Patent ID: 11952263
Assignee: ROBERT BOSCH GMBH
Field: Micro-structural and nano-technology (Chemistry)
Classification: CPC B | IPC B

Claim 5:
6. A method for manufacturing a micromechanical sensor device, comprising the following steps:
providing a cap substrate in the form of an SOI substrate, which has a first front side facing in a first direction and a first back side facing in a second direction, the cap substrate including a first silicon layer situated on the first front side, a second silicon layer situated on the first back side, and an insulating layer situated between the first silicon layer and the second silicon layer;
forming a trench grid which extends through the second silicon layer to the insulating layer;
forming a first through-opening underneath the trench grid, the first through-opening extending through the first silicon layer to the insulating layer;
providing a sensor substrate which has a second front side facing in the first direction and a second back side facing in the second direction, and in which a sensor region is entirely arranged, the sensor region being suspended on a remainder of the sensor substrate and being mechanically decoupled from the remainder of the sensor substrate by a lateral stress-relief trench;
bonding the first back side to the second front side in such a manner, that the first through-opening is situated above the sensor region;
starting from the second back side, forming a cavity in the sensor substrate in such a manner, that the sensor region is embedded in an island-like region, the island-like region being mechanically decoupled from remainder of the sensor substrate by the lateral stress-relief trench and the cavity situated in the sensor substrate;
forming a second through-opening, which extends through the second silicon layer to the insulating layer, by removing the trench grid;
removing the insulating layer between the first and second through-openings, so that a through-opening is formed as a media entry region; and
covering the sensor region with a gel, which, starting from the first front side, fills the through-opening and the stress-relief trench at least partially, such that an exterior surface of the sensor region that faces in the first direction is exposed to the gel at the second front side.