• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.247-248
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• 2006

Carbon nitride films were evaluated that they had many advantages for miniature micro-humidity-sensors using the standard CMOS technology humidity sensing properties and CV characteristics of the carbon nitride films have been investigated for fabricating one chip HUSFET(Humidity Sensitive Field Effect Transistor) humidity sensors Carbon nitride films were deposited on silicon substrate with meshed electrodes by reactive RF magnetron sputtering system. The capacitor-type humidity sensor revealed good humidity-impedance characteristics with a wide range of relative humidity changes, decreasing $254k{\Omega}$ to $16k{\Omega}$ according to increase of relative humidity between 5% ~ 95% and the films were very stable on the Si wafer. These results reveal that $CN_x$ thin films can be used for Si based or HUSFET structure one chip micro-humidity sensors.

• 한국전기전자재료학회논문지
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• 제14권4호
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• pp.302-308
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• 2001

The polymers with various composition of 4-vinylpyridine (4-VP) with n-butyl acrylate (n-BA) and 2-hydroxypropyl methacrylate (HPMA) were synthesized as a humidity sensitive material and quaternized with 1.5-dibromopentane. Resistance versus relative humidity decreased with increase in the content of n-BA in the copolymer. The introduction of HPMA increased the resistance of the humidity sensor as well as enhanced the adherence to the alumina substrate. In the case of 4-VP/n-BA/HPMA=80/10.10, the hysteresis and temperature coefficient were $\pm$2%RH and -0.42∼0.46%RH/$\^{C}$. The average resistance at 30%RH, 60%RH and 90%RH are 3.1㏁, 155 ㏀ and 7.9 ㏀, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1233-1235
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• 1994

In this work, polyimide thin films fabricated by the electrophoretic deposition are investigated as a humidity sensing material. Capacitance and impedance are measured with increasing relative humidity to find the nature of the film. From the results, the polyimide humidity sensor is not classified impedance change type but capacitance change type and appear more sensitive in the region of higher humidity than that of lower humidity.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1126-1135
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• 1996

This study was conducted to select the sensors for measuring temperature, relative humidity, and air velocity among the major environmental factors affecting the pig productivity as a part of the study for the optimum production system model development of pig-housing. The study results are summarized as the follows : Two sensors , HMP233L and HANI, were tested for measuring temperature and relative humidity , Test results were analyzed by the statistical methods. And the sensor, HMP233L was selected as a proper sensor for temperature sand relative humidity measurement . An air velocity sensor was tested. Test results showed that its accuracy was low and incongruent for the air velocity measurement when it was lower than 4m/s.

• 전자공학회논문지D
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• 제35D권9호
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• pp.77-86
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• 1998

본 논문에서는 정전용량형 센서 칩과 CMOS 인터페이스 칩으로 구성된 투 칩 집적화 습도 센서를 개발하였다. (100) 실리콘 기판위에 폴리이미드 박막을 이용해서 제작된 습도 센서 칩은 넓은 습도 및 온도 범위에 걸쳐 우수한 직선성(0.72%FS), 낮은 히스테리시스(<3%), 작은 온도계수(-0.0285∼-0.0542 pF/K)를 나타내었다. 40℃/90%RH에서 9주동안 방치한 후 측정된 정전용량은 약 2∼3% 변하였다. 신호처리 회로는 1.2-㎛, one poly double metal CMOS 공정으로 제작하였다. 측정된 센서 출력 전압은 상대습도에 비례해서 변하였으며, 이론치와 잘 일치하였다.

• 센서학회지
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• 제14권5호
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• pp.331-336
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• 2005

The influence of water molecule on the electrical properties of single-walled carbon nanotube field effect transistors (SWNT-FETs) was reported. Conductance suppression was observed with the increase of the humidity. This can be explained by doping of the SWNT-FETs, which has p-type semiconductor characteristic, with the water molecules acting as an electron donor. However, after 65 % of humidity, conductance of the SWNT-FETs started to increase again, due to the opening of electron channels. Upon annealing at $400^{\circ}C$ in Ar atmosphere, conductance increases more than 500 %, and the threshold voltage shifts toward further positive gate voltages. The results of this experiment support possible application of single-walled carbon nanotubes for humidity sensing material.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.347-357
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• 2024

