Patent ID: 11940346
Assignee: ROBERT BOSCH GMBH
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 11:
12. A method for producing a micromechanical pressure sensor device, the micromechanical pressure sensor device including a semiconductor base substrate of a first doping type, on which an intermediate layer of the first doping type is situated; a cavity, which includes a recess of a subregion of the semiconductor base substrate and a recess of the intermediate layer; a sealing layer, the cavity being sealed by a sealing layer of a second doping type and containing a reference pressure, the sealing layer having a diaphragm region situated on a topside of the cavity; a first grating of the second doping type, which is suspended on a buried connection region of the second doping type, the buried connection region extending laterally away from the cavity into the semiconductor base substrate; a second grating of the second doping type, which is situated on a side of the diaphragm region pointing to the cavity and is suspended on the diaphragm region, the first grating and the second grating being electrically insulated from each other and forming a capacitance; a first connection electrically connected to the first grating via the buried connection region; and a second connection electrically connected to the second grating; wherein a pressure change between an external pressure and the reference pressure is able to be detected by a capacitance change between the first connection and the second connection, the method comprising the following steps:
providing the semiconductor base substrate of the first doping type;
implanting the first grating of the second doping type and the buried connection region of the second doping type into the semiconductor base material;
epitaxially growing the intermediate layer of the first doping type;
implanting the second grating of the second doping type;
applying a mask;
forming a porous region using the mask;
removing the mask;
dissolving out the porous region;
epitaxially growing the sealing layer of the second doping type to form the cavity;
applying the first connection, which is electrically connected to the first grating via the buried connection region; and
applying the second connection, which is electrically connected to the second grating.