Abstract:
An integrated semiconductor chemical microreactor for real-time polymerase chain reaction (PCR) monitoring, has a monolithic body of semiconductor material; a number of buried channels formed in the monolithic body; an inlet trench and an outlet trench for each buried channel; and a monitoring trench for each buried channel, extending between the inlet and outlet trenches thereof from the top surface of the monolithic body to the respective buried channel. Real-time PCR monitoring is carried out by channeling light beams into the buried channels, possibly through one of the inlet or outlet trenches, whereby the light beams impinge on the fluid therein and collecting the emergent light coming out from the monitoring trench.
Abstract:
Method for manufacturing electromagnetic radiation reflecting devices, said method comprising the steps of: a) providing a silicon substrate defined by at least one first free surface, b) forming on said first surface a layer of protective material provided with an opening which exposes a region of the first free surface, and c)etching the region of the free surface by means of an anisotropic agent to remove at least one portion of the substrate and define a second free surface of the substrate inclined in relation to said first surface. Furthermore, said first free surface is parallel to the crystalline planes {110} of silicon substrate and said step (c) comprises a progressing step of the anisotropic agent such that the second free surface resulting from the etching step is parallel to the planes {100} of said substrate.
Abstract:
A method of forming buried cavities in a wafer of monocrystalline semiconductor material with at least one cavity formed in a substrate of monocrystalline semiconductor material by timed TMAH etching silicon; covering the cavity with a material inhibiting epitaxial growth; and growing a monocrystalline epitaxial layer above the substrate and the cavities. Thereby, the cavity is completely surrounded by monocrystalline material. Starting from this wafer, it is possible to form a thin membrane. The original wafer must have a plurality of elongate cavities or channels, parallel and adjacent to one another. Trenches are then excavated in the epitaxial layer as far as the channels, and the dividers between the channels are removed by timed TMAH etching.
Abstract:
A bi-dimensional position sensor that can be advantageously used in the turn system controlled from the steering wheel of a vehicle. The sensor includes a permanent magnet fixed to a control lever so as to move in a plane along first and second directions and to rotate about a third direction orthogonal to the preceding ones. The permanent magnet is movable with respect to an integrated device including a first group of sensor elements arranged spaced along the first direction, a second group of sensor elements arranged spaced along the second direction and a third group of sensor elements detecting the angular position of the permanent magnet. Electronics integrated with the sensor elements generate a code associated with each position which the permanent magnet may assume and generate a control signal corresponding to the desired function.
Abstract:
The method inlcudes the steps of forming a sacrificial buried region of insulating material on a substrate of monocrystalline semiconductor material, epitaxially growing a first semiconductor material layer on the substrate, the first semiconductor material layer including a polycrystalline region over the sacrificial buried region and a monocrystalline region elsewhere, the substrate and the semiconductor material layer surrounding the sacrificial buried region on all sides, and removing the sacrificial buried region. The portion of the polycrystalline region surrounded by the trench thus forms a suspended structure separated and isolated thermally from the rest of the semiconductor material layer. Using microelectronics processes, electronic components are formed in the monocrystalline region, and dedicated regions are formed at the suspended structure, so that the electronic components are integrated in the same chip with static, kinematic or dynamic microstructures.
Abstract:
The pressure sensor is integrated in an SOI (Silicon-on-Insulator) substrate using the insulating layer as a sacrificial layer, which is partly removed by chemical etching to form the diaphragm. To fabricate the sensor, after forming the piezoresistive elements and the electronic components integrated in the same chip, trenches are formed in the upper wafer of the substrate and extending from the surface to the layer of insulating material; the layer of insulating material is chemically etched through the trenches to form an opening beneath the diaphragm; and a dielectric layer is deposited to outwardly close the trenches and the opening. Thus, the process is greatly simplified, and numerous packaging problems eliminated.
Abstract:
For detecting the position of a magnetic element having a field component zeroing in at least one point in space, typically in a plane, a plurality of elementary Hall-effect sensors are integrated side by side and aligned in a direction perpendicular to the zeroing field component and to the current flowing through the elementary sensors. The elementary sensor generating a zero output voltage therefore indicates the zero position of the field component and consequently the position of the magnetic element with respect to the position sensor, so that The outputs of the elementary sensors provide a quantized numeric code indicating the position of the magnetic element.
Abstract:
A power transistor comprising a plurality of elementary transistors coupled in parallel and an identical number of current generators, each of which has a terminal coupled individually to the base of an elementary transistor is described. High power levels may be achieved with a transistor of this type without forward secondary breakdown taking place.
Abstract:
A method of forming buried cavities in a wafer of monocrystalline semiconductor material with at least one cavity formed in a substrate of monocrystalline semiconductor material by timed TMAH etching silicon; covering the cavity with a material inhibiting epitaxial growth; and growing a monocrystalline epitaxial layer above the substrate and the cavities. Thereby, the cavity is completely surrounded by monocrystalline material. Starting from this wafer, it is possible to form a thin membrane. The original wafer must have a plurality of elongate cavities or channels, parallel and adjacent to one another. Trenches are then excavated in the epitaxial layer as far as the channels, and the dividers between the channels are removed by timed TMAH etching.
Abstract:
The microreactor has a body of semiconductor material; a large area buried channel extending in the body and having walls; a coating layer of insulating material coating the walls of the channel; a diaphragm extending on top of the body and upwardly closing the channel. The diaphragm is formed by a semiconductor layer completely encircling mask portions of insulating material.