• 반도체디스플레이기술학회지
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• 제7권1호
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• pp.1-5
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• 2008

In this paper, we fabricated pressure difference type gas flow sensor using only dry etching technology by ICP-RIE(inductive coupled plasma reactive ion etching). The sensor's structure consists of a common shear stress type piezoresistive pressure sensor with an orifice fabricated in the middle of the sensor diaphragm. Generally, structure like diaphragm is fabricated by wet etching technology using TMAH, but we fabricated diaphragm by only dry etching using ICP-RIE. To equalize the thickness of diaphragm we applied insulator($SiO_2$) layer of SOI(Si/$SiO_2$/Si-sub) wafer as delay layer of dry etching. Size of fabricated diaphragm is $1000{\times}1000{\times}7\;{\mu}m^3$ and overall chip $3000{\times}3000{\times}7\;{\mu}m^3$. We measured the variation of output voltage toward the change of gas pressure to analyze characteristics of the fabricated sensor. Sensitivity of fabricated sensor was relatively high as about 1.5mV/V kPa at 1kPa full-scale. Nonlinearity was below 0.5%F.S. Over-pressure range of the fabricated sensor is 100kPa or more.

• 센서학회지
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• 제5권5호
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• pp.31-37
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• 1996

본 연구에서는 LPCVD(저압화학기상증착)로 형성된 폴리실리콘의 전단 압저항 효과를 이론적으로 분석하고, 전단 압저항체를 응용한 압력센서를 설계 제작하여 그 특성을 연구하였다. 제작된 센서는 $1kgf/cm^{2}$의 압력과 $-20{\sim}+125^{\circ}C$의 온도범위에서 3.1mV/V의 압력감도, ${\pm}0.012%FS/^{\circ}C$의 오프셀온도계수(TCO), ${\pm}0.08%FS/^{\circ}C$의 감도온도계수(TCS)를 나타내었다. 또한, 같은 온도범위에서 ${\pm}0.2%FS$의 히스테리시스, ${\pm}1.5%FS$의 비직선성 변화를 보였다. 전단형 압력센서는 브리지형과는 달리 하나의 저항체로 이루어져 있어 브리지의 각 저항값 불일치로 인한 특성의 오차를 줄일 수 있고, 절연층 위에 폴리실리콘이 형성되어 있으므로 온도범위를 확장할 수 있는 장점을 가진다.

• 대한금속재료학회지
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• 제56권11호
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• pp.835-843
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• 2018

In this work, we report a delta rosette strain sensor based on highly stretchable silver nanowire (AgNW) percolation piezoresistors. The proposed rosette strain sensors were easily prepared by a facile two-step fabrication route. First, three identical AgNW piezoresistive electrodes were patterned in a simple and precise manner on a donor film using a solution-processed drop-coating of the AgNWs in conjunction with a tape-type shadow mask. The patterned AgNW electrodes were then entirely transferred to an elastomeric substrate while embedding them in the polymer matrix. The fabricated stretchable AgNW piezoresistors could be operated at up to 20% strain without electrical or mechanical failure, showing a maximum gauge factor as high as 5.3, low hysteresis, and high linearity ($r^2{\approx}0.996$). Moreover, the sensor responses were also found to be highly stable and reversible even under repeated strain loading/unloading for up to 1000 cycles at a maximum tensile strain of 20%, mainly due to the mechanical stability of the AgNW/elastomer composites. In addition, both the magnitude and direction of the principal strain could be precisely characterized by configuring three identical AgNW piezoresistors in a delta rosette form, representing the potential for employing the devices as a multidimensional strain sensor in various practical applications.