Method for manufacturing micromechanical diaphragm sensors

Patent metadata

Field	Value
Publication number	US-11519803-B2
Application number	US-201816626097-A
Country	US
Kind code	B2
Filing date	Jun 14, 2018
Priority date	Jun 26, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A method for manufacturing a micromechanical sensor, in particular a pressure difference sensor, including creating a functional layer on a substrate; creating at least one rear side trench area proceeding from a rear side of a substrate, for exposing the functional layer for a sensor diaphragm; creating at least one front side trench area for forming at least one supporting structure, in particular an energy storage structure, preferably in the form of a spring structure, in the substrate as a mounting for the sensor diaphragm; and at least partially filling at least a front side trench area with a gel.

First claim

What is claimed is:

1. A method for manufacturing a micromechanical sensor, comprising the following steps:
creating a functional layer on a substrate;
creating at least one rear side trench area, proceeding from a rear side of a substrate to expose the functional layer for a sensor diaphragm;
creating at least one front side trench area to form at least one supporting structure, the supporting structure being an energy storage structure, in the substrate as a mounting for the sensor diaphragm; and
at least partially filling at least one of the at least one front side trench area with a gel,
wherein the energy storage structure is a spring structure, and wherein the spring structure is laterally exposed in the at least one front side trench area.

2. The method as recited in claim 1 , wherein the micromechanical sensor is a pressure difference sensor.

3. The method as recited in claim 1 , wherein multiple rear side trench holes for creating the at least one rear side trench area are generated.

4. The method as recited in claim 3 , wherein at least one cavity for forming a first connecting trench area between rear side trench holes is generated.

5. The method as recited in claim 4 , wherein multiple front side trenches for creating the at least one front side trench area are generated.

6. The method as recited in claim 1 , wherein:
a stop layer is created between the substrate and the functional layer,
the at least one rear side trench area is created up to the stop layer, and
the stop layer is subsequently removed in an area of the sensor diaphragm.

7. The method as recited in claim 5 , wherein at least one cavity for forming at least one second connecting trench area between multiple ones of the multiple front side trench areas is generated.

8. The method as recited in claim 7 , wherein a diameter of the rear side trench holes is selected to be smaller than a diameter of a cross section of at least one cavity of the first connecting area and/or the second connecting trench area.

9. The method as recited in claim 4 , wherein multiple first connecting trench areas are created, which are fluidically connected to one another via at least one trench channel, at least one of the first connecting trench areas being created directly beneath the functional layer for exposing it.

10. The method as recited in claim 1 , wherein the at least one front side trench area is created chronologically before the at least one rear side trench area.

11. The method as recited in claim 7 , wherein one or multiple access channels to the first connecting trench area and/or second connecting trench area is masked during the exposure of the functional layer.

Assignees

• Bosch Gmbh Robert

Inventors

• Dannenberg Arne
• Oppl Stephan

Classifications

• G01L9/0048

  Details about the mounting of the diaphragm to its support or about the diaphragm edges, e.g. notches, round shapes for stress relief · CPC title

• B81B7/0048 Primary

  between the MEMS die and the substrate · CPC title

• B81B2203/0163

  Spring holders · CPC title

• B81B2201/0264

  Pressure sensors · CPC title

• B81B2203/0338

  Channels · CPC title