Fabrication of a piezoresistive pressure sensor for enhancing sensitivity using silicon nanowire

Abstract

This paper presents a piezoresistive pressure sensor to enhance sensitivity using silicon nanowire. According to published paper, silicon nanowire under 340 nm has good piezoresistive effect. Silicon nanowire of 140 times 200 nm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> size has seven times more piezoresistive effect than bulk silicon. This paper proposes the piezoresistive pressure sensor using the high piezoresistive effect of the silicon nanowire. The nanowire is fabricated to be connected like a bridge between the bossed silicon diaphragm and the edge of the silicon substrate. The fabricated piezoresistive pressure sensor has high sensitivity of 337.5 mV/VmiddotMPa and dynamic range of 150 kPa ~ 300 kPa. The pressure sensor size is less than 1 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> using diaphragm of 200 times 200 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .