Pressure sensors and methods of making the same

摘要

A pressure sensor assembly comprising: three stacked silicon wafers which form a support, a sensor and a cover wherein the sensor includes a cavity extending from the bottom of the sensor up towards the top of the sensor to form a cavity bottom and a diaphragm; a dielectric layer covering the bottom of the sensor and the cavity and wherein the support is coupled to the dielectric layer along the bottom of the sensor; a plurality of ports located on a top of the support within an area defined by the cavity, the plurality of ports extending through the support to its bottom and wherein the cover is coupled to the top of the sensor covering the diaphragm; and, a second cavity cut into a bottom of the cover wherein the second cavity is sized and positioned to surround the diaphragm.

主权项

1. A method for manufacturing a pressure sensor assembly comprising:
forming a sensor from a first silicon wafer by creating a cavity that extends up into the first silicon wafer from a bottom; forming a conductive layer over the top of the first silicon wafer; forming a support from a second silicon wafer by creating a plurality of channels that pass through the second silicon wafer from a top surface to a bottom surface; bonding the bottom of the first silicon wafer to the top surface of the second silicon wafer such that a chamber is formed by the cavity and the plurality of channels open into the chamber; forming a dielectric layer that electrically isolates the chamber from the sensor; forming a cover from a third silicon wafer by creating a second cavity that extends up into the third silicon wafer from a bottom; and bonding the bottom of the third silicon wafer to a top of the first silicon wafer such that the second cavity surrounds the diaphragm.