Mo/SiO₂/Si(100)기판 위에 MOCVD법으로 성장시킨 AIN박막이용 GHz대역의 FBAR제작에 관한 연구

양충모,김성권,차재상,박구만,Yang, Chung-Mo,Kim, Seong-Kweon,Cha, Jae-Sang,Park, Ku-Man 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.4

본 논문에서는 $Mo/SiO_2/Si(100)$ 기판 위에 MOCVD(Metal-Organic-Chemical-Vapor Deposition)법을 이용하여 C축 방향으로 성장시킨 AIN(Aluminum Nitride) 박막을 이용하여 GHz대역 무선 통신에서 사용할 수 있는 FBAR(Film-Bulk-Acoustic Resonator)을 제작하였다. 제작된 공진부의 공진주파수와 반공진주파수는 각각 3.189[GHz]와 3.224[GHz]으로 측정되었으며, Q값(Quality Factor)과 유효한 전기기계 결합계수(${k_{eff}}^2$)는 각각 24.7과 2.65[%]로 평가되었다. AIN의 증착(Deposition) 조건은 $950[^{\circ}C]$의 기판표면(Substrate) 온도, 20Torr의 압력, 25000의 N/Al의 V/III비로 증착하였다. $4{\times}10^{-5}[\Omega{cm}]$의 Mo 하부전극 고유저항과 $Mo/SiO_2/Si(100)$ 기판 위에 AIN(0002) FWHM(Full-Width at Half-Maximum) 4를 갖는 C축 방향성의 AIN 박막을 성공적으로 성장시켰다. 따라서 증착된 AIN박막의 FWHM값은 GHz대역 무선 통신용 RF(Radio Frequency) 밴드 패스 필터 설계에 유용하게 사용될 것이다. In this paper, it is reported that film-bulk-acoustic resonator with high c-axis oriented AIN film on $Mo/SiO_2/Si(100)$ using metal-organic-chemical-vapor deposition was fabricated. The resonant frequency and anti-resonant frequency of the fabricated resonator were observed with 3.189[GHz] and 3.224[GHz], respectively. The quality factor and the effective electromechanical coupling coefficient(${k_{eff}}^2$) were measured with 24.7 and 2.65[%], respectively. The conditions of AIN deposition were substrate temperature of $950[^{\circ}C]$, pressure of 20Torr, and V-III ratio of 25000. A high c-axis oriented AIN film with $4{\times}10^{-5}[\Omega{cm}]$ resistivity of Mo bottom electrode and $4[^{\circ}]$ of AIN(0002) full-width at half-maximum(FWHM) on $Mo/SiO_2/Si(100)$ was grown successfully. The FWHM value of deposited AIN film is useful for the RF band pass filter specification for GHz-band wireless local area network.

Mo 화학기상증착에 있어서 불순물 농도에 미치는 증착조건의 영향

배상석,서성교,홍은식,김승모,조미정,한혜정,이두성,김세훈,민석홍 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

The thermal decomposition process of Mo(CO)_6 on chemical vapor deposition was investigated by analyzing the effects of deposition temperature, pressure, and reaction gas on the phase change of deposited films. Mo_2C was deposited at or below 350℃ due to the incompleteness of thermal decomposition of Mo(CO)_6, but Mo films was successfully deposited at 400℃ or higher temperatures. The variation of deposition pressure did not change the dependence of decomposition process on deposition temperature. The activation energy of surface reaction was 5.8 ㎉/mole.

SHS 공정에 의해 제조된 Mo_xW_1-xSi₂ 발열체의 열화메커니즘

이동원,이상헌,김용남,이성철,구상모,오종민,Lee, Dong-Won,Lee, Sang-Hun,Kim, Yong-Nam,Lee, Sung-Chul,Koo, Sang-Mo,Oh, Jong-Min 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.10

The degradation mechanism of $Mo_xW_{1-x}Si_2$ ultrahigh-temperature heating elements fabricated by self-propagating high-temperature synthesiswas investigated. The $Mo_xW_{1-x}Si_2$ specimens (with and without post-annealing) were subjected to ADTs (accelerated degradation tests) at temperatures up to $1,700^{\circ}C$ at heating rates of 3, 4, 5, 7, and $14^{\circ}C/min$. The surface loads of all the specimen heaters were increased with the increase in the target temperature. For the $Mo_xW_{1-x}Si_2$ specimens without annealing, many pores and secondary-phase particles were observed in the microstructure; the surface load increased to $23.9W/cm^2$ at $1,700^{\circ}C$, while the bending strength drastically reduced to 242 MPa. In contrast, the $Mo_xW_{1-x}Si_2$ specimens after post-annealing retained $single-Mo_xW_{1-x}Si_2$ phases and showed superior durability after the ADT. Consequently, it is thought that the formation of microcracks and coarse secondary phases during the ADT are the main causes for the degraded performance of the $Mo_xW_{1-x}Si_2$ heating elements without post-annealing.

