발전기 스테이터의 냉각코일에 pinhole 발생을 검지할 수 있는 수소센서 개발

최시영(Sie-Young Choi) 대한전기학회 1999 대한전기학회 학술대회 논문집 Vol.1999 No.11

Al2O3가 첨가된 지르코니아 산소센서의 제조 및 그 특성

손정덕,최시영 ( Jeong Duk Sohn,Sie Young Choi ) 한국센서학회 1992 센서학회지 Vol.1 No.1

Sinterability, mechanical and electrical properties of yttria-stabilized zirconia(92 mole % ZrO₂+8 mole % Y₂O₃) doped with 0.5 mole % Si₂O₃ and 0∼2.0 mole % Al₂O₃ were studied as a function of Al₂O₃ addition. Sintered density increased with increasing Al₂O₃ addition up to 0.5 mole% but leveled off with further addition. Vickers hardness is proportional to sintered density. The specimen with 0.5 mole % Al₂O₃ and 0.5 mole % SiO₂ exhibited the maximum electrical conductivity and revealed a maximum electromotive force for a given oxygen partial pressure. Experimental voltage curve of this oxygen sensor take on a sharper, more steplike transition at the stoichiometric A/F ratio than those of other commercial oxygen sensors.

$Al_{2}O_{3}$가 첨가된 지르코니아 산소센서의 제조 및 그 특성

손정덕,최시영,Sohn, Jeong-Duk,Choi, Sie-Young 한국센서학회 1992 센서학회지 Vol.29 No.3

이트리아 안정화(安定化) 지르코니아(92 mole% $ZrO_{2}$+8 mole% $Y_{2}O_{3}$)에 0.5 mole% $SiO_{2}$와 $0{\sim}2.0{\;}mole%{\;}Al_{2}O_{3}$가 첨가된 소결체의 소결성, 기계적 및 전기적 성질에 대하여 조사하였다. 소결밀도(燒結密度)는 0.5 mole% $Al_{2}O_{3}$가 첨가되었을 때 가장 높게 나타났으며 1.5 mole%이상 $Al_{2}O_{3}$가 첨가됨에 따라 감소하는 경향을 나타내었다. 비커스 경도(硬度)는 소결밀도(燒結密度)에 비례하여 나타났으며, 0.5 mole% $Al_{2}O_{3}$가 첨가되었을 때 가장 높은 전도성을 나타내었다. 일정한 산소분압(酸素分壓)에 따른 기전력 측정에서도 0.5 mole% $Al_{2}O_{3}$가 첨가되었을 매 가장 높았다. 제작된 산소(酸素)센서들의 응답특성(應答特性) 결과에서 $SiO_{2}$와 $Al_{2}O_{3}$가 각각 0.5 mole% 첨가된 센서의 응답특성이 가장 좋았다. Sinterability, mechanical and electrical properties of yttria-stabilized zirconia(92 mole% $ZrO_{2}$+8 mole% $Y_{2}O_{3}$) doped with 0.5 mole% $SiO_{2}$ and $0{\sim}2.0 mole%{\;}Al_{2}O_{3}$ were studied as a function of $Al_{2}O_{3}$ addition. Sintered density increased with increasing $Al_{2}O_{3}$ addition up to 0.5 mole % but leveled off with further addition. Victors hardness is proportional to sintered density. The specimen with 0.5 mole% $Al_{2}O_{3}$ and 0.5 mole% $SiO_{2}$ exhibited the maximum electrical conductivity and revealed a maximum electromotive force for a given oxygen partial pressure. Experimental voltage curve of this oxygen sensor take on a sharper, more steplike transition at the stoichiometric A/F ratio than those of other commercial oxygen sensors.

InSb MIS 구조에서의 계면의 전기적 특성 평가

이재곤,최시영 ( Jae Gon Lee,Sie Young Choi ) 한국센서학회 1996 센서학회지 Vol.5 No.6

The interfacial electrical properties of InSb MIS structure with low temperature remote PECVD SiO₂ have been characterized. The interface-state density at mid-bandgap of the MIS structure was about 1∼2 x 10^(11) cm^(-1)eV^(-1), when the SiO₂ film was deposited at 105℃. However, large amount of interface states and trap states were observed in the MIS structure fabricated at temperatures above 150℃. The time constant of 10 ^(-4)∼10^(-5) sec of interface states was extracted from G-V measurement. As the deposition temperature increased, the hysteresis of C-V curves were increased due to the high trap density.

SUS630 다이아프램을 이용한 반도체식 로드셀

문영순 ( Young Soon Moon ),이선길 ( Seon Gil Lee ),류상혁 ( Sang Hyuk Ryu ),최시영 ( Sie Young Choi ) 한국센서학회 2011 센서학회지 Vol.20 No.3

The load cell is a force sensor and a transducer that is used to convert a physical force into a electrical signal for weighing equipment. Most conventional load cells are widely used a metal foil strain gauge for sensing element when force being applied spring element in order to converts the deformation to electrical signals. The sensitivity of a load cell is limited by its low gauge factor, hysteresis and creep. But silicon-based sensors perform with higher reliability. This paper presents the basic design and development of the silicon type load cell with an SUS630 diaphragm. The load cell consists of two parts the silicon strain gauge and the SUS630 structure with diaphragm. Structure analysis of load cell was researched by theory to optimize the load cell diaphragm design and to determine the position of peizo-resistors on a silicon strain gauge. The piezo-resistors are integrated in the four points of silicon strain gauge processed by ion implantation. The thickness of the silicon strain gauge was polished by CMP under 100 μm. The 10 mm diameter SUS630 diaphragm was designed for loads up to 10 kg with 300 μm of diaphragm thickness. The load cell was successfully tested, the variation of ΔR(%) of four points on the silicon strain gauge is good linearity properties and sensitivity.

