阅读说明：本技术 用于电容式传感器或开关设备的微机械构件 (Micromechanical component for a capacitive sensor or switching device ) 是由 J·赖因穆特 于 2020-04-10 设计创作，主要内容包括：本发明涉及一种用于电容式传感器或开关设备的微机械构件,具有带着衬底表面(10a)的衬底(10)、跨越衬底表面的膜片(12)、构造在膜片上和/或中的第一测量电极(16)和固定的对应电极(18),该第一测量电极能够借助于膜片的至少一个悬置区域(14)的翘曲而置于移位或变形运动中,其中,第一测量电极位于对应电极的第一侧上,其中,第二测量电极(20)借助于至少一个支架元件(22)悬挂在第一测量电极和/或膜片上,使得第二测量电极保持在对应电极的第二侧上并且在膜片的所述至少一个悬置区域翘曲时与置于其移位或变形运动中的第一测量电极一起运动。本发明同样涉及一种用于微机械构件的制造方法。(The invention relates to a micromechanical component for a capacitive sensor or switching device, comprising a substrate (10) having a substrate surface (10a), a membrane (12) extending across the substrate surface, a first measuring electrode (16) formed on and/or in the membrane, and a fixed counter electrode (18), the first measuring electrode can be set in a displacement or deformation movement by means of the warpage of at least one suspension region (14) of the diaphragm, wherein the first measuring electrode is located on a first side of the counter electrode, wherein the second measuring electrode (20) is suspended on the first measuring electrode and/or the membrane by means of at least one carrier element (22), such that the second measuring electrode remains on the second side of the counter electrode and moves together with the first measuring electrode placed in its displacement or deformation movement when the at least one suspended area of the membrane is warped. The invention also relates to a method for producing a micromechanical component.)

1. Micromechanical component for a capacitive sensor or switching device, having:

a substrate (10) with a substrate surface (10 a);

a membrane (12) spanning the substrate surface (10a), having at least one suspension region (14) which can be respectively warped by means of a force (F) applied to the respective suspension region (14);

a first measuring electrode (16) which is formed on and/or in the membrane (12) and which can be set into a displacement or deformation movement relative to the substrate surface (10a) by means of a warpage of the at least one suspension region (14) of the membrane (12); and

a counter electrode (18) fixed with respect to the substrate surface (10a), arranged between the membrane (12) and the substrate surface (10a) such that the first measuring electrode (16) is located on a first side of the counter electrode (18);

characterized in that the micromechanical component is provided with a second measuring electrode (20) which is suspended on the first measuring electrode (16) and/or the membrane (12) by means of at least one carrier element (22) in such a way that the second measuring electrode (20) is held by means of the at least one carrier element (22) on a second side of the counter electrode (18) pointing away from the first side direction of the counter electrode (18) and moves together with the first measuring electrode (16) placed in its displacement or deformation movement when the at least one suspension region of the membrane (12) is warped.

2. Micromechanical component according to claim 1, wherein the at least one carrier element (22) is formed at least partially from at least one electrically insulating material in each case, such that the second measuring electrode (20) is electrically insulated with respect to the first measuring electrode (16).

3. Micromechanical component according to claim 1 or 2, wherein the second measuring electrode (20) is formed by a first semiconductor and/or metal layer (26) which is deposited directly on the substrate surface (10a) and/or directly on at least one cover layer (28) which at least partially covers the substrate surface (10a), wherein the counter electrode (18) is formed by a second semiconductor and/or metal layer (30) which is deposited on a side of the first semiconductor and/or metal layer (26) which is directed away from the substrate (10), and wherein the first measuring electrode (16) is formed by a third semiconductor and/or metal layer (34) which is deposited on a side of the second semiconductor and/or metal layer (30) which is directed away from the substrate (10) On one side of the substrate (10) direction.

4. Micromechanical component according to any of the preceding claims, wherein the membrane (12) is hermetically sealed with a reference pressure (p) present therein₀) Such that the at least one suspension region (14) of the diaphragm (12) can be assisted by the presence of a pressure (p) outside the housing (36) which is not equal to the reference pressure (p)₀) Is warped.

