DE102021204653A1 - In-plane MEMS varactor - Google Patents

Abstract

A MEMS component comprises a substrate arranged in a substrate plane and an electrode arrangement with a first electrode structure and a second electrode structure which are arranged opposite one another parallel to the substrate plane in order to form an electrical capacitor. The MEMS component includes an actuator which is coupled to the electrode arrangement and is designed to change an electrode spacing between the first electrode structure and the second electrode structure parallel to the substrate plane in order to change an electrical capacitance value of the electrical capacitor. The actuator has at least two bars spaced apart parallel to the substrate plane and mechanically connected to one another in discrete areas, which form a common movable element that is designed to move in-plane relative to the substrate plane in order to change the electrode spacing .

Description

The present invention relates to MEMS components and methods for changing an electrical capacitance value of a MEMS component, in particular those MEMS components that change a capacitance value by moving parallel to a substrate plane. In particular, the present invention relates to a varactor.

A MEMS varactor is a variable capacitance in which the change in capacitance is usually realized by changing the electrode spacing. MEMS varactors typically have small tuning ratios (TR) of less than 5 because the electrode excursion required for tuning is severely limited. The limitation is explained by the actuators that can be used. Usually this is a classic electrostatic or direct Coulombic attraction between the grounded electrode and the signal (RF) line. Because of such limitations as B. the Pull-In (PI) effect, for example, only about a third of the initial distance between the electrodes can be used to vary the capacitance. The use of this distance or gap is thus inefficient independent of the starting distance and leads to a small tuning ratio, which is defined as follows: $$TR=C/C_0$$

An additional problem with the pull-in is the sticking of the electrodes, which can occur.

Accordingly, MEMS components that have a high tuning ratio would be desirable.

One object of the present invention is therefore to create MEMS components with a high tuning ratio based on an electrical capacitance.

This object is solved by the subject matter of the independent patent claims.

The core idea of the present invention is to change an electrode of an electrode arrangement that forms an electrical capacitor in-plane, i.e. parallel to the substrate plane, and to provide a separate actuator element for this purpose, as a result of which a corresponding holding force is exerted on the moving electrode. which can reduce the pull-in effect, with which the effectively usable travel can be comparatively large and thus a high tuning ratio can also be achieved. On the one hand, actuators with two or more parallel bars spaced apart from the substrate plane and isolated in discrete areas and mechanically connected to one another are suitable for this purpose, as well as an arrangement in which several capacitance values are increased or decreased simultaneously.

According to one embodiment, a MEMS component includes a substrate arranged in a substrate plane. Furthermore, an electrode arrangement is arranged, which has a first electrode structure and a second electrode structure, the second electrode structure being arranged parallel to the substrate plane opposite the first electrode structure in order to form an electrical capacitor. The MEMS component includes an actuator which is coupled to the electrode arrangement and is designed to change an electrode spacing between the first electrode structure and the second electrode structure parallel to the substrate plane in order to change an electrical capacitance value of the electrical capacitor. The actuator comprises at least two beams spaced parallel to the substrate plane and mechanically connected to one another in discrete areas, if necessary also electrically insulated there, which form a common movable element which is designed to move in-plane relative to the substrate plane, to change the electrode spacing. The force of the actuator can provide a restoring force or holding force for an electrode moved by the actuator, which can prevent or inhibit the pull-in effect from occurring.

According to a further exemplary embodiment, a MEMS component comprises a substrate arranged in a substrate plane and an electrode arrangement which has a first electrode structure and a second electrode structure, the second electrode structure being arranged parallel to the substrate plane opposite the first electrode structure in order to form a first electrical capacitor with a first capacitance value. A second electrical capacitor is also arranged, which forms a second capacitance value and has a third electrode structure which, together with the first electrode structure or an additional fourth electrode structure, provides the second electrical capacitance value. An actuator device is provided, which is coupled to the electrode arrangement and is designed to set the first capacitance value and the second capacitance value independently of one another and/or to simultaneously increase or simultaneously reduce the first capacitance value and the second capacitance value.

According to one embodiment, a method for changing an electrical capacitance value of a MEMS device includes driving at least one bar of an actuator with at least two bars spaced parallel to a substrate plane of the MEMS component and isolated in discrete areas and mechanically connected to one another, which form a common movable element in order to move the movable element in-plane relative to the substrate plane. The method is carried out in such a way that an electrode spacing between a first electrode structure of an electrode arrangement and a second electrode structure of the electrode arrangement arranged parallel to the substrate plane is changed parallel to the substrate plane by the actuator exerting a force on the electrode arrangement by deforming a beam parallel to the substrate plane exercises

A method according to an embodiment for changing a first electrical capacitance value and a second electrical capacitance value of a MEMS component includes driving an actuator device to a first distance between a first electrode structure and a second electrode structure, parallel to a substrate plane of the MEMS component opposite to each other are arranged and form a first electrical capacitor having a first electrical capacitance value. Furthermore, the actuation changes a second distance between at least a third electrode structure and an electrode structure which forms the second electrical capacitance value with the third electrode structure and is arranged parallel to the substrate plane opposite the third electrode structure, in order to thereby reduce the second electrical capacitance value or to increase.

Further advantageous configurations are the subject matter of dependent patent claims.

• 1a eine schematische Draufsicht auf ein MEMS-Bauelement gemäß einem Ausführungsbeispiel;
• 1b eine schematische perspektivische Ansicht des MEMS-Bauelements aus 1a;
• 2a eine schematische Draufsicht auf ein MEMS-Bauelement gemäß einem Ausführungsbeispiel, das zwei Kapazitätswerte aufweist;
• 2b eine schematische Draufsicht auf das MEMS-Bauelement aus 2a, bei dem gegenüber dem unausgelenkten Zustand der 2a Elektrodenstrukturen ausgelenkt sind;
• 3 eine schematische Draufsicht auf ein MEMS-Bauelement gemäß einem Ausführungsbeispiel, das eine dielektrische Schicht zwischen Kondensatorelektroden aufweist;
• 4 eine schematische Draufsicht auf ein MEMS-Bauelement, gemäß einem Ausführungsbeispiel, das eine Oberflächenvergrößerung der Kondensatorelektroden aufweist;
• 5a eine schematische Draufsicht auf ein MEMS-Bauelement gemäß einem Ausführungsbeispiel mit einer weiteren Oberflächenvergrößerung der Elektrodenstrukturen;
• 5b eine schematische Draufsicht auf ein MEMS-Bauelementgemäß einem Ausführungsbeispiel, das das MEMS-Bauelement aus 5a dahin gehend erweitert, dass bei den Kondensatoren an zumindest einer der Elektrodenstrukturen eine Isolationsschichtangeordnet ist;
• 6 eine schematische Draufsicht auf ein MEMS-Bauelement gemäß einem Ausführungsbeispiel, bei dem mehrere vorteilhafte Weiterbildungen implementiert sind;
• 7 eine schematische Seitenschnittansicht des MEMS-Bauelements aus 2a;
• 8 eine schematische Seitenschnittansicht des MEMS-Bauelements aus 2a analog 7, aber in einem ausgelenkten Zustand;
• 9 eine schematische Seitenschnittansicht eines MEMS-Bauelements gemäß einem Ausführungsbeispiel, bei dem eine Signalleitung außerhalb einer Ebene weiterer Elektrodenstrukturen angeordnet ist; und
• 10 eine schematische Seitenschnittansicht des MEMS-Bauelements aus 6.

