According to one embodiment, an electronic device includes a base region, an element portion located on the base region, the element portion including a movable portion, and a protective film overlying the element portion and forming a cavity on an inner side of the protective film. The protective film includes a first protective layer and a second protective layer located on the first protective layer. A hole extends in a direction parallel to a main surface of the base region, and the second protective layer covers the hole.

A corrosion method of a passivation layer (320) of a silicon wafer (300) includes: pouring hydrofluoric acid solution (100) into a container (200) with an open top; putting the silicon wafer (300) to the opening of the container (200) and one side of the silicon wafer (300) with the passivation layer (320) is opposite to the hydrofluoric acid solution (100); the hydrogen fluoride gas generated from the volatilization of the hydrofluoric acid solution (100) corrodes the passivation layer (320) of the silicon wafer (300), the corrosion time is larger or equal to (thickness of the passivation layer/corrosion rate). By means of the corrosion of the passivation layer of silicon wafer by the fluoride gas generated from the volatilization of the hydrofluoric acid solution, the fluoride gas can fully touch the passivation layer; therefore the passivation layer can be completely corroded, and the corrosion precision is high.

The present invention relates to a micromechanical device comprising a multi-layer micromechanical structure including only homogenous silicon material. The device layer comprises at least a rotor and at least two stators. At least some of the rotor and at least two stators are at least partially recessed to at least two different depths of recession from a first surface of the device layer and at least some of the rotor and at least two stators are at least partially recessed to at least two different depths of recession from a second surface of the device layer.

Representative methods for sealing MEMS devices include depositing insulating material over a substrate, forming conductive vias in a first set of layers of the insulating material, and forming metal structures in a second set of layers of the insulating material. The first and second sets of layers are interleaved in alternation. A dummy insulating layer is provided as an upper-most layer of the first set of layers. Portions of the first and second set of layers are etched to form void regions in the insulating material. A conductive pad is formed on and in a top surface of the insulating material. The void regions are sealed with an encapsulating structure. At least a portion of the encapsulating structure is laterally adjacent the dummy insulating layer, and above a top surface of the conductive pad. An etch is performed to remove at least a portion of the dummy insulating layer.

A symmetrical MEMS accelerometer. The accelerometer includes a top half and a bottom half bonded together to form the frame and the mass located within the frame. The frame and the mass are connected through resilient beams. A plurality of hollowed parts and the first connecting parts are formed on the top and bottom side of the mass, respectively. The second connecting parts are formed on the top and bottom side of the frame, respectively. The resilient beams connect the first connecting part with the second connecting part. Several groups of comb structures are formed on top of the hollowed parts. Each comb structure includes a plurality of moveable teeth and fixed teeth. The moveable teeth extend from the first connecting part and the fixed teeth extend from the second connecting part. Capacitance is formed between the movable teeth and the fixed teeth. Since the accelerometer is symmetrical with a large mass, it has a large capacitance with a low damping force.

A sensor device is described. The sensor device includes at least one substrate; an edge region that is disposed on the substrate and laterally delimits an inner region above the substrate; a diaphragm that is anchored on the edge structure and at least partly spans the inner region, the diaphragm encompassing in the inner region at least one region which is movable by way of a pressure and which encloses a cavity between the diaphragm and the substrate; and a first intermediate carrier that extends in the movable region below the diaphragm and is connected to the diaphragm, and in particular has at least one trench.

A method of manufacturing a semiconductor substrate according to an embodiment includes a first step of forming a groove having a bottom surface and a side surface on which scallops are formed by performing a process including isotropic etching on a main surface of a substrate, a second step of performing at least one of a hydrophilic treatment on the side surface of the groove and a degassing treatment on the groove, and a third step of removing the scallops formed on the side surface of the groove and planarizing the side surface by performing anisotropic wet etching in a state where the bottom surface of the recess is present.

A method for manufacturing a MEMS unit for a micromechanical pressure sensor. The method includes the steps: providing a MEMS wafer including a silicon substrate and a first cavity formed therein, under a sensor membrane; applying a layered protective element on the MEMS water; and exposing a sensor core from the back side, a second cavity being formed between the sensor core and the surface of the silicon substrate, and the second cavity being formed with the aid of an etching process which is carried out with the aid of etching parameters changed in a defined manner; and removing the layered protective element.

A method for DRIE matched release and/or the mitigation of photo resist pooling, comprising: depositing a first mask layer over a first surface of a silicon substrate; exposing a first portion and second portion of the first mask layer to a first etch process, wherein the exposing forms a first exposed layer; depositing a second mask layer over the first mask layer; exposing a third portion of the second mask layer to a second etch process, wherein the exposing forms a second exposed mask layer, and wherein the third portion overlaps the first portion of the first mask layer; developing the second mask layer and etching the third portion of the second mask layer and developing the first portion of the first mask layer; etching the first portion of the first mask layer to a first depth; and developing the first mask layer to reveal exposed portions of the first mask layer and etching the second portion of the silicon substrate to a second depth.

Various embodiments may provide a method of fabricating a meta-lens structure. The method may include forming a first dielectric layer in contact with a silicon wafer. The method may also include forming a second dielectric layer in contact with the first dielectric layer. A refractive index of the second dielectric layer may be different from a refractive index of the first dielectric layer. The method may further include, in patterning the second dielectric layer. The method may additionally include removing at least a portion of the silicon wafer to expose the first dielectric layer.