Open AccessDifferential capacitive pressure sensor design based on standard CMOS
Author(s) -
Unigarro E.,
Bohórquez J.C.,
Achury A.,
Ramirez F.,
Sacristán J.,
SeguraQuijano F.
Publication year - 2017
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2017.0463
Subject(s) - capacitive sensing , cmos , pressure sensor , electronic engineering , electrical engineering , differential (mechanical device) , pressure measurement , differential pressure , computer science , engineering , physics , mechanical engineering , aerospace engineering , mechanics
A microelectromechanical system capacitive pressure sensor with a differential configuration (patent pending), including a reference and sensitive capacitor, is presented. A single cavity includes both reference and sensitive electrodes. This implementation is achieved by a size reduction of the sensitive electrode. A reduction of the 40% on the sensible electrode area represents a decrease in the sensor sensitivity of only 12.5%, and allows the reference capacitor implementation in the area commonly used only for the sensitive capacitor. A tridimensional model of the sensor was simulated using a finite‐element solver considering coupled mechanical and electrostatic models. The simulations show that this pressure sensor has a sensitivity of 4.2 fF/bar. The proposed pressure sensor designs use only materials available in complementary metal oxide silicon (CMOS) standard processes. A CMOS compatible post‐process, based on the sacrificial material technique and its restrictions is presented.