Preferred embodiments of the present invention are explained below with reference to the accompanying drawings. show:

• 1a a schematic plan view of a MEMS component according to an embodiment;
• 1b Figure 12 shows a schematic perspective view of the MEMS device 1a ;
• 2a a schematic plan view of a MEMS component according to an embodiment, which has two capacitance values;
• 2 B shows a schematic plan view of the MEMS device 2a , in which compared to the undeflected state of 2a electrode structures are deflected;
• 3 12 shows a schematic plan view of a MEMS device according to an embodiment, which has a dielectric layer between capacitor electrodes;
• 4 a schematic plan view of a MEMS component, according to an embodiment, which has an increase in the surface area of the capacitor electrodes;
• 5a a schematic plan view of a MEMS component according to an embodiment with a further increase in surface area of the electrode structures;
• 5b FIG. 12 is a schematic plan view of a MEMS device according to an embodiment comprising the MEMS device. FIG 5a extended to the effect that an insulation layer is arranged on at least one of the electrode structures in the case of the capacitors;
• 6 a schematic plan view of a MEMS component according to an embodiment, in which several advantageous developments are implemented;
• 7 Figure 12 shows a schematic side sectional view of the MEMS device 2a ;
• 8th Figure 12 shows a schematic side sectional view of the MEMS device 2a analogue 7 , but in a deflected state;
• 9 a schematic side sectional view of a MEMS component according to an embodiment, in which a signal line is arranged outside a plane of further electrode structures; and
• 10 Figure 12 shows a schematic side sectional view of the MEMS device 6 .

Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical elements, objects and/or structures that have the same function or have the same effect are provided with the same reference symbols in the different figures, so that the elements shown in different exemplary embodiments Description of these elements is interchangeable or can be applied to each other.

Exemplary embodiments described below are described in connection with a large number of details. However, example embodiments can also be implemented without these detailed features. Furthermore, for the sake of comprehensibility, exemplary embodiments are described using block diagrams as a substitute for a detailed illustration. Furthermore, can Details and/or features of individual exemplary embodiments can be combined with one another without further ado, as long as it is not explicitly described to the contrary.

1a FIG. 1 shows a schematic plan view of a MEMS component 10 according to an embodiment. The MEMS device has a substrate 12, which may be, for example, a semiconductor material, such as comprising silicon, gallium arsenide, or the like, in accordance with MEMS designs. However, without restricting the exemplary embodiments described herein, any other carrier material can also be used as the substrate 12, for example a metallic material, a fiber material or the like. The substrate 12 extends in a substrate plane, which is shown as an x/y plane, for example. In other words, the substrate plane x/y can result from the orientation of the substrate 12 . In semiconductor processes, the substrate level can be that level, for example, in which a used wafer is oriented, from which at least part of the MEMS component is formed.

The MEMS device further comprises an electrode arrangement comprising an electrode structure 14 ₁ and an electrode structure 14 ₂ . The electrode structures 14 ₁ and 14 ₂ are arranged opposite one another to form or provide an electrical capacitor. The opposite arrangement is parallel to the substrate plane, so that a change in a distance 16 between the electrode structures 14 ₁ and 14 ₂ includes a movement of at least one of the electrode structures 14 ₁ and/or 14 ₂ parallel to the substrate plane x/y, which means is oriented in-plane.

eine Änderung in dem durch den elektrischen Kondensator bereitgestellten elektrischen Kapazitätswerts erzielt wird. Dabei ist ε₀ die Dielektrizitätskonstante des Vakuums, ε_r eine relative Permittivität des Mediums zwischen den Elektroden, A die Elektrodenfläche, und d der Elektrodenabstand.Furthermore, the MEMS component 18 comprises an actuator 18 which is coupled to the electrode arrangement. Although in 1a a mechanical coupling is shown by a coupling element 22 and with the electrode structure 14 ₂ , a mechanical coupling with the electrode structure 14 ₁ can also take place as an alternative or in addition. Actuation of actuator 18 may cause distance 16 to change, thus based on the capacitor equation $$C=e_0{e}_{\mathrm{right}}\frac{A}{\mathrm{i.e}}$$

a change in the electrical capacitance value provided by the electrical capacitor is achieved. Here ε ₀ is the dielectric constant of the vacuum, ε _r is a relative permittivity of the medium between the electrodes, A is the electrode area, and d is the distance between the electrodes.

In the present exemplary embodiment, the actuator comprises at least two bars 24 ₁ and 24 ₂ which are mechanically connected to one another at two or more discrete areas 26 ₁ , 26 ₂ and/or 26 ₃ and are thus fixed. The connected beams form a common moveable element configured to move in-plane with respect to the substrate plane to change the electrode spacing by imparting movement 28 of the actuator 18 to at least one of the electrode structures.

Although a symmetrical arrangement of two actuators and two electrode structures 14 ₁ and 14 ₃ with respect to the electrode structure 14 and 14 ₂ is shown, the MEMS component 20 can also comprise only one of these arrangements, which has already been explained in 1 is indicated.

Different actuator principles can be used for deflecting the movable element or the beam 24 ₁ and/or 24 ₂ , including an electrostatic drive, a piezoelectric drive and a thermomechanical drive. That is, the beams 24 ₁ and/or 24 ₂ may possibly, but not necessarily, be formed as electrode structures. In the event that electrode structures are used, e.g. to implement electrostatic actuation, the beams can also be electrically isolated from each other by means of the discrete regions 26 ₁ to 26 ₃ , e.g. by providing an electrical insulator as the connecting material, for example silicon oxide or silicon nitride. A possible structure of the actuator 18 is based on an implementation in a MEMS loudspeaker, for example WO 2018/193109 A1 refer to.

Based on a functional principle of the actuator 18 and/or an interconnection of the bar 24 ₂ and/or the electrode structure 14 ₂ , the coupling element 22 can be formed either electrically insulating or electrically conductive.

1b FIG. 12 shows a schematic perspective view of the MEMS device 10. FIG 1a . It is shown again there that the electrode structures 14 ₁ and 14 ₂ are arranged parallel to the substrate plane opposite one another. An extension along a third Cartesian direction z is selected merely as an example and can, in particular, also be larger than a dimension of the electrode structures along x and/or y, in order to generate a large capacitance.

The actuator 18 or the beams 24 ₁ and/or 24 ₂ can be arranged in the same plane as the electrode structures 14 ₁ and 14 ₂ , but can can also be arranged in another plane, which is easily possible by transferring the movement of the actuator into the plane of the electrode structures 14 ₁ and/or 14 ₂ by means of mechanical elements aligned perpendicularly to the substrate plane.

The MEMS component 10 can be formed, for example, as a MEMS varactor or as a capacitive high-frequency switch.

Furthermore, it should be pointed out that the electrode structures 14 ₁ and 14 ₂ as well as the actuator 18 can be supported on the substrate 12 in different ways. For example, the electrode structure 14 ₁ can be supported along the z-direction and/or clamped or supported along the x-direction and/or y-direction. Alternatively or additionally, it is possible for an electrode structure to be supported on the substrate 12 via the actuator, as is shown, for example, for the electrode structure 14 ₂ . The actuator can be mechanically connected to the substrate 12 in any plane and can be supported on it.

2a 12 shows a schematic plan view of a MEMS device 20 according to an embodiment. The MEMS component 20 is formed, for example, in such a way that two actuators 18 ₁ and 18 ₂ are provided in order to set distances 16 ₁ and 16 ₂ of a first electrical capacitor 32 ₁ and a second electrical capacitor 32 ₂ to change as represented by C ₁ and C ₂ .

The actuators 18 ₁ and 18 ₂ are formed, for example, in such a way that three bars 24 ₁ , 24 ₂ and 24 ₃ on the one hand and 24 ₄ , 24 ₅ and 24 ₆ on the other hand are attached to discrete areas 26 ₁ to 26 ₁₀ or 26 ₁₁ to 26 ₂₀ are mechanically connected and fixed to one another.

For example, the beams 24 ₁ to 24 ₆ are each formed as electrode structures in order to generate electrostatic forces between adjacent beams so as to cause a deflection of the actuator 18 ₁ and/or 18 ₂ . The actuators 18 ₁ and/or 18 ₂ can be supported on the substrate 12 in that the beams 24 ₁ to 24 ₆ are implemented as clamped beams, with both one-sided and two-sided support or clamping being considered.

The electrical capacitors 32 ₁ and 32 ₂ have a common electrode 14 ₂ formed as a radio frequency (RF) line, by way of example only. This line can be connected to a signal input 34 and/or a signal output 36, so that a corresponding signal is routed from the input 34 to the output 36, for example.

This signal line or electrode 14 ₂ can now have a capacitance value C ₁ or C ₂ applied to it on both sides or form part thereof, with electrodes 14 ₁ and 14 ₃ being set jointly or independently of one another by means of actuators 18 ₁ and 18 ₂ can become.

