Micromechanical element for a microelectromechanical converter, method for manufacturing a micromechanical element, method for operating a micromechanical element, device and microelectromechanical converter

Description

State of the art

[0001] The approach is based on a micromechanical element for a microelectromechanical transducer, a method for manufacturing a micromechanical element, a method for operating a micromechanical element, a device, and a microelectromechanical transducer according to the class of independent claims. A computer program is also part of the present approach. Microelectromechanical transducers form an indispensable technical basis for modern, innovative solutions in electronics, such as in the automotive, medical, security and measurement technology, sports, logistics, and entertainment sectors.

[0002] US 2019 / 0161338 A1 describes a microelectromechanical actuator comprising a fixed part and a movable part. Documents EP 3 809 476 A1, DE 10 2017 109575 A1, and US 2008 / 122317 A1 describe further micromechanical elements, some of which exhibit features of the micromechanical element according to claim 1. Disclosure of the invention

[0003] Against this background, the approach presented here provides an improved micromechanical element for a microelectromechanical

[0004] A converter, an improved method for manufacturing a micromechanical element, an improved method for operating a micromechanical element, furthermore an improved microelectromechanical converter, a device employing at least one of the methods, and finally a corresponding computer program according to the main claims are presented. Advantageous further developments and improvements of the device specified in the independent claim are possible through the measures listed in the dependent claims.

[0005] The presented approach enables, for example, bidirectional quasi-static motion and bidirectional driving of vibrations, thereby allowing for faster achievement of a target amplitude and attaining a larger maximum amplitude.

[0006] A micromechanical element for a microelectromechanical transducer according to independent claim 1 is presented.

[0007] The microelectromechanical transducer can be referred to, for example, as a microelectromechanical system (MEMS) or a MEMS transducer. The micromechanical element can be integrated as part of the microelectromechanical transducer and is, for example, bidirectionally controllable. The support layer can, for example, be a silicon-based substrate. Alternatively or additionally, the support layer can also consist of other materials. Advantageously, the support layer can be at least partially bidirectionally deformable, so that, for example, a target amplitude is reached more quickly during transducer oscillation. Furthermore, the maximum amplitude can advantageously be increased. The piezoelectric elements can each have two electrodes, which can be arranged on opposite sides of a piezoelectric layer. This means that, for example, one electrode of each piezoelectric element can contact the support layer.Piezoelectric elements, for example, are implemented as components that can perform a mechanical movement using an electrical voltage or produce an electrical voltage when a mechanical force is applied.

[0008] According to one embodiment, the first and second piezoelectric elements can be arranged offset from each other or on an axis that lies transversely to a longitudinal axis of the substrate. For example, in a rest state of the micromechanical element, the longitudinal axis can be parallel to the neutral axis of the substrate. The longitudinal axis of the substrate can, for example, correspond to a direction of extension of the piezoelectric elements. In this way, a fast and flexibly adjustable bending behavior of the substrate can be achieved.

[0009] Advantageously, the micromechanical element can have at least one further first piezoelectric element arranged on the first side of the neutral fiber of the substrate layer. In other words, the piezoelectric elements can be arranged in a zigzag pattern, alternating above and below the neutral fiber. The area can, for example, encompass both sides of the neutral fiber and be bounded between two adjacent piezoelectric elements. Such an embodiment offers the advantage of high flexibility in shaping or adjusting the vibration behavior of the micromechanical element.

[0010] According to one embodiment, the first piezoelectric element and, additionally or optionally, the second piezoelectric element can be arranged in a cavity in or on the substrate layer. The cavity can, in particular, have a depth that, within a tolerance range of 100%, corresponds to the thickness of the first and, additionally or alternatively, the second piezoelectric element. Advantageously, the depth of the cavity, or a plurality of cavities, allows for efficient use of installation space. Furthermore, the piezoelectric elements can be protected, as they can be surrounded by the substrate layer on at least three sides. The cavities can therefore, for example, be implemented as recesses.

