CAPACITIVE PRESSURE SENSOR AND A METHOD OF FABRICATING THE SAME

摘要

The invention discloses a capacitive pressure sensor and a method of fabricating the same. The capacitive pressure sensor includes a fixed plate configured as a back plate, a movable plate configured as diaphragm for sensing pressure, wherein a cavity is formed between the fixed plate and the movable plate, an isolation layer between the fixed plate and the movable plate and electrical contacts thereof for minimizing the leakage current, plurality of damping holes for configuring the contour of the fixed plate as the deflected diaphragm when pressure is exerted, a vent hole extending to the cavity having resistive air path for providing equilibrium to the diaphragm and an extended back chamber for increasing the sensitivity of the capacitive pressure sensor. The capacitive pressure sensor is also configured for minimizing parasitic capacitance.

主权项

1. A capacitive pressure sensor fabricated on a sensor die comprising:
a fixed plate configured as a back plate anchored at the edge keeping the remaining area afloat for minimizing parasitic capacitance; a movable plate configured as diaphragm for sensing pressure, wherein a cavity is formed between the fixed plate and the movable plate to allow deflection of the diaphragm; an isolation layer between the fixed plate and the movable plate and electrical contacts thereof for minimizing the leakage current; plurality of damping holes disposed on the fixed plate for configuring the contour thereof as the deflected diaphragm when pressure is exerted thereon; a vent hole extending to the cavity having resistive air path for providing equilibrium to the diaphragm when exposed to the environmental pressure; and an extended back chamber with extended volume for increasing the sensitivity of the capacitive pressure sensor.