However, it immediately follows that an additional electrode structure can also be arranged instead of the common electrode 14 ₂ , so that, for example, the electrode structures 14 ₁ and 14 ₂ on the one hand and the electrode structure 14 ₃ and an electrode structure arranged opposite thereto and not shown have a respective electrical capacitor form.

2 B shows a schematic top view of the MEMS component 20, in which compared to the undeflected state of FIG 2a the electrode structures 14 ₁ and 14 ₃ are moved toward the intervening electrode structure 14 ₂ such that gaps 16' ₁ and 16' ₂ are opposite to gaps 16 ₁ and 16 ₂ , respectively 2a are reduced. An increased electrical capacitance of the capacitors 32 ₁ and 32 ₂ results from the capacitor equation.

In the configuration of the MEMS device 20 in such a way that a signal line can be used to provide an electrode structure, it can be advantageous to form the electrical capacitor with an electrode which is on a floating potential or is contacted with a reference potential, such as 0 volts, ground/GND or the like.

In the exemplary configuration of the actuator 18 ₁ and 18 ₂ by means of three bars arranged adjacent to one another, these bars can advantageously be contacted in such a way that an inner bar 24 ₂ or 24 ₅ is acted upon by a control signal, indicated by a “+V “. The outer bars 24 ₁ and 24 ₃ on the one hand and 24 ₄ and 24 ₆ on the other hand can be charged with the reference potential GND. If this potential is also provided for the electrodes 14 ₁ and 14 ₃ , the coupling elements 22 ₁ and/or 22 ₂ can be made electrically conductive, for example, in order to easily transfer the potential from the bar 24 ₃ to the electrode 14 ₁ and/or from the bar 24 ₄ to the electrode 14 ₃ or vice versa, which can keep circuit complexity low.

like it in 2 B is shown by way of example, an electrode of the actuator 18 ₁ or 18 ₂ facing the electrode arrangements 14 ₁ or 14 ₃ and an electrode structure of the electrode arrangement facing the actuator can be electrically connected to one another.

The MEMS component 20 can have a control device 37 which is designed to control the actuator 18 ₁ and/or 18 ₂ . Optionally, but not necessarily, the control device 37 can provide the reference potential GND, for example. A control potential 39, indicated as "+V", can be provided for both actuators jointly or also individually. The actuator 18 ₁ and/or 18 ₂ can be set up to set a linear relationship or a hyperbolic relationship, ie for example a quadratic relationship, between the control signal 39 and an effected change in the electrical capacitance value. With regard to its changes, the electrical capacitance value can have a relationship that can be represented via a function, which can be set without any problems via the geometry, the forces caused, the change in the distance and the other geometric properties.

g ist dabei ein Anfangsabstand und x(t) eine Elektrodenverschiebung. Für x(t) gilt $$\text{x}\left(\text{t}\right)=\text{f}\left(\text{U}\left(\text{t}\right)\right)$$

und ist eine Funktion der Aktuatorspannung. Wird eine spezielle Form der elektrischen Aktuatorspannung erzeugt und verschiebt damit die Elektrode nicht linear sondern quasi „invers hyperbolisch“ ändert sich die Kapazität basierend auf dieser Anpassung eher linear mit der angelegten Spannung als hyperbolisch.A hyperbolic connection, i.e. in accordance with a hyperbola, is given, for example, by an inverse dependence of the capacity on the distance. Hyperbolic motion can be obtained by linearly displacing the movable electrode, since the capacitance can be expressed as: $$\text{C}\sim \text{1/}\left(\text{G}-\text{x}\left(\text{t}\right)\right)$$

g is an initial distance and x(t) is an electrode displacement. For x(t) holds $$\text{x}\left(\text{t}\right)=\text{f}\left(\text{u}\left(\text{t}\right)\right)$$

and is a function of the actuator voltage. If a special form of the electrical actuator voltage is generated and the electrode is not shifted linearly but rather "inversely hyperbolically", the capacitance changes more linearly with the applied voltage than hyperbolically based on this adaptation.

The control device 37 can alternatively or additionally be designed to control the actuator in a quasi-static manner. A change in the deflection of the actuator far away from a resonant frequency is understood to be quasi-static. This is effected, for example, with a control frequency of at most 80%, preferably at most 50% and particularly preferably at most 20% of the resonant frequency of the actuator.

An embodiment can be based on 2a and 2 B and are presented and explained in more detail on the basis of LNED actuators 18 clamped on both sides, the design of the actuators (e.g. type of clamping, number of actuator electrodes, number of actuators, actuator shape, etc.) being variable. The varactor 20 consists of the RF line 14 ₂ fixed to the substrate 12 or handle wafer, in which a high-frequency signal (HF signal) can propagate. The grounded movable varactor electrodes 14 ₁ , 14 ₃ are arranged on both sides of the RF line.

The varactor electrodes are mechanically connected to the LNED actuators 18 clamped on both sides in the example by means of connecting elements 22 and are at a defined distance (e.g. from 1 µm to 50 µm, preferably from 2.5 µm to 5 µm) from the RF line 14 ₂ away. The electrodes 14 ₁ , 14 ₃ are also mechanically connected to the surrounding substrate 12 .

wobei ε₀ - die Dielektrizitätskonstante des Vakuums, ε_r - relative Permittivität des Mediums, A - Elektrodenfläche, g - initiale Elektrodenabstand sind. Wird nun eine elektrische Spannung an die LNED-Aktoren 18 angelegt, führt das zum Auslenken der Aktoren 18 in der Chipebene und somit zur Verschiebung der geerdeten Varaktorelektroden 14₁, 14₃ um x in Richtung der RF-Line 14₂. Der Abstand 16 zwischen den Elektroden wird kleiner, was die Kapazität des Systems vergrößert. $$C\left(x\right)=\frac{{\epsilon }_0{\epsilon }_{r}A}{g-x}$$

Embodiments have a connection that has low rigidity than the substrate 12 and the electrode 14 ₁ , 14 ₃ (spring-like). They can also be connected to actuators and accordingly to the substrate only by connecting elements 22 and not to the surrounding substrate 12 . The connecting elements 22 can be designed in the manner of springs, which means that the rigidity of these elements is less than the rigidity of the electrodes 14 ₁ , 14 ₃ or the actuators 18 . The distance 16 between the RF line 14 ₂ and the grounded electrodes 14 ₁ , 14 ₃ defines an initial capacitance, which for one electrode side of the varactor 20 can be described by a plate capacitor model with a simple formula: $$C_0=\frac{e_0{e}_{\mathrm{right}}A}{G}$$

where ε ₀ - the dielectric constant of the vacuum, ε _r - relative permittivity of the medium, A - electrode area, g - initial electrode spacing. If an electrical voltage is now applied to the LNED actuators 18, this leads to the deflection of the actuators 18 in the chip level and thus to the displacement of the grounded varactor electrodes 14 ₁ , 14 ₃ by x in the direction of the RF line 14 ₂ . The distance 16 between the electrodes decreases, which increases the capacity of the system. $$C\left(x\right)=\frac{e_0{e}_{\mathrm{right}}A}{G-x}$$

The unitless number that describes the change in capacitance is called the tuning ratio (TR) and is defined as follows: $$TR=\frac{C\left(x\right)}{C_0}$$

In comparison to the classic MEMS varactors, in this arrangement the movement of the GND electrode is not realized by the classic electrostatic attraction to the RF line, but instead is made possible by the LNED actuators 18, which are decoupled from the parasitic electrostatic attraction. This enables a more efficient utilization of the initial electrode spacing and a continuous movement of the GND plate almost up to touching the RF line 14 ₂ . As a result, significantly higher TR can be achieved than the state of the art can offer.

In other words shows 2 B in a plan view, the varactor 30 in a deflected state. In this case, the electrode spacing is significantly smaller and the volume of the cavity is reduced. The reduction in volume can be used to dampen the system. Embodiments of the varactor provide adjustable damping. In this case, the cavities can be connected to the environment via openings in the cover and/or handle wafer (not shown). In this case, fluid (air) can flow into or out of the cavity via the openings.

