Abstract:
A resonant pressure sensor with a provision for
incorporating appropriate actuation and detection
mechanism using fully surface micromachined process is
presented in this paper. The pressure sensing element is a Tshaped
resonating beam encapsulated beneath a polysilicon
rectangular diaphragm and fully enclosed in a sealed vacuum
cavity. This design enables high pressure sensitivity,
miniature chip size and as well as good environmental
isolation. The proposed structure is evaluated for pressure
sensitivity theoretically and numerically using MEMS CAD
tool CoventorWare. The pressure sensitivity of the sensor
with a T-shaped 1.2 μm thick beam is found to be 10.2%/bar
with the beam resonance frequency of about 792 kHz