5. Capacitive sensor or switching device with a micromechanical component according to any one of claims 1 to 4.

6. Capacitive sensor device according to claim 5, wherein the capacitive sensor device comprises an evaluation electronics which is designed to determine and output a measured value for a force (F) applied to the at least one suspension region (14) of the diaphragm (12) or a physical quantity (p) corresponding to the force (F) or an environmental condition, taking into account at least a currently acquired measured quantity in terms of a difference between a first capacitance acting between the first measuring electrode (16) and the counter electrode (18) and a second capacitance acting between the second measuring electrode (20) and the counter electrode (18).

7. Capacitive sensor device according to claim 6, wherein the micromechanical component of the capacitive sensor device, which is designed as a capacitive pressure sensor device, has the features of claim 4, and wherein the evaluation electronics are designed for determining and outputting a measured value with respect to the physical pressure (p) present outside the housing (36), at least taking into account the currently acquired measured variable.

8. Method for producing a micromechanical component for a capacitive sensor or switching device, comprising the following steps:

distracting a membrane (12) having at least one suspension area (14) such that the membrane (12) spans a substrate surface (10a) of a substrate (10) and the at least one suspension area (14) of the membrane (12) is capable of buckling (S1) by means of a force (F) applied to the respective suspension area (14);

configuring a first measuring electrode (16) on and/or in the membrane (12) such that the first measuring electrode (16) is placed in a displacement or deformation motion with respect to the substrate surface (10a) when the at least one suspension region (14) of the membrane (12) is warped (S2); and is

Arranging a counter electrode (18) fixed with respect to the substrate surface (10a) between the membrane (12) and the substrate surface (10a) such that the first measuring electrode (16) is located on a first side of the counter electrode (18) (S3);

the method is characterized by comprising the following steps:

suspending a second measuring electrode (20) on the first measuring electrode (16) and/or the membrane (12) by means of at least one carrier element (22) such that the second measuring electrode (20) is held by means of the at least one carrier element (22) on a second side of the counter electrode (18) pointing away from the first side direction of the counter electrode (18) and moves (S4) together with the first measuring electrode (16) placed in its displacing or deforming movement when the at least one suspension area (14) of the membrane (12) is warped.

9. Manufacturing method according to claim 8, wherein the second measuring electrode (20) is formed by a first semiconductor and/or metal layer (26) which is deposited directly on the substrate surface (10a) and/or directly on at least one cover layer (28) which at least partially covers the substrate surface (10a), wherein the counter electrode (18) is formed by a second semiconductor and/or metal layer (30) which is deposited on a side of the first semiconductor and/or metal layer (26) which is directed away from the substrate (10), and wherein the first measuring electrode (16) is formed by a third semiconductor and/or metal layer (34) which is deposited on a side of the second semiconductor and/or metal layer (30) which is directed away from the substrate (10 10) On one side of the direction.

10. Method for manufacturing a capacitive sensor device, the method having the steps of:

manufacturing a micromechanical component according to the manufacturing method of claim 8 or 9; and is

The evaluation electronics of the capacitive sensor device are designed to determine and output a measured value for the force applied to the at least one suspension region of the diaphragm (12) or a physical variable (p) corresponding to the force or an environmental condition, taking into account at least the currently acquired measured variable relating to the difference between the first capacitance acting between the first measuring electrode (16) and the counter electrode (18) and the second capacitance acting between the second measuring electrode (20) and the counter electrode (18).

Technical Field

The present invention relates to a micromechanical component for a capacitive sensor or switching device and to a capacitive sensor or switching device. The invention also relates to a method for producing a micromechanical component for a capacitive sensor or switching device and to a method for producing a capacitive sensor device.

Background

DE 102009000403 a1 describes a micromechanical capacitive pressure sensor and a method for producing such a pressure sensor. The pressure sensor comprises a substrate, an electrode fixed on a substrate surface of the substrate, and a further electrode displaceably suspended by means of a diaphragm spanning the fixed electrode. Furthermore, the suspended area of the membrane should be able to be warped by means of a force applied to the suspended area, whereby the capacitance acting between the electrodes should be variable.

