EP3592694A1 - Actionneur mems électrostatique et procédé de fabrication de celui-ci - Google Patents

Actionneur mems électrostatique et procédé de fabrication de celui-ci

Info

Publication number
EP3592694A1
EP3592694A1 EP18709000.6A EP18709000A EP3592694A1 EP 3592694 A1 EP3592694 A1 EP 3592694A1 EP 18709000 A EP18709000 A EP 18709000A EP 3592694 A1 EP3592694 A1 EP 3592694A1
Authority
EP
European Patent Office
Prior art keywords
electrode
substrate
electrodes
dimension
mems
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP18709000.6A
Other languages
German (de)
English (en)
Inventor
Sergiu Langa
Holger Conrad
Matthieu Gaudet
Klaus Schimmanz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Original Assignee
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV filed Critical Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Publication of EP3592694A1 publication Critical patent/EP3592694A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B3/00—Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes
    • B81B3/0035—Constitution or structural means for controlling the movement of the flexible or deformable elements
    • B81B3/0056—Adjusting the distance between two elements, at least one of them being movable, e.g. air-gap tuning
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B3/00—Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes
    • B81B3/0002—Arrangements for avoiding sticking of the flexible or moving parts
    • B81B3/0008—Structures for avoiding electrostatic attraction, e.g. avoiding charge accumulation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B3/00—Devices comprising flexible or deformable elements, e.g. comprising elastic tongues or membranes
    • B81B3/0002—Arrangements for avoiding sticking of the flexible or moving parts
    • B81B3/0013—Structures dimensioned for mechanical prevention of stiction, e.g. spring with increased stiffness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00134—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems comprising flexible or deformable structures
    • B81C1/00166—Electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/02—Sensors
    • B81B2201/0257—Microphones or microspeakers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/03—Microengines and actuators
    • B81B2201/038—Microengines and actuators not provided for in B81B2201/031 - B81B2201/037
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/01—Suspended structures, i.e. structures allowing a movement
    • B81B2203/0145—Flexible holders
    • B81B2203/0163—Spring holders
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/03—Static structures
    • B81B2203/0315—Cavities
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/04—Electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/05—Type of movement
    • B81B2203/051—Translation according to an axis parallel to the substrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2201/00—Manufacture or treatment of microstructural devices or systems
    • B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
    • B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
    • B81C2201/0128—Processes for removing material
    • B81C2201/013—Etching
    • B81C2201/0132—Dry etching, i.e. plasma etching, barrel etching, reactive ion etching [RIE], sputter etching or ion milling

Definitions

  • the present invention relates to microelectromechanical actuators (MEMS) which can be moved in the chip plane (laterally) where the occurrence of a vertical pull-in effect is difficult and / or where large dimensions in the direction of the diode are possible ,
  • MEMS microelectromechanical actuators
  • the present invention further relates to methods of manufacturing such MEMS.
  • the invention relates to a retraction of a voltage-guided electrode of a laterally deflectable, electrostatic bending actuator LNED (Lateral Nanoscopic Electrostatic Drive) for avoiding vertical pull-in effects in the encapsulation of LNED actuators.
  • LNED Lateral Nanoscopic Electrostatic Drive
  • Nanoscopic Electrostatic Drive (NED) actuators may have vertical (VNED) or lateral (LNED) configurations.
  • NED can be used for MEMS speakers.
  • the MEMS loudspeaker based on LNED can be produced by SD integration using wafer bonding.
  • the LNED actuator moves laterally, which
  • the LNED component is supplied with control voltage, an electric voltage difference arises between differently charged areas.
  • the voltage difference is used for the operation of the electrostatic bending actuator LNED and is therefore not fundamentally necessary.
  • the voltage difference can lead to a vertical pull-in effect between the LNED
  • the bottom or top wafer may be arranged in the vertical direction, so that this effect may be referred to as a vertical pull-in effect.
  • the term vertical refers to the arrangement in the layer stacking direction but does not have any restrictive effect. 5
  • MEMS loudspeakers are described, for example, in WO 2012/095185 A1.
  • the problems listed there also apply to MEMS-based icon pumps.
  • the object of the present invention is therefore to provide E S and methods of making the same, which are robust against the occurrence of a vertical pull-in effect.
  • a MEMS comprises a substrate having a cavity.
  • the MEMS comprises a movable element arranged in the cavity, comprising a first electrode, a second electrode and a third electrode which is arranged between the first and second electrodes and is electrically insulated from the same at discrete areas.
