p-n접합을 이용한 ISFET의 encapsulation

權大赫 慶一大學校 1992 論文集 Vol.8 No.1

The p-n junction isolation method for the electrical isolation of ISFET chip from the liquid environments has been presented instead of the conventional encapsulant castings carried out by the manual labors which requires much time and experiences. This junction-isolated ISFET showed similar operational characteristics compared with those of the encapsulant-coated ISFET.

Ta₂O_(5) 게이트 pH-ISFET의 제조 및 그 동작특성

권대혁,김명규,이광만,손병기 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

To improve sensing characteristics of the pH-ISFET using LPCVD-grown Si_(3)N_(4), Ta_(2)O_(5) thin film depositied by RF reactive sputtering was used for hydrogen ion sensing gate and investigated sensing characteristics at various annealing temperatures. The XRD pattern showed that the crystal structure of the Ta20s thin film was amorphous when the annealing temperature was less than 500℃, δ-Ta_(2)O_(5) poly-crystal at MC Ta_(2)O_(5) gate pH-ISFET annealed at 400℃, O_(2) ambient for 1hour, the AES and RBS spectrum showed good stoichiometry (O/Ta=2.5). And its sensing characteristics showed good linearity and high sensitivity(57~59MV/pH) in the wide pH range(pH 2~12), and excellent long-term stability (0.03~0.05 pH/day). It can be concluded from these results that the sensing characteristics of Ta_(2)O_(5) gate pH-ISFET is more excellent than Si_(3)N_(4) gate pH-ISFET.

광섬유 Fabry-Perot 간섭형 압력센서의 제조 및 동작특성

權大赫 慶一大學校 1999 論文集 Vol.16 No.2

The strain characteristics of a fiber optic Fabry-perot pressure sensor with linearity using a silicon diaphragm is experimentally investigated. A 50 ㎛ thick silicon diaphragm was fabricated by anisotropic etching technology in 44 wt% KOH solution. An interferometric fiber optic pressure sensor has been manufactured by using a fiber optic Fabry-Perot interferometer and a silicon diaphragm. The 2 ㎝ length fiber optic Fabry-Perot interferometers in the continuous length of single mode fiber were produced with two pieces of single mode fiber coated with TiO₂dielectric film utilizing the fusion splicing technique. The one end of the fiber optic Fabry-Perot interferometer was bonded to a silicon diaphragm, and the other end was connected to an optical setup through a 3 dB coupler. For the silicon diaphragm sized 5×5 ㎜², the pressure sensitivity was measured about 0.0066 radian/mmHg and 0.053 radian/mmHg at 15 ㎛ and 50 ㎛thickness diaphragm, respectively.

불소가 첨가된 실리콘 산화막의 다층금속절연 특성에 관한 연구

權大赫,南基泓,吳相光 慶一大學校 1997 論文集 Vol.14 No.2

The characteristics of fluorinated silicon oxide (SiOF) films prepared by plasma enhanced chemical vapor deposition(PECVD) were discussed. The deposition of these films was carried out in the temperature range of 80 - 220℃ in a conventional parallel plate plasma reactor with 〈 ±3% uniformity by flowing 2 sccm of disilane (Si₂H6), 100 sccm of nitrous oxide (N₂O), and 20 sccm of tetrafluoromethane (CF₄). AS the deposition temperature increased from 80 to 220℃, the deposition rate of the films increased from 16.7 to 18.4 nm/min; meanwhile, the etch rate decreased from 2.69 to 1.48 nm/sec. The refractive index was 1.46 regardless of the deposition temperature. The Fourier transform infrared (FTIR) spectra of the films showed decreasing Si-O stretching wave number with increasing full width at half maximum (FWHM) as deposition temperature increased. The high frequency capacitance-voltage (C-V) measurements of the metal-oxide-semiconductor (MOS) capacitors fabricated using the films showed increasing effective oxide charge density and decreasing dielectric constant with increasing deposition temperature. Deposition temperature of 180℃ resulted in films with the smallest dielectric constant of 3.75. These films showed an average breakdown strength of 9.14 MV/cm with 77.5% of the MOS capacitors having breakdown field strength ≥9.5 MV/cm

