• 마이크로전자및패키징학회지
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• 제9권3호
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• pp.37-41
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• 2002

본 연구에서는 자기 공명 특성을 이용한 박막 센서의 멤브레인 및 박막 센서의 특성을 알아보았다. 멤브레인으로 유망한 물질로 $Si_xN_y$과 SiC가 있으며, 최적의 멤브레인 형성 조건을 알고자 박막의 잔류 응력 및 물성을 비교 분석하였다. 그 중에서 박막 센서에 적용 가능한 멤브레인으로 SiC보다 적절한 인장응력과 낮은 열팽창 계수를 가지는 $Si_xN_y$이 센서의 구조층으로 우수하였으며, $Si_xN_y$위에 박막 센서 물질을 증착 및 패턴닝(patterning)을 함으로써 센서의 자기 이력 곡선 및 자기 공진 주파수를 분석하였다. 센서에 인가되는 외부 자기장을 제거하면 자장에 의해 형성된 자화(magnetization)가 탄성 모드로 바뀌면서 에너지 방출에 의해 센서에서 전압이 발생하는데 이때 전압 발생 구간이 길어지면 기계적 진동이 야기되어 신호가 발생한다. 그리고 센서의 길이 및 폭이 증가할수록 자기공명 주파수가 감소하는 것을 볼 수 있다.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.612-616
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• 2000

This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the Si membrane in which MgO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$layer. The MgO layer improved adhesion of Pt thin-film to SiO$_2$layer without any chemical reactions to Pt thin-film under high annealing temperatures. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 82 mV at $N_2$flow rate of 2000 sccm/min heating power of 1.2 W. The response time($\tau$:63%) was about 50 msec when input flow was stepinput

• 센서학회지
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• 제15권1호
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• pp.65-70
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• 2006

Characteristics of thin-film NTC thermal sensors fabricated by micromachining technology were studied as a function of the thickness of membrane. The overall-structure of thermal sensor has a form of Au/Ti/NTC/$SiO_{X}$/(100)Si. NTC film of $Mn_{1.5}CoNi_{0.5}O_{4}$ with 0.5 mm in thickness was deposited on $SiO_{X}$ layer (1.2 mm) by PLD (pulsed laser deposition) and annealed at 873-1073 K in air for 1 hour. Au(200 nm)/Ti(100 nm) electrode was coated on NTC film by dc sputtering. By the results of microstructure, X-ray and NTC analysis, post-annealed NTC films at 973 K for 1 hour showed the best characteristics as NTC thermal sensing film. In order to reduce the thermal mass and thermal time constant of sensor, the sensing element was built-up on a thin membrane with the thickness of 20-65 mm. Sensors with thin sensing membrane showed the good detecting characteristics.

• 한국전기전자재료학회논문지
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• 제14권8호
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• pp.658-662
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• 2001

This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the SOI(Si-on-insulator) membrane and trench structures, in which MGO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$ layer. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 250 nV at N$_2$ flow rate of 2000 sccm/min, heating power of 0.3 W. The response time($\tau$:63%) was about 42 msec when input flow was step-input. The results indicated that micro-flowsensors with the SOI membrane and trench structures have properties of a high-resolution and ow consume power.

• ETRI Journal
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• 제34권2호
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• pp.226-234
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• 2012

The novelty of this study resides in the fabrication of stoichiometric and stress-reduced $Si_3N_4/SiO_2/Si_3N_4$ triple-layer membrane sieves. The membrane sieves were designed to be very flat and thin, mechanically stress-reduced, and stable in their electrical and chemical properties. All insulating materials are deposited stoichiometrically by a low-pressure chemical vapor deposition system. The membranes with a thickness of 0.4 ${\mu}m$ have pores with a diameter of about 1 ${\mu}m$. The device is fabricated on a 6" silicon wafer with the semiconductor processes. We utilized the membrane sieves for plasma separations from human whole blood. To enhance the separation ability of blood plasma, an agarose gel matrix was attached to the membrane sieves. We could separate about 1 ${\mu}L$ of blood plasma from 5 ${\mu}L$ of human whole blood. Our device can be used in the cell-based biosensors or analysis systems in analytical chemistry.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 추계 기술심포지움 논문집
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• pp.31-34
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• 2000

