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.

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.

한국인의 연, 망간, 알루미늄 및 실리콘의 혈중 농도

김정만,안정모,김원술,김정일,신해림,정갑열,김준연 동아대학교 산업의학연구소 2000 산업의학연구소 논총 Vol.- No.5

Blood Lead, Manganese, Aluminium and Silicon Concentrations in Korean Adults Jung Man Kim, Jung Mo Ahn, Won Sul Kim1), Jung Il Kim2), Hai Rim Shin, Kap Yeol Jung2), Joon Youn Kim Department of Preventive Medicine, College of Medicine and Industrial Medicine Research Institute. Dong-A University Department of Health Care, Handong University Sunlin Presbyterian Hotpital1) Department of Occupational Medicine, College of Medicine, Dong-A University2) 0bjectives : This study was performed to determine the reference values of blood lead, manganese, aluminium, and silicon in healthy adults. Methods : The subjects were 132 (67 male and 65 female), and classified to three age groups (≤39,40∼49, and 50≤). Hood lead, manganese and aluminium were analyzed by atomic absorption spectrophotometer, and blood silicon was analyzed by direct current plasma optical omission spectrometer. Results : Blood lead levels(geometric mean, S.D) were (3.49, 1.70) ㎍/dL in male auld (3.04, 1.65) ㎍/dL in female, but the difference is not significant, and there was no significant difference between age groups. Mean blood manganese level was 0.99±0.41㎍/dL, and there was no significant difference between sex or age groups. Mean blood aluminium level was 0.59±0.35㎍/dL and there was no significant difference between sex or age groups. Mean blood silicon level was 54.41±27.64㎍/dL in male and 43.34±23.51㎍/dL in female, and the level in male was significantly higher than that in female (p〈0.05). There was significant difference between age groups, and the oldest showed the highest level in male (p〈0.05), but no significant difference between age groups in female. Conclusions : Authors hope that this study would provide basic data for determininig reference values and evaluating health effects.

A Study on the Magnetic Properties of Al-Doped Sulphur Spinel

Chin Mo Kim,Sam Jin Kim,Chul Sung Kim IEEE 2010 IEEE transactions on magnetics Vol.46 No.2

<P>FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> ( x=0.1, 0.3, and 0.5) samples were prepared by solid state reaction method. The crystallographic structure and magnetic properties of the fabricated compounds were investigated by X-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometer, and Mo¿ssbauer spectroscopy. The crystal structure is determined to be a cubic spinel with the space group of Fd-3m and the lattice constants <I>a</I> <SUB>0</SUB>= 9.998, 10.004, and 10.010 A¿ , respectively. The temperature dependence of magnetization, measured from 5 to 300 K, suggests that FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> (x=0.1, 0.3, and 0.5) samples show ferrimagnetic behavior. The decrease of Ne¿el temperature compared with FeCr<SUB>2</SUB>S<SUB>4</SUB> could be interpreted by weakening of the exchange interaction by substitution of nonmagnetic Al ions. Mo¿ssbauer spectra of FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> ( x= 0.1, 0.3, and 0.5) were obtained at various temperatures ranging from 4.2 to 300 K. Isomer shift values of the samples at various temperatures for FeCr<SUB>2-x</SUB>Al<SUB>x</SUB>S<SUB>4</SUB> (x=0.1 , 0.3, and 0.5) were 0.50 ¿ ¿ ¿ 0.73 mm/s, relative to the Fe metal, which are consistent with the Fe<SUP>2+</SUP> valence state.</P>

AlN Epitaxial Film Growth Using MOCVD For a GHz-band FBAR

Chung-Mo Yang,Seong-Kweon Kim 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

