흰쥐의 일차배양 간세포에서 Daidzin, Daidzein, Genistein 및 Puerarin의 간 보호 활성 평가

박진구,천호준,김영식,강삼식,최재수,이선미,Park, Jin-Goo,Cheon, Ho-Joon,Kim, Yeong-Shik,Kang, Sam-Sik,Choi, Jae-Sue,Lee, Sun-Mee 대한약학회 2007 약학회지 Vol.51 No.2

The aim of this study was to investigate the protective activities of daidzin, daidzein, genistein or puerarin, active isoflavonoids of Puerariae Radix, on the hepatocyte injury induced by carbon tetrachloride (CCl$_4$, 10 mM), tert-butyl hydroperoxide (TBH, 0.5 mM) and D-galactosamine (GalN, 30 mM). Primary cultures of rat hepatocytes (18 hr cultured) were treated with CCl$_4$, TBH or GalN and various concentrations (0.1, 1, 10 and 100 ${\mu}$M) of daidzin, daidzein, genistein or puerarin. CCl$_4$ significantly increased the levels of lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The increase in LDH level was attenuated by daidzein, genistein and puerarin. Puerarin also inhibited the increase in AST level induced by CCl$_4$. The increases in LDH and ALT levels induced by TBH were significantly attenuated by daidzin and genistein treatments. GalN markedly increased the levels of LDH, ALT and AST These increases were significantly attenuated by daidzein. Daidzin also inhibited the increases in LDH and AST levels induced by GalN. The increases in LDH and ALT levels were attenuated by genistein and puerarin, respectively. These results suggest that daidzin and daidzein possess hepatoprotective activities.

CMP 공정 후의 오염 제어

박진구(Jin-Goo Park),이상호(Sang-Ho Lee),김형균(Hyoung-Gyun Kim) 한국정밀공학회 1998 한국정밀공학회 학술발표대회 논문집 Vol.1998 No.5월

Scanning Tunneling Microscopy (STM)/Atomic Force Microscopy (AFM) Studies of Silicon Surfaces Treated in Alkaline Solutions of Interest to Semiconductor Processing

Jin-Goo Park(박진구) 한국표면공학회 1994 한국표면공학회 학술발표회 초록집 Vol.1994 No.-

나노 Imprinting을 위한 몰드 제작에 관한 연구

이진형(Jin-Hyung Lee),임현우(Hyun-Uoo Lim),김태곤(Taegon Kim),이승섭(Seung-Seoup Lee),박진구(Jin-Goo Park),이은규(Eun-Eyu Lee),김양선(Yang-Sun Kim),한창수(Chang-Su Han) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4

This study aims to investigate the fabrication process of nano silicon mold using electron beam lithography (EBL) to generate the nanometer level patterns by nano-imprinting technology. The nano-patterned mold including 100nm pattern size has been fabricated by EBL with different doses ranged from 22 to 38 μC/cm² on silicon using the conventional polymethymenthacrylate (PMMA) resist. The silicon mold is fabricated with various pattems such as circles, rectangles, crosses, oblique lines and mixed forms. The effect of dosage on pattern density in EBL is discussed based on SEM(Scanning Electron Microscopy) analysis of fabricated molds. The mold surface is modified by hydrophobic fluorocarbon (FC) thin films to avoid the stiction during nano-imprinting process.

초순수내에서의 오존의 용해도와 세정효과

한정훈,박진구,곽영신,Han, Jeoung-Hoon,Park, Jin-Goo,Kwak, Young-Shin 한국재료학회 1998 한국재료학회지 Vol.8 No.6