• 대한기계학회논문집A
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• 제26권3호
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• pp.428-435
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• 2002

Pyroelectric $Pb(Zr_{0.3}Ti_{0.7})O_3$ (PZT30/70) thin film IR detectors has been fabricated and characterised. The PZT30/70 thin film was deposited onto $Pt/Ti/Si_3N_4/SiO_2/Si$ substrate by the sol-gel process. Four different substrate conditions were studied for their effects on the pyroelectric responses of the IR detectors. The substrate conditions were the combinations of the Si etching and the Pt/Ti patterning. In the Si etched substrate, the $Si_3N_4/SiO_2$ composite layer was used as silicon etch-stop, and was used as the membrane to support the PZT pyroelectric film element as well. The measured pyroelectric current and voltage responses of detectors fabricated on the micro-machined thin $Si_3N_4/SiO_2$ membrane were two orders higher than those of the detectors on the bulk-silicon. For detectors on the membrane substrate, the Pt/Ti patterned detectors showed a 2-times higher pyroelectric response than that of not-patterned detectors. On the other hand, the pyroelectric response of the detectors on the not-etched Si substrate was almost the same, regardless of the Pt/Ti patterning. It was also found that the rise time strongly depended on the substrate thickness: the thicker the substrate was, the longer the rise-time.

• 센서학회지
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• 제31권6호
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• pp.366-370
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• 2022

A 12 ㎛ pixel-sized 360 × 240 microbolometer focal plane array (MBFPA) was fabricated using a complementary metaloxide-semiconductor (CMOS)-compatible process. To release the MBFPA membrane, an amorphous carbon layer (ACL) processed at a low temperature (<400 ℃) was deposited as a sacrificial layer. The thermal time constant of the MBFPA was improved by using serpentine legs and controlling the thickness of the SiNx layers at 110, 130, and 150 nm on the membrane, with response times of 6.13, 6.28, and 7.48 msec, respectively. Boron-doped amorphous Si (a-Si), which exhibits a high-temperature coefficient of resistance (TCR) and CMOS compatibility, was deposited on top of the membrane as an IR absorption layer to provide heat energy transformation. The structural stability of the thin SiNx membrane and serpentine legs was observed using field-emission scanning electron microscopy (FE-SEM). The fabrication yield was evaluated by measuring the resistance of a representative pixel in the array, which was in the range of 0.8-1.2 Mohm (as designed). The yields for SiNx thicknesses of SiNx at 110, 130, and 150 nm were 75, 86, and 86%, respectively.

• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.39-43
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• 2001

$SiC_{x}N$_{y}$ film is deposited by electron cyclotron resonance plasma chemical vapor deposition system using $SiH_4$(5% in Ar), $CH_4$ and $N_2$. Ternary phase $SiC_{x}N$_{y}$ thin film deposited at the microwave power of 600 W and substrate temperature of 700 contains considerable amount of strong C-N bonds. Change in $CH_4$flow rate can effectively control the residual film stress, and typical surface roughness of 34.6 (rms) was obtained. Extreme]y high hardness (3952 Hv) and optical transmittance (95% at 633 nm) was achieved, which is suitable for a LIGA mask membrane application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.609-611
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• 1997

Pt thin films flow sensors were fabricated by using aluminum oxide films as medium layer and their characteristics were investigated after annealing at $600^{\circ}C$ for 60min. Aluminum oxide improved adhesion of Pt thin films to $SiO_2$ layer without any chemical reactions to Pt thin films under high annealing temperatures. Output voltages increased as gas flow rate and gas conductivity increased because heat loss of heater, which was integrated with a sensing resistor in the flow sensor, increased. Output voltage of flow sensor fabricated on membrane structure was 101mV at $O_2$ flow rate of 2000sccm, heating power of 0.8W while flow sensor fabricated on Si substrate without membrane had output voltage of 78mV under the same conditions.