Integrated differential pressure sensor and manufacturing process thereof
First Claim
1. 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.
1 Assignment
0 Petitions
Accused Products
Abstract
A process for manufacturing an integrated differential pressure sensor includes forming, in a monolithic body of semiconductor material having a first face and a second face, a cavity extending at a distance from the first face and delimiting therewith a flexible membrane, forming an access passage in fluid communication with the cavity, and forming, in the flexible membrane, at least one transduction element configured so as to convert a deformation of the flexible membrane into electrical signals. The cavity is formed in a position set at a distance from the second face and delimits, together with the second face, a portion of the monolithic body. In order to form the access passage, the monolithic body is etched so as to form an access trench extending through it.
35 Citations
12 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A process for manufacturing an integrated differential pressure sensor using a monolithic body of semiconductor material having a first face and a second face, the process comprising:
-
forming a cavity having internal walls within the monolithic body, 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 that follows the epitaxial growth and the cavity delimited before the second face by a portion of the monolithic body, and forming the cavity comprises; forming trenches within the monolithic body, the trenches delimiting structures of semiconductor material; growing a closing layer of semiconductor material from the structures to close the trenches; and performing the thermal annealing to cause migration of the semiconductor material of the structures and transform the trenches into the cavity. forming an oxidation trench in the monolithic body that is in communication with the cavity; oxidizing the internal walls of the cavity through the oxidation trench to form a stop oxide layer thereon; forming an access passage in the monolithic body that is in fluid communication with the cavity; and forming in the flexible membrane at least one transduction element configured to convert a deformation of the flexible membrane into electrical signals. - View Dependent Claims (11, 12)
-
Specification