Micromechanical capacitive transducer and method for producing the same
AssigneeInfineon Technologies AG
InventorsStefan Barzen, Alfons Dehe, Marc Füldner
Life of this patent
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Abstract
A micromechanical capacitive converter and a method for manufacturing a micromechanical converter comprise a movable membrane and an electrically conductive face element in a carrier layer. The electrically conductive face element is arranged opposite the membrane above a cavity. The electrically conductive face element and the carrier layer are perforated by perforation openings. The opening width of the perforation openings corresponds approximately to the thickness of the carrier layer.
Claims14
A method for manufacturing a micromechanical capacitive converter, comprising the following steps:
- a) providing a carrier layer on a substrate, the carrier layer having a first surface that faces away from the substrate,
- b) providing an electrically conductive face layer on at least a portion of the first surface of carrier layer;
- c) providing a mask layer over the first surface and the electrically conductive face layer, the mask layer having first openings;
- d) etching a perforation opening below each of the first openings, the perforation extending to the substrate;
- e) forming a sacrificial layer over the mask layer, the electrically conductive face layer, and walls of the perforation opening;
- f) providing a membrane over the sacrificial layer;
- and
- g) removing at least a portion of the substrate below the perforations.
A method for manufacturing a micromechanical capacitive converter, comprising the following steps:
- a) providing a substrate,
- b) providing a carrier layer on the substrate,
- c) providing a mask layer over a surface of the carrier layer that faces away from the substrate,
- d) structuring the mask layer such that it comprises first openings having a smallest expansion that corresponds at maximum to double a later distance between a membrane and the surface,
- e) generating perforation openings in an area below the first openings in the mask layer that extends through the carrier layer, wherein a smallest opening width of the perforation openings corresponds to more than double the later distance between the membrane and the surface,
- f) generating a substantially planar sacrificial layer over the structured mask layer with a thickness, which is dependent on a later desired distance between the carrier layer and the membrane,
- g) providing the membrane on the substantially planar sacrificial layer,
- h) exposing at least one part of a side of the carrier layer that abuts the substrate,
- i) removing the sacrificial layer and the mask layer to open the perforation openings and to generate a cavity between the membrane and the carrier layer in which the perforation openings are formed.
Dependencies are inferred from the claim text.