Oxide semiconductor gas sensors are widely used for detecting toxic, explosive, and flammable gases due to their simple structure, cost-effectiveness, and potential integration into compact devices. However, their reliable gas detection is hindered by a longstanding issue known as humidity dependence, wherein the sensor resistance and gas response change significantly in the presence of moisture. This problem has persisted since the inception of oxide semiconductor gas sensors in the 1960s. This paper explores the root causes of humidity dependence in oxide semiconductor gas sensors and presents strategies to address this challenge. Mitigation strategies include functionalizing the gas-sensing material with noble metal/transition metal oxides and rare-earth/rare-earth oxides, as well as implementing a moisture barrier layer to prevent moisture diffusion into the gas-sensing film. Developing oxide semiconductor gas sensors immune to humidity dependence is expected to yield substantial socioeconomic benefits by enabling medical diagnosis, food quality assessment, environmental monitoring, and sensor network establishment.

• Macromolecular Research
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• 제12권3호
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• pp.311-315
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• 2004

We have prepared new polyelectrolytes containing trialkoxysilyl groups by copolymerizing 3-(trimethoxysilyl)propyl methacrylate (TSPM) with either [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride (METAC), [2-(methacryloyloxy)ethyl]dimethyl propyl ammonium bromide (MEDPAB), or [2-(acryloyloxy)ethyl]trimethyl ammonium chloride (AETAC). The copolymers TSPM/METAC, TSPM/MEDPAB, and TSPM/METAC having compositions of 15/85, 10/90, and 5/95, respectively, were self-crosslinkable polyelectrolytes that possess humidity-sensitive properties. We measured the impedances of the copolymers at various relative humidities (RHs) and found that the resistance was dependent on the content of METAC, MEDPAB, or AETAC. The impedance changed from 10$\^$7/ $\Omega$ at 20% RH to 10$^3$ $\Omega$ at 95% RH, which is quite a suitable range for a humidity sensor that is to be utilized at ambient humidity. We also performed tests of the materials temperature dependence, hysteresis, response time, and water durability.

• 센서학회지
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• 제7권2호
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• pp.83-89
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• 1998

$TiO_{2-x}$ 박막 습도센서를 스퍼터링법에 의해 제조하고, 스퍼터링 조건과 열처리조건에 따른 습도 감지특성 및 동작온도에 따른 특성 등을 조사하였으며, Auger 전자 분광기와 전자현미경으로 그 원인을 분석하였다. $TiO_{2-x}$ 박막 습도센서는 부임피던스 습도특성을 보였으며, rf power가 200 W, 압력은 50 mTorr 및 기판 온도는 $200^{\circ}C$ 에서 증착하고, $600^{\circ}C$에서 1시간 동안 열처리한 소자의 상대습도 변화에 따른 임피던스 변화는 $0.794\;K{\Omega}/%RH$로 가장 컸으며, 응답 시간은 흡착시 약 2분, 탈착시 약 3분이었다.

• 한국재료학회지
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• 제11권2호
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• pp.126-131
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• 2001

4 차 암모늄염을 형성할 수 있는 공중합체들 poly[(vinylbenzyl chloride)-co-(n-butyl acrylate)-co-(2-hydroxyethyl methacrylate)]와 poly[(4-vinylpyridine)-co-(n-butyl acrylate)-co-(2-hydroxyethyl methacrylate)]를 고분자막 습도센서의 감습재료로 사용하기 위하여 합성하였다. 습도센서는 30%RH, 60%RH 그리고 90%RH에서 평균 저항 값은 각각 8.6 M $\Omega$, 310 k$\Omega$ 그리고 12 k$\Omega$을 보여 주었다. 또한 히스테리시스는 $\pm$3%RH 안에서 나타났으며, 온도의존성 계수는 -0.37~-0.407RH/$^{\circ}C$이었다. 감습막의 조성에서 공중합체 중 n-BA와 HEMA의 도입은 저항을 증가시키는 요인이 되나 기판과의 접착성은 크게 향상되었다. 33%RH에서 85%RH로 또는 역으로 변화할 때의 응답속도는 54초이며 수중에 2시간 침적 후 저항의 변화는 +0.2%RH 이내에서 존재하였다.