가스누출 감지용 실리콘 압저항형 절대압센서의 제조 및 온도보상

손승현,김우정,최시영 ( Seung Hyun Son,Woo Jeong Kim,Sie Young Choi ) 한국센서학회 1998 센서학회지 Vol.7 No.3

Silicon piezoresistive absolute pressure sensor for gas leakage alarm system was developed. This sensor must operate normally in the range of 0∼600 mmH₂O pressure, and 100 temperature. To make the most of this sensor for gas leakage alarm system, gas must not leak from the sensor itself when the diaphragm of the sensor fractures. Thus, the sealed diaphragm cavity was anodically bonded to Pyrex 7740 glass under the condition of 10^(-4) torr at 400 ℃. The sensitivity of developed sensor was 4.06 ㎶/VmmH₂O for 600 mmH₂O full-scale pressure range. And temperature compensation method of this sensor is to change bridge-input-voltage linearly in proportion to the temperature variation by using diode(YXIN4001) or Al thin film resistor. By these methods the temperature effect in the range of 0∼100℃ was compensated over 80% for offset drift, 95% for sensitivity.

SDB 웨이퍼를 이용한 절대압 실리콘 압력센서의 제조

이창준,강신원,최시영 ( Chang Jun Lee,Shin Won Kang,Sie Young Choi ) 한국센서학회 1995 센서학회지 Vol.4 No.1

The absolute silicon pressure sensors are fabricated using SDB(silicon direct bonded) wafer. The fabricated pressure sensors consist of four bridge type piezoresistances and a diaphragm which plays a role of mechanic amplifier to supplying pressure. In order to make the diaphragm cavity in low vaccum condition, we anodically bonded Si diaphragm with Pyrex 7740 glass in 0.02mmHg, at 400℃. The sensitivity and offset voltage of the fabricated sensors were 30.4 ㎶/VmmHg and 30.6mV. respectively.

사각뿔 형태의 Mass 보상된 실리콘 압저항형 가속도 센서

손병복,이재곤,최시영 ( Byoung Bok Sohn,Jae Gon Lee,Sie Young Choi ) 한국센서학회 1994 센서학회지 Vol.3 No.1

When etching rectangular convex corners of silicon using anisotropic etchants such as KOH, deformation of the edges always occurs due to undercutting. Therefore, it is necessary to correct the mass pattern for compensation. Experiments for the compensation method to prevent this phenomenon were carried out. In the result, the compensation pattern of a regular square is suitable for acceleration sensors considering space. With this consequence, silicon piezoresistive acceleration sensor with compensated square pillar type of mass has been fabricated using SDB wafer.

Au 와 Pt 확산에 의한 실리콘 p+-n 접합 스위칭다이오드의 전기적 특성

정기복,이재곤,최시영 ( Kee Bock Chung,Jae Gon lee,Sie Young Choi ) 한국센서학회 1996 센서학회지 Vol.5 No.3

The silicon p^+-n junction diodes were fabricated. The fabricated wafers were treated by single or double annealing steps. Single annealing process was performed by diffusion of either Au or Pt into the wafer under the oxygen or nitrogen ambient at 800∼1010℃. Second annealing step involved additional annealing of the single annealed wafer under the oxygen ambient at 800∼1010℃ for one hour. Electrical characteristics of the diodes were investigated to evaluate the effect of the annealing treatments. In the case of single annealing under nitrogen ambient at 1010℃ for one hour, the amount of leakage current of Pt diffused diode was 75 times larger than that of Au diffused one. The optimum processing condition to achieve high speed silicon p^+-n junction diodes from this study was obtained when Pt diffused wafer(treated under the nitrogen ambient at 1010℃ for one hour) was secondly annealed in an oxyen ambient at 800℃ for one hour. The resulting leakage current of two step annealed diodes were remarkably reduced to 1/1100 of the single annealed one. The diode characteristics such as recovery time, breakdown voltage, leakage current, and forward voltage were 4ns, 138V, 1.72nA, and 1V, respectively.

다결정 실리콘을 이용한 p+n 다이오드의 누설전류 개선

김원찬,이재곤,최시영 ( Weon Chan Kim,Jae Con Lee,Sie Young Choi ) 한국센서학회 1996 센서학회지 Vol.5 No.1

To decrease the leakage current of p^+n junction diode with hyperabrupt structure, the 3000Å polysilicon was deposited on the top of conventional p^+n diode and then annealed for 30 minutes at 900℃ in the N₂ ambient. It was estimated for both p^+n diodes with and without polysilicon layer, and the impurity materials of n diffused layer to observe the influence of the polysilicon layer on leakage current characteristics. The leakage current was reduced to the order of 3 by using polysilicon layer. A large number of dislocation loops, which were believed to be generated by As-implanted diffused layer, were found to be removed by using polysilicon through TEM analysis.