Disclosure of Invention

The invention relates to a micromechanical component for a capacitive sensor or switching device, comprising: a substrate with a substrate surface; a membrane spanning the substrate surface, the membrane having at least one suspension area that is capable of being warped by means of a force applied to the respective suspension area; a first measuring electrode which is formed on and/or in the membrane and which can be set into a displacement or deformation movement relative to the substrate surface by means of a warpage of the at least one suspension region of the membrane; and a counter electrode fixed with respect to the substrate surface, the counter electrode being arranged between the membrane and the substrate surface such that the first measuring electrode is located on a first side of the counter electrode; the micromechanical component is provided with a second measuring electrode, which is suspended on the first measuring electrode and/or the membrane by means of at least one carrier element, in such a way that the second measuring electrode is held by means of the at least one carrier element on a second side of the counter electrode, which is directed away from the first side of the counter electrode, and moves together with the first measuring electrode, which is set in its displacement or deformation movement, when the at least one suspension region of the membrane is warped. The invention also relates to a corresponding capacitive sensor or switching device, to a corresponding method for producing a micromechanical component for a capacitive sensor or switching device, and to a corresponding method for producing a capacitive sensor device.

The invention provides micromechanical components, in which the outer side of the membrane facing away from the substrate of the respective micromechanical component can be used as a "sensitive membrane surface", or capacitive sensors or switching devices equipped with such micromechanical components. In contrast to the filling of the recesses structured in the substrate by a gel, the "sensitive diaphragm-side" gelation of the micromechanical component or of the capacitive sensor or switching device equipped with the micromechanical component according to the present invention can therefore be carried out simply and with only relatively little effort. The invention thus makes it possible to realize micromechanical components or capacitive sensors or switching devices equipped with micromechanical components that have an increased service life due to their good protection of the "sensitive diaphragm side".

At the same time, the micromechanical component according to the invention is suitable for so-called "fully differential analysis processes" in which the force acting on the "sensitive diaphragm surface" or a physical variable or an environmental condition corresponding to said force can be obtained by means of a difference (diffrenzbildung) between a first capacitance acting between the first measuring electrode and the (fixed) counter electrode and a second capacitance acting between the second measuring electrode and the counter electrode. The signal obtained from this difference is larger by a factor of 2 than the comparison signal obtained from only the first capacitance change of the first capacitance (or only the second capacitance change of the second capacitance). Thus, the "fully differential evaluation design" can be used for the miniaturization of micromechanical components while maintaining their sensitivity and/or their measurement accuracy. Accordingly, a "fully differential analysis process design" may also be used to increase the sensitivity and/or measurement accuracy of the micromechanical component while maintaining its structural dimensions. For the analytical processing of the micromechanical component according to the invention, therefore, simple, low-space and cost-effective analytical processing electronics can generally be used.

A further advantage of the "fully differential analysis process design" and the differencing is the often automatic "filtering" of the temperature offset. The temperature changes occurring at the micromechanical component according to the invention generally cause the same temperature-dependent capacitance change of the first and second capacitance, so that the temperature offset is automatically "filtered out" when the difference is determined. In the case of "fully differential evaluation design", error signals occurring in the conventional manner, which are due to the bending of the substrate of the respective micromechanical component, are likewise often automatically "filtered out" by means of the difference. Furthermore, the signals obtained by means of the difference in the case of a "fully differential evaluation design" are generally "linear" with respect to the force acting on the "sensitive diaphragm side" or the physical variable or the environmental condition corresponding to the force.

In an advantageous embodiment of the micromechanical component, the at least one carrier element is formed at least in sections from at least one electrically insulating material, so that the second measuring electrode is electrically insulated from the first measuring electrode. Different values for a first capacitance acting between the first measuring electrode and the counter electrode and a second capacitance acting between the second measuring electrode and the counter electrode can thereby be achieved.

In a further preferred embodiment of the micromechanical component, the second measuring electrode is formed by a first semiconductor and/or metal layer which is deposited directly on the substrate surface and/or directly on a cover layer which at least partially covers the substrate surface, while the counter electrode is formed by a second semiconductor and/or metal layer which is deposited on the side of the first semiconductor and/or metal layer which points away from the substrate direction, and the first measuring electrode is formed by a third semiconductor and/or metal layer which is deposited on the side of the second semiconductor and/or metal layer which points away from the substrate direction. In this case, the production of the micromechanical component can be carried out particularly simply and with relatively little production effort.

The diaphragm can, for example, hermetically seal a housing having a reference pressure present therein, so that the at least one suspension region of the diaphragm can be warped by means of a physical pressure present outside the housing which is not equal to the reference pressure. Thus, the embodiments described herein of the micromechanical component may be advantageously used in a capacitive pressure sensor.