Effect of post annealing on the microstructure, mechanical properties, and failure of Mo_xW_1-xSi₂ heaters produced by self-propagating high-temperature synthesis

Cho, Myung-Yeon,Lee, Sung-Chul,Park, Chulhwan,Lee, Daeseok,Koo, Sang-Mo,Moon, Kyoung-Sook,Lee, Dong-Won,Oh, Jong-Min Elsevier 2019 INTERMETALLICS Vol.110 No.-

<P><B>Abstract</B></P> <P>High-performance tungsten molybdenum disilicide (Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB>) heating elements were prepared using a self-propagating high temperature synthesis process. The effect of post annealing on the degradation behavior of the alloy was experimentally investigated. Increasing the attrition milling time up to 20 min during powder preparation resulted in Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB> heaters with the highest density, which increased the fracture strength compared to samples with shorter attrition times. Such samples were annealed and evaluated as heating elements using accelerated degradation tests and failure analysis in order to compare their structural characteristics and flexural strength with as-fabricated samples. The annealed Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB> heater showed a relatively dense structure with few pores and no secondary phases, apart from a SiO<SUB>2</SUB> layer. This favorable structure prevented bubble formation, which can result in fracturing of the heater, as revealed by evaluation at high temperatures with various heating rates. The flexural strength of the annealed specimen was 2.5-times higher than that of the as-fabricated specimen, which was attributed to removal of secondary phases during annealing. Failure time and surface load analyses were used to investigate the fracture mechanism of the Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB> heaters in detail at 1790 °C by quantifying bubble formation and the presence of secondary phases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Self-propagating high temperature synthesis of Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB> heaters demonstrated. </LI> <LI> Post-annealed Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si<SUB>2</SUB> heaters were highly dense, with good flexural strength. </LI> <LI> Bubble formation (the main cause of fracture) suppressed at ultra-high temperature (above 1700 °C). </LI> <LI> Surface load, failure time, and bubble formation used to study fracture mechanisms. </LI> </UL> </P>

해남 모이산 천열수 금은광상의 지구화학적 특성

문동혁,고상모,이길재,Moon, Dong-Hyeok,Koh, Sang-Mo,Lee, Gill-Jae 대한자원환경지질학회 2010 자원환경지질 Vol.43 No.5