  • the movable element is configured to perform a movement along a movement direction in a substrate plane in response to an electric potential between the first electrode and the third electrode and / or in response to an electric potential between the second electrode and the third electrode.
  • a dimension of the third electrode perpendicular to the substrate plane is less than a dimension of the first electrode and a dimension of the second electrode perpendicular to the substrate plane.
  • the smaller dimension of the third electrode perpendicular to the substrate plane and compared to the first electrode Rode and the second electrode makes it possible that occurring field lines and thus electrostatic attraction forces on adjacent electrodes, so that a proportion of electrostatic forces on the surrounding, about underlying and / or overlying substrate is low, resulting in low attraction forces against the substrate and reduces or prevents the occurrence of a vertical pull-in effect.
  • the occurrence of the vertical pull-in effect can be shifted at least to a region that is not disturbing to the operation.
  • a MEMS comprises a substrate having a cavity.
  • the MEMS comprises a movable element disposed in the cavity comprising a first electrode connected to the substrate, a second electrode connected to the substrate, and a third electrode connected to the substrate between the first and second electrodes and connected to the first electrode Electrode is fixed at discrete areas electrically isolated with a fixation.
  • the movable element is configured to perform a movement along a movement direction in a substrate plane in response to an electric potential between the first electrode and the third electrode and / or in response to an electric potential between the second electrode and the third electrode.
  • the first electrode and the second electrode are in a state without the electric potential under mechanical stress, so that the first and second electrodes move away from the third electrode due to separation of the fixation.
  • the arrangement of the first and second electrodes under the mechanical stress makes it possible to produce actuators with a large extent along the direction perpendicular to the substrate plane.
  • the achievable aspect ratios can be used to obtain a large dimension along the direction perpendicular to the substrate plane, and subsequently reduce resulting gaps using the stress to obtain an efficient MEMS.
  • the large dimension along the direction perpendicular to the substrate plane allows a high vertical stiffness, which reduces or prevents the occurrence of a vertical pull-in effect. Further, by the high or large dimension along the direction perpendicular to the substrate plane, a large amount of fluid can be moved, increasing the efficiency and power density of the MEMS device.
  • a method of manufacturing a MEMS according to the first aspect of the present invention comprises providing a substrate.
  • the method further comprises arranging, in a cavity of the substrate, a movable element comprising one first electrode, a second electrode, and a third electrode disposed between the first and second electrodes, so that the third electrode is fixed to the first and second electrodes electrically isolated at discrete areas.
  • the first, second and third electrodes are arranged so that the movable element moves in a substrate plane in response to an electric potential between the first electrode and the third electrode or in response to an electric potential between the second electrode and the third electrode performs.
  • the third electrode is arranged such that a dimension of the third electrode perpendicular to the substrate plane is less than a dimension of the first electrode and a dimension of the second electrode perpendicular to the substrate plane, thus the third electrode has a retraction or offset from the first and second Electrode on.
  • a method of manufacturing a MEMS according to the second aspect of the present invention comprises providing a substrate.
  • the method further comprises forming a first electrode in a cavity of the substrate such that the first electrode is suspended from the substrate.
  • the method includes forming a second electrode in the cavity of the substrate such that the second electrode is suspended from the substrate.
  • the method includes forming a third electrode in the cavity of the substrate between the first electrode and the second electrode.
  • the method includes fixing the first electrode, the second electrode, and the third electrode to each other and electrically isolated at discrete areas, such that the first, second, and third electrodes are in response to an electrical potential between the first electrode and the third electrode or in response to a electric potential between the second electrode and the third electrode perform a movement along a moving direction in a substrate plane, and so that the first electrode and the second electrode are in a state without the electric potential under mechanical stress, so that the first and the second Remove the electrode from the third electrode due to a separation of the fixation.
  • a schematic sectional view of a MEMS according to an embodiment and according to a first aspect a schematic plan view and longitudinal section of a MEMS according to an embodiment of the second aspect before a fixation of electrodes with each other; the MEMS of Figure 2a in a state in which the electrodes are fixed to each other at discrete areas; a schematic plan view of a comparison with FIG 2b modified MEMS according to an embodiment in which a spring element is removed; a schematic plan view and longitudinal section of a MEMS according to an embodiment of the second aspect, the bistable springs; the MEMS of Figure 2d in a state in which the electrodes are fixed to each other at discrete areas; a schematic view of a spring suspension, which is usable, according to an embodiment; a schematic cross-sectional view of a MEMS having features of the first aspect and the second aspect, according to an embodiment; a schematic cross-sectional view of the MEMS of Figure 3a during or
  • the MEMS 10 includes a substrate 12 having a cavity 14.
