Litef Gmbh

Northrop Grumman Litef Gmbh

Martin Hafen

Eberhard Handrich

Bruno F Ryrko

Uwe Breng

Thomas Gessner

Peter Leinfelder

Maik Wiemer

Egbert Vetter

Guenter Spahlinger

Wolfram Geiger

Wolfram Ebert

In a method for producing a component, a first layer composite is first produced, comprising a structured layer and a trench filled with an insulating material. The structured layer is electrically conductive at least in a first region. The trench filled with an insulating material extends outwards from a first surface of the structured layer and is arranged in the first region of the structured layer. The first surface of the structured layer faces a first surface of the first layer composite. The method additionally has the step of producing a second layer composite, which has a first depression in a first surface of the second layer composite, and the step of connecting the first layer composite to the second layer composite. The first surface of the first layer composite adjoins the first surface of the second layer composite at least in some regions, said filled trench being arranged within the lateral position of the first depression. After the first layer composite has been connected to the second layer composite, the thickness of the first layer composite from a second surface of the first layer composite to the depth of the filled trench is reduced. The second surface of the first layer composite lies opposite the first surface of the first layer composite. The method further has the step of producing an active structure in the structured layer, said active structure comprising two second regions which are arranged in the first region of the structured layer and which are mechanically connected to each other in a rigid manner but are electrically insulated from each other by means of the filled trench.

Method for producing a component

A micromechanical rotation rate sensor based on the Coriolis principle includes two plate-like oscillators arranged one above the other in two planes for excitation to oscillate by means of an electrostatic drive. Three elements in each case form an oscillator structure. The oscillators are in each case suspended on opposite side edges by at least one web between an associated plate-like support and an associated drive plate element. The two supports and the two drive plate elements are, in each case, arranged one above the other in layers. A fixed plate element is located between the two drive plate elements so that, in each case, an identical narrow drive gap is defined between the drive plate elements. The drive gap is considerably smaller than the distance between the plate-like oscillators. An intermediate support that fills the intermediate space is inserted between the two plate-like supports and is completely electrically isolated from the surrounding frame to further reduce the respective capacitances to be recharged. The invention reduces the electrodynamic coupling between the drive and the read-out by a factor of about 100 in comparison with known micromechanical rotation rate sensors of like design.

Micromechanical rpm sensor

Micromechanical rotation speed sensor

A high precision micromechanical accelerometer comprises a layered structure of five (5) semiconductor wafers insulated from one another by thin oxide layers. The accelerometer is formed by first connecting a coverplate and a baseplate to associated insulating plates. Counter-electrodes, produced by anisotropic etching from the respective insulating plates, are fixed to the coverplate and the baseplate respectively. The counter-electrodes are contactable through the cover or baseplate via contact windows. A central wafer contains a unilaterally linked mass (pendulum) that is also produced by anisotropic etching and which serves as a movable central electrode of a differential capacitor. The layered structure is hermetically sealed by semiconductor fusion bonding. A stepped gradation from the top is formed at a wafer edge region for attaching contact pads to individual wafers to permit electrical contacting of individual wafers. The invention permits fabrication of a .mu.B device characterized by extremely small leakage capacitances and high temperature stability.

Micromechanical accelerometer with plate-like semiconductor wafers

A high precision micromechanical accelerometer comprises a layered structure of five (5) semiconductor wafers insulated from one another by thin semiconductor material oxide layers. The accelerometer is formed by first connecting a coverplate and a baseplate to associated insulating plates. Counter-electrodes, produced by anisotropic etching from the respective insulating plates, are fixed to the coverplate and the baseplate respectively. The counter-electrodes are contactable through the cover or baseplate via contact windows. A central wafer contains a unilaterally linked mass (pendulum) that is also produced by anisotropic etching and which serves as a movable central electrode of a differential capacitor. The layered structure is hermetically sealed by semiconductor fusion bonding. A stepped gradation from the top is formed at a wafer edge region for attaching contact pads to individual wafers to permit electrical contacting of individual wafers. The invention permits fabrication of a .mu.B device characterized by extremely small leakage capacitances and high temperature stability.

Micromechanical accelerometer and method of manufacture thereof

A micromechanical bending spring joint is formed of selectively etched wafer material. The joint includes a pair of leaf springs arranged alongside each other. Each spring is inclined at an oblique angle to the opposed surfaces of the wafer and such springs cross to define a point of intersection. The joint, selectively etched from a single wafer, is characterized by high precision of fulcrum position, bending spring constant and transverse axis rigidity.

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Rottweil, Germany

Martin Hafen