전남 해남군 모이산 금광상에서 지구화학적 특성에 대한 연구를 수행하기 위하여 모이산 지표 및 갱내, 대산 지표에서 채취한 총 140개 시료에 대한 지구화학분석결과를 상관분석, 요인분석 그리고 군집분석 등 다변수 통계처리 하였다. 상관분석 결과, 금의 함량이 100 ppb 미만인 비광화대와 100 ppb 이상인 광화대에서 동시에 금과 높은 상관관계를 가지는 원소는 Ag, Cu, Bi, Te 등이며, 이는 연구지역에서 수반되는 함금 은 광석광물들(엘렉트럼, 실바나이트, 칼라버라이트 및 스퉤자이트)과 기타광석광물들(황동석, 텔룰로비스무타이트 및 비스무시나이트)의 산출과 일치된 결과로 인지된다. Mo은 비광화대(0.269)에서 보다 광화대(0.615)에서 상대적으로 높은 상관계수를 가지므로 금광화작용에 의해 그 함량이 강하게 지배되고 있는 것으로 해석된다. Mn, Cs, Fe, Se 등은 비광화대에서는 금과 정의 상관관계를 가지지만 광화대에서는 음의 상관관계를 가지므로 금광화작용 시 모암으로부터 용탈되는 원소군으로 해석된다. Sb은 광화대에서 금과 높은 상관성을 보이지만 비광화대에서는 음의 상관관계를 가지므로 금광화작용 시 부화되는 원소로 지시될 수 있다. 요인분석결과, 비광화대에서 금의 함량에 영향을 받는 요인군에 속하는 원소는 Se, Ag, Cs, Te 등이며 이들은 연구지역 내 비광화대에서 금의 존재 여부를 알려줄 수 있는 원소로 해석될 수 있다. 반면 광화대에서는 Mo과 Te 등이 강하게 금광화작용의 여부를 지시해 주며, 금과 함께 수반되는 은광화작용의 여부를 지시해 줄 수 있는 원소는 Sb과 Cu 등으로 해석된다. 군집분석 결과 비광화대에서 Cd-Zn-Pb-S, Bi-Fe-Cu-Mn, Se-Te-Au-Cs-Ag, As-Sb-Ba 등이 유사한 거동을 보이는 원소군으로 나타나는 반면, 광화대에서는 Cd-Zn-Mn-Pb, Fe-S-Se, As-Bi-Cs, Ag-Sb-Cu, Au-Te-Mo 등이 유사한 거동을 보여주는 원소군으로 나타난다. 이상과 같은 지구화학분석 자료의 다변수 통계처리를 이용하여 금광화대와 비광화대의 산출광물의 거동 및 지구화학적 특성 차이의 비교가 가능하므로 추후 이러한 방법이 이와 유사한 유형의 광상탐사에 유용한 방법으로 적용될 수 있을 것으로 기대된다. Geochemical characteristics of the Moisan epithermal gold-silver deposit with total 140 samples in Haenam area, Jeollanamdo were studied by using multivariate statistical analysis (correlation analysis, factor analysis and cluster analysis). The correlation analysis reveals that Ag, Cu, Bi, Te are highly correlated with Au in the both non-mineralized and mineralized zone. It is resulted from the presence of Au-Ag bearing minerals (electrum, sylvanite, calaverite and stuezite) and non Au-Ag containing minerals (chalcopyrite, tellurobismuthite and bismuthinite). Mo shows relatively much higher correlation at the mineralized zone (0.615) than non-mineralized zone (0.269) which implies Mo content is strongly affected by Au-mineralization. While Mn, Cs, Fe, Se correlated with Au at the nonmineralized zone, they have negative correlation at the mineralized zone. Therefore, they seem to be eluviated elements from the host rock during gold mineralization. Sb is enriched during the gold mineralization showing high correlation at the mineralized zone and negative correlation at the non-mineralized zone. According to the factor analysis, Se, Ag, Cs, Te are the indicators of gold mineralization presence due to the strong affection of gold content in the non-mineralized zone. In the mineralized zone, on the other hand, Mo, Te and Sb, Cu are the indicators of gold and silver mineralization, respectively. While the cluster analysis reveals that Cd-Zn-Pb-S, Bi-Fe-Cu-Mn, Se-Te-Au-Cs-Ag, As-Sb-Ba are the similar behavior elements groups in the non-mineralized zone, Cd-Zn-Mn-Pb, Fe-S-Se, As-Bi-Cs, Ag-Sb-Cu, Au-Te-Mo are the similar behavior elements groups in the mineralized zone. Using multivariate statistical analysis as mentioned above makes it possible to compare the behavior of presented minerals and difference of geochemical characteristics between mineralized and non-mineralized zone. Therefore, it will be expected a useful tool on the similar type of mining exploration.

부산지역 고등학교 급식서비스에 대한 학생과 급식종사자의 평가

모성종,서재수,류은순 한국조리과학회 2005 한국식품조리과학회지 Vol.21 No.2

The purpose of this study was to evaluate the perception of students' and employees' perception with for their high school foodservicein Bustin area. For this purpose, questionnaires were distributed among the 324 students and 93 employees in 12 high schools in the Busan area. The students assessed the importance and performance of school foodservice as 4.00/5.00 and 2.97/5.00,, respectively, and the employees assessed the importance and performance of as 4.07/5.00 and 3.77/100, respectively. Tice importance mean scores of students wereshowed significantly (p<0.01) higher scores in internal environment factor and sanitation factor than those of employees, hut the performance mean scores of students wereshowed significantly (p<0.01) lower scores in all the factors than those of employees. The importance grid of students and employees showed that the items of the high with to the low with of consideration of preference in menu, appropriate the meal hours, rapidnessrapidity of service, and prompt dealing with complaints were high scores to the students, but low scoresto the employees. The performance grid of students and employees showed that the items of the low with students to the high with employeesfreslrness of food ingredients, offering the consistency of consistently good service, rapidnessrapidity of service, prompt dealing with complaints, communication between students and employees, and food cleanliness were low scores to the students, but high scores to the employees of dish. 'Therefore, it would seem to be desirable that the foodservice manager may be plans the strategies with the involvement of students in the process from planning the menu to proposinge of ideas for improvement.