[0011] The first and, additionally or alternatively, the second piezoelectric element can be positioned between the substrate and a passivation layer. The passivation layer can be created, for example, through a chemical reaction with substances that differ from the substrate material, or it can be applied externally to the substrate. This advantageously protects components of the micromechanical element from environmental influences.

[0012] Furthermore, the micromechanical element can have a stabilizing zone in the support layer that exhibits a different bending behavior than a material of the support layer. In particular, the stabilizing zone can be arranged opposite the first piezoelectric element. Advantageously, the support layer can comprise a plurality of materials that may differ, for example, in their strength, elasticity, or, more generally, in their deformability. This allows a desired bending behavior of the support layer of the micromechanical element to be set or adapted through a simple design option.

[0013] Furthermore, a method for manufacturing a micromechanical element in a previously mentioned variant according to claim 5 is presented.

[0014] The process can be carried out using semiconductor processes, which advantageously allows for consistent precision in the alignment of the individual components of the micromechanical element. This can advantageously improve the longevity of the final product and / or reduce its susceptibility to defects.

[0015] According to one embodiment, the provisioning step can include a sub-step of arranging the first piezoelectric element in a cavity of an auxiliary layer, a sub-step of covering the first piezoelectric element with the substrate layer, and a sub-step of applying the second piezoelectric element to the substrate layer. Advantageously, this allows the piezoelectric elements to be arranged precisely in a line above one another.

[0016] In one embodiment, during the provisioning step, the first and second piezoelectric elements can be arranged on an auxiliary layer in a sub-step of the assembly process. In a sub-step of the deposition process, at least a portion of the carrier layer can be applied to the second piezoelectric element, allowing the second piezoelectric element to be arranged in a cavity. Advantageously, in such a case, the second piezoelectric element can be surrounded by the auxiliary layer on one side and by the carrier layer, for example, on three other sides, so that the second piezoelectric element can be fully embedded. Advantageously, this protects the second piezoelectric element from external influences.

[0017] Furthermore, in the covering step and additionally or alternatively in the deposition step, at least one cavity can be formed in or on the substrate layer to accommodate the first and additionally or alternatively the second piezoelectric element. More precisely, at least one of the piezoelectric elements can be produced in the cavity, for example, using semiconductor processes.

[0018] Furthermore, a method for operating a micromechanical element, as previously mentioned, is presented, wherein the method comprises a step of applying an electrical voltage to the first and additionally or alternatively the second piezoelectric element and additionally or alternatively a step of detecting an electrical voltage from the first and additionally or alternatively the second piezoelectric element.

[0019] Advantageously, this allows the micromechanical element to be bent quickly in both directions.

[0020] These methods can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example in a control unit.

[0021] The approach presented here also creates a device designed to carry out, control, and implement the steps of a variant of one of the methods presented here in appropriate facilities. This device-based implementation of the approach also allows the underlying problem to be solved quickly and efficiently.

[0022] For this purpose, the device may have at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface to a sensor or actuator for reading sensor signals from the sensor or for outputting data or control signals to the actuator, and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The processing unit may, for example, be a signal processor, a microcontroller, or the like, and the storage unit may be flash memory, EEPROM, or a magnetic storage device.The communication interface can be configured to read or output data wirelessly and / or via wired connections, whereby a communication interface that can read or output wired data can, for example, read this data electrically or optically from or output it into a corresponding data transmission line.

[0023] In this context, a device can be understood as an electrical device that processes sensor signals and outputs control and / or data signals accordingly. The device may have an interface, which can be implemented in hardware and / or software. In the case of a hardware-based interface, the interfaces can, for example, be part of a so-called system ASIC, which incorporates various functions of the device. However, it is also possible that the interfaces are separate integrated circuits or consist at least partially of discrete components. In the case of a software-based interface, the interfaces can be software modules, which, for example, are present on a microcontroller alongside other software modules.

[0024] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular if the program product or program is executed on a computer or device.

[0025] Furthermore, a microelectromechanical transducer is presented, which has a support substrate and a micromechanical element in a previously mentioned variant, which is arranged on the support substrate.