The advantages described above are also ensured in a capacitive sensor or switching device having such a micromechanical component. Preferably, the capacitive sensor device comprises an evaluation electronics which is designed to determine and output a measured value for the force applied to the at least one suspension region of the diaphragm or a physical variable or an environmental condition corresponding to the force, taking into account at least the currently acquired measured variable with respect to the difference between the first capacitance acting between the first measuring electrode and the counter electrode and the second capacitance acting between the second measuring electrode and the counter electrode. Thus, the analysis processing electronics can ensure the advantages of the "fully differential analysis processing design" already explained above.

The micromechanical component of the capacitive sensor device, which is designed as a capacitive pressure sensor device, may have the features of the micromechanical component described in the second paragraph above, for example, wherein the evaluation electronics are designed to determine and output a measured value relating to the physical pressure prevailing outside the housing, at least taking into account the currently acquired measured variable.

The advantages described above are also brought about by the implementation of a corresponding manufacturing method for a micromechanical component of a capacitive sensor or switching device. These advantages are likewise achieved by the implementation of a corresponding method for producing a capacitive sensor device. It is explicitly noted that the method listed here can be further extended according to the embodiments of the micromechanical component and the capacitive sensor device explained above.

Drawings

Further features and advantages of the invention are explained below with reference to the drawings. The figures show:

fig. 1a and 1b are schematic illustrations of a first embodiment of a micromechanical component;

fig. 2a and 2b are schematic diagrams of a second embodiment of a micromechanical component;

fig. 3a to 3c are schematic diagrams of a third embodiment of a micromechanical component;

fig. 4a and 4b are schematic diagrams of a fourth embodiment of a micromechanical component;

fig. 5 is a flow chart for explaining a first embodiment of a method for manufacturing a micromechanical component for a capacitive sensor or switching device; and

fig. 6 is a flow chart for explaining a second embodiment of a method for producing a micromechanical component for a capacitive sensor or switching device.

Detailed Description

Fig. 1a and 1b show a schematic representation of a first embodiment of a micromechanical component.

The micromechanical component schematically depicted in cross section in fig. 1a and 1b has a substrate 10 with a substrate surface 10 a. Additionally, the micromechanical component has a membrane 12 spanning the substrate surface 10a, which membrane has at least one suspension region 14, wherein the at least one suspension region 14 of the membrane 12 is/are warped by means of a force F applied to the respective suspension region 14 (see fig. 1a and 1 b). The first measuring electrode 16, which is formed on and/or in the diaphragm 12, can be/is placed in a displacement or deformation movement with respect to the substrate surface 10a by means of the warpage of the at least one suspension region 14 of the diaphragm 12. The first measuring electrode 16 can be understood in particular as at least one part of the at least one suspension region 14 of the diaphragm 12. Alternatively, the first measuring electrode 16 can also be designed as a reinforcement/thickening of the at least one suspension region 14 of the diaphragm 12. Likewise, the first measuring electrode 16 can also be "suspended" on the diaphragm inner side 14a of the at least one suspension region 14. The configuration of the first measuring electrode 16, schematically depicted in fig. 1a, as a (single) suspension region 14 of the diaphragm 12 is therefore only exemplarily elucidated.

The micromechanical component also has a counter electrode 18 which is fixed with respect to the substrate surface 10a and which is arranged between the membrane 12 and the substrate surface 10a in such a way that the first measuring electrode 16 is located on a first side of the counter electrode 18. The fixed arrangement of the counter electrode 18 is understood to mean that the counter electrode 18 can only be displaced with respect to the substrate surface 10a due to damage of the micromechanical component. Therefore, the position of the counter electrode 18 with respect to the substrate surface 10a or the shape of the counter electrode 18 is not hampered by the warping of the at least one suspension region 14 of the membrane 12.

The micromechanical component of fig. 1a and 1b (in addition to the first measuring electrode 16) also comprises a second measuring electrode 20, which is suspended on the first measuring electrode 16 and/or the membrane 12 by means of at least one carrier element 22 in such a way that the second measuring electrode 20 is held by means of the at least one carrier element 22 on a second side of the counter electrode 18 pointing away from the first side of the counter electrode 18. Furthermore, the second measurement electrode 20 moves together with the first measurement electrode 16 placed in its displacement or deformation motion when the at least one suspension region 14 of the diaphragm 12 is warped.

