The Improvement in Offset and Temperature Drift on Silicon Piezoresistive Pressure Sensor

실리콘 압저항 압력센서의 오프셋 및 온도 드리프트 개선

  • Kim, Jae-Mun (Department of Electronic Engineering Yeung-Nam University) ;
  • Lee, Young-Tae (Department of Electronic Engineering Education An-Dong University) ;
  • Seo, Hee-Don (Department of Electronic Engineering Yeung-Nam University) ;
  • Choi, Se-Gon (Department of Electronic Engineering Yeung-Nam University)
  • Published : 1996.05.31

Abstract

In order to reduce the offset and its temperature drift by the different properties of the piezoresistors and the residual stress of the piezoresistive pressure sensor, a double Wheatstone-bridge pressure sensor was studied. Because the compensation bridge was arranged near by the pressure sensitive bridge, which have the similar offset component, reduction of the offset and its temperature drift was realized by the mathematical subtraction of the output of two bridges. It was configured the compensation of the offset and its temperature drift. By this compensation method, the offset and its temperature drift were reduced approximately 95% respectively. The sensitivity of the fabricated pressure sensor was $11.7\;mV/Vkg/cm^{-2}$ for $0.9\;kgfcm^{-2}$ full-scale pressure range.

이 논문은 압력센서의 압저항 소자 값에 영향을 미치는 실리론 박막의 잔류응력과 4개 저항의 특성 차에 의해 발생하는 오프셋과 온도 드리프트 특성을 보상하기 위하여 2중 브리지구조의 압력센서에 대하여 연구한 것이다. 압력 변화에 무관한 브리지회로의 각 저항 소자를 압력 변화를 감지하는 브리지회로의 각 저항 소자 가까이 배치하여 각 브리지회로의 출력을 감산하므로 오프셋과 온도 드리프트를 소자내부에서 제거하는 것이다. 이 방법에 의해 오프셋과 온도 드리프트 성분의 약 95%가 제거되었다. 제작된 압력센서의 감도는 $0.9\;kgfcm^{-2}$ full-range에 대해서 $11.7\;mV/Vkg/cm^{-2}$ 이었다.

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