[0026] The microelectromechanical transducer can be configured, for example, as a sensor or an actuator. It can be referred to as a MEMS transducer designed to interact, for example, with a volumetric flow rate of a fluid. The substrate can, for example, have a cavity in which the micromechanical element can be arranged.

[0027] Examples of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows: Fig. 1 a schematic sectional view through at least one micromechanical element according to an exemplary embodiment; Fig. 2 a schematic sectional view of an exemplary embodiment of at least one micromechanical element; Fig. 3 a schematic sectional view of a microelectromechanical transducer according to an exemplary embodiment; Fig. 4a schematic sectional view of an embodiment of a microelectromechanical transducer; Figs. 5-8 a schematic sectional view of an embodiment of a micromechanical element during a manufacturing process; Figs. 9-11 a schematic sectional view of an embodiment of a micromechanical element during a manufacturing process; Fig. 12 a flowchart of a process according to an exemplary embodiment for manufacturing a micromechanical element; Fig. 13 a block diagram of a device according to an exemplary embodiment; Fig. 14 a flowchart of a method according to an exemplary embodiment for operating a micromechanical element; and Fig. 15 a block diagram of a device according to an exemplary embodiment.

[0028] In the following description of favorable embodiments of the present approach, the same or similar reference numerals are used for the elements shown in the various figures and which have a similar effect, without repeating these elements.

[0029] Fig. 1Figure 1 shows a schematic sectional view through at least one micromechanical element 100 according to an exemplary embodiment. The micromechanical element 100 can be used, for example, for a microelectromechanical transducer, also referred to as a microelectromechanical system (MEMS) or, in short, as a MEMS transducer, and has a support layer 105 which is shaped as a bending beam or as a membrane. The micromechanical element 100 also has a first piezoelectric element 110 and a second piezoelectric element 115. The first piezoelectric element 110 is arranged on a first side 120 of the neutral fiber 125 of the support layer, and the second piezoelectric element 115 is arranged on a second side 130 of the neutral fiber, with the second side 130 being opposite the first side 120. According to this exemplary embodiment, the support layer 105 is shown in a resting state, such that the neutral fiber 125 runs parallel to an axis of extension 135 of the micromechanical element 100.The first piezoelectric element 110 and the second piezoelectric element 115 are arranged offset from each other, as shown in the following . Fig. 2 As described above, the piezoelectric elements 110, 115 are arranged on an axis 140 that runs perpendicular to the axis of extension 135 of the support layer 105. According to this embodiment, the first piezoelectric element 110 has a first electrode 140 and a second electrode 145. A piezoelectric layer 150 is arranged between the electrodes 140, 145. Similarly, the second piezoelectric element 115 has a third electrode 155 and a fourth electrode 160, between which another piezoelectric layer 165 is arranged. According to this embodiment, two identically shaped micromechanical elements 100 are also shown, which are arranged adjacent to each other and share the support layer 105.

[0030] In other words, and in a shortened form, this embodiment shows a cross-section through a micromechanical element 100 with piezo elements 110, 115 arranged one above the other on both sides in a planar embodiment.

[0031] In general, bidirectional deflection from a rest position is sometimes desirable for micromechanical elements 100. This enables a larger deflection stroke or a larger measuring range and differential measurement of a microelectromechanical transducer as a MEMS sensor. Bending beams and membranes are used as MEMS actuators or sensors for microelectromechanical elements 100. Typically, in piezo-based microelectromechanical transducers, also referred to as PiezoMEMS, Piezo actuators, and / or Piezo sensors, at least one piezoelectric element 110, 115 is integrated onto a moving element, so that only a quasi-static unidirectional deflection is possible. Alternatively, a dynamic drive can be implemented such that the deflection is caused by the piezo actuator, while movement in the opposite direction is accomplished solely by mechanical inertia.