우리 나라 해사중재의 현황과 개선 방안

성재모,김성준 한국해운물류학회 2003 해운물류:이론과실천 Vol.- No.5

해운, 무역, 보험과 관련한 분쟁은 법원보다는 중재에 회부되는 경우가 일반적이다. 그러나 국내 해운선사들이 해운 분쟁을 대한상사중재원에 회부하는 건수는 갈수록 줄어들고 있고, 대부분은 런던해사 중재에 회부되고 있다. 이번 연구에서는 해운선사의 해사중재현황을 5개 선사를 중심으로 조사하였다. 조사결과 용선분쟁의 90% 이상이 런던해사중재에 회부되고 있고, 대한상사중재원에 회부되는 중재는 2.2%에 불과했다. 이는 해사 분쟁의 당사자가 국내 선사와 제3국 기업이 주류를 차지하고 있는 것이 가장 큰 원인인 것으로 파악된다. 그밖에 해운과 관련한 영국의 판례가 용선계약서 해석의 원칙이 되고 있는 것이 해운업계의 오랜 관행으로 자리잡고 있는 것도 주요한 원인으로 작용하였다. 해운과 관련한 계약은 대부분 국제간에 이루어지기 때문에 해상법이 발달한 영국법에 기초한 런던중재조항이 분쟁 당사자들에게는 공평하게 느껴질 수 있다. 하지만, 국내 선사들간의 해사 분쟁 중 다수가 런던중재를 이용하고 있는 것으로 나타나고 있다. 따라서 현재 대한상사중재원에서 취급하고 해사중재제도가 갖고 있는 문제점을 파악하고, 그 개선방안을 모색해 보았다. It is quite general that a dispute concerned with shipping, trading and insurance is referred to the arbitration panel instead of court. But, the number of case referred to the Korea Commercial Arbitration Board in respect of shipping become fallen every year. Instead, most disputes are referred to the London Maritime Arbitrators Association. The focus of this research is to investigate the current situation of arbitration cases in Korean shipping companies in more details. In the result of the research, it shows that more than 90% of charterparty dispute is referred to the London Maritime Arbitrators Association and only 2.2% is referred to the Korea Commercial Arbitration Board. That is why many leading cases under English law has become a principle of interpretation of the shipping contracts and become a custom in the shipping area. The contributory cause of the above situation is that the Korea Commercial Arbitration Board has a systematic problem. As many contracts concerned with shipping is internationally made, many people in the shipping area might feel that the London Arbitration Clause based on English law would be fair and reasonable. Nevertheless, we should recognize the Korea Commercial Arbitration Board's systematic problem and grope for a method of improving the systematic problem.

플루오르 화합물을 플라즈마 처리한 PET 직물의 방수성 및 투습성

모상영,김태년 忠南大學校 産業技術硏究所 1996 산업기술연구논문집 Vol.11 No.2

Glow discharge plasmas have been arisen much interests in the field of surface modification of polymers. There are much activated species in glow discharge plasma such as electrons(average energy:10eV), radicals and ultra-violet rays(∼40eV)etc. Those of activated energies can be used properly to modify the polymer surfaces. Recently, the demands on fabric which poses a water repellent, proofing and a moisture transpirate characters have been more and more increased. General preparing techniques of those materials are known as (1) surface modification of high bulky and high density fabrics, (2) surface coating with urethane or fluoro resins, (3) lamination with porous films. Among those methods the (1) is superior at moisture transpiration than (2) or (3), but is inferior at water proofing than (2) or (3). If, however, we could improve the water repellency and proofing characters, the process (1) would be the most preferable to other methods. In this work, we have treated PET fabric with each of CF₄, C₂F6, SF 6 and CF₃CF=CF₂plasmas to develop high functional fabric which preserves a moisture transpiration and water proofing natures. Modified properties were evaluated by breakthrough water pressure and water vapor permeation rate. The change of surface morphology was observed by SEM. Results obtained are (1) The moisture transpiration of CF₄-treated fabric was superior as much as untreated fabric, and those of C₂F6-treated, SF6-treated fabrics were inferior in 1∼3%, and that of C₃F6-treated fabric was the most inferior in 15%. (2) At very low pressure treatment condition, it tend to be more hydrophilic except C₃F6-treated fabric. (3) The best treatment condition were 0.09 torr, 90∼120 seconds in CF₄, 0.05 torr, 60∼90 seconds in C₂F6, 0.1 torr, 90 seconds in SF6 and 01 torr, 60 seconds in C₃F6 respectively.

