• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2501-2503
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• 1998

In this paper, the silicon-nitride membrane structure for IR sensor was fabricated through the etching and the direct bonding. The PTO layer as a IR detection layer was deposited on the membrane and its characteristics were measured. The attack of PTO layer during the etching of silicon wafer as well as the thermal isolation of the IR detection layer can be solved through the method of bonding/etching of silicon wafer. Because the PTO layer of c-axial orientation raised thermal polarization without polling, the more integration capability can be achieved. The surface roughness of the membrane was measured by AFM, the micro voids and the non-contacted area were inspected by IR detector, and the bonding interface was observed by SEM. The polarization characteristics and the dielectric characteristics of the PTO layer were measured, too.

• 대한전자공학회논문지
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• 제24권4호
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• pp.590-596
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• 1987

In this paper, it was studied on the design of a sun sensor which is able to sense the declinations of an azimuth angle and a zenith angle for a digital sun seeker control system so that it will seek the sun accurately. And, it was considered the construction of digital controllable algorithms through experiments. Peculiar design method of the sun sensor is that sensor box was constructed with three square silicon solar cells and that the three cells were mounted unsymmetrical forming the

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2504-2508
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• 1998

In this paper, we propose the new detecting method for three dimensional piezoresistive silicon accelerometer. Furthermore the accelerometer is formed to have endurance for high temperature by perfect isolation of the piezoresistors using Silicon On Insulator(SOI) wafer. Sensor size are optimized with analytical formulae and extended with FEM simulation for the more detailed results. The accelerometer was fabricated by bulk micromachining techonology. We measured the temperature characteristics and the output characteristics, and the both characteristics were compared with the simulated results

• 한국전기전자재료학회논문지
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• 제24권5호
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• pp.364-369
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• 2011

Analyzing electrical degradation of polycrystalline silicon transistor to applicable at several environment is very important issue. In this research, after fabricating p channel poly crystalline silicon TFT (thin film transistor) electrical characteristics were compare and analized that changed by gate bias with first measurement. As a result on and off current was reduced by variation of gate bias and especially re duce ratio of off current was reduced by $7.1{\times}10^1$. On/off current ratio, threshold voltage and electron mobility increased. Also, when channel length gets shorter on/off current ratio was increased more and thresh old voltage increased less. It was cause due to electron trap and de-trap to gate silicon oxide by variation of gate bias.

• 센서학회지
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• 제5권1호
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• pp.71-77
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• 1996

마이크로머시닝의 구조재료인 다결정 Si이 희생산화막의 영향을 받음을 고려하여 다결정 Si을 열산화시킨 다결정-산화막을 새로운 희생산화막의 재료로서 제안하고 평가하였다. 다결정-산화막상에 성장시킨 다결정 Si은 통상의 희생산화막상에 성장시키는 경우보다 grain size가 증가하였고, XRD결과를 통해 (111) texture의 증가와, 부가적인 (220) texture가 형성됨을 관찰하였다. 또한, 다결정-산화막상에 성장시킨 다결정 Si의 경우, 그 응력이 작고 균일한 분포를 나타내었다.

• 통합자연과학논문집
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• 제2권4호
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• pp.275-279
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• 2009

Recently, number of studies for porous silicon (PSi) have been investigated by many researchers. Multistructured porous silicon such as a distributed Bragg reflector (DBR) PSi, has been a topic of interest, because of its unique optical properties. DBR PSi were prepared by using an electrochemical etch of $P{^+}{^+}$-type silicon wafer with resistivity between 0.1 and $10m{\Omega}cm$. The electrochemical etch with square wave current density results in two different refractive indices in the porous layer. In this work, DBR porous silicon chips for a simple and portable organic vapor-sensing device have fabricated. The optical characteristics of DBR PSi have been investigated. DBR porous silicon have been characterized by FT-IR and Ocean optics 2000 spectrometer. The device used DBR PSi chip has been demonstrated as an excellent gas sensor, showing a great senstivity to organic vapor at room temperature.

• 센서학회지
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• 제23권6호
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• pp.392-396
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• 2014

The 2-dimensional silicon vertical Hall devices, which are sensitive to X,Y components of the magnetic field parallel to the surface of the chip, are fabricated using a modified bipolar process. It consists of the thin p-layer at Si-$SiO_2$ interface and n-epi layer to improve the sensitivity and influence of interface effect. Experimental samples are a sensor type K with and type J without $p^+$ isolation dam adjacent to the center current electrode. The results for both type show a more high sensitivity than the former's 2-dimensional vertical Hall devices and a good linearity. The measured non-linearity is about 0.8%. The sensitivity of type J and type K are about 66 V/AT and 200 V/AT, respectively. This sensor's behavior can be explained by the similar J-FET model.

• 한국기계가공학회지
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• 제4권4호
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• pp.34-38
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• 2005

This is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. Today, a large number of uncooled infrared detector developments are under progress due to the availability of silicon technology that enables realization of low cost IR sensor. System prices are continuing to drop, and swelling production volume will soon drive process substantially lower. The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple Structurefor developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. This paper reports a micromachined silicon uncooled thermal imager intended for applications in automated process control. This paper presents the design, fabrication, and the behavior of cantilever for thermomechanical sensing.

• 센서학회지
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• 제17권1호
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• pp.35-40
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• 2008

Low power bridge type micro gas sensors were fabricated by micro machining technology with TMAH (Tetra Methyl Ammonium Hydroxide) solution. The sensing devices with different heater materials such as metal and poly-silicon were obtained using CMOS (Complementary Metal Oxide Semiconductor) compatible process. The tellurium films as a sensing layer were deposited on the micro machined substrate using shadow silicon mask. The low power micro gas sensors showed high sensitivity to NO with high speed. The pure tellurium film used micro gas sensor showed good sensitivity than transition metal (Pt, Ti) used tellurium film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1226-1228
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• 1994

Applications of poly-Si layers which are important as sensing and structural material of various sensors were reviewed in this research. A piezoresistive pressure sensor with piezoresistors has sensitivity of $6.93{\mu}$ V/(VmmHg) within 300mmHg. Temperature sensor was studied with measurement range of $-40{\sim}140^{\circ}C$ and $400{\sim}800^{\circ}C$ using boron-doped and undoped poly-Si resistors, respectively. Poly-Si layer was used to transduce volume change of polyimide to stress of silicon diaphragm for humidity sensor.