  • the substrate may be, for example, a semiconductor material, such as a silicon material or the like. Alternatively or additionally, it may be a material made of a semiconductor material, such as silicon oxide, silicon nitride, or the like. In general, the material may consist of or comprise a conductive or non-conductive layer.
  • a material of the substrate 12 is preferably a material which can be processed and / or produced at the wafer level in order to enable production of the MEMS 10 at the wafer level.
  • the substrate 12 is provided by thermal bonding of silicon wafers or by the use of a semi-finished product - the so-called BSOI wafers (bonded silicon on insulator wafer).
  • the MEMS 10 includes a movable member 16 disposed in the cavity 14.
  • the movable element comprises, for example, three electrodes 18a, 18b and 18c, the electrode 18c being arranged between the electrodes 18a and 18b, the electrodes being arranged side by side in a substrate plane.
  • the electrodes 18a, 18b and 18c may consist of a doped, conductive semiconductor (eg silicon) but also of a conductive metal.
  • electrostatic forces can be obtained between the electrodes 18a and 18c which, for example, can lead to an attraction or repulsion between the electrodes.
  • an attractive force may be obtained based on a voltage difference.
  • a repulsive force can be obtained by keeping both electrodes at the same potential and building up a voltage difference with respect to a further (external) potential.
  • an electrical voltage between the electrodes 18b and 18c lead to an attraction or repulsion between these electrodes.
  • the movable member 16 is configured to move along a magnetic field in response to an electric potential between the electrodes 18a and 18c and / or in response to an electric potential between the electrodes 18b and 18c, that is, based on the attractive forces or the repulsive forces positive or negative y direction, which is located in a substrate plane.
  • the electrode 18a is fixed electrically insulated from the electrode 18c at at least one discrete region 21a. That is, the electrodes 18a and 18b are mechanically bonded together at the at least one discrete region 21a so that the attractive or repulsive force between the electrodes is translated into movement along the positive or negative y-direction, as described in detail later becomes.
  • the electrodes 18b and 18c are electrically isolated from each other at at least one discrete region 21b, that is, mechanically connected.
  • the areas 21a and 21b extend only over a limited area along the x-direction.
  • the regions 21a and / or 21b may cover a portion of the electrode 18c or cover the electrode 18c in a planar manner.
  • the discrete regions 21 a and 21 b may be discrete along a bar length (ie in the x direction).
  • the regions 21 a and 21 b may be at least one spacer or spacer, which mechanically and electrically separates all three electrodes 18 a to 18 c from one another. But it is also possible that the areas 21 a and / or 21 b along the z-direction in the same height, as the first electrode 18 a and the second electrode 18 b are executed, such as when a collection of the central electrode is implemented.
  • the electrode 18c arranged between the electrodes 18a and 18b parallel thereto with main sides perpendicular to the substrate plane has a smaller dimension along a z-direction than the electrodes 18a and 18b along the z-direction.
  • the z-direction may also be referred to as the thickness direction, wherein the substrate plane is spanned by the y-direction and a third spatial coordinate perpendicular to the y-direction and the z-direction.
  • a dimension 24 of the electrodes 18a and 18b along the z-direction thus has a larger value than a dimension 26 of the electrode 18c.
  • the electrodes 18a and 18b along the positive and negative z-direction from the electrode 18c have an overhang 28a and 28b respectively, that is, they project beyond the electrode 18c along the positive and negative z-directions.
  • This allows an electric field represented by field lines 32 of the electrode 18c to be shielded from the electrodes 18a and 18b, for example, from the substrate 12.
  • the electrodes 18a and 18b are shown as having a same dimension 24 along the z-direction, the electrodes 8a and 18b may be made to have a different dimension 24 along the z-direction.
  • the electrodes 18a and 18b are shown as having a same position along the z-direction, the electrodes 18a and 8b may be arranged offset from each other along the z-direction.
  • the dimension 26 of the electrodes 18c is at least 2% less, at least 10% smaller, at least 15% smaller, or at least 20% smaller, compared to the dimension 24 of the electrodes 18a and 18b. This means that a sum of the overhangs 28a and 28b has a share of at least
  • the dimension 26 may be adjusted to the dimension 24 based on different design criteria. Thus, a reduced dimension 26 may result in lower attractive or repulsive forces between the electrodes, which may result in a reduced exhaustion or deflection force of the movable member 16. At the same time, however, reduced field effects can be obtained with respect to the substrate 12 and, on the contrary, with increased dimension 26, stronger forces between the electrodes to reduce the shielding of the electric field.
