Patent ID: 11905166
Assignee: ROBERT BOSCH GMBH
Field: Micro-structural and nano-technology (Chemistry)
Classification: CPC B  G  H | IPC B  H

Claim 0:
1. A production method comprising the following steps:
patterning a plurality of first trenches through a substrate surface of a monocrystalline substrate, the monocrystalline substrate being made of at least one semiconductor material, using an anisotropic etching method;
covering lateral walls of the plurality of first trenches with a passivation layer, while bottom areas of the plurality of first trenches are kept free or are freed of the passivation layer;
etching at least one first cavity, into which the plurality of first trenches open, into the monocrystalline substrate using an isotropic etching method, in which an etching medium of the isotropic etching method is conducted through the plurality of first trenches;
covering the plurality of first trenches by epitaxially growing a monocrystalline sealing layer on the substrate surface of the monocrystalline substrate, wherein the monocrystalline sealing layer is made of at least one identical semiconductor material as the monocrystalline substrate;
forming at least one semiconductor and/or metal layer and/or at least one insulating layer, as a layer stack on and/or over the monocrystalline sealing layer on a side of the monocrystalline sealing layer facing away from the at least one first cavity; and
forming at least one second cavity by removing at least one partial area of the at least one semiconductor and/or metal layer and/or of the at least one insulating layer on the side of the monocrystalline sealing layer oriented away from the at least one first cavity, with a remaining portion of the at least one semiconductor and/or metal layer and/or of the at least one insulating layer surrounding the at least one second cavity;
wherein:
the production method results in a micromechanical component for a sensor or microphone device, the micromechanical component including:
the monocrystalline substrate made of the at least one semiconductor material, with the plurality of first trenches (a) patterned through the substrate surface of the monocrystalline substrate and (b) opening into the at least one first cavity etched into the monocrystalline substrate;
the monocrystalline sealing layer that (a) is epitaxially grown on the substrate surface of the monocrystalline substrate, (b) is made of the at least one identical semiconductor material as the monocrystalline substrate, and (c) covers the plurality of first trenches; and
the remaining portion of the at least one semiconductor and/or metal layer and/or at least one insulating layer that (a) is formed as the layer stack on the side of the monocrystalline sealing layer facing away from the at least one first cavity and (b) surrounds at least one second cavity; and

in the resulting micromechanical component:
a partial area, adjoining the at least one second cavity, of an outermost silicon layer of the layer stack is developed as a deformable diaphragm; and
at least one connecting channel is formed, by which the at least one first cavity formed within the monocrystalline substrate is connected to the at least one second cavity embedded in the layer stack.