The movement of the electrodes 14 ₁ , 14 ₃ relative to the RF line 14 ₂ is static or quasi-static. Typical frequencies of the movement are between 0 and 100% of the resonant frequency of the actuators 18. The range of <0-20% is to be regarded as quasi-static and is particularly preferred. 0% of the resonant frequency is the static range. Preferred frequencies are between <0 - 50% of the resonance frequency.

3 12 shows a schematic plan view of a MEMS device 30 according to an embodiment. This has a comparable structure to the MEMS component 20 and also has dielectric layers 38 ₁ and 38 ₂ which comprise a dielectric material, for example silicon oxide or silicon nitride or another dielectric material that can preferably be processed using MEMS processes, for example an electrically non-conductive material. The dielectric layers 38 ₁ and/or 38 ₂ can be continuous or, as shown, structured. While dielectric layer 38 ₁ is disposed between electrode structures 14 ₁ and 14 ₂ , dielectric layer 38 ₂ may be disposed between electrode structures 14 ₂ and 14 ₃ . Although both dielectric layers 38 ₁ and 38 ₂ are shown structured the same, they may be structured differently from each other, or only one of the two layers may be structured, or both layers may be unstructured. Optionally, only one of the two layers can be arranged in a structured or unstructured manner, or neither of the two layers can be arranged, as is the case, for example, in FIGS 2a and 2 B is shown.

The dielectric layer can also be referred to as an insulating layer and, on the one hand, makes it possible to avoid an electrical short circuit between electrode structures 14 ₁ and 14 ₂ or electrode structures 14 ₂ and 14 ₃ that are moved toward or away from one another.

In addition to increasing the capacitance by means of a dielectric constant ε _r >1, an anti-stiction function can be implemented in particular by structuring the layers 38 ₁ and/or 38 ₂ . By reducing a surface that can be mechanically brought into abutment with the opposing electrode, for example compared to the illustration in FIG 2a , the adhesion forces are also reduced, for example, so that it is easier to detach and/or avoid the adhesion of the electrodes.

In the case of a mechanical contact between the first electrode structure and the insulation layer on the one hand and the insulation layer and the second electrode structure on the other hand, a non-illustrated control device of the MEMS component can be designed to apply a potential to an electrode structure affected by the mechanical contact in order to enable charge carriers to flow away from the electrode structure and thus the adhesion (stiction) is released.

Although dielectric layer 38 ₁ is shown as being disposed on electrode structure 14 ₁ and dielectric layer 38 ₂ is shown as being disposed on electrode structure 14 ₃ , a dielectric layer may alternatively or additionally be disposed on the electrode structure 14 ₂ can be arranged, for example facing the electrode structure 14 ₁ and/or the electrode structure 14 ₂ .

In other words shows 3 an alternative embodiment of a varactor 30 containing alternative electrodes 14 ₁ , 14 ₃ with an insulating layer 38 . This insulating layer is preferably interrupted. This advantageously increases the effective relative permittivity in the electrode gap 16 ₁ , 16 ₂ . Likewise, unintentional sticking of the electrode 14 ₁ , 14 ₃ to the RF line 14 ₂ is prevented. A similar preferably discontinuous insulating layer can be patterned on the RF line 14 ₂ .

4 FIG. 4 shows a schematic plan view of a MEMS device 40 configured in accordance with the other embodiments described herein. Unlike the MEMS component 20, for example, the electrode structure 14 ₁ and the side of the electrode structure 14 ₂ facing the electrode structure 14 ₁ and/or the electrode structure 14 ₃ and/or the side of the electrode structure 14 ₂ facing the electrode structure 14 ₃ can have an enlarged surface. This can be done, for example, by means of a topography and/or structuring. One or both capacitors 32 ₁ and/or 32 ₂ can also be formed in such a way that one of the two electrode structures or both of the electrode structures also have no surface enlargement.

The increase in surface area can also be understood to mean that at least one of the two electrode structures of a capacitor has a variable electrode spacing from one another at least in regions along a variable location, for example along the y-direction, on a respective electrode surface of the electrode structure. As is shown, for example, using the distances 16 _1-1 and 16 _1-2 , the distance between the electrode structures 14 ₁ and 14 ₂ can change along the y-direction.

Such a configuration has several positive advantages for the capacitor and therefore the varactor. First, the effective surface of the electrodes compared to the design in the 2a and 2 B be enlarged. In addition, for example, in the case of a mechanical contact, for example as a result of a pull-in, there is mechanical contact between the electrode surfaces of the electrode structures 14 ₁ and 14 ₂ on the one hand and 14 ₃ and 14 ₂ on the other hand on a comparatively smaller surface, which advantageously leads to low adhesive forces between the electrode structures. In addition, geometry-supported field inhomogeneities are generated by the non-planar shape of the surfaces, in particular when the electrode spacing changes.

In other words shows 4 an alternative embodiment of a varactor 40 containing alternative electrodes 14 ₁ , 14 ₂ and an alternative RF line 14 ₂ . In the top view it can be seen that neither the electrode 14 ₁ , 14 ₂ nor the RF line 14 ₂ have any smooth facing surfaces. Rather, the surfaces can have wavy or zigzag-shaped bulges that increase the respective surface area. Zigzag-shaped bulges are shown as examples. The bulges on the two opposite surfaces can be made non-periodic and non-symmetrical. Such an embodiment advantageously minimizes the contact area between the electrode 14 ₁ , 14 ₃ and the RF line 14 ₂ in the event of contact. Another advantage of this design is the increase in the effective capacitance area and thus the capacitance value itself. In addition, the geometry-supported field inhomogeneities on the non-plane-parallel surfaces lead to larger changes in capacitance when the electrode spacing 16 ₁ , 16 ₂ decreases or increases.

5a 1 shows a schematic plan view of a MEMS device 50 ₁ according to an embodiment. The MEMS device 50 ₁ has an increase in the surface area of the electrode structures 14 ₁ , 14 ₂ and 14 ₃ . Unlike, however, in connection with the 4 described, this increase in surface area is configured in the manner of a comb, for example, so that a substantially constant distance 16 ₁ and 16 ₂ is obtained in the capacitors 32 ₁ and 32 ₂ . The feature that can also be implemented in the MEMS components 20, 30 and/or 40 is clearly visible, namely that the electrode structures 14 ₁ and 14 ₃ are only supported on the substrate above the actuator 18 ₁ or 18 ₂ , but towards the substrate 12 in the shown level have a distance. This can bring about a homogeneous movement of the electrode structures 14 ₁ and 14 ₂ , it being entirely possible for additional stabilization along the z-direction to connect the electrode structures 14 ₁ and 14 ₃ to the substrate 12 in the plane shown.

5b shows a schematic plan view of a MEMS component 50 ₂ , which expands the MEMS component 50 ₁ in such a way that the capacitors 32 ₁ and/or 32 ₂ on at least one of the electrode structures 14 ₁ and/or 14 ₂ or 14 ₂ and/or 14 ₃ the insulation layer 38 is arranged as a structured or unstructured layer. This leads to the related to the 3 explained benefits.

In other words, the dielectric layer 38 ₁ on the electrode structure 14 ₁ , the dielectric layer 38 ₂ on a side of the electrode structure 14 ₂ facing the electrode structure 14 ₁ , the dielectric layer 38 ₃ on a side of the electrode structure 14 ₂ facing the electrode structure 14 ₃ and /or the dielectric layer 38 ₄ can be arranged on the electrode structure 14 ₃ in a structured or unstructured manner.

In other words, the 5b an alternative varactor 50 ₂ with an advantageously increased capacitance area and thus the capacitance value itself. The alternative RF line 14 ₂ is structured like a comb, just like the alternative electrodes 14 ₁ , 14 ₃ . This comb-like structure is designed so that the fingers of each gene ridges of the electrodes 14 ₁ , 14 ₃ and 14 ₂ mesh. This advantageously increases the dielectric constant in the gap and an improved tuning ratio TR is established.

