• 한국세라믹학회지
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• 제41권2호
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• pp.97-101
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• 2004

W $O_{x}$-based semiconductor type thin film gas sensor was fabricated for the detection of N $O_{x}$ by reactive d.c. sputtering method. The relative oxidation state of the deposited W $O_{x}$ films was approximately compared by the calculation of the difference of the binding energy between Ols to W4 $f_{7}$2/ core level XPS spectra in the standard W $O_3$ powder of known composition. As the annealing temperature increased from 500 to 80$0^{\circ}C$, relative oxygen contents and grain size of the sputtered films were gradually increased. As the results of sensitivity ( $R_{gas}$/ $R_{air}$) measurements for the 5 ppm N $O_2$ gas, the sensitivity was 110 and the sensor showed recovery time as fast as 200 s. The other sensor properties were examined in terms of surface microstructure, annealing temperature, and relative oxygen contents. These results indicated that the W $O_3$ thin film with well controlled structure is a good candidate for monitoring and controlling of automobile exhaust.haust.t.t.t.

• E2M - 전기 전자와 첨단 소재
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• 제8권3호
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• pp.278-284
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• 1995

Thin fihn SnO$_{2}$ Gas Sensor was fabricated by electron-beam evaporation system and the target made by general firing method for the purpose of detecting gas components in air, especially methane gas. SnO$_{2}$ thin film was prepared on the polished alumina substrate which Pt interdigital electrode was precoated. The effects of annealing temperature and substrate temperature on the structural properties of SnO$_{2}$ thin film on glass were investigated using the X-ray diffraction. The good crystalline structure is formed when substrate temperature is 150[.deg. C] and annealing condition is 550[.deg. C], 1[hour]. And the sensing properties at various thickness of the SnO$_{2}$ thin film and the effects of PdCI$_{2}$ addition were also investigated. The good result is showed when the thickness is below 1000[.angs.] and the quantity of PdCI$_{2}$ addition is 4[wt%]. The thickness of SnO$_{2}$ thin film was measured by .alpha.-step and Elliopsometer.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1448-1452
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• 2003

A scratch tester was developed to evaluate the adhesive strength at interface between thin-film and substrate(silicon wafer). Under force control, the scratch tester can measure the normal and the tangential forces simultaneously as the probe tip of the equipment approaches to the interface between thin-film and substrate of wafer. The capacity of each component of force sensor is 0.1 N ${\sim}$ 100 N. In addition, the tester can detect the signal of elastic wave from AE sensor(frequency range of 900 kHz) attached to the probe tip and evaluate the bonding strength of interface. Using the developed scratch tester, the feasibility test was performed to evaluate the adhesive strength of thin-film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.846-850
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• 2003

Thin film $SnO_2$ Gas Sensor was fabricated by using ion beam sputtering and ultra thin film Pt catalyst of $45{\AA}$ was deposited on $SnO_2$ thin film. The effects of annealing temperature on the structural properies of $SnO_2$ were investigated using the X-ray diffraction. Using SEM, microstructures of thin film were investigated. The good gas sensitivity is shown when annealing condition is $650^{\circ}C$, 5hr and ultra thin film Pt catalyst thickness is $45{\AA}$.

• 센서학회지
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• 제6권3호
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• pp.214-220
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• 1997

본 연구에서는 생화학 물질을 정량적으로 분석하기 위하여 소산장(Evanescent field) 흡수를 이용한 박막 광도파로형 칼륨이온센서를 제작하였다. 도파로는 Pyrex glass($26{\times}19{\times}1mm$, $n_{1}=1.485$ at 514nm, Ar laer ; Coherent 사 M532) 기판위에 RF sputtering법으로 Coming-7059 glass($n_{2}=1.588$, at 514nm, Ar laer ; Coherent사 M532) 2 종류의 박막 광도파로를 형성하였으며, 그 두께는 프리즘 결합법으로 측정한 결과 각각 $T_{1}=1.04{\mu}m$ 와 $T_{2}=1.41{\mu}m$ 였다. 칼륨이온 선택성의 이온감지막은 변색성 이온감응물질인 ETH 5294와 중성이온감응물질인 valinomycin을 poly(vinyl chloride-co-vinyl acetate-co-vinyl alcohol) ( 91 : 3 : 6 ) 공중합체 막내에 포괄법으로 고정화한 후 도파로 위에 스핀코팅법으로 제조하였다. 그리고, 센서의 특성을 평가하기 위해 감지막의 작용길이, 도파로의 두께 및 변색성 이온감응물질의 조성비 변화에 따른 감도 의존성을 조사하였다. 본 센서는 약 $1{\times}10^{-6}M\;{\sim}1.0\;M$의 넓은 측정범위를 가지며, 90%의 응답시간은 약 1분 이내의 빠른 응답특성을 나타내었다. 또한 분광분석법에 의한 투과광도법 및 광섬유를 이용한 optode형 센서를 제작하여 본 센서와 그 특성을 비교한 결과, 본 센서의 우수성을 알 수 있었다. 따라서 본 센서는 생화학 및 의용, 환경감시 분야 등에 응용 가능할 것으로 사료된다.