  • the overhangs or indentations 28a and / or 28b of the middle electrode 18c may have any desired value.
  • they Preferably, they have an extension along the z-direction, which is at least the distance (gap width) between the electrode 18c and the adjacent electrode 8a and / or 18b along the y-direction.
  • an extension along the z-direction which is at least the distance (gap width) between the electrode 18c and the adjacent electrode 8a and / or 18b along the y-direction.
  • indentations which amount to a multiple of the distance along the y-direction, for example by at least a factor of 2, at least by one factor
  • the distance 34 may be a value of at most 1 pm, at most 0.5 ⁇ , at most 0.25 ⁇ or even at most 0.1 im.
  • the center electrode 18c of the LNED actuator becomes with a feeder each at the top and the bottom, that is provided along the positive and negative z-direction.
  • the term indentation here means the possibility of structuring the electrode 18c such that both the upper and lower sides of the electrode 18c are shorter than those of the electrodes 8a and 18b. In this way, the electrode 8c is electrically shielded partially to strongly from the outer electrodes 18a and 18b with respect to the substrate 12.
  • the pull-in effect will be much higher Tension, as compared with the case in which the electrode 18c has no indentation, that is, no overhang is provided by the outer electrodes.
  • the vertical pull-in voltage may thereby be greater than the normal drive voltage of the actuators, such that no vertical pull-in effect occurs in the regular operation of the MEMS 10.
  • FIG. 2 a shows a schematic view of a longitudinal section of a MEMS 20, the longitudinal section being shown parallel to the substrate plane, that is, the x / y plane.
  • FIG. 2a shows the MEMS 20 in a state before a fixation between the electrodes 18a or 18b with the electrode 18c has taken place or after this fixation has been released.
  • a gap 42 may be arranged, which is influenced for example by process parameters or possibility of the process.
  • the gap 42 or a dimension of the gap 42 may be a result of the aspect ratio used. see the expansion along the z-direction and a gap 42 resulting therefrom.
  • the gap 42 can be produced, for example, by trench etching or deep reactive ion etching (DRIE: deep reactive ion etching), with the technologically reliably achievable aspect ratio currently being 25 to 30. In the future, this ratio may possibly be further increased.
  • DRIE deep reactive ion etching
  • an aspect ratio of 400 to 10,000 makes sense for the function of the LNED actuator 14 encapsulated by the substrate 12 and for preventing the vertical pull-in - which, however, can not be achieved today with the prior art.
  • the dimension of the gap 42 may be approximately 10 ⁇ m to 30 ⁇ m.
  • the dimension of the gap 42 may be approximately 13 pm to 16 pm.
  • Embodiments may have different aspect ratios with a value of at least 50, of at least 100, of at least 400, or even higher.
  • the aspect ratio of at least 50 may have an upper limit of 10,000 or more
  • the aspect ratio of at least 100 may have an upper limit of 7,000 or more
  • / or the aspect ratio of at least 400 may have an upper limit of 3,500 or more.
  • the middle electrode 18c has projections at discrete regions 22a to 22f, while the electrodes 18a and 18b extending substantially parallel to the electrode 18c also have attachment regions at corresponding locations or regions, for example in the form of a groove.
  • the protrusions may be designed as regions 21 according to FIG. 1, or comprise any other, preferably electrically insulating material. This means that by joining the discrete regions 22a to 22f with corresponding regions of the electrodes 18a and 18b, a fixation of the electrode 18a to the electrode 18c and a fixation of the electrode 18b to the electrode 18c can take place.
  • FIG. 2a shows a state after the structures of the electrodes 18a to 18c have been formed out of the substrate 12, such as by an etching process.
  • a reactive ion etching process (DRIE), for example, in silicon wafer substrates is suitable for this purpose.
  • the formation of the electrodes 18a to 18c in the cavity 14 of the substrate 12 can be carried out such that the electrode 18a and the electrode 18b are connected to the substrate 12 via spring elements 36a and 36b, respectively.
  • the electrode 18c may be connected via a spring element 37 to the substrate 12, which allows a deflection of the electrode 18c along the direction of movement y.