In addition, in 5b shown that the RF line 14 ₂ and the comb-shaped electrodes 14 ₁ , 14 ₃ are equipped with an insulation layer 38 . Adhesion effects between the electrode 14 ₁ , 14 ₃ and the RF line 14 ₂ are thereby advantageously avoided.

6 shows a schematic plan view of a MEMS component 60 according to an embodiment in which several advantageous developments are implemented, which can be implemented individually or in combination and can also be combined individually or in combination with other MEMS components described herein.

On the one hand, the MEMS component 60 has modified electrical capacitors 32' and 32' ₂ . In contrast to the previously described exemplary embodiments with two electrical capacitors, each of the electrical capacitors is equipped with its own pair of electrodes. The electrical capacitor 32' ₁ has electrode structures 14 ₁ and 14 ₂ . Furthermore, the electrical capacitor 32' ₂ has electrode structures 14 ₃ and 14 ₄ . The electrode structures 14 ₂ and 14 ₄ are optionally arranged in a mechanically fixed manner on the high-frequency line 42, while the high-frequency line 42 in the exemplary embodiment of FIG 6 although not part of the electric capacitors 32' ₁ and 32' ₂ , is influenced by the variable capacitance of the electric capacitors 32' ₁ and 32' ₂ in terms of signal line characteristics.

The arrangement or attachment of the electrode structures 14 ₂ and 14 ₄ to the high-frequency line 42 can be effected by means of an insulator layer 44 ₁ and/or 44 ₂ . Although these can be formed from the same material as the dielectric layer 38 of the other exemplary embodiments, mechanical contacting and electrical insulation are more important here, while in other exemplary embodiments the dielectric constant of the material used may also be taken into account. Notwithstanding this, suitable insulating materials may include, for example, silicon oxide and/or silicon nitride.

The electrode structures 14 ₁ and/or 14 ₃ can be electrically insulated from the respectively facing beams 26 ₃ and 26 ₄ , but this is optional. However, electrical insulation can also be used, for example, when actuating the actuators 18 ₁ and 18 ₂ by applying a potential that is different from that used for the actuator. In the present exemplary embodiment, for example, an insulator layer 46 ₁ is provided between the coupling element 22 ₁ . The coupling element 22 ₁ is continued by an extension segment 48 in order to transfer the force of the actuator 18 ₁ to the electrode structure 14 ₁ over a large area.

The insulator layer 46 ₁ can have the same or different materials compared to the insulator layers 44 ₁ and/or 44 ₂ . A comparable effect can also be obtained by forming the coupling element 22 ₁ in an electrically insulating manner. In such a case, the insulator layer 46 ₁ can be dispensed with while obtaining a comparable effect.

In a comparable manner, an insulator layer 46 ₂ is arranged between the extension segment 48 ₂ of the coupling element 22 ₂ and the electrode structure 14 ₃ in order to electrically insulate the beam 26 ₄ from the electrode structure 14 ₃ . Here, too, a comparable effect can be obtained by forming the coupling element 22 ₂ in an electrically insulating manner.

In the representation of 6 All electrode structures 14 ₁ , 14 ₂ , 14 ₃ and 14 ₄ are electrically isolated from a respective environment, which makes it possible to apply an individual potential to each of the electrode structures 14 ₁ to 14 ₄ . For example, the electrical potential 52 ₁ is applied to the electrode structure 14 ₁ at one or more points. The electrical potential 52 ₂ is applied to the electrode structure 14 ₂ at one or more points. The electrical potential 52 ₃ can be arranged on the electrode structure 14 ₃ at one or more points, and the electrical potential 52 ₄ can likewise be applied to the electrode structure 144 at one or more points. The potentials 52 ₁ to 52 ₄ can be generated, for example, by the control device 37, which is shown in 6 not shown can be provided.

The individual application of individual potentials also makes it possible to create so-called "flying" potentials. For example, while the 2a , 2 B , 3 , 4 , 5a and 5b Show illustrations in which at least one of the electrode structures forms at least part of a signal line for conducting a signal from a signal line input 34 to a signal line output 36 and the electrical capacitor is designed to be based on the electrical capacitance C ₁ and/or C ₂ on a signal line property of the Act signal line and the actuator is coupled to the other electrode structure to this electrode structure relative to the electrode structure of the signal line to move parallel to the substrate plane 6 a representation in which the electrode structures 14 ₂ and 14 ₄ are mechanically firmly connected to the signal line. However, the signal line 42 itself could also readily provide an electrode structure for the capacitor 32 ₁ or 32 ₂ , as is described in connection with other exemplary embodiments. The configuration of the electrode structures 14 ₁ and 14 ₃ as electrically insulated electrode structures and, if necessary, to which a floating potential is to be applied, remains unaffected by this.

In addition, the 6 another way of increasing the surface area, namely a kind of sawtooth pattern which interlocks in the opposing electrode structures 14 ₁ and 14 ₂ or 14 ₃ and 14 ₄ . This optional configuration is also independent of the other advantageous configurations 6 implementable.

Coming back to the possibility of applying a flying or floating potential to the electrode structures 14 ₁ , 14 ₂ , 14 ₃ and/or 14 ₄ with respect to the signal line 42, it should also be mentioned that this offers the possibility in particular of applying potentials which, for example, In the event of sticking, enable charge carrier transport away from the electrode structures in order to end or dissolve the adhesion.

Optionally, the MEMS component 60 can also be provided with a dielectric layer, as is the case, for example, in connection with the 3 or the 5b is explained. A corresponding dielectric layer can be connected to at least one of the electrode structures, for example 14 ₁ and/or 14 ₂ or 14 ₃ and/or 14 ₄ . A control device, for example the control device 37 for controlling at least part of the MEMS, for example the actuators 18 ₁ and/or 18 ₂ can be designed to prevent a change in the electrode spacing and/or in the case of mechanical contact between the electrode structures and the dielectric layer, to discharge the dielectric or to charge it with charge carriers to a predetermined potential.

If the potential of both electrodes 14 ₁ and 14 ₂ or 14 ₃ and 14 ₄ can be controlled independently of one another, this also enables the parallel control/charging/discharging of the electrode structures independently of one another.

In the 2a , 2 B , 3 , 4 , 5a , 5b and 6 the signal line is acted upon on two opposite sides by two electrical capacitors 32 ₁ and 32 ₂ or 32' and 32' ₂ . Corresponding MEMS components can be designed to control the respective actuators 18 ₁ and 18 ₂ in order to achieve a matching capacitance value and /or to obtain matching electrode spacing in the capacitors 32 ₁ and 32 ₂ . Alternatively, provision can also be made to obtain a capacitance value that differs from one another and/or an electrode spacing that differs from one another in the first electrical capacitor and the second electrical capacitor. This means it is not absolutely necessary to synchronously approach the two capacitors to the RF line. It is also possible to control at different speeds or asynchronously. As a result, the slope of the time capacity change function can be varied slightly in the sense of C=C(t), provided that this is advantageous in terms of influencing the signal line properties.

MEMS devices in accordance with embodiments described herein may be configured to adjust an electrical capacitance value of the electrical capacitor 32 ₁ and/or 32 ₂ between a minimum capacitance value (largest electrode spacing) and a maximum capacitance value (minimum electrode spacing). The actuators 18 ₁ and/or 18 ₂ or the actuator 18 can be designed to provide an actuator stroke that causes a ratio between the minimum capacitance value and the maximum capacitance value of at least 15. The change in capacitance can be in a ratio of at least 1, at least 15 or preferably at least 20. An upper limit of the ratio can alternatively or additionally be 1000, 500 or 100. Thus, exemplary ratios of capacitance values between 1 and 100, 15 and 50 and/or 20 and 30 can be achieved.

