Abstract:
A harsh environment transducer including a substrate having a first surface and a second surface, wherein the second surface is in communication with the environment. The transducer includes a device layer sensor means located on the substrate for measuring a parameter associated with the environment. The sensor means including a single crystal semiconductor material having a thickness of less than about 0.5 microns. The transducer further includes an output contact located on the substrate and in electrical communication with the sensor means. The transducer includes a package having an internal package space and a port for communication with the environment. The package receives the substrate in the internal package space such that the first surface of the substrate is substantially isolated from the environment and the second surface of the substrate is substantially exposed to the environment through the port. The transducer further includes a connecting component coupled to the package and a wire electrically connecting the connecting component and the output contact such that an output of the sensor means can be communicated. An external surface of the wire is substantially platinum, and an external surface of at least one of the output contact and the connecting component is substantially platinum.
Abstract:
A pressure sensor including a movable component that is configured to move when the pressure sensor is exposed to differential pressure thereacross, and a pressure sensing component located on the movable component. The pressure sensing component includes an electrically conductive electron gas which changes its electrical resistance thereacross upon movement of the movable component. The pressure sensor is configured such that leads can be coupled to the pressure sensing component and the pressure sensing component can output a signal via the leads, the signal being related to a pressure to which the pressure sensor is exposed.
Abstract:
Disclosed are capacitive pressure probes or sensors for high temperature applications. The capacitive pressure sensors of the present invention include, inter alia, a sapphire diaphragm which is disposed within an interior sensing chamber of the probe housing and has a first electrode formed on a central portion thereof. The central portion of the diaphragm and the first electrode are adapted and configured to deflect in response to pressure variations encountered within an interior sensing chamber and by the pressure sensor. A sapphire substrate which has a second electrode formed thereon is fused to the sapphire diaphragm about its periphery to form a sapphire stack and to define a reference chamber therebetween. Prior to fusing the sapphire diaphragm to the sapphire substrate, all contact surfaces are chemically treated and prepared using plasma activation, so as to create a bonding layer and to reduce the temperature required for the fusion.
Abstract:
A method for forming a transducer including the step of providing a semiconductor-on-insulator wafer including first and second semiconductor layers separated by an electrically insulating layer, wherein the first layer is formed or provided by hydrogen ion delamination of a starting wafer. The method further includes doping the first layer to form a piezoresistive film and etching the piezoresistive film to form at least one piezoresistor. The method also includes depositing or growing a metallization layer on the semiconductor-on-insulator wafer, the metallization layer including an electrical connection portion that is located on or is electrically coupled to the piezoresistor. The method includes removing at least part of the second semiconductor layer to form a diaphragm, with the at least part of the piezoresistor being located on the diaphragm, and joining the wafer to a package by melting a high temperature braze material or a glass frit material.
Abstract:
A harsh environment transducer including a substrate having a first surface and a second surface, wherein the second surface is in communication with the environment. The transducer includes a device layer sensor means located on the substrate for measuring a parameter associated with the environment. The sensor means including a single crystal semiconductor material having a thickness of less than about 0.5 microns. The transducer further includes an output contact located on the substrate and in electrical communication with the sensor means. The transducer includes a package having an internal package space and a port for communication with the environment. The package receives the substrate in the internal package space such that the first surface of the substrate is substantially isolated from the environment and the second surface of the substrate is substantially exposed to the environment through the port. The transducer further includes a connecting component coupled to the package and a wire electrically connecting the connecting component and the output contact such that an output of the sensor means can be communicated. An external surface of the wire is substantially platinum, and an external surface of at least one of the output contact and the connecting component is substantially platinum.
Abstract:
A process for fabricating a pendulous accelerometer, including the steps of: providing a first substrate having a top planar surface, etching a portion of the first substrate to a first predetermined depth from the top planar surface to form a plurality of first protrusions, providing a second substrate, etching a portion of the second substrate to a second predetermined depth to form a plurality of second protrusions, bonding planar surfaces of the first protrusions to planar surfaces of the second protrusions, and etching a portion of the first substrate from an opposite side of the first substrate to a third predetermined depth equal to or greater than the difference between the total thickness of the first substrate and the first predetermined depth to form a freely rotatable sensing plate that includes a substantially hollow proof mass.
Abstract:
A micro mirror array including an upper wafer portion having a plurality of movable reflective surfaces located thereon, the upper wafer portion defining a coverage area in top view. The array further includes a lower wafer portion located generally below and coupled to the upper wafer portion. The lower wafer portion includes at least one connection site located thereon, the at least one connection site being electrically or operatively coupled to at least one component which can control the movement of at least one of the reflective surfaces. The at least one connection site is not generally located within the coverage area of the upper wafer portion.
Abstract:
A micro mirror structure including a plurality of individually movable mirrors. Each mirror has a generally concave shape from a top perspective at a temperature of about 20 degrees Celsius and has a generally convex shape from a top perspective at a temperature of about 85 degrees Celsius. In one embodiment, the radius of curvature may be greater than about 500 mm at a temperature of about 20 degrees Celsius and may be less than about −600 mm at a temperature of about 85 degrees Celsius at a thickness of about 10 microns. In another embodiment, the invention is a micro mirror structure including a plurality of individually movable mirrors arranged in an array. Each mirror includes a substrate, a diffusion barrier layer located above the substrate, and a reflective layer located above the diffusion barrier layer. The diffusion barrier layer generally limits the diffusion of the top reflective layer through the diffusion barrier layer.
Abstract:
The present invention relates to a micromachined hemispherical resonance gyroscope, which comprises a resonant layer, said resonant layer comprising a hemispherical shell which has a concave inner surface and an outer surface opposite to the inner surface, and top point of the hemispherical shell being its anchor point; several silicon hemispherical electrodes being arranged around said hemispherical shell, the silicon hemispherical electrodes including driving electrodes, equilibrium electrodes, signal detection electrodes and shielded electrodes, the shielded electrodes separating the driving electrodes and the equilibrium electrodes from the signal detection electrodes, the hemispherical shell and the several silicon spherical electrodes which surround the hemispherical shell constituting several capacitors; the resonant layer being made of polysilicon or silica or silicon oxide or diamond. The hemispherical resonance micromechanical gyroscope utilizes a processing method on the basis of silicon micromachining, which leads to small size and low production cost, as well as batch production capacity, meanwhile its sensitivity is independent of amplitude and its driving voltage could be very low, as a result its output noise could be significantly reduced, and its accuracy is better than the gyroscope products in the prior art.
Abstract:
A system for determining in-plane acceleration of an object. The system includes an in-plane accelerometer with a substrate rigidly attached to an object, and a proof mass—formed from a single piece of material—movably positioned a predetermined distance above the substrate. The proof mass includes a plurality of electrode protrusions extending downward from the proof mass to form a gap of varying height between the proof mass and the substrate. The proof mass is configured to move in a direction parallel to the upper surfaces of each of the plurality of substrate electrodes when the object is accelerating, which results in a change in the area of the gap, and a change in capacitance between the substrate and the proof mass. The in-plane accelerometer can be fabricated using the same techniques used to fabricate an out-of-plane accelerometer and is suitable for high-shock applications.