Abstract:
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.
Abstract:
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.
Abstract:
Methods for filtering particles from a fluid are disclosed, wherein an array of microstructures defining respective microchannels having respective minimum widths are used to separate the fluid from particles to be filtered. The fluid flows through the minimum widths into the microchannels defined between adjacent microstructures. The particles to be filtered are prevented from passing through the respective minimum widths, resulting in filtration of those particles from the fluid. The microchannels can be provided with gradient characteristics to separate particles in the fluid according to size.
Abstract:
Methods for filtering particles from a fluid are disclosed, wherein an array of microstructures defining respective microchannels having respective minimum widths are used to separate the fluid from particles to be filtered. The fluid flows through the minimum widths into the microchannels defined between adjacent microstructures. The particles to be filtered are prevented from passing through the respective minimum widths, resulting in filtration of those particles from the fluid. The microchannels can be provided with gradient characteristics to separate particles in the fluid according to size.
Abstract:
The invention relates to a method for the fabrication of a membrane oriented in a (111) plane of a (100) silicon wafer. To this end the method comprises the following steps: applying a mask to both sides of the wafer, wherein portions of the sides are covered by the mask; and the at least partial removal by etching away silicon material from the portions of the two sides of the wafer that are not covered. This method is characterised in that the etching step substantially removes the silicon material forming recesses in the two surfaces of the wafer, such that the walls of the recesses are formed by (111) planes, and in that not covered portions at both sides of the wafer are aligned in relation to one another such that a (111) plane is formed and the distance d between said two planes is less than the thickness of the silicon wafer, so as to form a membrane in the (111) plane having a thickness d. Such a membrane has many application possibilities in the field of MEMS, for example by dividing the membrane into individual cantilevers.
Abstract:
The invention is a method for fabricating molecular filters which can separate objects approximately 1-5 nm in range, where the filtration size is controlled by using thin films of materials and technologies to form a filtration channel or pore in a middle thin film layer in a multilayered structure. Lithography is used to define two offset arrays of blind holes into the opposing sides of a multi-layer membrane. The blind holes extend across a thin central filtration layer. A selective etch is used to attack the filtration layer to form a communicating channel between the two holes. The only connection between one side of the filter and the other is through the channel in the filter layer, whose thickness, d, determines the largest size object which can traverse the filter.
Abstract:
A hole plate and a MEMS microphone arrangement are disclosed. In an embodiment a hole plate includes a substrate with a first main surface, a second main surface, and a lateral surface and a perforation structure formed within the substrate, the perforation structure having a plurality of through-holes through the substrate, wherein the through-holes and the lateral surface are a result of a simultaneous dry etching step.
Abstract:
A method for structuring a substrate and a structured substrate are disclosed. In an embodiment a method includes providing a substrate with a first main surface and a second main surface, wherein the substrate is fixed to a carrier arrangement at the second main surface, performing a photolithography step at the first main surface of the substrate to mark a plurality of sites at the first main surface, the plurality of sites corresponding to future perforation structures and future kerf regions for a plurality of future individual semiconductor chips to be obtained from the substrate, and plasma etching the substrate at the plurality of sites until the carrier arrangement is reached, thus creating the perforation structures within the plurality of individual semiconductor chips and simultaneously separating the individual semiconductor chips along the kerf regions.
Abstract:
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.
Abstract:
Using phase separation technique perforated as well as non-perforated polymeric structures can be made with high aspect ratios (>5). By varying the phase separation process the properties (e.g. porous, non-porous, dense, open skin) of the moulded product can be tuned. Applications are described in the field of micro fluidics (e.g. micro arrays, electrophoretic boards), optics, polymeric solar cells, ball grid arrays, and tissue engineering.