A method of fabricating a semiconductor substrate includes the following steps. A first wafer is provided and a first surface of the first wafer is etched to form a plurality of cavities. A second wafer is formed on the first surface, where forming the second wafer includes the following steps: providing a core substrate; forming a first insulating layer on the core substrate; and depositing a polysilicon layer on the first insulating layer and the core substrate. In addition, the polysilicon layer is bonded with the first wafer to cover the cavities, where the polysilicon layer is disposed between the first insulating layer and the first wafer. In addition, a semiconductor substrate and MEMS devices using the semiconductor substrate are also provided.

An electromechanical device includes a stack formed of an insulating layer interposed between two solid layers, and a micromechanical structure of predetermined thickness suspended above a recess of predetermined depth, the recess and the micromechanical structure forming one of the two solid layers of the stack, and the insulating layer forming the bottom of the recess.

A MEMS microphone includes a substrate having a cavity, a back plate disposed over the substrate and having a plurality of acoustic holes, a diaphragm disposed over the substrate to cover the cavity, the diaphragm being disposed under the back plate to be spaced apart from the back plate, including venting holes communicating with the cavity, and sensing an acoustic pressure to create a displacement, a first insulation layer interposed between the substrate and the diaphragm to support the diaphragm, and the first insulation layer including an opening formed at a position corresponding to the cavity to expose the diaphragm, a second insulating layer formed over the substrate to cover an upper face of the back plate and an insulating interlayer formed between the first insulation layer and the second insulation layer, and the insulation interlayer being located outside the diaphragm and supporting the second insulation layer to make the back plate be spaced from the diaphragm. Thus, a process of manufacturing the MEMS microphone may be simplified.

A semiconductor structure is provided. The semiconductor structure includes a substrate, a plurality of vias, a signal transmitting portion, a heater and a sensing material. The plurality of vias penetrates the substrate, wherein each of the plurality of vias includes a conductive or semiconductive portion surrounded by an oxide layer. The signal transmitting portion is disposed in the substrate, wherein adjacent vias of the plurality of vias surrounds the signal transmitting portion. The heater is electrically connected to the signal transmitting portion, and the sensing material is disposed over the heater and electrically connected to the substrate. A method of manufacturing a semiconductor structure is also provided.

According to an embodiment, a method of forming a MEMS transducer includes forming a transducer frame in a layer of monocrystalline silicon, where forming the transducer frame includes forming a support portion adjacent a cavity and forming a first set of comb-fingers extending from the support portion. The method of forming a MEMS transducer further includes forming a spring support from an anchor to the support portion and forming a second set of comb-fingers in the layer of monocrystalline silicon. The second set of comb-fingers is interdigitated with the first set of comb-fingers.

A process for manufacturing a MEMS pressure sensor having a micromechanical structure envisages: providing a wafer having a substrate of semiconductor material and a top surface; forming a buried cavity entirely contained within the substrate and separated from the top surface by a membrane suspended above the buried cavity; forming a fluidic-communication access for fluidic communication of the membrane with an external environment, set at a pressure the value of which has to be determined; forming, suspended above the membrane, a plate region made of conductive material, separated from the membrane by an empty space; and forming electrical-contact elements for electrical connection of the membrane and of the plate region, which are designed to form the plates of a sensing capacitor, the value of capacitance of which is indicative of the value of pressure to be detected. A corresponding MEMS pressure sensor having the micromechanical structure is moreover described.

A microfabricated pressure transducer is formed in a multilayer substrate by etching a plurality of shallow and deep wells into the layers, and then joining these wells with voids formed by anisotropic etching. The voids define a flexible membrane over the substrate which deforms when a force is applied.

Aspects of the disclosure provide a capacitive pressure sensor. The capacitive pressure sensor can include a first substrate having a first surface and a second surface, a movable plate at a bottom of a first cavity recessed into the substrate from the first surface, and a second substrate bonded to the first substrate over the first surface. A second cavity is formed between the movable plate and the second surface. The second substrate includes a fixed plate disposed over the movable plate to form a capacitor. The second substrate further includes a third cavity between a surface of the fixed plate opposite to the movable plate and a surface of the second substrate opposite to the first substrate.

A MEMS capacitive pressure sensor is provided. The MEMS capacitive pressure sensor includes a substrate having a first region and a second region, and a first dielectric layer formed on the substrate. The capacitive pressure sensor also includes a second dielectric layer having a step surface profile formed on the first dielectric layer, and a first electrode layer having a step surface profile formed on the second dielectric layer. Further, the MEMS capacitive pressure sensor includes an insulation layer formed on the first electrode layer, and a second electrode layer having a step surface profile with a portion formed on the insulation layer in the peripheral region and the rest suspended over the first electrode layer in the device region. Further, the MEMS capacitive pressure sensor also includes a chamber having a step surface profile formed between the first electrode layer and the second electrode layer.

The present invention provides a diaphragm structure of a sounding apparatus comprising: a thin-film layer; a first circuit thin-film layer fixed on a first side of the thin-film layer by means of a first electrolytic bonding layer; a second circuit thin-film layer fixed on a second side of the thin-film layer by means of a second electrolytic bonding layer; multiple holes passing through the first circuit thin-film layer, the thin-film layer and the second circuit thin-film layer; and multiple conductive layers disposed on inner circumferential walls of the holes and in contact with the first circuit thin-film layer and the second circuit thin-film layer. In the diaphragm structure provided by the present invention, instead of using back adhesives, electrolytic bonding is used to fix the circuit thin-film layers on two sides of a thin-film layer, thereby greatly reducing the thickness of the diaphragm structure.