[0032] Against this background, the described approach is suitable for acoustic transducers, such as microphones, microspeakers, piezoelectric micromachined ultrasonic transducers. (Piezoelectric Micromachined Ultrasonic Transducer; PMUT), but also for micromirrors, microlenses, bulk acoustic wave (BAW) or film bulk acoustic wave (FBAR) resonators, radio frequency (RF) filters, and / or similar devices. The presented approach therefore describes the micromechanical element 100. The micromechanical element 100 can be used both as an actuator and as a sensor. In actuator mode, it can actively drive oscillatory movements in two different directions and also perform quasi-static movements in two directions from a rest position.

[0033] According to this embodiment, the micromechanical element 100 is realized, or can be realized, as a freestanding, at least one-sidedly clamped, deformable micromechanical element comprising the support layer 105 and two piezoelectric transducers 110, 115 integrated on opposite sides 120, 130 on either side of the neutral fiber 125 of the support layer 105, the deformation of which is causally related to an electrical voltage signal at the piezoelectric transducers 110, 115. The support layer 105 is, for example, shaped as a bending beam or a membrane. Optionally, the micromechanical element 100 is clamped on two sides or around its perimeter and / or has, for example, corrugations that run parallel or perpendicular to the direction of extension of the piezoelectric transducers 110, 115. Furthermore, the micromechanical element 100 is essentially planar.

[0034] The micromechanical element 100 can be used as both an actuator and a sensor and interacts, for example, with an ambient fluid. Specifically, it is, alone or in multiples, part of an acoustic MEMS transducer, which, according to this embodiment, is referred to as a microelectromechanical transducer and is described in more detail in at least one of the following figures. When the micromechanical element 100 is used as an actuator, movements in two directions can be actively driven alternately via the piezoelectric elements 110 and 115, with the other element being used passively for motion detection. When the micromechanical element 100 is used as a sensor, the signals from the opposing piezoelectric elements 110 and 115, which are also referred to as piezoelectric transducers, can be used for differential evaluation in a sigma-delta converter. For example, the micromechanical element 100 can be shaped differently depending on the application.For example, the piezoelectric transducers 110, 115 are arranged offset or without offset to each other on opposite surfaces of the support layer 105. The support layer 105 is, for example, either planar or with corrugations along the length of the piezoelectric transducers 110, 115. The support layer 105 is, for example, designed as a membrane or as a bending beam. The micromechanical element 100 is anchored to a substrate in various ways, for example, around its perimeter or by means of a plurality of anchor points.

[0035] The support layer 105 can optionally be made electrically conductive, so that in such a case it can be used simultaneously as an electrode for one and / or both piezoelectric transducers 110, 115, and the electrodes 145, 155 can optionally be omitted. Preferably, the electrodes 145, 155 facing the support layer 105 are at the same electrical ground potential, while control signals are applied to or tapped from the electrodes 140, 160 facing away from the support layer 105.

[0036] Fig. 2 Figure 1 shows a schematic sectional view of an exemplary embodiment of at least one micromechanical element 100. The micromechanical element 100 shown is similar to the one in Figure 1. Fig. 1The micromechanical element 100 described above also has a common support layer 105 for both, or optionally also for a plurality of, micromechanical elements 100, which, however, is formed in a serpentine shape around the piezoelectric elements 110, 115. According to this embodiment, the neutral fiber 125 is positioned such that it maintains as equal a distance as possible from the piezoelectric elements 110, 115, which are offset from each other. According to this embodiment, the second piezoelectric element 115 is integrated precisely into the support layer 105. The first piezoelectric element 110, on the other hand, is arranged in a cavity 200 that is longer than the first piezoelectric element 110 and / or the second piezoelectric element 115. Only optionally is the second piezoelectric element 115 also arranged in a cavity.The cavity 200 has, for example, a depth that corresponds, within a tolerance range of 100%, to the thickness of the first piezoelectric element 110 and / or the second piezoelectric element 115. According to this embodiment, the micromechanical element 100 has at least one further second piezoelectric element 205, which is arranged on the second side 130 of the neutral fiber 125 of the support layer 105. In particular, the first piezoelectric element 110 is arranged in a region between the second piezoelectric elements 115 and 205. In other words, according to this embodiment, a cross-section through a micromechanical element 100 with piezoelectric elements 110 and 115 arranged offset from each other on both sides is shown in a corrugated embodiment.