光섬유를 이용한 레벨센서의 開發

권대혁 경북대학교 센서기술연구소 1996 연차보고서 Vol.1996 No.-

KOH 수용액을 이용하여 실리콘 식각공정기술을 확립하였으며, 이를 이용하여 실리콘 기판 위에 스트레스 균형이 이루어진 600 ㎚ 두께의 Si_3N_4/SiO_2/Si_3N_4 다이아프램을 제조하였다. 이때의 실리콘의 식각률은 약 1.45 ㎛/min정도였다. NON 박막과Au/NiCr/NON 박막에 대한 광투과도, 광흡수도 및 광반사율을 측정한 결과 광흡수는 두 박막에 대해 수%였다. NON 다이아프램 뒷면에 약 100 ㎚의 금을 진공증착하여 제조된 Au/NiCr/NON 박막의 광특성을 조사한 결과, 박막의 광투과도를 수%정도로 감소시킬 수 있어서 센서의 광반사막으로 사용할 수 있었다. NON 다이아프램을 이용하여 제조한 수위측정용 압력센서는 3×3 ㎟, 4×4 ㎟, 5×5 ㎟ 의 정사각형 다이아프램 크기에서 약 3.886 ㎻/㎪, 4.857 ㎻/㎪ 및 5.829 ㎻/㎪의 압력감도를 나타내었으며, 광출력은 인가압력이 증가함에 따라 감소하였다. 광손실을 줄이기 위해 광송수신용 광섬유를 코아 직경이 62.5 ㎛인 멀터모드 광섬유를 사용하였고 다이아프램의 크기를 3×3 ㎟, 4×4 ㎟ 및 5×5 ㎟ 등으로 각각 변화시켜 광강도형 멀터모드 광섬유 압력센서를 제조하고 그 압력특성을 조사하였다. 측정된 광섬유 압력센서의 감도는 각각 약 20.689 ㎻/㎪, 26.694 ㎻/㎪ 및 39.331 ㎻/㎪였다. 광섬유 단면위에 RF 마그네트론 스퍼터링법으로 TiO_2를 증착하였다. TiO_2 박막의 굴절률 및 두께는 각각 약 2.43과 800 Å였다. 광섬유 Fabry-Peort 간섭계를 실리콘 다이아프램과 NON 다이아프램과 결합하여 광간섭형 압력센서를 제조하였다. 5×5 ㎟ 크기의 실리콘 다이아프램의 경우, 그 감도는 두께를 각각 15 ㎛와 50 ㎛로 변화시켰을 때 0.497 radian/㎪ 및 0.392 radian/㎪였다. 또한, 600 ㎚-NON 다이아프램의 경우에는 다이아프램의 크기fmf 2×2 ㎟, 5×5 ㎟ 및 8×8 ㎟로 변화하였을 때 약 0.119radian/㎪, 1.003 radian/㎪ 및 1.571 radian/㎪의 압력감도를 나타내었다. Using KOH solution, silicon etching technology has been established and stress-balanced flat 600 ㎚ thick triple dielectric membrane(150 ㎚-Si_3N_4/300 ㎚ -SiO_2/150 ㎚-Si_3N_4) on silicon substrate has been fabricated. At this time, etching rate of silicon was around 1.45 ㎛/min. At the wavelength of the sensor light source near 1.3 ㎛, optical loss of the NON diaphragm was decreased to a few percents by depositing 100 ㎚-Au layer on it, which is sufficient to be used as a light reflection layer of the sensor. From the optical output power-pressure characteristics of the fabricated intensity-type pressure sensors, the sensitivities of the pressure sensor for measuring water level were about 3.886, 4.857, and 5.829 ㎻/㎪ for the diaphragm sizes of 3×3 ㎟, 4×4 ㎟ and 5×5 ㎟, indicating that the output power linearly decreased with increasing applied pressure. We have used 62.5/126 ㎛ multi-mode fiber for the light transmission to minimize optical loss, and the pressure characteristics were examined for the diaphragm sizes of 3×3 ㎟, 4×4 ㎟, 5×5 ㎟. The respective sensitivities were, about 20.689 ㎻/㎪, 26.694 ㎻/㎪, and 39.331 ㎻/㎪. TiO_2 mirror at the cross section of fiber optic was deposited by using RF magnetron sputter. The refractive index and thickness of the TiO_2 thin film was about 2.43 and 800 Å. An interferometric fiber optic sensor has been manufactured using a fiber optic Fabry-Perot interferferometer and a silicon diaphragm or a NON diaphragm. For the silicon diaphragm sizes of 5×5 ㎟, the sensitivities of the sensor silicon diaphragm thickness of 15 ㎛ and 50 ㎛ were 0.497 radian/㎪ and 0.392 radian/㎪, respectively. And for the silicon diaphragm sizes of 2×2 ㎟, 5×5 ㎟, 8×8 ㎟, the sensitivities were 0.110 radian/㎪, 1.003 radian/㎪, and 1.571 radian/㎪, respectively.