In other words is in 6 a so-called floating electrode, the concept of the floating electrode is presented. The alternative varactor 60 knows in the gap 16 ₁ , 16 ₂ between the electrode 48 ₁ , 48 ₂ and RF line 42 on one/two additional electrodes 14 ₁ , 14 ₃ and/or 14 ₂ , 14 ₄ , which are connected to the electrode via an electrically insulating compound 44 and / or 46 is mechanically connected. The electrodes 14 ₁ , 14 ₃ and/or 14 ₂ , 14 ₄ are floating electrodes which each have a separate electrical connection 52 ₁ , 52 ₄ and/or 52 ₂ , 52 ₃ . The floating electrodes 14 ₁ , 14 ₃ and/or 14 ₂ , 14 ₄ are normally kept electrically floating or supplied with signals other than the GND and RF signals applied to the electrodes 48 ₁ , 48 ₂ and .the RF Line 42 to be given. In the standard case only one floating electrode with connecting dielectric is used, normally the electrode 14 ₁ , 14 ₃ with insulator 44, together with an unstructured HF line 42. In the case of the illustrated electrode 14 ₁ , 14 ₃ this follows the movement of the electrode 48 ₁ , 48 ₂ and is further connected to the surrounding substrate. As a rule, this connection area is less rigid than the surrounding substrate and the electrodes themselves. In addition, another exemplary embodiment is designed in such a way that the electrodes 48 ₁ , 48 ₂ and 14 ₁ , 14 ₃ are not connected to the surrounding substrate. About the electrical contact 52 ₁ , 52 ₄ with a soft spring (English: soft spring) or a direct connection in a clamped state (English: direct connection in a clamped-clamped case), the electrodes 14 ₁ , 14 ₃ with separate electrical connections connected, whereas the electrode 48 ₁ , 48 ₂ according to 3 connected to an electrical signal (e.g. GND).

These designs result in a large number of advantages, which will be discussed below. The further electrodes 14 ₁ , 14 ₃ and/or 14 ₂ , 14 ₄ reduce the risk of the actuators self-actuating as a result of the DC component of the applied RF signal in the RF line and improve the operational reliability of the component. The DC component of the RF signal increases with increasing RF signal power and frequency. A floating electrode thus increases the HF power to be transmitted and the HF frequency at which the varactor 60 can be used reliably. In addition, it is possible to use a continuous dielectric, since there is less likelihood of the dielectric charging up and causing static friction, since the contact surfaces are metallic, ie electrically conductive. This increases the dielectric constant in the gap 16 ₁ , 16 ₂ and as a result an improved tuning ratio is established. In addition, short circuits between electrodes 48 ₁ , 48 ₂ and RF line 42 are prevented. The structured surface of the electrodes 14 ₁ , 14 ₃ and 14 ₂ , 144 prevents adhesion between these two assemblies in the event of sticking. By connecting electrodes 14 ₁ , 14 ₃ and/or 14 ₂ , 14 ₄ to GND or a specific voltage signal, this electrode can be discharged before each operating cycle or charged to a certain level (in this case it is not connected to GND) , which improves the reliability and result reproducibility of the device.

7 shows a schematic side sectional view of the MEMS component 20. The illustration relates to the sectional plane AA in FIG 2a . As can also be implemented in other exemplary embodiments, the electrode structure 14 ₂ is at least part of a signal line. This is connected to the substrate 12 by an insulating layer 38 and supported thereon. In contrast, the actuators 18 ₁ and 18 ₂ can be arranged such that they can move with respect to the substrate 12 .

8th shows a schematic side sectional view of the MEMS device 20 analogously 7 , but in a deflected state such that due to the applied signals the distances 16 ₁ and 16 ₂ off 7 are reduced as illustrated by spacings 16' ₁ and 16' ₂ .

In other words, the 7 and 8th the varactor 20 in the preferred exemplary embodiment in a view along the section axis AA. 7 shows the varactor 20 in an undeflected state. 8th shows the varactor 20 in a deflected state. In this case, the cavity defined by the distances 16' has a smaller volume. The necessary insulation layer 38, which is continuous in exemplary embodiments, is shown here. This layer is preferably discontinuous. Typical electrically insulating materials here are oxides, for example silicon oxides, or electrically non-conductive polymers.

9 FIG. 9 shows a schematic side sectional view of a MEMS device 90 according to an embodiment. Compared with, for example, the representation from 7 the signal line, which also serves as the electrode structure 14 ₂ , is arranged outside the plane of the electrode structures 14 ₁ and 14 ₃ and forms a kind of cover for the arrangement of the actuators 18 ₁ and 18 ₂ . Such a cover can, possibly in cooperation with a corresponding cover, both terms not restricting the orientation in space, used to control the movement of the electrode structures 14 ₁ du 14 ₃ on each other, since a fluid arranged in between through the Column to cover 14 ₂ and the bottom is performed. Such a fluidic resistance can set or influence an oscillation behavior of the electrodes, so that a space between the electrode structures 14 ₁ and 14 ₂ on the one hand and 14 ₂ and 14 ₃ on the other hand as well as to the ground can be a design criterion of the MEMS component.

In 9 It is clear that electrode structures, such as electrode structures 14 ₁ and 14 ₃ arranged opposite one another, can move towards and/or away from one another or can change an electrode spacing of the capacitor formed by the electrode structures. Under the influence of a further electrode structure 14 ₂ , however, a constant distance between the electrode structures 14 ₁ and 14 ₃ lead to variable influences on a component if, for example, the distance between the electrode structures 14 ₁ and 14 ₂ is increased at the same time and the distance between the electrode structures 14 ₂ and 14 ₃ is reduced to the same extent, or vice versa.

As with the other MEMS components described herein, a substrate 12 arranged in a substrate plane x/y can be provided for the MEMS component 90 . Electrode structures 14 ₁ and 14 ₃ can be arranged parallel to the substrate plane x/y opposite one another. Electrode structures 14 ₁ and 14 ₂ on the one hand and 14 ₂ and 14 ₃ on the other hand can also have an offset perpendicular to the substrate plane to one another, with the electrode structures 14 ₁ and 14 ₂ , 14 ₁ and 14 ₃ and 14 ₂ and 14 ₃ each having an electrical capacitor to be able to form. An actuator, which is coupled to the electrode arrangement, is designed to change an electrode spacing between at least two of the electrode structures parallel to the substrate plane. In the MEMS device 90 this is possible for all electrode pairs, for example by a displacement of the electrode structures 14 ₁ and 14 ₃ towards each other affecting the distance between them and a movement of the electrode structures 14 ₁ and 14 ₂ and/or the electrode structures 14 ₂ and 14 ₂ , relative to each other meet this criterion to change an electric capacitance value of the electric capacitor. The two actuators are designed to generate the in-plane movement, it also being possible for only one of the actuators to be provided with an electrode arranged on it.

In the embodiment shown, two of the three electrode structures 14 ₁ and 14 ₃ are arranged in a common plane parallel to the substrate plane and a third electrode structure 14 ₂ of the three electrode structures is arranged offset perpendicular to the substrate plane. The effect of this exemplary embodiment can also be obtained by arranging, for example, only the electrode structure pair 14 ₁ and 14 ₂ or 14 ₂ and 14 ₃ , which can correspond to an offset of one of the electrode structures of the MEMS component 10 along the z-direction.

In other words shows 9 a varactor 90 with an RF line 14 ₂ placed above the actuation plane. In this case, the gap 16 is larger than in the previously shown solutions, for example in the MEMS component 20, so that the electrodes 14 ₁ and 14 ₃ can perform a larger stroke.

10 FIG. 12 shows a schematic side sectional view of the MEMS device 60 in the BB plane.

Exemplary embodiments described above relate to MEMS components with one or more actuators, each of which comprises at least two beams connected to one another at discrete areas. However, embodiments of the present invention are not limited thereto. Particularly in the case of at least two actuators that are arranged opposite a signal line, other actuators can also be used, for example piezoelectric bending actuators and/or stack actuators, other forms of electrostatic or thermomechanical actuators or other functional principles, such as coil drives or the like. Such a MEMS device includes, for example, referring to the 2a and 2 B a substrate 12 arranged on a substrate plane and an electrode arrangement with a first electrode structure and a second electrode structure, such as the electrode structures 14 ₁ and 14 ₂ , which are arranged opposite one another parallel to the substrate plane, around a first electrical capacitor 32 ₁ with a first capacitance value C to form ₁ . Furthermore, at least one third electrode structure 14 ₃ is provided, which is arranged parallel to the substrate plane opposite the second electrode structure. With the second electrode structure 14 ₂ or with a fourth electrode structure 14 ₄ , see for example 6 , a second electrical capacitor 32 ₂ having a second capacitance value C ₂ is formed. An actuator device, which is coupled to the electrode arrangement, is designed to set and/or simultaneously increase or reduce the first capacitance value and the second capacitance value independently of one another. The actuator device may include the beam-based actuators described herein or the other actuators just discussed.