본 연구는 반도체 공정중 습식세정시 사용되는 초순수내에서의 오존의 거동과 오존이 주입된 초순수와 실리콘 웨이퍼와의 반응성에 대해 연구하였다. 초순수내 오존의 용해도는 주입되는 오존의 농도와 초순수의 온도가 낮을수록 증가하였고 주입되는 오존의 농도에 정비례하여 증가하였다. 초순수내 오존의 반감기는 초순수내 오존의 용해농도와 초순수의온도가 낮을수록 증가함을 나타내었고 반응차수는 약 1.5로 계산되었다. 초순수의산화환원전위(redox potential)값은 오존 주입시 5분 이내에 포화되어 일정한 값을 나타내었고 주입되는 오존의 농도가 증가함에 따라 약간 증가하였다. HF처리된 실리콘 웨이퍼는 오존이 2ppm 이상 용해된 초순수에서 세정하였을 때 1분 이내에 접촉각이 $10^{\circ}$미만의 친수성 표면을 형성하였고 piranha 세정액($H_2SO_4$과 $H_2O_2$의 혼합액)에 의해 형성된 자연산화막보다 오존이 주입된 초순수에 의해 형성된 산화막이 약간 더 두꺼움을 Spectroscopic Ellip-someter에 의해 관찰하였다. 오존의 농도가 1.5ppm에서 90초내에 계면활성제로 오염된 실리콘 웨이퍼를 piranha용액과 오존이 함유된 황산 그리고 오존이 함유된 초순수에서 세정시 오존이 함유된 초순수가 가장 탁월한 오염제거능력을 나타내었다. The purpose of this study was to investigate the behavior of ozone in DI water and the reaction with wafers during the semiconductor wet cleaning process. The solubility of ozone in DI water was not only dependent on the temperature but also directly proportional to the input concentration of ozone. The lower the initial ozone concentration and the temperature, the longer the half-life time of ozone. The reaction order of ozone in DI water was calculated to be around 1.5. The redox potential reached a saturation value in 5min and slightly increased as the input ozone concentrations increased. The completely hydrophilic surface was created in Imin when HF etched silicon wafer was cleaned in ozonized DI water containing higher ozone concentrations than 2ppm. Spectroscopic ellipsometry measurements showed that the chemical oxide formed by ozonized DI water was measured to be thicker than that by piranha solution. The wafers contaminated with a non-ionic surfactant were more effectively cleaned in ozonized DI water than in piranha and ozonized piranha solutions.

기상 자기조립박막 법을 이용한 나노임프린트용 점착방지막 형성 및 특성평가

차남구,김규채,박진구,정준호,이응숙,윤능구,Cha, Nam-Goo,Kim, Kyu-Chae,Park, Jin-Goo,Jung, Jun-Ho,Lee, Eung-Sug,Yoon, Neung-Goo 한국재료학회 2007 한국재료학회지 Vol.17 No.1

Nanoimprint lithography (NIL) is a new lithographic method that offers a sub-10nm feature size, high throughput, and low cost. One of the most serious problems of NIL is the stiction between mold and resist. The antistiction layer coating is very effective to prevent this stiction and ensure the successful NIL results. In this paper, an antistiction layer was deposited by VSAM (vapor self assembly monolayer) method on silicon samples with FOTS (perfluoroctyltrichlorosilane) as a precursor for making an antistiction layer. A specially designed LPCVD (low pressure chemical vapor deposition) was used for this experiment. All experiments were achieved after removing the humidity. First, the evaporation test of FOTS was performed for checking the evaporation temperature at low pressure. FOTS was evaporated at 5 Tow and $110^{\circ}C$. In order to evaluate the temperature effect on antistiction layer, chamber temperature was changed from 50 to $170^{\circ}C$ with 0.1ml of FOTS for 1 minute. Good hydrophobicity of all samples was shown at about $110^{\circ}$ of contact angle and under $20^{\circ}$ of hysteresis. The surface energies of all samples calculated by Lewis acid/base theory was shown to be about 15mN/m. The deposited thicknesses of all samples measured by ellipsometry were almost 1nm that was similar value of the calculated molecular length. The surface roughness of all samples was not changed after deposition but the friction force showed relatively high values and deviations deposited at under $110^{\circ}$. Also the white circles were founded in LFM images under $110^{\circ}$. High friction forces were guessed based on this irregular deposition. The optimized VSAM process for FOTS was achieved at $170^{\circ}C$, 5 Torr for 1 hour. The hot embossing process with 4 inch Si mold was successfully achieved after VSAM deposition.

