Micromechanical sensor and method for its production

摘要

A micromechanical sensor and a method for its production are proposed, which sensor consists of a silicon substrate (1) having a silicon epitaxial layer (5) applied onto the silicon substrate. Using an etching process, a part of the epitaxial layer (5) is uncovered as at least one micromechanical deflection (displacement) part (12 to 15). According to the invention, the uncovered deflection part (12 to 15) consists of polycrystalline silicon which has grown in polycrystalline fashion during the epitaxy process above a silicon oxide layer (2) removed by etching. In the support region, or at the connection with the silicon substrate (regions 6, 7) there is transition of the uncovered deflection part into monocrystalline silicon. A large working capacity of the sensor is possible as a result of high layer thicknesses. The sensor structure is distinguished by advantages in regard to mechanical stability, ease of processing and configurational possibilities and can, in particular, be integrated in a bipolar process or hybrid process (bipolar CMOS, bipolar CMOS/DMOS).