Further exemplary embodiments relate to methods for driving such MEMS devices. While some methods for changing an electrical capacitance value of a MEMS component involve driving at least one beam of an actuator with at least two beams that are spaced apart parallel to a substrate plane of the MEMS component and are mechanically connected to one another in discrete areas, which form a common movable element in order to move the movable Element to move in-plane relative to the substrate plane, include, and be carried out in such a way that an electrode spacing between a first electrode structure of an electrode arrangement and one parallel to the substrate plane arranged second electrode structure of the electrode arrangement is changed parallel to the substrate plane, in that the actuator exerts a force on the electrode arrangement by deforming at least one bar parallel to the substrate plane, other methods for changing a first electrical capacitance value and a second electrical capacitance value of a MEMS Component, for example independently of the specific implementation of the actuator, have the step of: controlling an actuator device in order to create a first distance between a first electrode structure and a second electrode structure, which are arranged opposite one another parallel to a substrate plane and which have a first electrical capacitor with a first form electrical capacitance value to change. Furthermore, it is achieved that a second distance between at least a third electrode structure and a center of the third electrode structure, the electrode structure forming a second electrical one, for example the second electrode structure 14 ₂ or an electrode structure 14 ₄ , and with which the third electrode structure forms a second electrical capacitor forms with the second capacitance value to reduce or increase.

Exemplary embodiments are based on the solution idea of adjusting the grounded varactor electrode, for example in one exemplary embodiment by means of electrostatic lateral LNED actuators. This solves the pull-in problem for MEMS varactors described above, because the movement or pull-in of the GND plate is decoupled from the pull-in of the actuator. This enables almost the entire initial electrode spacing to be used, which enables TR factors of >30...50. The problem of sticking does not exist here either, because the actuators represent a kind of additional return spring. A linearity of the tunability can also be achieved through a special form of the electrical voltage. Another advantage of using the LNED actuator is that the chip depth and not the chip footprint can be used to increase the electrode area and thus the initial capacitance C ₀ . This leads to cost savings and enables miniaturization of the MEMS varactors with larger initial capacitances.

Exemplary embodiments relate to micromechanical components. These are required, for example, to translate electrical signals into mechanical effects.

In the case of the present deformable elements, deformation of the element results from an electrical input signal. In this case, the deformable element is an actuator 18.

A deformable element consists of at least two spaced beam-shaped electrodes separated from each other by an electrically insulating layer 26, which may be discontinuous. Both electrodes have different electrical potentials, as a result of which an electrical field is created between the electrodes. As a result, the electrodes are deformed relative to one another. The direction of deformation can be influenced by the geometric conditions of the electrodes. In the present case, a lateral deformation takes place within the substrate plane (in plane).

Some of the exemplary embodiments described herein relate to electrodes that are connected to one another via mechanical fixations and are configured to perform a movement based on an electrical potential. However, embodiments are not limited to this, but can be any type of beam structure, i. H. Beams that are designed to respond to an actuation by providing a force converted into a movement via the mechanical fixation (actuator), for example using piezoelectric materials or other actuatable substances. For example, the beams may be electrostatic, piezoelectric, magnetostrictive, and/or thermomechanical electrodes that provide deformation based on an applied potential.

The MEMS components presented below are layer stacks that consist of at least one substrate layer in which the electrodes and the passive elements are arranged. Further layers relate to a base, which is also referred to as a handle wafer, and a cover, which is also referred to as a cover wafer. Both the cover wafer and the handle wafer are connected to the substrate level using material-to-material methods, preferably bonding, which creates sealed gaps in the component. In this intermediate space, which corresponds to the device plane, the deformable components deform, in other words the deformation takes place in plane.

The layers can have, for example, electrically conductive materials, for example doped semiconductor materials and/or metal materials. The layered arrangement of electrically conductive layers enables a simple design, since electrodes (for deflectable elements) and passive elements can be formed by selectively removing them from the layer. If electrically non-conductive materials have to be arranged, these materials are applied in layers using deposition processes.

Features of individual exemplary embodiments described herein can be combined with one another without further ado. Further advantages resulting from the features and exemplary embodiments described herein are that the distances 16 allow a large stroke of the electrodes. Likewise, the exemplary embodiments show that an RF-HF signal in the RF line can be completely separated from the drive signals of the actuators. As a result, the maximum power and the maximum frequency within the RF line of the varactors presented can be significantly increased. The risk of self-excitation due to the DC component of the applied RF signal, which can result in a pull-in, can be reduced by using electrode configurations with high rigidity, for example double-clamped configuration of the beams of the actuators or floating electrodes, see 6 , to be further reduced.

• • Ein MEMS Bauelement mit mindestens einem auslenkbaren Element und mindestens einer feststehenden Elektrode, zwischen denen ein elektrisches Feld aufgespannt ist
  • ◯ durch die Relativbewegung zwischen auslenkbaren Element erfolgt eine Änderung der Kapazität des MEMS Bauelement
  • ◯ Die Änderung der Kapazität erfolgt beispielsweise linear mit der Änderung des Eingangssignals (Zukunft)
  • ◯ Aktuell: hyperbolischer Verlauf der Spannungs- Kapazitätsänderung
• • Eine Bewegungsrichtung in plane
• • Eine Bewegungsart quasistatisch oder von 0-100% der Resonanzfrequenz der Aktoren, bevorzugt 0-50% und besonders bevorzugt 0-20%. 0% stellt dabei eine statische Auslenkung dar. Der Bereich 0-20% kann als quasistatisch angesehen werden.
• • Das MEMS Bauelement ist ein Varaktor
• • Das auslenkbare Element basiert auf einem elektrostatischen, piezo-, thermomechanischen Auslenkungsprinzip
• • Eine Änderung der Kapazität kann in einem Verhältnis von 1-100, bevorzugt 15-50, bes. bevorzugt 20-30 eingestellt werden
• • In einigen Ausführungsbeispielen kann die Änderung der Kapazität in einem Verhältnis von bis zu 1000 einstellbar sein
• • RF Line ist mit dem Handle-Wafer elektrisch isoliert durch eine Isolationsschicht verbunden. Die Isolationsschicht kann unterbrochen sein. Das bedeutet, dass die RF-Line nur partiell mit dem Handle-Wafer verbunden ist
• • Eine Verwendung der Vorrichtung als Varaktor oder als HF- kapazitativ Schalter

Examples refer to:

• • A MEMS component with at least one deflectable element and at least one stationary electrode between which an electrical field is spanned
  • ◯ due to the relative movement between the deflectable element, there is a change in the capacitance of the MEMS component
  • ◯ For example, the change in capacitance occurs linearly with the change in the input signal (future)
  • ◯ Current: hyperbolic course of the voltage-capacitance change
• • A direction of movement in plane
• • A type of movement quasi-static or from 0-100% of the resonant frequency of the actuators, preferably 0-50% and particularly preferably 0-20%. 0% represents a static deflection. The range 0-20% can be viewed as quasi-static.
• • The MEMS component is a varactor
• • The deflectable element is based on an electrostatic, piezo, thermomechanical deflection principle
• • A change in capacity can be adjusted in a ratio of 1-100, preferably 15-50, particularly preferably 20-30
• • In some embodiments, the change in capacitance can be adjustable in a ratio of up to 1000
• • The RF line is connected to the handle wafer with an electrically insulated connection using an insulation layer. The insulation layer can be broken. This means that the RF line is only partially connected to the handle wafer
• • A use of the device as a varactor or as an RF capacitive switch

Although some aspects have been described in the context of a device, it is understood that these aspects also represent a description of the corresponding method, so that a block or a component of a device is also to be understood as a corresponding method step or as a feature of a method step. Similarly, aspects described in connection with or as a method step also constitute a description of a corresponding block or detail or feature of a corresponding device.

