Micromechanical component and corresponding method for its manufacture

• US 7,834,409 B2
• Filed: 01/25/2006
• Issued: 11/16/2010
• Est. Priority Date: 02/03/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schelling, Christoph, Reichenbach, Frank, Laermer, Franz, Kronmueller, Silvia, Fuchs, Tino, Leinenbach, Christina
• Primary Examiner(s): Lee; Calvin
• Application Number:
  US11/883,671
• Publication Number:
  US 20090026561A1
• Time in Patent Office: 1,756 Days
• Field of Search: 257414-420, 257/E21.613, 257/E29.324, 438 50- 53, 381174-175
• US Class Current: 257/419
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81C 1/00182 Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182

Abstract

A micromechanical component having a conductive substrate, an elastically deflectable diaphragm including at least one conductive layer, which is provided over a front side of the substrate, the conductive layer being electrically insulated from the substrate, a hollow space, which is provided between the substrate and the diaphragm and is filled with a medium, and a plurality of perforation openings, which run under the diaphragm through the substrate, the perforation openings providing access to the hollow space from a back surface of the substrate, so that a volume of the medium located in the hollow space may change when the diaphragm is deflected. Also described is a corresponding manufacturing method.

Claims

1. A micromechanical component comprising:

a conductive substrate;

an elastically deflectable diaphragm having at least one conductive layer, which is provided over a front side of the substrate, the conductive layer being electrically insulated from the substrate;

a hollow space filled with a medium, which is provided between the substrate and the diaphragm; and

a plurality of perforation openings running under the diaphragm through the substrate;

wherein the perforation openings provide access to the hollow space from a back surface of the substrate, so that a volume of the medium located in the hollow space may change when the diaphragm is deflected.

2. The micromechanical component of claim 1, wherein the diaphragm is arched over the front side of the substrate.

3. The micromechanical component of claim 1, wherein the diaphragm is planarly over the front side of the substrate.

4. The micromechanical component of claim 1, wherein the perforation openings lead into a cavity, which is in the back surface of the substrate under the diaphragm.

5. The micromechanical component of claim 1, wherein the diaphragm includes a single conductive layer.

6. The micromechanical component of claim 1, wherein the diaphragm includes an upper conductive layer and a lower, first dielectric layer.

7. The micromechanical component of claim 1, wherein the substrate has a wafer substrate, a second dielectric layer situated on it, and a layer of silicon material situated on the second dielectric layer, and wherein the perforation openings run through the second dielectric layer, the second dielectric layer electrically insulating the wafer substrate and the silicon-material layer on it from each other.

8. The micromechanical component of claim 1, wherein a third dielectric layer is on the front side of the substrate between the substrate and the diaphragm.

9. The micromechanical component of claim 8, wherein the third dielectric layer constitutes a diffusion barrier for Ge and is made of silicon oxide, for example.

10. The micromechanical component of claim 1, wherein the medium is a gas.