کنفرانس مهندسی برق ایران

صفحه اصلی / سی و چهارمین کنفرانس بین المللی مهندسی برق

Fabrication Processes Impact on Sensitivity and Linearity of piezoresistive Pressure Sensors

نویسندگان :

Mahsa Rashidifar¹ Behdad Barahimi² Sara Darbari³

1- دانشگاه تربیت مدرس 2- دانشگاه تربیت مدرس 3- دانشگاه تربیت مدرس

کلمات کلیدی :

pressure sensor،piezoresistive،mems،sensitivity،linearity

چکیده :

Piezoresistive MEMS pressure sensors remain one of the most widely adopted pressure-sensing technologies due to their simple readout circuitry, compact size, and low fabrication cost. Despite the emergence of alternative fabrication approaches such as silicon-on-insulator (SOI), microholes inter-etch and sealing (MIS), and silicon-on-glass structures, conventional silicon–silicon diaphragm–handle layer configurations continue to attract significant interest. In this work, the influence of fabrication-induced structural geometries on the performance of absolute piezoresistive pressure sensors is systematically investigated. Four pressure sensor structures—vertical sidewall, positive-angle sidewall, negative-angle sidewall, and negative-angle sidewall with extended walls—are analyzed using finite-element simulations in COMSOL Multiphysics. The sensors employ square silicon diaphragms with lateral dimensions of 400 × 400 µm² and a thickness of 10 µm, and p-type piezoresistors with lengths and widths of 30 µm and 15 µm, respectively. Key performance parameters, including output sensitivity (107–129 mV/V/MPa), endpoint nonlinearity, and first resonance frequency (approximately 640–806 kHz), are evaluated and compared. The results indicate that fabrication geometry has a pronounced impact on stress distribution and electromechanical response. Among the investigated designs, the positive-angle sidewall structure provides the most favorable combination of sensitivity, linearity, and dynamic stability. These findings offer practical guidelines for optimizing fabrication strategies and structural design in piezoresistive MEMS pressure sensors.