The embodiments described above are merely illustrative of the principles of the present invention. It is understood that modifications and variations to the arrangements and details described herein will occur to those skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2018/193109 A1 [0021]

Claims (23)

MEMS component with: a substrate (12) arranged in a substrate plane (x/y); an electrode arrangement (14) having a first electrode structure (14 ₁ ) and a second electrode structure (14 ₂ ) which are arranged parallel to the substrate plane (x/y) opposite one another to form an electrical capacitor (32); an actuator (18) which is coupled to the electrode arrangement and is designed to change an electrode spacing (16) between the first electrode structure (14 ₁ ) and the second electrode structure (14 ₂ ) parallel to the substrate plane (x/y), to change an electrical capacitance value of the electrical capacitor (32); wherein the actuator (18) has at least two beams (24) spaced parallel to the substrate plane (x/y) and mechanically connected to one another at discrete areas, which form a common movable element which is designed to move in-plane with respect to to move the substrate plane (x/y) to change the electrode spacing (16). MEMS device according to claim 1 , which is formed as a MEMS varactor or as a capacitive high-frequency switch. MEMS device according to claim 1 or 2 wherein the second electrode structure (14 ₂ ) forms at least part of a signal line for conducting a signal from a signal line input (34) to a signal line output (36); wherein the electrical capacitor (32) is designed to act on a signal line property of the signal line by means of the electrical capacitance; wherein the actuator (18) is coupled to the first electrode structure (14 ₁ ) in order to move the first electrode structure (14 ₁ ) relative to the second electrode structure (14 ₂ ) parallel to the substrate plane (x/y). MEMS device according to claim 1 or 2 , having a signal line for conducting a signal from a signal line input (34) to a signal line output (36), the electrical capacitor (32) being designed to act on a signal line property of the signal line by means of the electrical capacitance; wherein the first electrode structure (14 ₁ ) is electrically isolated from the signal line and mechanically firmly connected to the signal line. MEMS device according to claim 4 , the first electrode structure (14 ₁ ) and/or the second electrode structure (14 ₂ ) are coupled to a floating potential with respect to the signal line. MEMS device according to claim 5 , having a dielectric (38) which is connected to the first or second electrode structure (14 ₂ ), and having a driving device (37) for controlling at least a part of the MEMS, which is formed prior to a change in the electrode spacing (16) the dielectric (38) to discharge or charge to a predetermined potential with charge carriers. MEMS device according to one of the preceding claims, in which the actuator is a first actuator (18 ₁ ) and the electrical capacitor is a first electrical capacitor (32 ₁ ) with an electrical capacitance value (C ₁ ); wherein the MEMS component comprises at least a third electrode structure (14 ₃ ) which is arranged parallel to the substrate plane (x/y) opposite the second electrode structure (14 ₂ ) and with this or a fourth electrode structure (14 ₄ ) a second electrical capacitor (32 ₂ ); wherein the MEMS device comprises a second actuator (18 ₂ ), which is coupled to the third electrode structure (18 ₃ ) and is configured to have an electrode spacing (16 ₂ ) of the second electrical capacitor (32 ₂ ) parallel to the substrate plane (x /y) in order to change an electric capacitance value (C ₂ ) of the second electric capacitor (32 ₂ ). MEMS device according to claim 7 , in which the MEMS component is designed to drive the first actuator (18 ₁ ) and the second actuator (18 ₂ ) in order to achieve a matching capacitance value and/or a matching electrode spacing (16) in the first electrical capacitor ( 32 ₁ ) and the second electrical capacitor (32 ₂ ) to obtain. MEMS device according to claim 7 , in which the MEMS component is designed to control the first actuator (18 ₁ ) and the second actuator (18 ₂ ) in order to achieve a different capacitance value and/or a different electrode spacing (16) in the first electrical capacitor (32 ₁ ) and the second electrical capacitor (32 ₂ ). MEMS device according to one of Claims 7 until 9 , in which two of the three electrode structures are arranged in a common plane parallel to the substrate plane and a third electrode structure of the three electrode structures is arranged offset perpendicularly to the substrate plane. MEMS component according to one of the preceding claims, which is designed to have the electrical capacitance value between a mini mal capacitance value and a maximum capacitance value, wherein the actuator (18) is designed to provide an actuator stroke which causes a ratio between the minimum capacitance value and the maximum capacitance value of at least 15. MEMS component according to one of the preceding claims, having a structured or unstructured insulation layer (38) which is arranged between the first electrode structure (14 ₁ ) and the second electrode structure (14 ₂ ). MEMS device according to claim 12 , with a control device ( ₃₇ ) which is designed to apply a potential to at least _one of the first electrode structure ( 14 ₁ ) and the second electrode structure (14 ₂ ) to apply in order to transport away charge carriers and counteract adhesion. MEMS component according to one of the preceding claims, in which the first electrode structure (14 ₁ ) and the second electrode structure (14 ₂ ) have a surface topography adapted to one another at least in regions, and compared to a planar configuration of the electrodes an increase in the surface area of the electrical capacitor (32) exhibit. MEMS component according to one of the preceding claims, in which the first electrode structure (14 ₁ ) and the second electrode structure (14 ₂ ) have an electrode spacing (16) from one another that is variable along a variable location on an electrode surface at least in regions. MEMS component according to one of the preceding claims, in which the second electrode structure (14 ₂ ) forms at least part of a signal line which is mechanically firmly connected to the substrate (12) by an insulating layer. MEMS component according to one of the preceding claims, in which an electrode of the actuator (18) facing the electrode arrangement and an electrode structure of the electrode arrangement facing the actuator (18) are electrically connected to one another. MEMS component according to one of the preceding claims, having a control device (37) for controlling the actuator (18), which is designed to output a control signal (39) to the actuator (18), which causes a change in the electrode spacing (16). ; wherein the actuator (18) is set up to set a linear relationship or a hyperbolic relationship between the control signal (39) and an effected change in the electrical capacitance value. MEMS component according to one of the preceding claims, having a control device (37) for controlling the actuator (18), which is designed to control the actuator (18) quasi-statically. MEMS component according to one of the preceding claims, in which the actuator (18) is designed to provide at least one of electrostatic, piezoelectric and thermomechanical displacement. MEMS component with: a substrate (12) arranged in a substrate plane (x/y); an electrode arrangement with a first electrode structure (14 ₁ ) and a second electrode structure (14 ₂ ) arranged parallel to the substrate plane (x/y) opposite to each other to form a first electrical capacitor (32 ₁ ) with a first capacitance value; and with at least one third electrode structure, which is arranged parallel to the substrate plane (x/y) opposite the first electrode structure (14 ₁ ) and forms a second electrical capacitor (32 ₂ ) with a second capacitance value with this or a fourth electrode structure; an actuator device which is coupled to the electrode arrangement and is designed to set the first capacitance value and the second capacitance value independently of one another; and/or increase or decrease at the same time. Method for changing an electrical capacitance value of a MEMS component with the following steps: activating at least one bar (24) of an actuator (18) with at least two parallel to a substrate plane (x / y) of the MEMS component at a distance and mechanically connected to each other connected beams (24) forming a common movable element to move the movable element in-plane with respect to the substrate plane (x/y); so that an electrode spacing (16) between a first electrode structure (14 ₁ ) of an electrode arrangement and a second electrode structure (14 ₂ ) of the electrode arrangement arranged parallel to the substrate plane (x/y) is changed parallel to the substrate plane (x/y), in that the actuator (18) exerts a force on the electrode arrangement parallel to the substrate plane (x/y) by deforming at least one bar (24). A method for changing a first electrical capacitance value and a second electrical capacitance value of a MEMS component, comprising the following step: controlling an actuator device by a first distance between a first electrode structure (14 ₁ ) and a second electrode structure (14 ₂ ) parallel to a substrate plane (x/y) of the MEMS device are arranged opposite to each other and form a first electrical capacitor (32 ₁ ) having a first capacitance value; and to reduce or increase a second distance between at least a third electrode structure and an electrode structure which forms a second electrical capacitor (32 ₂ ) with the third electrode structure and is arranged parallel to the substrate plane (x/y) opposite the third electrode structure .

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