The present invention relates to a micromechanical component for a capacitive pressure sensor device, and a capacitive pressure sensor device. Moreover, the present invention relates to a manufacturing method for a micromechanical component for a capacitive pressure sensor device, and a method for manufacturing a capacitive pressure sensor device.
German Patent Application No. DE 10 2009 000 403 A1 describes a capacitive pressure sensor that includes a substrate, an intermediate layer applied to one side of the substrate, a frame structure that frames a partial surface of the intermediate layer, and a diaphragm that is stretched with the aid of the frame structure. A cantilevered area of the diaphragm spans the framed partial surface. A reinforcement structure is formed at an inner side of the cantilevered area, oriented toward the framed partial surface; a counter electrode is fastened to the reinforcement structure in such a way that a distance between the counter electrode and a measuring electrode situated on the framed partial surface varies during a pressure-induced deformation of the cantilevered area. The reinforcement structure is formed at the inner surface of the cantilevered area, centrally with respect to the frame structure.
The present invention provides a micromechanical component for a capacitive pressure sensor device, a capacitive pressure sensor device, a manufacturing method for a micromechanical component for a capacitive pressure sensor device, and a method for manufacturing a capacitive pressure sensor device.
In accordance with an example embodiment of the present invention, micromechanical components for a capacitive pressure sensor device or capacitive pressure sensor devices are provided, in which a cantilevered area of a diaphragm that is stretched with the aid of a frame structure has an improved deformability due to the second distance of the reinforcement structure from the frame structure in the second spatial direction being greater than the first distance of the reinforcement structure from the frame structure in the first spatial direction. The present invention takes into account that, while a deformation of a middle area of the cantilevered area is generally undesirable and therefore is to be prevented with the aid of the reinforcement structure, a good deformability of an edge area of the cantilevered area that surrounds the middle area is advantageous. Via the different distances of the reinforcement structure from the frame structure according to the present invention, the undesirable deformation of the middle area may be prevented and a good deformability of the edge area may be ensured. As discussed in greater detail below, the present invention thus contributes to providing capacitive pressure sensor devices having a high pressure sensitivity.
In one advantageous specific embodiment of the micromechanical component in accordance with the present invention, an edge area of the cantilevered area is definable which extends within the first distance from the frame structure in the first spatial direction, and extends within the second distance from the frame structure in the second spatial direction. The edge area of the cantilevered area is preferably kept away from the reinforcement structure. Thus, there is little or no impairment of a deformability of the edge area of the cantilevered area by the reinforcement structure.
The reinforcement structure preferably includes strip-shaped, cubically shaped, and/or circular sector-shaped reinforcement pieces. As explained in greater detail below, such a multipart design of the reinforcement structure advantageously contributes to prevention of a deformation of the middle area of the cantilevered area, and to improvement of a deformability of the edge area of the cantilevered area. However, it is pointed out here that the reinforcement structure may also have a one-part design.
In a further advantageous specific embodiment of the micromechanical component in accordance with the present invention, an inner volume that is enclosed by the frame structure and the diaphragm is sealed off air-tight with a reference pressure present therein, the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area being deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies, and the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure being electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable. The specific embodiment of the micromechanical component described here is advantageously suited for use as part of a capacitive pressure sensor device.
In accordance with an example embodiment of the present invention, a capacitive pressure sensor device is advantageous that includes the micromechanical component described in the preceding paragraph, and evaluation electronics that are designed to establish and output a measured value with regard to the physical pressure prevailing in each case on the outer side of the cantilevered area, at least taking the tapped measuring voltage into account. The capacitive pressure sensor device is well suited for establishing the measured value with a relatively high measuring accuracy and a comparatively low error rate.
In addition, carrying out a corresponding manufacturing method for a micromechanical component for a capacitive pressure sensor device may yield the advantages described above. It is pointed out that the manufacturing method according to the specific embodiments of micromechanical components explained above may be refined.