The micromechanical component equipped with the electrodes 16, 18 and 20 is therefore advantageously suitable for the "fully differential analysis process design" already described above. The force F triggering the buckling of the at least one suspension region 14 of the diaphragm 12 or a physical quantity or an environmental condition corresponding to the force F can be detected/determined by means of a difference between a first capacitance acting between the first measuring electrode 16 and the (fixed) counter electrode 18 and a second capacitance acting between the second measuring electrode 20 and the counter electrode 18. The advantages already described above of the "fully differential evaluation process design" are therefore also ensured when using the micromechanical component described here.

As can be seen from a comparison with reference to fig. 1a and 1b, the diaphragm outer face 14b of the at least one suspension region 14 of the diaphragm 12 pointing away from the substrate 10 can serve as a "sensitive diaphragm face" of the micromechanical component, on which a force F is applied that triggers a warpage of the at least one suspension region 14 of the diaphragm 12. The "sensitive membrane side" of the micromechanical component can thus be subjected to a gelling treatment in a simple, reliable manner and with relatively low effort, as a result of which the service life of the micromechanical component can be increased.

The electrode surfaces of the electrodes 16, 18 and 20 are preferably (approximately) equally large. The at least one carrier element 22, by means of which the second measuring electrode 20 is suspended on the first measuring electrode 16 and/or the membrane 12, preferably extends in a direction oriented perpendicularly to the substrate surface 10 a. The at least one carrier element 22 can, for example, extend through a corresponding through-opening formed in the counter electrode 18, as is shown in fig. 1a and 1 b. The first measuring electrode 16 and the second measuring electrode 20 can thus be arranged "on top of one another", with the (fixed) counter electrode 18 being arranged between the measuring electrodes 16 and 20. Thus, the membrane 12 spanning all of the electrodes 16, 18 and 20 can be constructed in a relatively small area. This simplifies the miniaturization of the micromechanical component. The miniaturization by means of micromechanical components also makes it possible to save material when manufacturing the micromechanical components, so that the micromechanical components can be manufactured relatively cost-effectively.

The arrangement of the measuring electrodes 16 and 20 "on top of one another" (with the counter electrode 18 arranged between the measuring electrodes 16 and 20) also has the following advantages: the (approximately) same capacitance change of the first capacitance and the second capacitance occurs when the substrate 10 is bent. Thus, the capacitance changes of the first and second capacitances attributable to the bending of the substrate 10 are automatically "filtered out" when differencing. Therefore, the micromechanical component equipped with electrodes 16, 18 and 20 arranged "on top of each other" is also very insensitive to stress.

Preferably, the at least one support element 22 is configured in the "middle region" of the respective suspension region 14 of the membrane 12. In this case, the configuration of the at least one carrier element 22 also leads to a reinforcement of the "middle region" of the at least one suspension region 14 of the membrane, which leads to an increase in the capacitance change of the first and second capacitances when the at least one suspension region 14 is warped.

Preferably, the at least one carrier element 22 is formed at least in part from at least one electrically insulating material, in each case, so that the second measuring electrode 20 is electrically insulated from the first measuring electrode 16. But does not require the complete construction of the at least one carrier element 22 from its at least one electrically insulating material. It is sufficient that only one electrically insulating buffer region 24 is present as part of the respective carrier element 22, as is shown in fig. 1a and 1 b. The at least one carrier element 22 can therefore also be produced in each case partially from at least one electrically conductive material, such as in particular from an electrically conductive material deposited for producing the counter electrode 18. The at least one electrically insulating material of the at least one standoff element 22 may be, for example, a silicon-rich nitride.

The second measuring electrode 20 can be formed from a first semiconductor and/or metal layer 26 which is deposited directly on the substrate surface 10a and/or directly on at least one cover layer 28 which at least partially covers the substrate surface 10 a. The at least one cover layer 28 can be understood in particular as at least one insulating layer 28. The exposure of the second measuring electrode 20 can be brought about by means of a partial etching of the substrate surface 10a and/or of at least one cover layer 28 located between the first semiconductor and/or metal layer 26 and the substrate surface 10 a. At least one anchoring structure 26a, by means of which the counter electrode 18 is anchored on the substrate 10, can also be formed from the material of the first semiconductor and/or metal layer 26.