  • the electrodes 18a, 18b and 18c are connected to the Substrate connected or suspended on the substrate 12, wherein between the substrate 12 and the electrode 18a, the spring element 36a may be arranged, while between the substrate 12 and the electrode 18b, the spring element 36b may be arranged.
  • an electrically nonconductive can be provided on sidewalls of the substrate 12 and / or on sidewalls of the electrodes 18a to 18c, at least in the area of the fixings 22a to 22f but also generally on all surfaces or electrically insulating layer 38, for example comprising silicon nitride (Si 3 N 4 ), silicon dioxide (SiO 2 ), aluminum oxide (Al 2 O 3 ) and / or aluminum nitride (AIN).
  • the MEMS 20 is shown in a state where the electrode 18a is fixed to the electrode 18c and the electrode 18b is fixed to the discrete regions 22a to 22f opposite to the electrode 18c.
  • the gap 42 can be reduced to a gap 42 ', which is, for example, less than 5 ⁇ , less than 3 pm or at most 1 pm. There are also smaller dimensions possible, for example at most 0.8 pm or at most 0.2 pm.
  • the movable element 16 comprising the electrodes 18a, 18b and 18c is adapted to move along the y direction in the x direction in response to an electric potential between the electrode 18a and the electrode 18c and / or between the electrode 18b and the electrode 18c / y level.
  • the movable element can have one of a plurality of geometries.
  • the movable element 16 or the electrodes 18a to 18c may have a multiply bent course along the x-direction.
  • the electrodes 18a to 18c can, for example, run essentially parallel to one another or, for example, in a dome-shaped bent path relative to one another.
  • Other embodiments are also possible.
  • an attractive force between the electrodes 18b and 18c or a repulsive force between the electrodes 18a and 18c causes the deformable element 16 to move along the negative y-direction.
  • a repulsive force between the electrodes 18b and 18c and / or an attractive force between the electrodes 8c and 18c may result in movement of the movable member 16 along the positive y-direction.
  • Other geometries are also implementable, that is, the electrodes 18a, 18b and / or 18c may have a different shape or shape.
  • another arrangement and / or a different number of discrete areas 22a to 22f may be used to fix the electrodes against each other. For example, it is illustrated in FIG. 2b that the projections of the electrode 18c rise substantially parallel to the y-direction from the electrode 18c.
  • At least one discrete region 22a-22f may be disposed at an angle to the y-direction.
  • a protrusion may be disposed on an electrode 18a or 18b, while a corresponding fitting, which may also be formed as a tongue or groove, is disposed on the electrode 18c.
  • the fitting may, for example, have the shape of a dovetail or other gearing geometry.
  • the electrodes 18a and 18b are moved toward the electrode 18c, when Fig. 2a is comparatively used.
  • the spring elements 36a and 36b are at least partially tensioned, that is to say a tensile stress prevails, so that when the fixation in the discrete regions 22a to 22f, that is to say when the fixation is separated, the electrodes 18a and 18b remove from the electrode 18c, such as by the spring elements 36a and 36b relax and / or contract and at least partially take the arrangement of Fig. 2a.
  • the separation of the fixation may be a theoretical operating state, which is not intended for the actual operation of the MEMS.
  • the mechanical stress that results in removal of the electrodes 18a and 18b from the electrode 18c may be provided by the spring members 36a and 36b. Bonding of the electrodes 18a and 18b to the electrode 18c can be accomplished, for example, by generating electrical attractive forces such as by applying a control potential to the electrode 18c and applying a reference potential to the electrodes 18a and 18b. By virtue of the resulting attractive forces, the electrodes 18a and 18c or 18b and 18c can be brought into mechanical contact with each other, wherein an electrical insulation of the electrodes can be provided by the insulating layer 38 from each other. In order to produce an effective, possibly final or irreversible mechanical combination of the electrodes, one or more mechanisms of action can be used.
  • a fixation between the electrode 18a and the electrode 18c and / or between the electrode 18b and the electrode 18c at the discrete regions 22a to 22f may be achieved by mechanical latching using mechanical latching geometries, such as tongue and groove connections, dovetailing. Tail compounds or the like can be obtained.
  • an electrostatic sticking can be used, a fixation by subsequent deposition of a thin layer and / or a solid compound by surface forces, such as Van der Waals forces are obtained.
  • the fixation by subsequent deposition of thin layers may be accomplished by first approximating the electrodes to each other, such as by electrostatic sticking or another method described herein, and in that state depositing a layer that introduces forces into the system. which hold the electrodes together.
  • a holding together of the electrodes can be obtained.