실험 계획법을 이용한 점착방지막용 플라즈마 증착 공정변수의 최적화 연구

차남구,박창화,조민수,박진구,정준호,이응숙,Cha Nam-Goo,Park Chang-Hwa,Cho Min-Soo,Park Jin-Goo,Jeong Jun-Ho,Lee Eung-Sug 한국재료학회 2005 한국재료학회지 Vol.15 No.11

NIL (nanoimprint lithography) technique has demonstrated a high potential for wafer size definition of nanometer as well as micrometer size patterns. During the replication process by NIL, the stiction between the stamp and the polymer is one of major problems. This stiction problem is moi·e important in small sized patterns. An antistiction layer prevents this stiction ana insures a clean demolding process. In this paper, we were using a TCP (transfer coupled plasma) equipment and $C_4F_8$ as a precursor to make a Teflon-like antistiction layer. This antistiction layer was deposited on a 6 inch silicon wafer to have nanometer scale thicknesses. The thickness of deposited antistiction layer was measured by ellipsometry. To optimize the process factor such as table height (TH), substrate temperature (ST), working pressure (WP) and plasma power (PP), we were using a design of experimental (DOE) method. The table of full factorial arrays was set by the 4 factors and 2 levels. Using this table, experiments were organized to achieve 2 responses such as deposition rate and non-uniformity. It was investigated that the main effects and interaction effects between parameters. Deposition rate was in proportion to table height, working pressure and plasma power. Non-uniformity was in proportion to substrate temperature and working pressure. Using a response optimization, we were able to get the optimized deposition condition at desired deposition rate and an experimental deposition rate showed similar results.

텅스텐 화학적-기계적 연마 공정에서 부식방지막이 증착된 금속 컨디셔너 표면의 전기화학적 특성평가

조병준,권태영,김혁민,박문석,박진구,Cho, Byoung-Jun,Kwon, Tae-Young,Kim, Hyuk-Min,Venkatesh, Prasanna,Park, Moon-Seok,Park, Jin-Goo 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.1

반도체 산업에서 회로의 고집적화와 다층구조를 형성하기 위해 화학적-기계적 연마(CMP: Chemical-Mechanical Planarization) 공정이 도입되었으며 반도체 패턴의 미세화와 다층화에 따라 화학적-기계적 연마 공정의 중요성은 더욱 강조되고 있다. 화학적-기계적 연마공정이란 화학적 반응과 기계적 힘을 동시에 이용하여 표면을 평탄화하는 공정으로, 화학적-기계적 연마 공정은 압력, 속도 등의 공정조건과, 화학적 반응을 유도하는 슬러리(Slurry), 기계적 힘을 위한 패드 등에 의해 복합적으로 영향을 받는다. 패드 컨디셔닝이란 컨디셔너가 화학적-기계적 연마 공정 중에 지속적으로 패드 표면을 연마하여 패드의 손상된 부분을 제거하고 새로운 표면을 노출시켜 패드의 상태를 일정하게 유지시키는 것을 말한다. 한편, 금속박막의 화학적-기계적 연마 공정에 사용되는 슬러리는 금속박막과 산화반응을 하기 위하여 산화제를 포함하는데, 산화제는 금속 컨디셔너 표면을 산화시켜 부식을 야기한다. 컨디셔너의 표면부식은 반도체 수율에 직접적인 영향을 줄 수 있는 스크래치(Scratch) 등을 발생시킬 뿐만 아니라, 컨디셔너의 수명도 저하시키게 되므로 이를 방지하기 위한 노력이 매우 중요하다. 본 연구에서는 컨디셔너 표면에 슬러리와 컨디셔너 표면 간에 일어나는 표면부식을 방지하기 위하여 유기박막을 표면에 증착하여 부식을 방지하고자 하였다. 컨디셔너 제작에 사용되는 금속인 니켈과 니켈 합금을 기판으로 하고, 증착된 유기박막으로는 자기조립단분자막(SAM: Self-Assembled Monolayer)과 불화탄소(FC: FluoroCarbon) 박막을 증착하였다. 자기조립단분자막은 2가지 전구체(Perfluoroctyltrichloro silane(FOTS), Dodecanethiol(DT))를 사용하여 기상 자기조립 단분자막 증착(Vapor SAM) 방법으로 증착하였고, 불화탄소막은 10 nm, 50 nm, 100 nm 두께로 PE-CVD(Plasma Enhanced-Chemical Vapor Deposition, SRN-504, Sorona, Korea) 방법으로 증착하여 표면의 부식특성을 평가하였다. 표면 부식 특성은 동전위분극법(Potentiodynamic Polarization)과 전기화학적 임피던스 측정법(Electrochemical Impedance Spectroscopy(EIS)) 등의 전기화학 분석법을 사용하여 평가되었다. 또한 측정된 임피던스 데이터를 전기적 등가회로(Electrical Equivalent Circuit) 모델에 적용하여 부식 방지 효율을 계산하였다. 동전위분극법과 EIS의 결과 분석으로부터 유기박막이 증착된 표면의 부식전류밀도가 감소하고, 임피던스가 증가하는 것을 확인하였다. Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

