公开(公告)号：US20210276044A1

公开(公告)日：2021-09-09

申请号：US17191475

申请日：2021-03-03

Applicant: STMicroelectronics S.r.l.

Inventor： Federico VERCESI ,  Alessandro DANEI ,  Giorgio ALLEGATO ,  Gabriele GATTERE ,  Roberto CAMPEDELLI

IPC: B06B1/06 ,  H01L41/22

Abstract: A method for manufacturing a PMUT device including a piezoelectric element located at a membrane element is provided. The method includes receiving a silicon on insulator substrate having a first silicon layer, an oxide layer, and a second silicon layer. Portions of a first surface of the second silicon layer are exposed by removing exposed side portions of the first silicon layer and corresponding portions of the oxide layer, and a central portion including the remaining portions of the first silicon layer and of the oxide layer is defined. Anchor portions for the membrane element are formed at the exposed portions of the first surface of the second silicon layer. The piezoelectric element is formed above the central portion, and the membrane element is defined by selectively removing the second layer and removing the remaining portion of the oxide from under the remaining portion of the first silicon layer.

公开(公告)号：US20240051817A1

公开(公告)日：2024-02-15

申请号：US18363599

申请日：2023-08-01

Applicant: STMICROELECTRONICS S.r.l.

Inventor： Federico VERCESI ,  Gabriele GATTERE ,  Giorgio ALLEGATO ,  Mikel AZPEITIA URQUIA ,  Alessandro DANEI

IPC: B81B7/00 ,  B81B7/02 ,  H03K17/975

CPC classification number: B81B7/0058 ,  B81B7/02 ,  H03K17/975 ,  H01H2231/028 ,  B81B2203/04

Abstract: A microelectromechanical button device is provided with a detection structure having: a substrate of semiconductor material with a front surface and a rear surface; a buried electrode arranged on the substrate; a mobile electrode, arranged in a structural layer overlying the substrate and elastically suspended above the buried electrode at a separation distance so as to form a detection capacitor; and a cap coupled over the structural layer and having a first main surface facing the structural layer and a second main surface that is designed to be mechanically coupled to a deformable portion of a case of an electronic apparatus of a portable or wearable type. The cap has, on its first main surface, an actuation portion arranged over the mobile electrode and configured to cause, in the presence of a pressure applied on the second main surface, a deflection of the mobile electrode and its approach to the buried electrode, with a consequent capacitive variation of the detection capacitor, which is indicative of an actuation of the microelectromechanical button device.