  • the insulating layer 38 may be electrically charged due to manufacturing and act as an additional voltage source holding the electrodes together. It can thus be used an electrostatic attraction.
  • a subsequent fuse can be used, with which the mechanical connection between the electrodes by a thermal activation, such as the insulating layer 38, is obtained. Upon activation, force may be obtained at interfaces between two material surfaces, such as between a surface of the insulating layer 38 and an adjacent layer.
  • the insulation layer 38 may, for example, consist of or comprise a so-called thermal SiO 2 and may be thermally activated after the mechanical connection with each other, so that the insulation layer 38 provides the fixation.
  • a chemical compound such as an adhesive bond can be used, for example by using a polymer which is cured. It is also possible to introduce a liquid which is vaporized or evaporated after assembly. By such a drying process, surface forces can be obtained between the electrodes, which also provide fixation.
  • the approach of the electrodes may be accomplished by the application of an electrical voltage between the electrodes 18a and 18c and / or between the electrodes 18a and 18c and the attendant attractive forces.
  • the electrodes are thereby approximated until they reach the mechanical contact in the region of the fixings 22a to 22f and temporarily or permanently adhere due to surface forces.
  • an approach by applying suitable electrical charges remaining on the electrodes is possible.
  • the approximation can be achieved in which a suitable liquid is introduced into the gap 42, which is subsequently dried by drying. the electrodes 18a and 18c and / or 18b and 18c are moved toward each other until they come into mechanical contact in the region of the fixings 22a to 22f and temporarily or permanently adhere due to surface forces.
  • the electrodes 18a, 8b and 18c of the MEMS 20, which is shown in FIG. 2b can be deposited another, suitable thin film permanently fixed together.
  • the thin film may comprise an electrically insulating material such as silicon nitride (Si 3 N 4 ), silicon dioxide (SiO 2 ), and / or alumina (Al 2 O 3 ) and / or aluminum nitride (AIN).
  • the reduced distance between the electrodes compared to FIG. 2a enables the generation of high electrostatic forces between the electrodes.
  • the shaping of the electrodes according to the representation of FIG. 2 a allows the existing limitations of processes used to form the electrodes 18 a, 18 b and 18 c not or only to a limited extent to extend the electrodes and thus along the MEMS 20 affect the z-direction. This allows a high expansion of the MEMS 20 along the thickness direction z, so that even by the high expansion and the resulting high stability of the electrodes a vertical, ie, along the z-direction, pull-in effect can be reduced or avoided.
  • a lateral dimension of the MEMS 20 or the electrodes 8a and 18b perpendicular to the movement direction x, ie along the thickness direction z, may for example be greater than 150 pm, greater than 400 pm, greater than 600 pm or at least 700 pm.
  • a frame condition can be specified according to which a 700 pm device layer is to be produced, that is to say the dimension of the electrodes 18a and 18b, possibly also of the electrode 18c along the z direction, is at least 700 pm.
  • DRIE can continue to be used for the etching of the NED gap, that is, in the case of deep etching, a currently technologically realizable aspect ratio of 25 to 30 should continue to be used.
  • the gap is provided, subsequently reduced by merging the electrodes and the electrodes are firmly joined together.
  • Such a thick device layer of at least 400 ⁇ , at least 600 [im or at least 700 ⁇ is advantageous.
  • the efficiency of the actuator may be at least affected by the spacing between the electrodes, which is also referred to as the LNED gap, gap, or electrode spacing.
  • the smaller the gap the greater the electrostatic forces of the actuator can be; the LNED actuator can be more efficient with regard to large bending moments and large deflections; the smaller control voltages can be used; the larger, for example, achievable sound pressure levels when the LNED actuator is used as a speaker; and / or the less chip area may be necessary to produce a comparable sound power pressure, which may have an advantageous effect on a component price.
  • the LNED gap can be produced by means of DRIE etching.
  • DRIE is very dependent on the aspect ratio (aspect ratio of trench depth to trench width) of the trench, and aspect ratios of more than 30 may present problems with etch stability, such an aspect ratio can be maintained for fabricating embodiments described herein, such as by a device Layer is made with 75 m and a gap is formed with a width of 3 m or less, so that an aspect ratio for the DRIE etching of 25 results, these dimensions are arbitrarily adaptable.
  • actuators with a layer thickness of 700 ⁇ (or more) can be obtained by the procedure described, in which the NED gap is only 200 nm (or less). This can result in a post-aspect ratio of 3500 or more, which is difficult or impossible to achieve with DRIE etching.