연마제 특성에 따른 차세대 금속배선용 Al CMP (chemical mechanical planarization) 슬러리 평가

차남구,강영재,김인권,김규채,박진구,Cha, Nam-Goo,Kang, Young-Jae,Kim, In-Kwon,Kim, Kyu-Chae,Park, Jin-Goo 한국재료학회 2006 한국재료학회지 Vol.16 No.12

It is seriously considered using Al CMP (chemical mechanical planarization) process for the next generation 45 nm Al wiring process. Al CMP is known that it has a possibility of reducing process time and steps comparing with conventional RIE (reactive ion etching) method. Also, it is more cost effective than Cu CMP and better electrical conductivity than W via process. In this study, we investigated 4 different kinds of slurries based on abrasives for reducing scratches which contributed to make defects in Al CMP. The abrasives used in this experiment were alumina, fumed silica, alkaline colloidal silica, and acidic colloidal silica. Al CMP process was conducted as functions of abrasive contents, $H_3PO_4$ contents and pressures to find out the optimized parameters and conditions. Al removal rates were slowed over 2 wt% of slurry contents in all types of slurries. The removal rates of alumina and fumed silica slurries were increased by phosphoric acid but acidic colloidal slurry was slightly increased at 2 vol% and soon decreased. The excessive addition of phosphoric acid affected the particle size distributions and increased scratches. Polishing pressure increased not only the removal rate but also the surface scratches. Acidic colloidal silica slurry showed the highest removal rate and the lowest roughness values among the 4 different slurry types.

Cu ECMP 공정에서 전해액이 연마거동에 미치는 영향

권태영,김인권,김태곤,조병권,박진구,Kwon, Tae-Young,Kim, In-Kwon,Kim, Tae-Gon,Cho, Byung-Gwun,Park, Jin-Goo 한국재료학회 2008 한국재료학회지 Vol.18 No.6

The purpose of this study is to characterize various electrolytes on electrochemical mechanical planarization (ECMP). The ECMP system was modified from conventional CMP system to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat for the evaluation of the polishing behavior on ECMP. KOH (alkaline) and $NaNO_3$ (salt) were selected as electrolytes which have high conductivity. In static and dynamic states, the corrosion potential decreased and the corrosion current increased as a function of the electrolyte concentration. But, the electrochemical reaction was prevented by mechanical polishing effect in the dynamic state. The static etch and removal rate were measured as functions of concentration and applied voltage. When $NaNO_3$ was used, the dissolution was much faster than that of KOH. It was concluded that the removal rate was strongly depended on electrochemical dissolution. The removal rate increased up to 350 nm/min in $NaNO_3$ based electrolyte.