The counter electrode 18 is preferably formed by a second semiconductor and/or metal layer 30 which is deposited on the side of the first semiconductor and/or metal layer 26 which points away from the substrate 10. The second semiconductor and/or metal layer 30 is deposited, for example, on a layer of buffer material, such as a silicon-rich nitride layer and/or at least one first sacrificial layer. The at least one electrically insulating buffer region 24 of the at least one carrier element 22 and, if appropriate, also at least one further electrically insulating buffer region 32 for the electrical insulation of the counter electrode 18 can be structured from a buffer material layer. In this case, the at least one carrier element 22 can also be partially structured by the second semiconductor and/or metal layer 30, wherein the second measuring electrode 20 is still electrically insulated from the first measuring electrode 16. The exposure of the counter electrode 18 can be brought about by means of a partial etching of the at least one first sacrificial layer.

The first measuring electrode 16 may be formed by a third semiconductor and/or metal layer 34 which is deposited on the side of the second semiconductor and/or metal layer 30 which points away from the substrate 10. Preferably, the entire membrane 12 is formed in this case by the third semiconductor and/or metal layer 34. A third semiconductor and/or metal layer 34 is deposited, for example, on the at least one second sacrificial layer. Thus, the exposure of the first measuring electrode 16 can be brought about by means of a partial etching of the at least one second sacrificial layer.

The micromechanical component described above is well suited for use in capacitive sensors or switching devices. The capacitive sensor device with the micromechanical component may comprise, for example, an evaluation electronics designed to determine and output a measured value for the force F applied to the at least one suspension region 14 of the diaphragm 12 or a physical variable or an environmental condition corresponding to the force F, taking into account at least the currently acquired measured variable for the difference between the first capacitance acting between the first measuring electrode 16 and the counter electrode 18 and the second capacitance acting between the second measuring electrode 20 and the counter electrode 18.

In the micromechanical component of fig. 1a and 1b, the membrane 12 is thus hermetically sealed with the reference pressure p present therein₀Such that the at least one suspension region 14 of the diaphragm 12 is unequal to the reference pressure p by virtue of the unequal reference pressures p being present on the outside of the housing 36 and thus also on the "sensitive diaphragm side"₀May warp/become warped. The micromechanical component is therefore well suited for use in a capacitive sensor device designed as a capacitive pressure sensor device, whose evaluation electronics are designed to determine and output a measured value for a physical pressure p present outside the housing 36, at least taking into account the currently acquired measurement variable.

Preferably, the electrodes 16, 18 and 20 are arranged relative to one another in such a way that a first average distance a1(p ═ p) between the first measuring electrode 16 and the counter electrode 18 is obtained if no force F is acting on the at least one suspension region 14, said force triggering a warpage thereof₀) Is greater than a second average distance a2(p ═ p) between counter electrode 18 and second measuring electrode 20₀) (see FIG. 1 a). At a first average pitch a1(p ═ p)₀) And a second average pitch a2(p ═ p)₀) The difference between them can be selected such that the physical pressure p present on the diaphragm outer side 14b is equal to the so-called operating pressure p of the micromechanical component_workThen, the first average pitch a1(p ═ p)_work) Equal to the second average pitch a2(p ═ p)_work) (see FIG. 1 b). Operating pressure p of a micromechanical component_workCan be understood asThe physical pressure p prevailing on the diaphragm outer side 14b during operation of the micromechanical component is/are usually present. In this case, the physical pressure p is relative to the operating pressure p of the micromechanical component_workResults in a signal obtained by means of differencing, which signal relates to the physical pressure p relative to the operating pressure p_workThe deviation of (a) is approximately linear. The evaluation electronics can therefore be constructed relatively simply.

Fig. 2a and 2b show schematic representations of a second embodiment of a micromechanical component.

In the production of the micromechanical component depicted in cross-sections oriented perpendicular to one another in fig. 2a and 2b, the recesses 40 have been structured into the substrate surface 10a of the substrate 10 before the layers 26, 28, 30 and 34 are deposited. Such a recess 40, upon deposition of the at least one cover layer 28, leads to a cavity in the recess 40 which accelerates the distribution of an etching medium at least for etching the at least one cover layer 28. Accordingly, the recess 40 may serve as an etch accelerating structure. Fig. 2a and 2b also show the remaining portion 38a of the at least one first sacrificial layer and the remaining portion 38b of the at least one second sacrificial layer.