  • Embodiments may provide different aspect ratios of up to 3,500, up to 7,000, or even up to 10,000.
  • the pull-in effect is reduced or prevented by making the electrode 18c smaller along the z-direction than the surrounding electrodes 18a and 18b.
  • increased stability is also obtained for reducing or avoiding the vertical pull-in effect by obtaining a large dimension along the z-direction.
  • the first aspect and the second aspect as well as the advantageous embodiments described in connection therewith can be provided independently of each other, but also any can be combined with each other, that is, the MEMS 20 can also be designed with electrodes of different sizes as described in connection with the MEMS 10.
  • a dimension of the electrodes 18a and 18b of the MEMS 10 in FIG. 1 may be 400 ⁇ or more.
  • the electrode 18a may be connected to the substrate 12 via a spring element under tension, such as the spring element 36a.
  • the electrode 18b may be connected to the substrate 12 via a tensioned, ie tensioned spring element, such as the spring element 36b. It is also possible to realize the embodiments according to the first aspect and the embodiments according to the second aspect independently of each other in the absence of the other aspect.
  • FIG. 2c shows a schematic plan view of a modified MEMS 20 ', in which the spring element 36a is removed from the MEMS 20.
  • the spring elements 36b or 37 may also be removed, wherein at least one of the spring elements is retained in order to support the movable element with respect to the substrate 12.
  • the removal of one or more of the spring elements 36a and / or 36b and / or 37 can be done after receiving the fixation, such as when a MEMS is to be manufactured, which has a low natural frequency, such as speakers, which are designed to emit low-frequency sound ,
  • the aspect ratio of the MEMS and / or the attachment of the electrodes remain together. It is understood that in an intentional removal of the spring element 36a, 36b or 37 Although the same can be formed as a deflectable spring, but this is not required, in particular with respect to the spring element 37. This means that a structure to be removed can be formed as a sacrificial structure , which remains stationary during fixing (spring 37), can be deflected or possibly break. Damage may be insignificant in view of the subsequent removal.
  • the MEMS 20 ' may be described as MEMS comprising the substrate 12 having the cavity 14.
  • the movable element 16 arranged in the cavity 14 comprises the first electrode 18a, the second electrode 18b and the third electrode 18c arranged between the first electrode 18a and second electrode 18b, which are connected to the first electrode 18a and the second electrode 18b discrete areas 22a-f electrically isolated with a fixation is fixed.
  • the movable member 16 is configured to move along the moving direction y in response to an electric potential between the first electrode 18a and the third electrode 18c and / or in response to an electric potential between the second electrode 18b and the third electrode 18c the substrate plane x / y execute.
  • the MEMS 20 ' may be formed the same as the MEMS 20.
  • the first electrode 18a and the second electrode 18b may be spaced apart from the third electrode 18c at the discrete regions by a functional layer 38' and mechanically fixed together.
  • the functional layer 38 ' may comprise at least one layer of material - such as a conformally deposited thin film - and provides the function of electrically insulating the electrodes 18a and 18c and 18b and 18c from each other.
  • the functional layer 38 ' provides the function of mechanical connection or adhesion.
  • At least one of the electrodes 18a, 18b and / or 18c is connected to the substrate 12 via a spring element, as illustrated for the spring elements 36b and 37.
  • At least one of the electrodes 18a, 18b and / or 18c is connected exclusively to the substrate 12 indirectly via an adjacent electrode.
  • the electrode 18a is mechanically fixedly connected to the electrode 18c at the discrete regions 22b, 22d, and 22f and supported against the substrate 12 via them.
  • the electrode 18a, 8b and / or 8c which is supported exclusively indirectly relative to the substrate, can be separated from the spring element after a fixation of this electrode to another electrode, which is indirectly or directly supported relative to the substrate.
  • one or more other spring elements may be removed.
  • a symmetry is preferably obtained, for example by removing a middle spring, for example the spring 37, and retaining the outer or vice versa.
  • the spring elements 36a, 36b and 37 of the MEMS 37 also serve as an electrical path to the electrodes 18a, 18b and 18c. If such a spring is removed, a path can be obtained via a remaining spring, possibly electrically isolated from a crossed electrode. For example.
  • a path electrically isolated from the electrode 18c may be routed from the substrate 12 to the electrode 18a via the electrode 18c.
  • wireless energy transfer or sliding contact between substrate and electrode 18a may be implemented.
