Micromechanical structure, in particular for an acceleration sensor or yaw rate sensor and a corresponding method for producing the same

• Main Authors: HENNING FRANK, FISCHER FRANK, FRANZ JOCHEN, ILLING MATTHIAS, HEIN PETER
• Format: Patent
• Language: English
• Published: 26.06.2003
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GYROSCOPIC INSTRUMENTS; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION,OR SHOCK; MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICALDEVICES; MICROSTRUCTURAL TECHNOLOGY; NAVIGATION; PERFORMING OPERATIONS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTUREOR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS; SEMICONDUCTOR DEVICES; SURVEYING; TESTING; TRANSPORTING

A micromechanical structure and a corresponding manufacturing method are described. The structure includes a substrate (10), which has an anchoring device (20), and a centrifugal mass (30), which is connected to the anchoring device (20) via a flexible spring device (40), so that the centrifugal mass (30) is elastically deflectable from its rest position. The centrifugal mass (30) has clearances and is designed to be deflectable by etching a sacrificial layer (50) underneath it. The sacrificial layer (50) is present in a first area located underneath the centrifugal mass (30) with a first etchable thickness (d1), and in a second area located underneath the centrifugal mass (30) with a second etchable thickness (d1+d2+d3), the second thickness being greater than the first thickness (d1). The centrifugal mass (30) is structured in the first area so that in etching only a maximum of two etching fronts may come together in order to limit the etching residue deposits.