A semiconductor oxide plate is formed on a recessed surface in a semiconductor matrix material layer. Comb structures are formed in the semiconductor matrix material layer. The comb structures include a pair of inner comb structures spaced apart by a first semiconductor portion. A second semiconductor portion that laterally surrounds the first semiconductor portion is removed selective to the comb structures using an isotropic etch process. The first semiconductor portion is protected from an etchant of the isotropic etch process by the semiconductor oxide plate, the pair of inner comb structures, and a patterned etch mask layer that covers the comb structures. A movable structure for a MEMS device is formed, which includes a combination of the first portion of the semiconductor matrix material layer and the pair of inner comb structures.

A process for fabricating a micromechanical structure made of silicon carbide including a cavity, from a stack including a first silicon-carbide layer and a silicon layer on the first silicon-carbide layer, the process including shaping the silicon layer so as to form a discrete silicon structure on the first silicon-carbide layer. The process further includes, after the shaping of the silicon layer, a carbonization to initiate the removal of the discrete silicon structure; depositing a second silicon-carbide layer; and an annealing step, the discrete silicon structure being entirely removed at the end of the annealing.

The MEMS sensor includes: a device substrate on which a device pattern is formed; a cap substrate disposed on top of the device substrate, the cap substrate comprising a first cavity area; a base substrate disposed on the bottom of the device substrate; a first-through silicon via formed through the base substrate, the first-through silicon via including a first core area for outputting an electrical signal provided from the device pattern to the outside or transmitting an electrical signal provided from the outside to the device pattern, a first insulating area surrounding an outer surface of the first core area, a first peripheral area surrounding an outer surface of the first insulating area, and a second insulating area surrounding an outer surface of the first peripheral area; and a circuit board, electrically connected to the first-through silicon via, for processing electrical signals for the device pattern.

Disclosed examples provide gas cells and a method of fabricating a gas cell, including forming a cavity in a first substrate, forming a first conductive material on a sidewall of the cavity, forming a glass layer on the first conductive material, forming a second conductive material on a bottom side of a second substrate, etching the second conductive material to form apertures through the second conductive material, forming conductive coupling structures on a top side of the second substrate, and bonding a portion of the bottom side of the second substrate to a portion of the first side of the first substrate to seal the cavity.

A semiconductor sensor device includes a substrate including a first main face and a second main face opposite the first main face, a semiconductor element including a sensing region, the semiconductor element on the first main face of the substrate and being electrically coupled to the substrate, a lid on the first main face of the substrate and forming a cavity, wherein the semiconductor element is in the cavity, and a vapor deposited dielectric coating covering the semiconductor element and the first main face of the substrate, the vapor deposited dielectric coating having an opening over the sensing region, wherein the second main face of the substrate is at least partially free of the vapor deposited dielectric layer.

Microdevices containing a chamber bound on one side by a nanoporous membrane are provided. The nanoporous membrane may contain hollow nanotubes that extend through the nanoporous membrane, from one surface to the other, and extend beyond the surface of the nanoporous membrane opposite the surface interfacing with the chamber. The nanotubes may provide a fluidic conduit between an environment external to the microdevice and the chamber, which is otherwise substantially fluid-tight. Also provided are methods of making a microdevice and methods of using the microdevices.

The invention presents a method for producing micro- or nano-structures of an anodized valve metal on a substrate. The method allows for accurate production of the structures, involves a small number of steps and is highly repeatable.

A method for forming a cavity of a sensor chip. The method comprises forming a first groove (a2) on a substrate (a1); bonding a covering layer (a4) onto the substrate (a1) to cover the first groove (a2), thereby forming a cavity; and etching the covering layer (a4) to decrease a thickness of the covering layer. The method can implement a thinner thickness of a film, thereby improving the sensitivity of a sensor.

In a first aspect, the invention relates to a method for producing a gas-filled reference chamber which is hermetically sealed. Thereby, the gas with which the reference chamber is filled is introduced via an opening in a separate coating chamber only after bonding of the wafers forming the reference chamber. The reference chamber preferably contains MEMS devices.

In another aspect, the invention relates to a photoacoustic gas sensor comprising such a reference chamber within which a MEMS sensor is present.

An illustrate method (and device) includes etching a cavity in a first substrate (e.g., a semiconductor wafer), forming a first metal layer on a first surface of the first substrate and in the cavity, and forming a second metal layer on a non-conductive structure (e.g., glass). The method also may include removing a portion of the second metal layer to form an iris to expose a portion of the non-conductive structure, forming a bond between the first metal layer and the second metal layer to thereby attach the non-conductive structure to the first substrate, sealing an interface between the non-conductive structure and the first substrate, and patterning an antenna on a surface of the non-conductive structure.