Abstract:
This disclosure provides systems, methods, and apparatus for fabricating electromechanical systems devices. In one aspect, a method of sealing an electromechanical systems device includes etching a sacrificial layer. The sacrificial layer is formed between a surface of a substrate and a shell layer and is etched through etch holes in the shell layer formed over the electromechanical systems device. The etch holes in the shell layer have a diameter greater than about one micron. The shell layer is then treated. A seal layer is deposited on the treated shell layer. The seal layer hermetically seals the electromechanical systems device.
Abstract:
A method of manufacturing a microphone using epitaxially grown silicon. A monolithic wafer structure is provided. A wafer surface of the structure includes poly-crystalline silicon in a first horizontal region and mono-crystalline silicon in a second horizontal region surrounding a perimeter of the first horizontal region. A hybrid silicon layer is epitaxially deposited on the wafer surface. Portions of the hybrid silicon layer that contact the poly-crystalline silicon use the poly-crystalline silicon as a seed material and portions that contact the mono-crystalline silicon use the mono-crystalline silicon as a seed material. As such, the hybrid silicon layer includes both mono-crystalline silicon and poly-crystalline silicon in the same layer of the same wafer structure. A CMOS/membrane layer is then deposited on top of the hybrid silicon layer.
Abstract:
A method for manufacturing a MEMS sensor and its thin film and cantilever beam includes steps of etching a top surface of a single-crystal silicon wafer in combination of a deposition process, an outer epitaxial growth process, a wet etching process and a back etching process in order to form a pressure-sensitive single-crystal silicon film, a cantilever beam, a mass block, a front chamber, a back chamber and trenches connecting the front and the back chambers. The single-crystal silicon film is prevented from etching so that the thickness thereof can be well controlled. The method of the present invention can be used to replace the traditional method which forms the back chamber and the pressure-sensitive single-crystal silicon film from the bottom surface of the silicon wafer.
Abstract:
The invention provides a method of fabricating and electromechanical device having an active element on at least one substrate, the method having the steps of: a) making a heterogeneous substrate having a first portion, an interface layer, and a second portion, the first portion including one or more buried zones sandwiched between first and second regions formed in a first monocrystalline material, the first region extending to the surface of the first portion, and the second region extending to the interface layer, at least one said buried zone being made at least in part out of a second monocrystalline material so as to make it selectively attackable relative to the first and second regions; b) making openings from the surface of the first portion and through the first region, which openings open out to at least one said buried zone; and c) etching at least part of at least one buried zone to form at least one cavity so as to define at least one active element that is at least a portion of the second region between said cavity and said interface layer; wherein the first and second portions of the substrate are constituted respectively from first and second substrates that are assembled together by bonding, at least one of them including at least one said interface layer over at least a fraction of its surface.
Abstract:
A method for making a pressure sensor by providing a wafer including a base silicon layer, a buried sacrificial layer, and a top silicon layer. The top silicon layer is arranged over the buried sacrificial layer and the buried sacrificial layer is arranged over the base silicon layer. Etching vents through the top silicon layer to the buried sacrificial layer and removing a portion of the buried sacrificial layer. Depositing silicon to seal the vents and arranging a strain gauge or a capacitance contact on the wafer. A method for making a pressure sensor including providing a bulk wafer and depositing a sacrificial layer on the bulk wafer. Depositing silicon on the sacrificial layer and the bulk wafer to form an encapsulation layer. Etching vents through the encapsulation layer to the sacrificial layer and removing the sacrificial layer. Closing the vents with a silicon deposition and arranging a strain gauge or a capacitance contact on the encapsulation layer. A pressure sensing device including a substrate, an encapsulation layer with vents, and voids between the substrate and the encapsulation layer. A portion of the encapsulation layer above the voids forms a membrane and deposited silicon plugs fill the vents. A strain gauge or a top capacitive contact arranged on the membrane.
Abstract:
A process for the production of accelerometers using the silicon on insulator method. The process comprises the following stages: a) producing a conductive monocrystalline silicon film on a silicon substrate and separated from the latter by an insulating layer; b) etching the silicon film and the insulating layer up to the substrate in order to fix the shape of the mobile elements and the measuring devices; c) producing electric contacts for the measuring devices; d) partial elimination of the insulating layer in order to free the mobile elements, the remainder of the insulating layer rendering integral the substrate and the moving elements.
Abstract:
A free-standing microstructure may be formed from an engineered substrate including a first silicon layer, a second silicon layer, and an intermediate layer. The second silicon layer may include a monocrystalline silicon film. The intermediate layer may be between the first silicon layer and the second silicon layer. The intermediate layer may include a silicon- or germanium-based material having a different lattice constant than the first silicon layer or the second silicon layer. The intermediate layer of the free-standing microstructure may further include one or more voids wherein at least a portion of the silicon- or germanium-based material is absent between the first silicon layer and the second silicon layer.
Abstract:
A method for manufacturing a multi-layer MEMS component includes: providing a multi-layer substrate that has a monocrystalline carrier layer, a monocrystalline functional layer having a front side and a back side, and a bonding layer located between the back side and the carrier layer; growing a first polycrystalline layer over the front side of the monocrystalline functional layer; removing the monocrystalline carrier layer; and growing a second polycrystalline layer over the back side of the monocrystalline functional layer.
Abstract:
A method is provided for manufacturing a micromechanical component including a substrate and including a cap, which is connected to the substrate and, together with the substrate, encloses a first cavity, a first pressure prevailing and a first gas mixture having a first chemical composition being enclosed in the first cavity. A first crystalline layer or a first amorphous layer or a first nanocrystalline layer or a first polycrystalline layer is deposited on or grown on a surface of the substrate or of the cap. A recess is introduced into the substrate or into the cap for accommodating the first crystalline layer or the first amorphous layer or the first nanocrystalline layer or the first polycrystalline layer.
Abstract:
A micromechanical structure comprises a substrate and a functional structure arranged at the substrate. The functional structure comprises a functional region which is deflectable with respect to the substrate responsive to a force acting on the functional region. The functional structure comprises a carbon layer arrangement, wherein a basis material of the carbon layer arrangement is a carbon material.