For further features and characteristics of the micromechanical component of fig. 2a and 2b, reference is made to the embodiments described above.

Fig. 3a to 3c show schematic representations of a third embodiment of a micromechanical component.

As shown in fig. 3a and 3b, the electrical contact of the second measuring electrode 20 can be guided by at least one spring element 42. In a comparison of fig. 3a and 3b, it follows that the at least one spring element 42 can react relatively elastically to a warpage of the at least one suspension region 14 of the diaphragm 12 and thus does not/hardly hamper a desired displacement of the second measuring electrode 20 together with the first measuring electrode 16.

The electrical contacting of the counter electrode 18 and the mechanical coupling of the counter electrode 18 to the substrate 10 can be realized by means of at least one connection element 44 which reacts without deformation to a warpage of the at least one suspension region 14 of the membrane 12, as is shown in the cross section of fig. 3b and the cross section of fig. 3c oriented perpendicularly thereto.

For further features and characteristics of the micromechanical component according to fig. 3a to 3c, reference is made to the embodiments described above.

Fig. 4a and 4b show schematic diagrams of a fourth embodiment of a micromechanical component.

As can be seen in fig. 4a and 4b, the through-groove 46 can be structured through the membrane 12, which can then be used particularly advantageously as a "horizontal" etching channel for the lower etching of the membrane 12. The through-opening 46 is then closed in an air-tight manner by means of a sealing layer 48 deposited on the membrane 12.

For further features and characteristics of the micromechanical component of fig. 4a and 4b, reference is made to the embodiments described above.

Fig. 5 shows a flow chart for explaining a first embodiment of a method for producing a micromechanical component for a capacitive sensor or switching device.

All micromechanical components described above can be produced, for example, by means of the production methods described in this document. The implementability of the manufacturing method is not limited to the manufacture of the micromechanical component described above.

In method step S1, the membrane having the at least one suspension region is stretched such that the membrane spans the substrate surface of the substrate and the at least one suspension region of the membrane can be/becomes warped by means of a force applied to the respective suspension region.

As a method step S2, the first measuring electrode is formed on and/or in the membrane in such a way that it is set into a displacement or deformation movement, which is oriented obliquely with respect to the substrate surface, with respect to the substrate surface when the at least one suspension region of the membrane is warped. As method step S3, a counter electrode fixed with respect to the substrate surface is arranged between the membrane and the substrate surface in such a way that the first measuring electrode is located on a first side of the counter electrode. Furthermore, as method step S4, the second measuring electrode is suspended by means of at least one carrier element on the first measuring electrode and/or the diaphragm in such a way that the second measuring electrode is held by means of the at least one carrier element on a second side of the counter electrode pointing away from the first side direction of the counter electrode and moves together with the first measuring electrode placed in its displacement or deformation movement when the at least one suspension region of the diaphragm is warped.

As is clear with reference to the following description, the method steps S1 to S4 do not have to be carried out in the order described here.

The manufacturing methods described herein may also be used to manufacture capacitive sensor devices. In this case, in an optional method step S5, the evaluation electronics of the capacitive sensor device are designed in such a way that they determine and output measured values with respect to the force applied to the at least one suspension region of the diaphragm or a physical variable or an environmental condition corresponding to the force, wherein the determination of the measured values takes place at least taking into account the currently acquired measured variable with respect to the difference between the first capacitance acting between the first measuring electrode and the counter electrode and the second capacitance acting between the second measuring electrode and the counter electrode.

Fig. 6 shows a flow chart for explaining a second embodiment of a method for producing a micromechanical component for a capacitive sensor or switching device.

As an optional method step S11, recesses can be structured into the substrate surface of the substrate. The recess may be used as an etch accelerating structure in an etching step performed later. Preferably, a narrow trench is etched into the substrate surface as a recess.

In a further optional method step S12, at least one cover layer, such as at least one insulating layer, is deposited or grown on the substrate surface of the substrate. The at least one cover layer can be structured, for example, in order to enable a subsequent contact region on the substrate. If the substrate is a silicon substrate, a silicon oxide layer can be produced as the at least one insulating layer on the substrate surface by means of thermal oxidation. If the recess is structured into the substrate surface on the basis of the previously performed optional method step S11, the at least one cover layer is deposited/formed such that cavities remain in the recess, which cavities accelerate the distribution of the etching medium at least for etching the at least one cover layer.