[0037] Fig. 3Figure 1 shows a schematic sectional view of a microelectromechanical transducer 300 according to an exemplary embodiment. The microelectromechanical transducer 300 is configured, for example, to interact with a volume flow 302 of a fluid and has a support substrate 305 and a micromechanical element 100, as described in one of the Figures 1 to 2 as described. The microelectromechanical transducer 300 is configured as both an actuator and a sensor. According to this embodiment, the microelectromechanical transducer 300 has two identical micromechanical elements 100, each connected to the substrate 305 on one side by means of an extension of the support layer 105 and exposed on the opposite side. In the area of ​​the micromechanical element 100, the support substrate 305 has a cavity 310, so that the micromechanical element 100 "floats" above the cavity 310 on its exposed side.

[0038] In other words, this embodiment shows a cross-section through a microelectromechanical transducer 300, which is also referred to, for example, as a MEMS device and has piezoelectric elements 110, 115 arranged on both sides. According to this embodiment, the microelectromechanical transducer 300, which is also referred to simply as the MEMS transducer 300, has the support substrate 305, a cavity 310 formed therein, and the micromechanical element 100, which delimits the cavity 310 and whose deformation along a direction of movement is causally related to the volume flow 302 of a fluid perpendicular to the micromechanical element 100. The MEMS transducer 300 is implemented, for example, as a MEMS sensor or as a MEMS actuator.The support layer 105 is only optionally implemented as electrically conductive, so that it fulfills, for example, a function of at least one electrode of the piezoelectric elements 110, 115, which are located at the same electrical ground potential. Control signals are applied, for example, to the electrodes located on the opposite side of the support layer 105. Ideally, the control signals are tuned such that the piezoelectric elements 110, 115 on opposite sides of the support layer 105 expand and / or contract with a phase shift of 180°.

[0039] The fluid is supplied to or discharged from the micromechanical element 100, for example, via the cavity 310 formed in the support substrate 305. The deformation of the micromechanical element 100 occurs along the direction of movement of the volume flow 302 of a fluid, for example, perpendicular to the micromechanical element 100. The volume flow 302 is either optionally generated by the micromechanical element 100 itself or alternatively supplied from the outside. In both cases, there is a causal relationship between the volume flow 302 and the deformation.

[0040] Fig. 4 Figure 1 shows a schematic top view of an embodiment of a microelectromechanical transducer 300. The microelectromechanical transducer 300 corresponds to the one described in Figure 2. Fig. 3The described microelectromechanical transducer 300 differs only in one aspect of its representation. In this embodiment, the microelectromechanical transducer 300 is shown in a top view. In this embodiment, a plurality of micromechanical elements 100 are shown, which together form a rectangular, in particular square, shape and substantially cover a cavity 310.

[0041] In the following Figures 5 to 11 Each schematic cross-sectional view of an embodiment of a micromechanical element 100 is shown in different phases during a manufacturing process.

[0042] The Figures 5 to 8 This represents a manufacturing process for the micromechanical element 100, as used, for example, in at least one of the Figure 1 , 3, 4 was described. Figures 9 to 11 In contrast, they represent a production of the micromechanical element 100, as is used, for example, in Fig. 2was described.

[0043] Fig. 5 Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The micromechanical element 100 shown in this embodiment corresponds to or is similar to, for example, the element shown in one of the Figure 1 , 3, 4 The micromechanical element 100 described above represents only a snapshot during the manufacturing process. According to this embodiment, the first piezoelectric element 110 is arranged on an auxiliary layer 505 coated with a passivation layer 500. The auxiliary layer 505 further comprises a cavity 200 into which the first piezoelectric element 110 is inserted.