We present the fabrication of a film-bulk-acoustic resonator (FBAR) with a highly c-axis- oriented AlN film on Mo/SiO2/Si (100) by using metal-organic chemical-vapor deposition (MOCVD). The resonant frequency and the anti-resonant frequency of the fabricated resonator were 3.219 GHz and 3.249 GHz, respectively. The quality factor and the effective electromechanical coupling coefficient (k2 eff ) were 24.7 and 2.65%, respectively. The conditions of AlN deposition were a substrate temperature of 950℃, a pressure of 20 Torr, and a V-III ratio of 25000. We successfully grew highly c-axis-oriented AlN film with 4 × 10−5 Ωcm resistivity for the Mo bottom electrode. The full widths at half maximum (FWHM) for the AlN (0002) deposited on Mo/SiO2/Si (100) and Mo/SiO2/Si (111) were 4˚ and 3.8˚, respectively. The FWHM value of the deposited AlN film meets the RF band-pass-filter specification for a GHz-band wireless local area network. We present the fabrication of a film-bulk-acoustic resonator (FBAR) with a highly c-axis- oriented AlN film on Mo/SiO2/Si (100) by using metal-organic chemical-vapor deposition (MOCVD). The resonant frequency and the anti-resonant frequency of the fabricated resonator were 3.219 GHz and 3.249 GHz, respectively. The quality factor and the effective electromechanical coupling coefficient (k2 eff ) were 24.7 and 2.65%, respectively. The conditions of AlN deposition were a substrate temperature of 950℃, a pressure of 20 Torr, and a V-III ratio of 25000. We successfully grew highly c-axis-oriented AlN film with 4 × 10−5 Ωcm resistivity for the Mo bottom electrode. The full widths at half maximum (FWHM) for the AlN (0002) deposited on Mo/SiO2/Si (100) and Mo/SiO2/Si (111) were 4˚ and 3.8˚, respectively. The FWHM value of the deposited AlN film meets the RF band-pass-filter specification for a GHz-band wireless local area network.

18 Ni 마르에이징 강의 기계적 성질에 미치는 Mo 첨가량의 영향

김학모,김인배,박세윤 ( Hak Mo Kim,In Bae Kim,Se Yoon Park ) 한국열처리공학회 1991 熱處理工學會誌 Vol.4 No.3

Effects of Mo content and aging conditions on the amount of retained austenite and mechanical properties of 18 Ni maraging steels were investigated. Maraging steels were fabricated with variation of Mo content, 3, 5, 7, 9% and heat treated by austenitizing at 840℃ for 1 hour and then aged at 480℃ for 0.5∼100 hours. It was found that the amount of retained austenite after aolution treatment was negligible up to 5% Mo. 8 and 11 volume percents of retained austenite were obtained with 7 and 9% Mo respectively. The maximum hardness and yield strength without great loss of impact toughness were attained in the range of 4∼8 hours of aging time at 480℃ with 5% Mo. It was concluded, as a result, that the optimum Mo content for the good combination of strength and toughness is to be 5% Mo.

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.

AF 115 초합금중의 γ' 분리 및 분석방법

김영근,윤정모 한국부식학회 1989 Corrosion Science and Technology Vol.18 No.1

After extrating and separating γ phases and γ' phases from Ni-based super alloy AF115, which was manufactured by a powder metallurgical method, by a potentiostatic method and a galvanostatic method, the results acquired by observing the composition of each phase and the shape of precipitate phases are as follows; (1) A potentiostatic method and a galvanostatic method for the extraction and separation of γ' phases were all possible, but most stable γ' phases could be acquired in the electrolytic condition of 10mA by a galvanostatic method. (2) The ratio of the composition of γ and γ' phases analyzed by ICP is as follows. γ phase: Ni_(1.81) Co_(1.0) Cr_(1.01) Al_(0.14) Ti_(0.04) Mo_(0.13) W_(0.10) Nb γ' phase: (Ni_(2.71) Co_(0.19) Cr_(0.09) Mo_(0.03)) (A1_(0.22) Ti_(0.26) Co_(0.19) W_(0.24) Nb_(0.09)) (3) The results of X-ray diffraction test show that γ phases are NiAl and γ' phases are Ni₃ Al or Ni₃ (Al, Ti).

차세대 고속철도 특수교량의 설계 및 기술사양 조사

박만호(Park Man-Ho),문제우(Mun Je-U),김성일(Kim Sung-Il),홍성모(Hong Seong-Mo),김종태(Kim Jong-Tae) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

Mo-Am arch bridge is only the long-span bridge (with 125m span) in the Kyong-Bu high-speed line in service, while other bridges are PSC box girder bridges and steel composite bridges with span lengths of 25~50m. However, in foreign high-speed lines, special cable-supported bridges like cable-stayed bridges and extradosed bridges are being adopted in earnest with technical specifications. The cable supported bridge is recognized as one of the indices of technology in civil engineering field, and thus it is being adpoted with a sense of rivalry in countries with advanced technology in railway engineering. In this paper, to apply the top-level cable-supported bridge technology to the domestic high-speed line up to 400㎞/h by establishing the technical specifications on cable-supported bridges including span length, the requirements for securing the dynamic stability and running safety of high speed train are analyzed through case studies for domestic and foreign cases.

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.