치조골 상실에 따른 상악 치아군 저항중심의 변화에 관한 유한요소해석

성상진,김인태,국윤아,전윤식,김성훈,모성서 대한치과교정학회 2009 대한치과교정학회지 Vol.39 No.5

효과적인 교정치료계획의 수립을 위하여 치열군의 저항중심의 위치에 대한 평가는 필수적이다. 이번 연구의 목적은 상악 치열군(4전치, 6전치, 14치아)에서 치조골 손실에 따른 저항중심의 위치변화를 조사해보고자 하였다. 상악 전치열 14개 치아와 치주인대 및 0 mm, 2 mm, 4 mm 손실된 치조골의 3차원 유한요소 모델을 제작하였고 각 치아군(4전치, 6전치, 14치아)별로 치관부를 협측, 설측호선 및 splint wire로 고정하여 치아군 모델을 제작한 후 상악 중절치의 절단연 중점에서 연장된 splint wire에 4전치와 6전치군에는 200 g, 14치아군에는 400 g의 후방 견인력과 압하력을 적용하여 저항중심의 수직적, 수평적 위치를 분석하였다. 4전치군에서 저항중심의 수직 위치는 치조골 0 mm, 2 mm, 4 mm 손실에 따라 중절치의 절단연에서 치근방향 13.5 mm, 14.5 mm, 15 mm, 수평 위치는 후방 12 mm, 12 mm, 12.5 mm, 6전치군에서는 치근방향 13.5 mm, 14.5 mm, 15.5 mm, 후방 14 mm, 14 mm, 14.5 mm, 14치아군에서는 치근방향 11 mm, 13 mm, 14.5 mm, 후방 26.5 mm, 27 mm, 25.5 mm에 위치하였다. 모든 치아군에서 저항중심은 치조골 손실에 따라 치근첨 방향으로 이동하였으나, 치조정과의 거리는 가까워졌고, 4전치군과 6전치군에서 저항중심은 치조골 손실에 따라 후방으로 이동하였으나, 14치아군에서는 치조골 2 mm 손실 시에는 후방으로 이동하였으나, 4 mm 손실 시에는 전방으로 이동하였다. Objective: The aim of this study was to investigate the changes in the center of resistance of the maxillary teeth in relation to alveolar bone loss. Methods: A finite element model, which included the upper dentition and periodontal ligament, was designed according to the amount of bone loss (0 mm, 2 mm, 4 mm). The teeth in each group were fixed with buccal and lingual arch wires and splint wires. Retraction and intrusion forces of 200 g for 4 and 6 anterior teeth groups and 400 g for the full dentition group were applied. Results: The centers of resistance were at 13.5 mm, 14.5 mm, 15 mm apical and 12 mm, 12 mm, 12.5 mm posterior in the 4 incisor group; 13.5 mm, 14.5 mm, 15 mm apical and 14 mm, 14 mm, 14.5 mm posterior in the 6 anterior teeth group; and 11 mm, 13 mm, 14.5 mm apical and 26.5 mm, 27 mm, 25.5 mm posterior in the full dentition group respectively according to 0 mm, 2 mm, 4 mm bone loss. Conclusions: The center of resistance shifted apically and posteriorly as alveolar bone loss increased in 4 and 6 anterior teeth groups. However, in the full dentition group, the center of resistance shifted apically and anteriorly in the 4 mm bone loss model.

SHS 공정으로 제조된 Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si₂ 발열체의 가속수명시험과 고장분석

이동원(Dong-Won Lee),이상헌(Sang-Hun Lee),김용남(Yong-Nam Kim),이희수(Heesoo Lee),이성철(Sung-Chul Lee),구상모(Sang-Mo Koo),오종민(Jong-Min Oh) 한국전기전자학회 2017 전기전자학회논문지 Vol.21 No.3

고온자전합성과 후열처리 공정으로 MoxW1-xSi₂ 발열체를 제조하였다. MoxW1-xSi₂ 발열체의 신뢰성을 검증하기 위해 가속수명시험을 수행하였으며, 수명시간을 Minitab 프로그램으로 추정하였다. 또한, 가속수명시험 후의 MoxW1-xSi₂ 발열체의 고장분석을 전기적과 구조적 특성으로부터 수행하였다. 그 결과, MoxW1-xSi₂ 발열체의 지배적인 고장 유형은 발열체 내부의 크랙 형성과 SiO₂ 보호층의 박리임을 확인하였다. MoxW1-xSi₂ heaters were fabricated by self-propagating high-temperature synthesis (SHS) process and post sintering process. To validate the reliability of the MoxW1-xSi₂ heaters, the accelerated life test (ALT) was conducted, and then lifetime to MoxW1-xSi₂ heaters was estimated by using Minitab programs. Also, the failure analysis of MoxW1-xSi₂ heaters after ALT was performed through electrical and structural properties. As the results, it was confirmed that the dominant failure mode of MoxW1-xSi₂ heaters is the crack formation in heaters and the delamination of protective SiO₂ layers.