[0044] For example, the auxiliary layer 505 is provided, and then the cavity 200 is created as trenches whose depth is on the order of the thickness of the piezoelectric element 110 or greater. Subsequently, a first layer of piezoelectric transducers 110 is applied and structured, each comprising the first electrode 140, the second electrode 145, and the piezoelectric layer 150.

[0045] Fig. 6 Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The figure is shown in Figure 2. Fig. 6 The micromechanical element 100 shown is similar to the one in Fig. 5 The micromechanical element 100 described here represents only a snapshot during the manufacturing process. Compared to the one described in Fig. 5The micromechanical element 100 shown in this embodiment is further developed. For example, a planarization layer 600 is deposited to planarize the substrate surface 605 of the auxiliary layer 505 in an optional polishing step. In this step, for example, a portion of the passivation layer located outside the cavity is removed. To completely flatten the substrate surface 605, the support layer 105 is applied to the auxiliary layer 505, acting as a lid, according to this embodiment. The support layer 105 is implemented as a mechanical support layer 105. According to this embodiment, the first piezoelectric element 110 is arranged between the support layer 105 and the passivation layer 500. Additionally or alternatively, a second piezoelectric element can also be arranged between the support layer 105 and the passivation layer 500.

[0046] Fig. 7Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The figure is shown in Figure 2. Fig. 7 The micromechanical element 100 shown is similar to the one in Fig. 6 The micromechanical element 100 described here represents only a snapshot during the manufacturing process. Compared to the one described in Fig. 6 The micromechanical element 100 shown in the illustration is further developed according to this embodiment. According to this embodiment, the micromechanical element 100 additionally features: Fig. 7 a second piezoelectric element 115, which is encased by a further passivation layer 700.

[0047] Fig. 8 Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The figure is shown in Figure 2. Fig. 8 The micromechanical element 100 shown is similar to the one in Fig. 7The micromechanical element 100 described here represents only a snapshot during the manufacturing process. Compared to the one described in Fig. 7 The micromechanical element 100 shown is further developed according to this embodiment. According to this embodiment, the auxiliary layer 505 is structured so that the first piezoelectric element 110, including the passivation layer 500, is exposed. Additionally, the support layer 105 is cut through on at least one side of the micromechanical element 100.

[0048] Fig. 9 Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. More precisely, this embodiment only depicts a snapshot during the manufacturing process. The micromechanical element 100 to be manufactured corresponds to or resembles the one shown in Figure 1. Fig. 2described micromechanical element 100. According to this embodiment, a stabilization area 900 is formed adjacent to the auxiliary layer 505, which may exhibit a different bending behavior than a material of the support layer, which in Fig. 11 is applied. A passivation layer 500 is arranged along a surface of the auxiliary layer 505 and the stabilization area 900, such that the stabilization area 900 is located between the auxiliary layer 505 and the passivation layer 500. The passivation layer 500 is, for example, shaped as a trapezoidal protrusion.

[0049] In other words, in Fig. 9 a result is shown that results from providing the auxiliary layer 505, depositing and structuring the stabilization area 900, and depositing the passivation layer 500.

[0050] Fig. 10Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The figure is shown in Figure 2. Fig. 10 The micromechanical element 100 shown is similar to the one in Fig. 9 The micromechanical element 100 described here represents only a snapshot during the manufacturing process. Compared to the one described in Fig. 9 The micromechanical element 100 shown is further developed according to this embodiment. According to this embodiment, a first piezoelectric element 110 and at least one second piezoelectric element 115 are arranged on the passivation layer 500. More precisely, the first piezoelectric element 110 is arranged opposite the stabilization area 900. The stabilization area can exhibit different or the same bending behavior as a material of a support layer, such as that found, for example, in Fig. 11described. However, it is also possible for the stabilization area to be formed from the same material and thickness as the support layer. According to the invention, the micromechanical element 100 has a further second piezoelectric element 205, which is aligned with the second piezoelectric element 115. The first piezoelectric element 110 is therefore offset in height from the second piezoelectric elements 115, 205 and from the stabilization area 900. According to this embodiment, the passivation layer 500 is open in the area of ​​the stabilization area 900 and thus no longer connected to the second piezoelectric elements 115, 205. An additional passivation layer 700 is arranged around the piezoelectric elements 110, 115, 205. An advantage of this manufacturing process is that the piezoelectric elements on both sides of the neutral fiber can be produced simultaneously using the same process steps.