중족골 단축증 일단계 신연술 : 증례 보고 A Case Report

민경대,권혁룡 순천향의학연구소;Soonchunhyang Medical Research Institute 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Congenital shortening of the matatarsal bone has both functional and cosmetic problems. The most widely used surgical correction techniques are either one-stage lengthening with intercalary bone graft or gradual lengthening by callotasis using external fixator. Authors present the case of 21-year-old female patient with brachymetatarsia who treated by one stage lengthening without bone graft or external fixator.

브로콜리 추출물의 향장활성 효과

김대용ㆍ조석철ㆍ권혁선ㆍ김미경(Dae Young KimㆍSeok chul ChoㆍHyuk sun KwonㆍMee Kyung Kim) 한국인체미용예술학회 2016 한국인체미용예술학회지 Vol.17 No.1

In this study, we investigated the anti-oxidative effects, antimicrobial, and anti-inflammatory activities of the extracts from broccoli to evaluate its use as a functional ingredient in cosmetics. The extracts are WE (water extract at RT), MWE (mineral water extract at RT), EE (70% ethanol extract at RT), and USEE (heat process for 12 hours at 60℃ after ultrasonification for six hours with 70% ethanol). The measurements of the total polyphenol content from broccoli extracts were highest in EE at 425.24±13.9 mg/g dry. The result of electron donating ability of EE was the highest at 10,000 ㎍/㎖ as 97.81% and increased in a concentration-dependent manner. The ferric reducing antioxidant powder (FRAP) of EE was the highest at 10,000 ㎍/㎖ as 1235.6 μM. In an antimicrobial activity test, the EE showed significant antimicrobial activity against S. epidermidis, S. aureus, E. coli, P. acnes, and P. ovale. Furthermore, broccoli extract exhibited no cytotoxicity in RAW 264.7 cells. Also anti- inflammatory activity by NO assay showed LPS-induced NO was significantly inhibited following treatment with EE of 1,000 ㎍/㎖. Therefore, the broccoli ethanol extract can be used as a resource of natural cosmetic material for functional cosmetics.

