US 12,474,368 B2
Z-axis microelectromechanical sensor device with improved stress insensitivity
Gabriele Gattere, Castronno (IT); Francesco Rizzini, Passirano (IT); and Cristian Dall'Oglio, Niscemi (IT)
Assigned to STMICROELECTRONICS S.R.L., Agrate Brianza (IT)
Filed by STMICROELECTRONICS S.R.L., Agrate Brianza (IT)
Filed on Nov. 15, 2022, as Appl. No. 18/055,804.
Claims priority of application No. 102021000029810 (IT), filed on Nov. 25, 2021.
Prior Publication US 2023/0160921 A1, May 25, 2023
Int. Cl. G01P 15/125 (2006.01); G01P 15/08 (2006.01); G01P 15/18 (2013.01)
CPC G01P 15/18 (2013.01) [G01P 15/0802 (2013.01); G01P 15/125 (2013.01)] 13 Claims
OG exemplary drawing
 
8. A device, comprising:
a substrate;
a central anchor on the substrate having a first surface opposite the substrate along a first direction;
a suspended mass on the substrate and coupled to the central anchor with elastic elements, the suspended mass including a first surface opposite a second surface along the first direction, the first surface of the suspended mass being further from the substrate than the second surface of the suspended mass, the suspended mass including:
a first reduced thickness portion with a first face coplanar with the second surface of the suspended mass and having a first thickness along the first direction; and
a second reduced thickness portion with a second face coplanar with the first surface of the suspended mass and the first surface of the central anchor and having a second thickness smaller than the first thickness along the first direction;
a first electrode between the central anchor and the suspended mass along a second direction transverse to the first direction, the first electrode having a third surface that is coplanar with the first surface of the suspended mass and the first surface of the central anchor, the first electrode being coupled to the substrate, the first reduced thickness portion being between the first electrode and the substrate along the first direction;
a second electrode between the central anchor and the suspended mass along the second direction, the second electrode spaced from the first electrode by the central anchor, the second electrode being coupled to the substrate, the second electrode being between the second reduced thickness portion and the substrate along the first direction; and
connection elements coupled between the central anchor and the elastic elements, the elastic elements extending along the second direction, the connection elements extending along a third direction transverse to both the first and second directions,
wherein the elastic elements enable a translation of the suspended mass along the first direction and minimize a translation of the inertial mass along the second and third directions.