Stmicroelectronics S.r.l.

Roberto Campedelli

Stefano Losa

Mikel Azpeitia Urquia

Raffaella Pezzuto

Pietro Corona

Matteo Perletti

Caterina Riva

Giuseppe Barillaro

Igor Varisco

Luigi Esposito

Alessandro Diligenti

Flavio Francesco Villa

Paolo Ferrari

Enri Duqi

Marco Ferrera

Gabriele Gattere

Giorgio Allegato

Federico Vercesi

Mauro Cattaneo

Ilaria Gelmi

Marco Mantovani

Maria Carolina Turi

Silvia Nicoli

Alessandro Danei

The present disclosure is directed to a method for manufacturing a micro-electro-mechanical device. The method includes the steps of forming, on a substrate, a first protection layer of crystallized aluminum oxide, impermeable to HF; forming, on the first protection layer, a sacrificial layer of silicon oxide removable with HF; forming, on the sacrificial layer, a second protection layer of crystallized aluminum oxide; exposing a sacrificial portion of the sacrificial layer; forming, on the sacrificial portion, a first membrane layer of a porous material, permeable to HF; forming a cavity by removing the sacrificial portion through the first membrane layer; and sealing pores of the first membrane layer by forming a second membrane layer on the first membrane layer.

Method for manufacturing a capacitive pressure sensor and capacitive pressure sensor

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.

Piezoelectric micromachined ultrasonic transducer

A process for manufacturing an interaction system of a microelectromechanical type for a storage medium, the interaction system provided with a supporting element and an interaction element carried by the supporting element, envisages the steps of: providing a wafer of semiconductor material having a substrate with a first type of conductivity and a top surface; forming a first interaction region having a second type of conductivity, opposite to the first type of conductivity, in a surface portion of the substrate in the proximity of the top surface; and carrying out an electrochemical etch of the substrate starting from the top surface, the etching being selective with respect to the second type of conductivity, so as to remove the surface portion of the substrate and separate the first interaction region from the substrate, thus forming the supporting element.

Process for manufacturing a microelectromechanical interaction system for a storage medium

A process for manufacturing an interaction system of a microelectromechanical type for a storage medium, the interaction system provided with a supporting element and an interaction element carried by the supporting element, envisages the steps of: providing a wafer of semiconductor material having a substrate with a first type of conductivity (P) and a top surface; forming a first interaction region having a second type of conductivity (N), opposite to the first type of conductivity (P), in a surface portion of the substrate in the proximity of the top surface; and carrying out an electrochemical etch of the substrate starting from the top surface, the etching being selective with respect to the second type of conductivity (N), so as to remove the surface portion of the substrate and separate the first interaction region from the substrate, thus forming the supporting element.

A method for manufacturing a protective layer for protecting an intermediate structural layer against etching with hydrofluoric acid, the intermediate structural layer being made of a material that can be etched or damaged by hydrofluoric acid, the method comprising the steps of: forming a first layer of aluminum oxide, by atomic layer deposition, on the intermediate structural layer; performing a thermal crystallization process on the first layer of aluminum oxide to form a first intermediate protective layer; forming a second layer of aluminum oxide, by atomic layer deposition, above the first intermediate protective layer; and performing a thermal crystallization process on the second layer of aluminum oxide to form a second intermediate protective layer and thereby completing the formation of the protective layer. The method for forming the protective layer can be used, for example, during the manufacturing steps of an inertial sensor such as a gyroscope or an accelerometer.

Method for manufacturing a protective layer against HF etching, semiconductor device provided with the protective layer and method for manufacturing the semiconductor device

A method for manufacturing a protective layer for protecting an intermediate structural layer against etching with hydrofluoric acid, the intermediate structural layer being made of a material that can be etched or damaged by hydrofluoric acid, the method comprising the steps of: forming a first layer of aluminum oxide, by atomic layer deposition, on the intermediate structural layer; performing a thermal crystallization process on the first layer of aluminum oxide, forming a first intermediate protective layer; forming a second layer of aluminum oxide, by atomic layer deposition, above the first intermediate protective layer; and performing a thermal crystallization process on the second layer of aluminum oxide, forming a second intermediate protective layer and thereby completing the formation of the protective layer. The method for forming the protective layer can be used, for example, during the manufacturing steps of an inertial sensor such as a gyroscope or an accelerometer.

A MEMS device formed by a body; a cavity, extending above the body; mobile and fixed structures extending above the cavity and physically connected to the body via anchoring regions; and electrical-connection regions, extending between the body and the anchoring regions and electrically connected to the mobile and fixed structures. The electrical-connection regions are formed by a conductive multilayer including a first semiconductor material layer, a composite layer of a binary compound of the semiconductor material and of a transition metal, and a second semiconductor material layer.

Micro-electro-mechanical device with buried conductive regions, and manufacturing process thereof

Disclosed herein is a microelectromechanical device and a process for manufacturing same. One or more embodiments may include forming a semiconductor structural layer separated from a substrate by a dielectric layer, and opening a plurality of trenches through the structural layer exposing a portion of the dielectric layer. A sacrificial portion of the dielectric layer is selectively removed through the plurality of trenches in membrane regions so as to free a corresponding portion of the structural layer to form a membrane. To close the trenches, the wafer is brought to an annealing temperature for a time interval in such a way as to cause migration of the atoms of the membrane so as to reach a minimum energy configuration.

Process for manufacturing a membrane microelectromechanical device, and membrane microelectromechanical device

A method for manufacturing a fluid ejection device, comprising the steps of: providing a first semiconductor body having a membrane layer and a piezoelectric actuator which extends over the membrane layer; forming a cavity underneath the membrane layer to form a suspended membrane; providing a second semiconductor body; making, in the second semiconductor body, an inlet through hole configured to form a supply channel of the fluid ejection device; providing a third semiconductor body; forming a recess in the third semiconductor body; forming an outlet channel through the third semiconductor body to form an ejection nozzle of the fluid ejection device; coupling the first semiconductor body with the third semiconductor body and the first semiconductor body with the second semiconductor body in such a way that the piezoelectric actuator is completely housed in the first recess, and the second recess forms an internal chamber of the fluid ejection device.

Method for manufacturing a fluid ejection device and fluid ejection device

A process for manufacturing a MEMS device, wherein a bottom silicon region is formed on a substrate and on an insulating layer; a sacrificial region of dielectric is formed on the bottom region; a membrane region, of semiconductor material, is epitaxially grown on the sacrificial region; the membrane region is dug down to the sacrificial region so as to form through apertures; the side wall and the bottom of the apertures are completely coated in a conformal way with a porous material layer; at least one portion of the sacrificial region is selectively removed through the porous material layer and forms a cavity; and the apertures are filled with filling material so as to form a monolithic membrane suspended above the cavity. Other embodiments are directed to MEMS devices and pressure sensors.

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Novate Milanese, Italy

Roberto Campedelli