Sensor element with trenched cavity

US7354786B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Hubert Benzel · Neckartenzlingen, DE
• Stefan Finkbeiner · Gomaringen, DE
• Matthias Illing · Tübingen, DE
• Frank Schaefer · Lörrach, DE
• Simon Armbruster · Wannweil, DE
• Gerhard Lammel · Lörrach, DE
• Christoph Schelling · Stuttgart, DE
• Joerg Brasas · Neckartenzlingen, DE

Key dates

• Filing date: Sep 8, 2005
• Grant date: Apr 8, 2008
• Expiry date: Jul 7, 2026

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B81B2203/0315
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A micromechanical sensor element and a method for the production of a micromechanical sensor element that is suitable, for example in a micromechanical component, for detecting a physical quantity. Provision is made for the sensor element to include a substrate, an access hole and a buried cavity, at least one of the access holes and the cavity being produced in the substrate by a trench etching and/or, in particular, an isotropic etching process. The trench etching process includes different trenching (trench etching) steps which may be divided into a first phase and a second phase. Thus, in the first phase, at least one first trenching step is carried out in which, in a predeterminable first time period, material is etched out of the substrate and a depression is produced. In that trenching step, a typical concavity is produced in the wall of the depression. A passivation process is then carried out in that first phase, in which the concavity produced in the walls of the depression by the first trenching step is covered with a passivation material. The first trenching step and the first passivation process may be carried out repeatedly in alternating succession within the first p…