Method for producing a micromechanical layer structure with high aspect ratio and micromechanical layer structure

A method for producing a micromechanical layer structure with a high aspect ratio of a layer thickness to a distance of a first structural element from an adjacent second structural element in a main direction of extent of the layer structure, the method comprising the following steps:

• (A) providing a substrate with an etching stop layer arranged on the substrate and a micromechanical functional layer arranged above the etching stop layer;
• (B) forming at least one recess in the functional layer by etching as far as the etching stop layer;
• (C) depositing an intermediate layer sequence including at least a first insulation layer, an intermediate layer, and a second insulation layer;
• (D) filling the recess by depositing a filling layer;
• (E) planarizing a surface of the filling layer;
• (F) etching the intermediate layer by etching access points through the intermediate layer sequence by a first etching process;
• and
• (G) exposing the first structural element and the second structural element by etching the first insulation layer and the second insulation layer by a second etching process.