment on rubbed self-assembled monolayers with fluorinated alkyl chain

오찬우,Seok-Gon Hwang,Sang Geon Park,박홍규 한국정보전자통신기술학회 2018 한국정보전자통신기술학회논문지 Vol.11 No.6

In this paper, we investigated the vertical alignment characteristics of liquid crystals (LCs) on fluorinated self-assembled monolayers (FSAMs). For comparison, a commercialized homeotropic polyimide (PI) layer was used as an LC alignment layer. We confirmed the successful deposition of FSAMs and the change of FSAMs before and after rubbing treatment through contact angle measurement and atomic force microscopy. The optical transmittance spectrum of the FSAMs is similar to that of the homeotropic PI layer, which is a superior optical characteristic applicable to LC devices. When FSAMs were applied to the vertically aligned (VA) LC cell, uniform and vertical LC alignments were achieved. In addition, the voltage-transmittance characteristic of VA LC cell with FSAMs was superior to that of VA LC cell with the conventional homeotropic PI layers. These results indicate that the FSAMs are suitable as the homeotropic LC alignment layer for enhanced LC devices.

UV 처리된 자기 조립 단분자막을 사용한 액정 셀의 전기광학특성 분석

오찬우,박홍규 한국정보전자통신기술학회 2023 한국정보전자통신기술학회논문지 Vol.16 No.2

In this paper, we demonstrated the orientation characteristics of liquid crystals using UV-treated FSAM as alignment layer. Moreover we confirmed the FSAM properties before and after UV treatment on indium tin oxide (ITO) glass substrates using physicochemical analysis. The hydrophobic property of the FSAM surface is change to hydrophilic through UV treatment. After UV treatment the LC molecules also were uniformly and horizontally aligned on the FSAM surfaces and the pretilt angle was obviously changed 90° degrees to 0° degrees. EO characteristic of TN cell which was fabricated with UV-treated FSAM was faster response time compare to conventional PI layer. The FSAM before and after UV treatment has a superior application potential as the LC alignment layer for LCD, potentially replacing the conventional polyimide layer. 본 논문은 UV(ultraviolet) 처리된 자기 조립 단분자막(fluorinated self-assembled monolayers; FSAM)을 배향막으로 사용한 액정의 배향 특성을 분석하였다. 물리화학적 분석을 사용하여 UV 처리 전후의 ITO(indium-tin-oxide) 유리 기판의 FSAM 특성을 확인하였다. FSAM 표면은 UV 처리에 의해 소수성에서 친수성으로 변화하였다. LC(liquid crystal) 분자는 UV 처리된 FSAM 표면에서 수평방향으로 정렬되었고 선경사각도 90°에서 0°로 변화하였다. UV 처리된 FSAM을 배향막으로 사용하여 제작된 TN(twist nematic) 셀의 전기광학(electro optics; EO) 특성은 기존의 PI(polyimide) 배향막에 비해 응답 시간이 빠른 것을 확인하였다. 이는 UV 처리된 FSAM이 LCD(liquid crystal display)의 기존 폴리이미드 배향막을 대체할 잠재적인 가능성을 가진다.

체외충격파 치료기(Extracorporeal Shockwave Therapy)의성능평가 및 보완사항에 관한 연구

오 찬 우,박 상 건,박홍규 대한전기학회 2018 전기학회논문지 P Vol.67 No.1

Extracorporeal shockwave therapy has been widely spread out showing an excellent efficacy compared to traditional medicinal treatments, interventional procedures or surgeries for diseases of tendons and musculoskeletal system. Major performance tests of extracorporeal shockwave therapy consist of pressure, energy flux, concentration, and effective amount of energy on the focus area of shockwave according to IEC 61846. Shockwave should be irradiated accurately to the lesion area to improve the performance of extracorporeal shockwave therapy, which makes it necessary to add the relevant section, IEC 60601-2-36 (12.1.101. Precision of Target Markers and Target Locations). International standards of extracorporeal shockwave therapy have been prepared based on European and western people. Thus, we need to conduct many studies on Korean patients to improve the quality of extracorporeal shockwave therapy and to develop the medical industry. In addition, the performance evaluation of extracorporeal shockwave therapy which has been prepared according to international standards should be additionally modified and supplemented corresponding to the Korean circumstances.