[0051] Fig. 11Figure 1 shows a schematic sectional view of an embodiment of a micromechanical element 100 during a manufacturing process. The figure is shown in Figure 2. Fig. 11 The micromechanical element 100 shown is similar to the one in Fig. 10 The micromechanical element 100 described here represents only a snapshot during the manufacturing process. Compared to the one described in Fig. 10The micromechanical element 100 shown in the illustration is further developed according to this embodiment. The support layer 105 is applied so that the second piezoelectric elements 115, 205 are completely integrated into the support layer 105. According to this embodiment, the first piezoelectric element 110 is arranged in a cavity 200 and is therefore not surrounded by the support layer 105. Furthermore, according to this embodiment, the auxiliary layer 505 is structured so that the stabilizing region 900 is exposed and the micromechanical element 100 is flexible. On one side of the support layer 105 facing away from the stabilizing region 900, the structure is only exemplary.According to this embodiment, the neutral fiber 125 of the micromechanical element 100 runs longitudinally through the support layer 105 between the first piezoelectric element 110 and the second piezoelectric elements 115, 205 and, for example, along an upper edge of the stabilization area 900.

[0052] Fig. 12 Figure 1200 shows a flowchart of a process according to an exemplary embodiment for manufacturing a micromechanical element. Using process 1200, for example, a micromechanical element is manufactured as described in one of the... Figures 1 to 11The process 1200, as described, comprises step 1205 of providing a support layer shaped as a bending beam or membrane. A first piezoelectric element is arranged on the first side of the neutral fiber of the support layer. A second piezoelectric element is also provided, arranged on the second side of the neutral fiber of the support layer, with the second side facing the first, to fabricate the micromechanical element. Optionally, process 1200, specifically step 1205 of providing the support layer, includes a sub-step 1210 of arranging, in which the first piezoelectric element is arranged in a cavity of an auxiliary layer. In sub-step 1215 of covering, the first piezoelectric element is covered by the support layer, and subsequently, in sub-step 1220 of applying, the second piezoelectric element is applied to the support layer.

[0053] In other words, for example, the auxiliary layer is provided, and a first layer of piezoelectric transducers, consisting of a lower passivation layer, a first electrode, a piezoelectric layer, a second electrode, and an upper passivation layer, is applied and / or structured. The mechanical support layer is then applied and / or structured. Furthermore, a cavity or cutout for the bidirectional micromechanical element is created. Structuring the support layer and / or applying and structuring a second layer of piezoelectric transducers is only optional. Before applying the first piezoelectric layer, grooves for the piezoelectric elements (also called piezos) are created in the substrate, i.e., the auxiliary layer. The depth of these grooves is equal to or greater than the thickness of the piezoelectric transducers.Subsequently, a chemical-mechanical polishing step to planarize the substrate is optionally carried out before or after the application of the mechanical support layer.

[0054] Fig. 13 Figure 1 shows a block diagram of a device 1300 according to an exemplary embodiment. The device 1300 is configured to control or carry out a method for manufacturing a micromechanical element, as is the case, for example, in Fig. 12The device 1300 can, for example, be realized as a control unit or implemented in a control unit and has a provisioning unit 1305. The provisioning unit 1305 is configured to provide a support layer that is shaped as a bending beam or membrane, wherein a first piezoelectric element is arranged on the support layer, which is arranged on a first side of the neutral fiber of the support layer, and a second piezoelectric element is provided, which is arranged on a second side of the neutral fiber of the support layer.

[0055] The second side is positioned opposite the first side to create the micromechanical element.

