Siemens Aktiengesellschaft

Ulrich Naeher

Christofer Hierold

Emmerich Bertagnolli

Thomas Scheiter

Markus Biebl

Max Steger

An acceleration sensor has a mass part movably attached over a substrate with pairs of electrodes arranged relative to the mass part so that one electrode of each pair is under the mass part and the other electrode of that pair is arranged above the mass part. The electrodes are attached immovably to the substrate. Controllable electrical voltages can be applied such via an electronic drive circuit to the electrically conductively doped mass part and to these electrodes so that excursions of the mass part can be electrostatically compensated and, at the same time, the magnitude of inertial forces acting on the mass part, and thus the magnitude of accelerations, can be measured.

Acceleration sensor

A metal layer provided for micromechanical components such as sensors or actuators is surrounded with a protective layer of, for example, TiN for protection against the influence of an etchant that is employed for etching out a cavity in a sacrificial layer of, for example, silicon dioxide. The lower part and the upper part of this protective layer are produced as layers. A supplementary protective layer is conformally deposited into the etching holes produced for etching the cavity out and is anisotropically re-etched, so that the metal layer is also laterally covered by the protective layer.

Corrosion protection for micromechanical metal layers

In a method for the selective removal of SiO.sub.2 relative to semiconductor materials and/or metal, a specimen to be processed and containing SiO.sub.2 is placed into a chamber having at least one gas admission opening and one gas outlet opening. Using controllable valves at the gas admission opening, dosed quantities of hydrogen fluoride gas and water vapor are admitted into the chamber. These gasses proceed to the SiO.sub.2 in a specimen in a quantity adequate for etching. However, the quantities of these gasses are limited such that a condensation of the water vapor to form liquid water on the specimen during the etching event is avoided. An etching event is then implemented. Water vapor that arises as a reaction product during the etching is eliminated through the gas outlet opening before the occurrence of condensation and, simultaneously, an inert gas is admitted into the chamber through the gas admission opening. These steps are repeated as needed.

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Munich, Germany

Ulrich Naeher