Micromechanical capacitive pressure transducer and production method

US8492855B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerhard Lammel · Lörrach, DE
• Hubert Benzel · Neckartenzlingen, DE
• Simon Armbruster · Wannweil, DE
• Christoph Schelling · Stuttgart, DE
• Joerg Brasas · Neckartenzlingen, DE

Key dates

• Filing date: Nov 22, 2006
• Grant date: Jul 23, 2013
• Expiry date: Apr 26, 2030

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L9/0073
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The present invention describes a method for producing a micromechanical capacitive pressure transducer and a micromechanical component produced by this method. First, a first electrode is produced in a doped semiconductor substrate.In a further method step, a diaphragm with a second electrode is produced at the surface of the semiconductor substrate. Furthermore, it is provided to apply a first layer, which preferably is made of dielectric material, on the diaphragm and the semiconductor substrate. With the aid of this first layer, the diaphragm and the semiconductor substrate of the finished micromechanical capacitive pressure transducer are mechanically connected to one another directly or indirectly. Furthermore, a buried cavity is produced in the semiconductor substrate between the first and second electrode. In a following etching step, the diaphragm is finally dissolved out of the semiconductor substrate through openings in the first layer, the mechanical connection from the diaphragm to the semiconductor substrate being accomplished with the aid of the first layer. Due to this mechanical connection the diaphragm or the second electrode is able to be movably suspended above …