Furthermore, carrying out a corresponding method for manufacturing a capacitive pressure sensor device may provide the advantages described above. Moreover, the method for manufacturing a capacitive pressure sensor device may be refined.
Further features, advantages, and example embodiments of the present invention are explained below with reference to the figures.
The micromechanical component illustrated in cross section in
The micromechanical component also includes a frame structure 12, which on a substrate side 10a of substrate 10 or at least one intermediate layer 14 present on substrate 10 is designed in such a way that frame structure 12 frames a partial surface 16 of substrate 10 and/or of the at least one intermediate layer 14. For example, frame structure 12 may be formed as an intermediate layer 14, on an insulating layer 14 that covers substrate side 10a. Intermediate layer 14 may also include multiple sublayers, for example a silicon oxide layer and a (silicon-rich) silicon nitride layer.
With the aid of frame structure 12, a diaphragm/diaphragm layer 18 is stretched in such a way that a cantilevered area 20 of diaphragm 18 spans framed partial surface 16. Diaphragm 18 may include at least one semiconductor material, for example silicon. However, it is pointed out that diaphragm 18 may include at least one further material instead of or in addition to silicon.
Cantilevered area 20 includes a one-part or multipart reinforcement structure 22 that is formed at an outer side 20a of cantilevered area 20 directed away from framed partial surface 16 or at an inner side 20b of cantilevered area 20 oriented toward framed partial surface 16. Reinforcement structure 22 may be understood in particular to mean a “local thickening” of cantilevered area 20 in a direction oriented perpendicularly with respect to outer side 20a and/or inner side 20b, compared to a minimal layer thickness d of cantilevered area 20 perpendicular to outer side 20a and/or inner side 20b. In the example in
It is also apparent in
Different distances a1 and a2 of reinforcement structure 22 from frame structure 12 in the various spatial directions x and y allow good deformability of cantilevered area 20. In particular, reinforcement structure 22 is thus adapted to different extensions I1 and I2 of cantilevered area 20 in the various spatial directions x and y. Despite the deviation of the shape of cantilevered area 20 from a circular shape, maintaining different distances a1 and a2 of reinforcement structure 22 from frame structure 12 allows a deformability of cantilevered area 20 that is (almost) like that for a circular cantilevered area. As explained in greater detail below, cantilevered area 20 of diaphragm 18 may thus be advantageously used for carrying out measurements, such as pressure measurements in particular.
For cantilevered area 20, an edge area 20-1 of cantilevered area 20 is definable which extends within first distance a1 from frame structure 12 in first spatial direction x, and within second distance a2 from frame structure 12 in second spatial direction y. As is apparent in
The formation of reinforcement structure 22 solely at middle area 20-2 of cantilevered area 20 effectuates the desired reinforcement of middle area 20-2, while at the same time a good deformability/bendability of edge area 20-1 is maintained. This is advantageous, since when cantilevered area 20 is used to carry out a measurement, in particular a pressure measurement, a good deformability of edge area 20-1 of cantilevered area 20 as a response to a change in at least one variable to be measured is often desired, while at the same time, the reinforcement of middle area 20-2 of cantilevered area 20 facilitates carrying out the particular measurement. This advantage is reliably ensured by maintaining different distances a1 and a2 of reinforcement structure 22 from frame structure 12 in the various spatial directions x and y.
As is apparent in
Reinforcement structure 22 may be understood to mean a one-part reinforcement structure 22. Likewise, the reinforcement structure may also have a multipart design, i.e., formed from individual reinforcement pieces 22a through 22c. Reinforcement structure 22 may include, for example, strip-shaped, cubically shaped, and/or circular sector-shaped reinforcement pieces 22a through 22c. However, reinforcement pieces 22a through 22c of reinforcement structure 22 may also have other shapes.