In a method step S13, the first semiconductor and/or metal layer is deposited directly on the substrate surface and/or directly on the at least one cover layer which at least partially covers the substrate surface. The first semiconductor and/or metal layer may be, for example, a (doped) polysilicon layer. The method step S4 already described above is then carried out, by means of which the second measuring electrode is formed from the first semiconductor and/or metal layer. In addition to the second measuring electrode, at least one conductor track may also be structured from the first semiconductor and/or the metal layer. Optionally, perforations can be formed in the first semiconductor and/or metal layer or in the second measuring electrode formed therefrom.

As an optional method step S14, a buffer material layer, for example a silicon-rich nitride layer, can then be deposited, from which at least one electrically insulating buffer region of the (following) at least one carrier element and possibly also at least one further electrically insulating buffer region for electrically insulating the (following) counter electrode are structured.

As a further optional method step S15, at least one first auxiliary layer can be deposited and structured in such a way that a subsequent layer thickness inhomogeneity of the subsequently deposited second semiconductor and/or metal layer is determined. The at least one first auxiliary layer may be formed of an electrically insulating material.

Then, as method step S16, a second semiconductor and/or metal layer is deposited on the side of the first semiconductor and/or metal layer pointing away from the substrate. The second semiconductor and/or metal layer is preferably a (doped) polysilicon layer. A fixed counter electrode is formed from the second semiconductor and/or metal layer by means of method step S3 already described above. The second semiconductor and/or the metal layer or the counter electrode formed therefrom may also be provided with perforations. Likewise, narrow trenches can be formed as recesses in the counter electrode, which recesses then serve as etch-accelerating structures.

If desired, at least one second sacrificial layer can then be deposited and structured in optional method step S17 in order to determine the layer thickness inhomogeneity of the subsequently deposited third semiconductor and/or metal layer. The at least one second auxiliary layer may also be formed of an electrically insulating material. If an etching acceleration structure is formed in the counter electrode, the at least one second sacrificial layer is deposited such that cavities which accelerate the distribution of the etching medium for etching remain on the counter electrode.

In a further method step S18, a third semiconductor and/or metal layer is deposited on the side of the second semiconductor and/or metal layer pointing away from the substrate. A (doped) polysilicon layer may also be deposited as a third semiconductor and/or metal layer. The first measuring electrode can then be formed from the third semiconductor and/or the metal layer by means of method step S2 already described above. Preferably, the entire membrane is formed from the third semiconductor and/or metal layer, so that the above-described method steps S1 and S2 can be jointly implemented. Otherwise method step S1 can be carried out after method step S2, for example by deposition of a film material layer. In both cases, the perforations through the membrane can optionally be structured as "horizontal etched channels".

As an optional method step S19, an etching method is then carried out, by means of which at least the at least one suspension region of the diaphragm, the first measuring electrode and the second measuring electrode are exposed. Gaseous hydrogen fluoride, liquid hydrogen fluoride or solutions containing hydrogen fluoride can be used as etching medium. The etching channel as etching medium can use a perforation structured through the membrane as a "horizontal etching channel" and/or at least one etching channel present outside the at least one suspension region of the membrane. The etch accelerating structure already described above may also be used in the etching method.

If the perforation is structured through the film web, a (gastight) sealing layer is deposited on the film web in an optional method step S20 after method step S19, so that the perforation is hermetically sealed. Reference pressures, for example reference pressures below 100mbar, may also be included here. The at least one etched channel present outside the at least one suspension region of the membrane can also be closed in this way.

In carrying out the above-described production method, the layer thicknesses of the at least one first sacrificial layer and of the at least one second sacrificial layer can be selected such that a first distance between the first measuring electrode and the counter electrode is greater than a second distance between the counter electrode and the second measuring electrode if no force is acting on the at least one suspension region of the membrane, said force triggering a warpage of the suspension region. However, the physical pressure p existing on the outside of the diaphragm is equal to the so-called working pressure p of the micromechanical component_workThe first pitch may be equal to the second pitch. If necessary, the etching method is preferably carried out such that the at least one first sacrificial layer is etched faster than the at least one second sacrificial layer.