신뢰도지표를 활용한 신 가치기반신뢰도평가 (VBDRA) 기반의 배전 설비 투자 선택 방안 연구

박성미(Seongmi Park),오찬우(Chanwoo Oh),박세준(Sejun Park),김발호(Balho Kim),이두희(Duehee Lee) 대한전기학회 2022 전기학회논문지 Vol.71 No.2

W-C-N 확산방지막의 전자거동(ElectroMigration) 특성과 표면 강도(Surface Hardness) 특성 연구

김수인,김창성,이재윤,박준,노재규,안찬근,오찬우,함동식,황영주,유경환,이창우,Kim, Soo-In,Hwang, Young-Joo,Ham, Dong-Shik,Nho, Jae-Kue,Lee, Jae-Yun,Park, Jun,Ahn, Chan-Goen,Kim, Chang-Seong,Oh, Chan-Woo,Yoo, Kyeng-Hwan,Lee, Chang-Woo 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.3

Copper is known as a replacement for aluminum wire which is used for semiconductor. Because specific resistance of Cu ($1.67{\mu}{\Omega}$-cm) is lower than that of Al ($2.66{\mu}{\Omega}$-cm), Cu reduce RC delay time. Although melting point of Cu($1085^{\circ}C$) is higher than melting point of Al, Cu have characteristic to easily react with Silicon(Si) in low temperature, and it isn't good at adhesive strength with Si. For above these reason, research of diffusion barrier to prevent reaction between Cu and Si and to raise adhesive strength is steadily advanced. Our study group have researched on W-C-N (tungsten-carbon-nitrogen) Diffusion barrier for preventing diffusion of Cu through semiconductor. By recent studies, It's reported that W-C-N diffusion barrier can even precent Cu and Si diffusing effectively at high temperature. In this treatise, we vaporized different proportion of N into diffusion barrier to research Cu's Electromigration based on the results and studied surface hardness in the heat process using nano scale indentation system. We gain that diffusion barrier containing nitrogen is more stable for Cu's electromigration and has stronger surface hardness in heat treatment process. 반도체 공정에서 기존 금속배선으로 사용되던 Al을 대체하여 사용되는 금속배선으로는 Cu가 그 대안으로 인식되고 있다. 이는 비저항값이 Al ($2.66{\mu}{\Omega}$-cm)보다 Cu ($1.67{\mu}{\Omega}$-cm)가 더 작아 RC 지연 시간 (RC delay time)을 극복하기 때문이다. 그러나 Cu의 녹는점은 $1085^{\circ}C$로 높지만 저온에서 쉽게 Si기판과 반응하는 특성을 가지고 있고, 또한 Si과의 접착력이 좋이 않는 것으로 알려져 있다. 이러한 이유로 Cu와 Si과의 반응을 방지하고 접착력을 높이기 위하여 확산방지막의 연구가 꾸준히 진행되고 있다. 본 연구그룹에서는 Cu의 확산을 방지하기 위하여 W-C-N의 확산방지막에 대하여 연구하여 왔다. 지금까지 보고된 연구 결과에 의하면 W-C-N (tungsten-carbon-nitrogen) 확산방지막은 고온에서도 Cu와 Si과의 확산을 효과적으로 방지하는 것으로 보고되었다. 이 논문에서는 W-C-N 확산방지막에 질소(N) 비율을 다르게 증착하여 지금까지 진행한 연구 결과를 기반으로 새로이 Cu의 전자거동현상(Electromigration)에 대하여 연구하였고, 고온 열처리 과정에서 박막의 표면강도 (Surface hardness)를 Nano-Indenter system을 이용하여 연구하였다. 이러한 연구를 통하여 박막내 질소가 포함된 W-C-N 확산방지막이 Cu의 전자거동에 더 안정적이며, 고온 열처리 과정에서도 표면 강도가 더 안정한 연구 결과를 획득하였다.

W-C-N 확산방지막의 전자거동(electromigration) 특성과 표면 강도(surface hardness) 특성 연구

김수인,김창성,이재윤,박준,노재규,안창근,오찬우,함동식,황영주,유경환,이창우 한국진공학회 2009 한국진공학회 학술발표회초록집 Vol.36 No.-

물질의 약리기전 및 독성기전관리를 위한 데이터베이스

이국경,양원형,박원근,송태웅,허창복,박전홍,홍용원,김송학,오찬우 濟州大學校亞熱帶農業硏究所 2004 아열대농업생명과학연구지 Vol.20 No.1

Managing, processing, and expressing the data, the database system makes users save the time and labors required to look up and organize the useful data as well as helps to create some new information and ideas. However in Korean situation, our the history of research is not too long and the resources including database systems is not enough. Because other previous database svstems manage the data in a form of text file. I t is not easy to obtain a useful analyzed results at once. The goals of this project are to extract experimental data from the research on endocrine disruptors. to manage the data as a code form, to process the data, to create the useful analyzed results, to help toxicological researchers. and eventually to enhance the availability of raw data. Before the systems design, we constructed the code tables from the reports and executed a pilot test. Depending upon the result of pilot test, we determined the factors to be extracted as data set from reports. constructed database tables, and designed the software to manage the data-input and to search and analyze data, Data-input module help users easily to analyze the report in a paper form and to input the data. Developed in the web-based form, data-search module is able to give an access to public as well a s researchers. Also depending on the data saved in a code form. data-search module can provide much useful information and have a potentiation to be developed as more powerful data-analyzing system.