In the example in
The specific embodiment in
The micromechanical component illustrated with the aid of
Reinforcement structure 22 in
In reinforcement structure 22 shown in
Also for reinforcement structure 22 in
In reinforcement structure 22 shown in
In contrast, for the reinforcement structure in
Reinforcement structure 22 shown in
With regard to further features of the micromechanical components schematically illustrated in
The specific embodiment described here is shown in cross section in
With regard to further features of the micromechanical component schematically illustrated in
In the specific embodiment in
In contrast, all strip-shaped partial electrodes 24a of counter electrode 24 in
In the specific embodiment in
With regard to further features of the micromechanical components schematically illustrated in
All micromechanical components described above may in each case be advantageously used in a capacitive sensor device, for example a capacitive pressure sensor device. Such a capacitive pressure sensor device preferably includes, in addition to the particular micromechanical component, evaluation electronics that are designed to establish and output a measured value with regard to physical pressure p prevailing in each case on outer side 20a of cantilevered area 20, at least taking the tapped measuring voltage into account.
The manufacturing method described below may be designed, for example, for manufacturing one of the micromechanical components described above.
However, practicability of the manufacturing method is not limited to the manufacture of these micromechanical components.
A frame structure is formed on and/or at a substrate in a method step S1 in such a way that the frame structure frames a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate. As method step S2, a diaphragm is stretched with the aid of the frame structure in such a way that a cantilevered area of the diaphragm spans the framed partial surface, a first spatial direction oriented in parallel to the framed partial surface being definable in which the cantilevered area has a minimal extension, and a second spatial direction oriented in parallel to the framed partial surface and perpendicularly with respect to the first spatial direction being definable in which the cantilevered area has a greater extension compared to the minimal extension.
As method step S3, a one-part or multipart reinforcement structure is also formed at an outer side of the cantilevered area directed away from the framed partial surface, or at an inner side of the cantilevered area oriented toward the framed partial surface. The reinforcement structure is formed at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance. Carrying out the manufacturing method described here thus also yields the advantages already explained above.
In particular, an edge area of the cantilevered area may be definable which extends within the first distance from the frame structure in the first spatial direction, and within the second distance from the frame structure in the second spatial direction, the edge area of the cantilevered area being kept away from the reinforcement structure. The reinforcement structure may likewise be formed from strip-shaped, cubically shaped, and/or circular sector-shaped reinforcement pieces.
As optional method step S4, an inner volume that is enclosed by the frame structure and the diaphragm may additionally be sealed off air-tight with a reference pressure present therein in such a way that the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area is deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies. In addition, the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure may be designed to be electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable.
The manufacturing method described here may also be part of a method for manufacturing a capacitive pressure sensor device. In this case, an optional method step S5 is also carried out, in which evaluation electronics are designed in such a way that the evaluation electronics establish and output a measured value with regard to the physical pressure that prevails in each case on the outer side of the cantilevered area, at least taking the tapped measuring voltage into account.
Method steps S1 through S5 explained above may be carried out in (virtually) any order and/or at the same time, at least in part.
Number | Date | Country | Kind |
---|---|---|---|
102018222719.5 | Dec 2018 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2019/085943 | 12/18/2019 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2020/127477 | 6/25/2020 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
6122973 | Nomura | Sep 2000 | A |
20130068022 | Jeung | Mar 2013 | A1 |
20140352445 | Kuisma | Dec 2014 | A1 |
Number | Date | Country |
---|---|---|
101087999 | Dec 2007 | CN |
105293418 | Feb 2016 | CN |
105940287 | Sep 2016 | CN |
102005029802 | Jan 2007 | DE |
102007029414 | Jan 2009 | DE |
102009000403 | Jul 2010 | DE |
102011083070 | Mar 2013 | DE |
102013209385 | Nov 2014 | DE |
102013213065 | Jan 2015 | DE |
2010016094 | Feb 2010 | WO |
2018041498 | Mar 2018 | WO |
Entry |
---|
International Search Report for PCT/EP2019/085943 dated Mar. 26, 2020. |
Number | Date | Country | |
---|---|---|---|
20220003621 A1 | Jan 2022 | US |