Patent ID: 7763487

Claim:
A process for manufacturing an integrated differential pressure sensor, comprising: forming a cavity in a monolithic body of semiconductor material having a first face and a second face, the cavity extending into the monolithic body a distance from said first face and terminating in the monolithic body a distance from said second face, the cavity delimited at the first face by a flexible membrane integrally formed with the monolithic body and formed in part by epitaxial growth from the monolithic body and in part by thermal annealing following the epitaxial growth, and forming said cavity comprises: digging trenches within said monolithic body, the trenches delimiting structures of semiconductor material; growing a closing layer of semiconductor material from said structures to close said trenches; and performing the thermal annealing such as to cause migration of the semiconductor material of said structures to the flexible membrane and transform said trenches into said cavity; forming an access passage in the monolithic body that is in fluid communication with said cavity, including etching said monolithic body to form an access trench extending through said monolithic body; and forming in said flexible membrane at least one transduction element configured to convert a deformation of said flexible membrane into electrical signals.