Multi semiconductor pressure sensor with steep passageway

摘要

A multivariate semiconductor pressure sensor includes differential pressure sensing elements formed by a polysilicon membrane (14) spanning a sensor cavity (38) formed in a substrate (12). The sensor cavity (38) is in communication with fluid pressure on the back surface of the substrate (12) by way of a fluid passageway (46) that connects an exterior opening in the back surface of the substrate with an interior opening into either the sensor cavity (38) itself or into a feeder (62) cavity that is in fluid communication with the sensor cavity. An anisotropic deep reactive ion etching (DRIE) is used for a steep passageway (46).