광섬유를 이용한 고감도 압력센서의 개발

김창원,권대혁,김진섭,이정희,손병기 경북대학교 센서기술연구소 1995 연차보고서 Vol.1995 No.-

KOH 수용액을 이용하여 실리콘 식각공정기술을 확립하였으며, 이를 이용하여 실리콘 기판 위에 스트레스 균형이 이루어진 150 ㎚-Si_3N_4/300 ㎚-SiO_2/150 ㎚-Si_3N_4 두께를 가지는 구조의 평탄한 3층 유전체 멤브레인을 제작하였다. 본 실험에서 사용되는 파장인 1.3 ㎛ 근방에서 다이아프레임의 광투과도는 약 50 %로 광반사막으로 사용이 불가능하였다. 따라서, 다이아프레임 뒷면에 약 1000 Å의 금을 증착하여 N/O/N/Au박막의 광투과도를 수 %정도로 감소시킴으로써, 센서의 광반사막으로 사용할 수 있었다. source fiber를 단일모드로 했을 때 다이아프레임의 크기에 따라 감도는 각각 0.52㎻/torr(3×3 ㎟), 0.65 ㎻/torr(4×4 ㎟), 0.77 ㎻/torr(5×5 ㎟)였다. 광손실을 최소화하기 위해 광전송용 다모드 광섬유를 사용하였을 때는, 2×2 ㎟의 다이아프레임의 크기에 대해 0∼800 torr의 넓은 측정범위에서 거의 선형적인 압력특성을 나타내었다. Using KOH solution, silicon etching technology has been established and stress-balanced flat 600 ㎚ thick triple dielectric membrane(150 ㎚-Si_3N_4/300 ㎚-SiO_2/150 ㎚-Si_3N_4) on silicon substrate has been fabricated. At the wavelength of the sensor light source near 1.3 ㎛, the optical transmittance of the diaphragm was about 50 %, it was impossible to be used as a reflecting film. To decrease to a few percents, the back-side of the diaphragm was deposited 1,000 Å thick gold layer, which is sufficient enough to be used as a light reflection layer of the sensor. When was used 8/126 ㎛ single-mode fiber, the respective sensitivities for diaphragm size were 0.52 ㎻/torr(3×3 ㎟), 0.65 ㎻/torr(4×4 ㎟), 0.77 ㎻/torr(5×5 ㎟). When was used 62/126 ㎛ multi-mode fiber for the light transmission to minimize optical loss, the pressure characteristics was showed almost linearly curve in a wide pressure range, 0 torr∼800 torr, for the 2×2 ㎟ diaphragm in dimensions.

Fabry-Perot 간섭형 광섬유 센서의 제조 및 온도특성

朴東洙,權大赫 慶一大學校 1993 論文集 Vol.9 No.1

A fiber optic Fabry-Perot interferometric sensor, compared with conventional sensor, has many advantages, such as high sensitivity in the wide range, rapid response, point measurement and multi-point detction. The Fabry-Perot interferomentric sensor was fabricated using TiO₂ thin film which has high refractive index and transparency in the visible and infrared and impervious of water vapor. The temperature dependent characteristics of the fiber optic sensor was investigated. As the result, it showed stable and linear response in the temperature range of 50~500℃.

ZnO 압전박막을 이용한 FET형 압력센서의 특성

양규석,권대혁,남기홍,손병기 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

A new FET type pressure sensor has been investigated to overcome the problems of the conventional silicon piezoresistive and capacitive pressure sensor. The PSFET( pressure sensitive field effect transistor) is a new FET type pressure sensor which the operation theory is combined with the field effect of MOSFET and the piezoelectric effect of piezoelectric thin films. This sensor can overcome the fabrication problems of conventional silicon pressure sensors and realize productivity, standardization, miniaturization, integration because the whole fab. process is compatible to the planar technology. A ZnO thin film as a piezoelectric material, 5000Å thick, was deposited on a FET gate by RF magnetron sputtering and the optimum deposition condition was 300℃ substrate temperature, 5mtorr working pressure, Ar ambient and 140watt RF power, respectively. And the device was annealed at 400℃, O_(2) ambient for 1 hour to obtain a better C-axis poling structure. The fabricated PSFET device showed piezoelectric voltage(40mV/kgf/cd) and sensitivity (21μA/kgf/cm^(2)) according to an applied pressure(1kgf/cm^(2)~4kgf/cm^(2)).