Development of Ultra-Miniaturized Piezoresistive Pressure Sensors for Biomedical Applications

Abstract

Ultra miniaturized 0.69-French piezoresistive pressure transducers are designed and fabricated for biomedical applications. Silicon on insulator (SOI) and deep reactive ion etching (DRIE) technologies are used for the fabrication of the pressure sensors. A combination of SOI and DRIE technologies eliminates the dicing step and results in uniform diaphragm thickness. The dimensions of the final fabricated sensor die are 650 mum times 230 mum times 150 mum (length, width, thickness) with 2.5 mum thick diaphragms. Sensitivity of the sensors with half Wheatstone bridge configuration is determined to be 27-31 muV/V/mmHg.