발전기 스테이터의 냉각코일에 pinhole 발생을 검지할 수 있는 수소센서 개발

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

$Al_{2}O_{3}$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.

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.

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.

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.

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.

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.

Pt/Ti 전극을 사용한 산하된 다공질 폴리 실리콘 전계방출소자의 특성

한상국,박근용,최시영,Han Sang-Kug,Park Keun-Yong,Choi Sie-Young 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.6

In this paper, OPPS(oxidized porous poly-silicon) field emitters were fabricated by using various emitter-electrode metal and these electron emission characteristics were investigated for different thermal annealing effects. The addressed OPPS field emitter with Pt/Ti emitter electrode annealed at $300^{\circ}C$-1hr showed the efficiency of $2.98\%$ at $V_{ps}$=12 V and one annealed at $350^{\circ}C$-1hr showed the highest efficiency of $3.37\%$at $V_{ps}$=16V. They are resulted from the improvement of interfacial contact characteristics of thin emitter metal to an oxidized porous poly-silicon and the decrease of electrical resistance of emitter metal. The brightness of the OPPS field emitter increases linearly in $V_{ps}$ and after oxidation process for $900^{\circ}C$-50min, the brightness of the OPPS field emitter with the as-deposited Pt/Ti emitter electrode was 3600 cd/$m^2$ at the $V_{ps}$=15 V, 6260 cd/$m^2$ at the $V_{ps}$=20 V. Thermal treatment improved the adhesion between the Ti buffer layer and the oxidized porous poly-silicon and also played an important role in the uniform distribution of electric field to the emitter electrode. 본 논문에서는 다양한 에미터 금속 재료를 이용하여 산화된 다공질 폴리실리콘(Oxidized Porous Poly-Silicon) 전계방출 소자를 제조하였으며 에미터 금속의 열처리 효과가 산화된 다공질 폴리실리콘 전계방출소자의 특성에 미치는 영향을 조사하였다. 다양한 에미터 금속 중 구동전극을 가진 Pt/Ti 에미터 전극을 $300^{\circ}C$-1hr 열처리한 경우 전자방출 효율은 $V_{ps}$=12 V에서 최대 $2.98\%$의 효율을 나타내었으며, $350^{\circ}C$-1hr 열처리한 경우 $V_{ps}$=16V에서 $3.37\%$의 가장 높은 효율을 나타내었다. 이는 열처리 공정을 통해 OPPS 전계방출 소자 표면에 다수의 결정립 경계와 무수히 많은 미세한 다공질 간의 흡착성의 개선으로 인한 면 저항 감소에 의한 것을 알 수 있다. OPPS 전계 방출 소자를 디스플레이소자로 적용하기 위해 형광체 발광 특성을 조사해 본 결과, $900^{\circ}C$-50min 산화 후 Pt/Ti(5nm/2nm) 에미터 전극을 사용하여 제조된 OPPS 전계 방출 소자의 경우 15 V에서 3600 cd/$m^2$, 20 V에서 6260 cd/$m^2$의 상대적으로 높은 휘도를 나타내었다. 열처리는 Ti층과 OPPS 간의 흡착성을 개선시키고 에미터 전극에 고른 전계를 가하는 중요한 역할을 한다.

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.