• 한국표면공학회지
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• 제29권5호
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• pp.459-466
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• 1996

A great amount of effort has been devoted to the constant improvement of such basic performance as dirvability, safety and enviromental protection. As a result, the total combination of various technologies has made it possible to produce safer and more comfortable automobiles. Among these technologies, plasma and thin film techniques are mainly cocerned with sensors, optics, electronics and surface modification. This paper first describes a concept of thin film processing in materials synthesis for sensors based on particle-surface interaction during deposition to provide a long life sensor applicable to sutomobiles. Some examples of parctical application of thin films to sensors are then given. These include(1) a thin films strain gauge for gravity sensors, (2) a giant magneto resistance film for speen sensors, and (3) a Magneto-impedance sensors fordetection of low magnetic field. Further progress of sophisticated thin film technology must be considered in detail to explore advanced thin film materials science and to ensure the field reliability of future sensor devices for automobile.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.272-272
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• 2014

SnO thin films, 100 nm in thickness, were deposited on glass substrates by RF magnetron sputtering. A stack structure of $SnO_2/SnO$, where few nanometers of $SnO_2$ were determined on the SnO thin film by X-ray photoelectron spectroscopy. In addition, XPS depth profile analysis of the pristine and heat treated thin films were introduced. The electrical behavior of the as-sputtered films during the annealing was recorded to investigate the working conditions for the SnO sensor. Subsequently, The NH3 sensing properties of the SnO sensor at operating temperature of $50-200^{\circ}C$ were examined, in which the p-type semiconducting sensing properties of the thin film were noted. The sensor shows good sensitivity and repeatability to $NH_3$ vapor. The sensor properties toward several gases like $H_2S$, $CH_4$ and $C_3H_8$ were also introduced. Finally, a sensing mechanism was proposed and discussed.

• 한국전기전자재료학회논문지
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• 제14권5호
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• pp.405-409
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• 2001

This paper describes fabrication and characteristics of metal thin-film pressure sensor for working at high temperature. The proposed pressure consists of a chrom thin-film, patterned on a Wheat stone bridge configuration, sputter-deposited onto thermally oxidized Si membranes with an aluminium interconnection layer. The fabricated pressure sensor presents a low temperature coefficient of resistance, high-sensitivity, low non-linearity and excellent temperature stability. The sensitivity is 1.097∼1.21mV/V$.$kgf/$\textrm{cm}^2$ in the temperature range of 25∼200$^{\circ}C$ and the maximum non-linearity is 0.43%FS.

• 한국재료학회지
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• 제29권5호
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• pp.297-303
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• 2019

A triple-layered $PMMA/Ni_{64}Zr_{36}/PDMS$ hydrogen gas sensor using hydrogen permeable alloy and flexible polymer layers is fabricated through spin coating and DC-magnetron sputtering. PDMS(polydimethylsiloxane) is used as a flexible substrate and PMMA(polymethylmethacrylate) thin film is deposited onto the $Ni_{64}Zr_{36}$ alloy layer to give a high hydrogen-selectivity to the sensor. The measured hydrogen sensing ability and response time of the fabricated sensor at high hydrogen concentration of 99.9 % show a 20 % change in electrical resistance, which is superior to conventional Pd-based hydrogen sensors, which are difficult to use in high hydrogen concentration environments. At a hydrogen concentration of 5 %, the resistance of electricity is about 1.4 %, which is an electrical resistance similar to that of the $Pd_{77}Ag_{23}$ sensor. Despite using low cost $Ni_{64}Zr_{36}$ alloy as the main sensing element, performance similar to that of existing Pd sensors is obtained in a highly concentrated hydrogen atmosphere. By improving the sensitivity of the hydrogen detection through optimization including of the thickness of each layer and the composition of Ni-Zr alloy thin film, the proposed Ni-Zr-based hydrogen sensor can replace Pd-based hydrogen sensors.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.174-178
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• 2001

The piezoelectric thin film sensor can be used to interpret variations in structural and material properties, e.g. for structural integrity monitoring and assessment. To illustrate one of this potential benefit, PVDF film sensors are used for monitoring impact damage initiation in Gr/Ep composite panel. Both PVDF film sensors and strain gages are surface mounted to the Gr/Ep specimens. A series of impact test at various impact energy by changing impact mass and height is performed on the instrumented drop weight impact tester. The sensor responses are carefully examined to predict the onset of impact damage such as matrix cracking, delamination, and fiber breakage, etc. Test results show that the particular waveforms of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. As expected, the PVDF film sensor is found to be more sensitive to impact damage initiation event than the strain gage.