Stmicroelectronics S.r.l.

Matteo Perletti

Sebastiano Conti

Giorgio Allegato

Federico Vercesi

Silvia Adorno

Laura Maria Castoldi

Stefano Losa

Igor Varisco

Roberto Carminati

Marco Ferrera

Mikel Azpeitia Urquia

Luca Zanotti

Roberto Campedelli

Pietro Petruzza

Ilaria Gelmi

Laura Oggioni

Luca Lamagna

Luigi Esposito

Raffaella Pezzuto

Lorenzo Baldo

Carlo Valzasina

Gabriele Gattere

Alessandro Morcelli

Marco Salina

Lorenzo Tentori

Alessandra Sciutti

Maria Carolina Turi

Francesco Tripodi

A method for manufacturing a filtering module comprising the steps of: forming a multilayer body comprising a filter layer of semiconductor material and having a thickness of less than 10 &#x3bc;m, a first structural layer coupled to a first side of the filter layer, and a second structural layer coupled to a second side, opposite to the first side, of the filter layer; forming a recess in the first structural layer, which extends throughout its thickness; removing selective portions, exposed through the recess, of the filter layer to form a plurality of openings, which extend throughout the thickness of the filter layer; and completely removing the second structural layer to connect fluidically the first and second sides of the filter layer, thus forming a filtering membrane designed to inhibit passage of contaminating particles.

Method for manufacturing a thin filtering membrane and an acoustic transducer device including the filtering membrane

A method for manufacturing a semiconductor die, comprising the steps of: providing a MEMS device having a structural body, provided with a cavity, and a membrane structure suspended over the cavity; coupling the structural body to a filtering module via direct bonding or fusion bonding so that a first portion of the filtering module extends over the cavity and a second portion of the filtering module extends seamlessly as a prolongation of the structural body; and etching selective portions of the filtering module in an area corresponding to the first portion, to form filtering openings fluidically coupled to the cavity. The semiconductor die is, for example, a microphone.

Method for manufacturing a semiconductor die provided with a filtering module, semiconductor die including the filtering module, package housing the semiconductor die, and electronic system

A MEMS acoustic transducer provided with: a substrate of semiconductor material, having a back surface and a front surface opposite with respect to a vertical direction; a first cavity formed within the substrate, which extends from the back surface to the front surface; a membrane which is arranged at the upper surface, suspended above the first cavity and anchored along a perimeter thereof to the substrate; and a combfingered electrode arrangement including a number of mobile electrodes coupled to the membrane and a number of fixed electrodes coupled to the substrate and facing respective mobile electrodes for forming a sensing capacitor, wherein a deformation of the membrane as a result of incident acoustic pressure waves causes a capacitive variation of the sensing capacitor. In particular, the combfingered electrode arrangement lies vertically with respect to the membrane and extends parallel thereto.

MEMS acoustic transducer with combfingered electrodes and corresponding manufacturing process

A transducer includes a first substrate and an integrated circuit coupled to the first substrate. A sensor is electrically coupled to the integrated circuit and includes a second substrate having a first surface and a second surface opposite the first surface. The second substrate has scribe boundaries defining an outer edge of the second substrate and a chamber extending from the first surface towards but not reaching the second surface. A chamber extends from the second surface to meet the chamber from first surface. Scribe trenches in the second surface at the scribe boundaries have a width from the scribe boundary towards the chamber extending from the second surface. A membrane extends over the first surface and over the chamber extending from first surface. A plate extends from the first surface of the second substrate over the membrane.

Dry scribing methods, devices and systems

An electroacoustic MEMS transducer, having a substrate of semiconductor material; a through cavity in the substrate; a back plate carried by the substrate through a plate anchoring structure, the back plate having a surface facing the through cavity; a fixed electrode, extending over the surface of the back plate; a membrane of conductive material, having a central portion facing the fixed electrode and a peripheral portion fixed to the surface of the back plate through a membrane anchoring structure; and a chamber between the membrane and the back plate, peripherally delimited by the membrane anchoring structure.