[0056] Fig. 14 Figure 1400 shows a flowchart of a method according to an exemplary embodiment for operating a micromechanical element. Method 1400 is performed or controlled for micromechanical elements such as those found, for example, in at least one of the Figures 1 to 11 The method 1400 comprises a step 1405 of applying an electrical voltage to the first and / or second piezoelectric element and / or a step 1410 of detecting an electrical voltage from the first and / or second piezoelectric element.

[0057] Fig. 15 Figure 1 shows a block diagram of a device 1500 according to an exemplary embodiment. The device 1500 is configured to control or carry out a method for operating a micromechanical element, as is the case, for example, in Fig. 14The device 1500 can, for example, be implemented as a control unit or within a control unit and comprises an application unit 1505 and / or a detection unit 1510. The application unit 1505 is configured to apply an electrical voltage 1515 to the first and / or the second piezoelectric element. The detection unit 1510 is configured to detect an electrical voltage 1515 from the second and / or first piezoelectric element.

[0058] The process steps presented here can be repeated and performed in a different order than described.

[0059] If an embodiment includes an "and / or" connection between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment either only the first feature or only the second feature.

Claims

1. Micromechanical element (100) for a microelectromechanical transducer (300), wherein the micromechanical element (100) has the following features: a carrier layer (105), which is designed as a bending beam or membrane; a first piezo element (110), which is arranged on a first side (120) of a neutral fibre (125) of the carrier layer (105); and a second piezo element (115), which is arranged on a second side (130) of the neutral fibre (125) of the carrier layer (105), wherein the second side (130) is situated opposite the first side (120), wherein there is at least one further second piezo element (115), which is arranged on the second side (130) of the neutral fibre (125) of the carrier layer (105), characterized in that the first piezo element (110) is arranged in a region between the second piezo elements (115).

2. Micromechanical element (100) according to Claim 1, wherein the first piezo element (110) and one of the second piezo elements (115) are arranged offset with respect to each other or on an axis (140) which lies perpendicular to a longitudinal extension axis (135) of the carrier layer (105).

3. Micromechanical element (100) according to either of the preceding claims, wherein the first piezo element (110) and one of the second piezo elements (115) is arranged in a cavity (200) in or on the carrier layer (105), in particular wherein the cavity (200) has a depth which corresponds to a thickness of the first piezo element (110) and one of the second piezo elements (115) within a tolerance range of 100%.

4. Micromechanical element (100) according to any of the preceding claims, wherein the first piezo element (110) and one of the second piezo elements (115) is arranged between the carrier layer (105) and a passivation layer (500).

5. Method (1200) for producing a micromechanical element (100) according to any of the preceding Claims 1 to 4, wherein the method (1200) comprises the following steps: providing (1205) a carrier layer (105), which is designed as a bending beam or membrane, wherein a first piezo element (110), which is arranged on a first side (120) of a neutral fibre (125) of the carrier layer (105), is arranged and a second piezo element (115), which is arranged on a second side (130) of the neutral fibre (125) of the carrier layer (105), is provided on the carrier layer (105), wherein the second side (130) is situated opposite the first side (120) in order to produce the micromechanical element (100), wherein a further second piezo element (205) is provided, which is arranged on the second side (130) of the neutral fibre (125) of the carrier layer (105), characterized in that the first piezo element (110) is arranged in a region between the second piezo elements (115, 205).

6. Method (1200) according to Claim 5, wherein a sub-step (1210) of arranging the first piezo element (110) in a cavity (200) of an auxiliary layer (505), a sub-step (1215) of covering the first piezo element (110) by the carrier layer (105) and a sub-step (1220) of applying one of the second piezo elements (115) to the carrier layer (105) are carried out in the providing step (1205).

7. Method (1200) according to Claim 6, wherein at least one cavity (200) is formed in or on the carrier layer (105) in the covering sub-step (1215) and / or in the application sub-step (1220) in order to receive the first piezo element (110) and one of the second piezo elements (115).

8. Microelectromechanical transducer (300), which has the following features: a carrier substrate (305); and a micromechanical element (100) according to any of Claims 1 to 4, which is arranged on the carrier substrate (305).