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 pressure sensor assembly comprising:
a first silicon wafer with a top and a bottom; a cavity formed in the silicon wafer, the cavity extending from the bottom of the first silicon wafer up towards the top of the first silicon wafer to form a cavity bottom such that a diaphragm is formed between the cavity bottom and the top of the first silicon wafer; an electrical circuit formed by a conductive layer deposited on the top of the first silicon wafer; a second silicon wafer coupled along the bottom of the first silicon wafer and covering the cavity to form a chamber; a dielectric layer that electrically isolates an interior of the chamber from the first silicon wafer; a plurality of ports located on a top of the second silicon wafer within an area defined by the cavity, the plurality of ports extending through the second silicon wafer to a bottom of the second silicon wafer; a third silicon wafer coupled to the top of the first silicon wafer such that the third silicon wafer covers the diaphragm; and, a second cavity cut into a bottom of the third silicon wafer wherein the second cavity is sized and positioned such that the second cavity surrounds the diaphragm.