Integrated electroacoustic MEMS transducer with improved sensitivity and manufacturing process thereof

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 method of forming semiconductor devices, such as capacitive type MEMS acoustic transducers, in a semiconductor includes forming a mask layer on a back surface of the semiconductor wafer and removing first etch portions of the mask layer and scribe trench portions of the mask layer. Each scribe trench portion is positioned in the mask layer to define a corresponding scribe boundary of a plurality of the semiconductor devices being formed in the semiconductor wafer. Etching the semiconductor wafer through the first etch portions and the scribe trench portions may be done simultaneously to form external back chambers and scribe trenches, respectively, in the semiconductor wafer. The semiconductor wafer is then cut along cutting lines in the scribe trenches to singulate individual MEMS acoustic transducers. The etching through the first and second etch portions and the scribe trench portions are dry etching of the semiconductor substrate in one embodiment.

An assembly of a MEMS sensor device envisages: a first die, integrating a micromechanical detection structure and having an external main face; a second die, integrating an electronic circuit operatively coupled to the micromechanical detection structure, electrically and mechanically coupled to the first die and having a respective external main face. Both of the external main faces of the first die and of the second die are set in direct contact with an environment external to the assembly, without interposition of a package.

Wafer level assembly of a MEMS sensor device and related MEMS sensor device

A micromechanical structure for a MEMS capacitive acoustic transducer, has: a substrate made of semiconductor material, having a front surface lying in a horizontal plane; a membrane, coupled to the substrate and designed to undergo deformation in the presence of incident acoustic-pressure waves; a fixed electrode, which is rigid with respect to the acoustic-pressure waves and is coupled to the substrate by means of an anchorage structure, in a suspended position facing the membrane to form a detection capacitor. The anchorage structure has at least one pillar element, which is at least in part distinct from the fixed electrode and supports the fixed electrode in a position parallel to the horizontal plane.

Micromechanical detection structure for a MEMS acoustic transducer and corresponding manufacturing process

A microelectromechanical sensing structure for a capacitive acoustic transducer, including: a semiconductor substrate; a rigid electrode; and a membrane set between the substrate and the rigid electrode, the membrane having a first surface and a second surface, which are in fluid communication, respectively, with a first chamber and a second chamber, respectively, the first chamber being delimited at least in part by a first wall portion and a second wall portion formed at least in part by the substrate, the second chamber being delimited at least in part by the rigid electrode, the membrane being moreover designed to undergo deformation following upon incidence of pressure waves and facing the rigid electrode so as to form a sensing capacitor having a capacitance that varies as a function of the deformation of the membrane. The structure moreover includes a beam, which is connected to the first and second wall portions and is designed to limit the oscillations of the membrane.

Microelectromechanical sensing structure for a capacitive acoustic transducer including an element limiting the oscillations of a membrane, and manufacturing method thereof

A process for manufacturing a micromechanical structure envisages: forming a buried cavity within a body of semiconductor material, separated from a top surface of the body by a first surface layer; and forming an access duct for fluid communication between the buried cavity and an external environment. The method envisages: forming an etching mask on the top surface at a first access area; forming a second surface layer on the top surface and on the etching mask; carrying out an etch such as to remove, in a position corresponding to the first access area, a portion of the second surface layer, and an underlying portion of the first surface layer not covered by the etching mask until the buried cavity is reached, thus forming both the first access duct and a filter element, set between the first access duct and the same buried cavity.

Process for manufacturing a micromechanical structure having a buried area provided with a filter

A MEMS acoustic transducer provided with a substrate having cavity, and a membrane suspended above the cavity and fixed peripherally to the substrate, with the possibility of oscillation, through at least one membrane anchorage. The membrane comprises at least one spring arranged in the proximity of the anchorage and facing it, and is designed to act in tension or compression in a direction lying in the same plane as said membrane.

Integrated acoustic transducer obtained using MEMS technology, and corresponding manufacturing process

A multilayer structure includes: a microfluidic circuit, delimited at least in part by a first sealing structure; a fluid-tight chamber delimited in part by a second sealing structure and in part by the first sealing structure, which is arranged in the fluid-tight chamber and is configured to provide a signal indicative of a leakage between the microfluidic circuit and the fluid-tight chamber.

Multilayer structure having a microfluidic channel and a system for detecting leakage from the microfluidic channel, and method of detecting leakage in a microfluidic device

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Boltiere, Italy

Matteo Perletti