  • the metallization or deposition and structuring can take place after the merging of the electrodes 18a-c, but it is also possible to arrange the metallization at any other time.
  • this allows an aspect ratio of a distance between the first electrode 18a and / or the second electrode 18b with respect to the third electrode 18c and a dimension of the first electrode 18a along a direction z perpendicular to the moving direction y to be larger than 100.
  • the aspect of removing one or more spring elements may be combined with all other embodiments described herein.
  • the MEMS 20" may comprise spring elements 36'a to 36'd, which may be, for example, are formed as bending springs or bending beams.
  • a respective spring element 36'a to 36'd can be arranged on a respective distal end and on a proximal end of the electrode 18a and the electrode 18b, wherein the proximal end can be arranged, for example, adjacent to a clamping of the electrode 18c. It is understood that these relative positional terms are arbitrarily interchangeable with each other without limitation, without limiting the teaching explained in connection with embodiments described herein.
  • an arrangement can also be made in each cell of a plurality or a plurality of cells of the bar-shaped MEMS 20 "A cell describes a bar section between the two points or regions 22a-22c where the electrodes come into mechanical contact.
  • the spring elements 36'a to 36'd can be designed as a bistable spring in order to minimize the forces that pull or push the electrodes 18a to 18c apart Shaping, such as monostable springs or springs having a higher number of stable states, is also possible
  • MEMS 20 may be modified such that the spring elements 36'a to 36'd are under a mechanical stress that is obtained by a beam bending of the spring elements 36'a and 36'b. This can also be understood as an alternative or in addition to the stressed springs, a multi-stable structure may be arranged which holds or positions the electrode 18a and / or 18b opposite to the
  • At least one of the springs 36'a-d or 37 may be removed.
  • the merging and subsequent fixing of the electrodes can also be effected by bistable springs.
  • bistable springs There are also mechanically bistable geometries, also in the MEMS range, which upon activation, for example a movement by electrostatic fields, can assume a second deflected state, which remains after a removal of the activation force, for example after removal of the electrostatic field.
  • Such an effect can also be described as a crack-frog effect or is known in the field of hair clips.
  • the springs 36'a to 36'd can be arranged in the x-direction and executed in their geometry, made approximately curved by their design in such a way that, after the merger, the electrodes are in a second stable position, for example in a mirrored S Position, and thereby permanently reduce the gap distance 42.
  • spring elements 36'a and 36'b or 36'c and 36'd can be arranged on both sides of the beam in order to obtain a beam clamped on both sides.
  • Figure 2f shows a schematic view of a spring suspension usable with the MEMS 20, 20 'and / or 20 "The three electrodes 18a-18c are spaced by DRIE-etched trenches and shown in a state prior to contacting the electrodes.
  • Both springs which are shown as wave-shaped formations, can be bent while the electrodes are brought together and can also change their length slightly, so that both tensile and compressive stresses can be introduced into the bent springs
  • dark areas may be a material such as silicon, while lighter areas may be trench structures
  • a region 39a and / or region 39b and / or region 39c may be useful as a contact surface for contacting the MEMS, such as contacting the electrodes 18a-18c
  • the electrodes 18a and 18b can be used by their curved structure itself as springs, which when applying the elec voltage for approaching the electrodes 18a to 18c yield to each other flexible.
  • the electrode 18c may be relatively rigid or non-rigid. movable, ie, formed solid
  • 3 a shows a schematic cross-sectional view of a MEMS 30 having the electrodes 18 a, 18 b and 18 c extending along the z-direction as described in connection with the MEMS 10 and having a state similar to that for the MEMS 20 has been described in connection with FIG. 2a. That is, between the electrode 18a and the electrode 18c, the gap 42 is arranged. Further, the gap 42 is disposed between the electrode 18b and the electrode 18c.
  • 3b shows a schematic cross-sectional view of the MEMS 30 during or after the fixation of the electrodes 8a, 8b and 18c at the discrete regions 22a and 22b.
  • the electrode 18c is subjected to a potential with respect to the electrodes 18a and 18b, so that a voltage Ui is established between the electrodes 18a and 18c and a potential U 2 is established between the electrode 18c and the electrode 18b.
  • the potentials Ui and U 2 can have the same magnitude value.
  • a voltage applied to the electrode 8c may be larger than a driving voltage.
  • the MEMS may later be controllable with a voltage in a range of 0 to 10V.
  • a voltage Ui and / or U 2 that can be applied for the fixation can have a value of approximately 100 V.
  • the electrodes 18a, 18b, and 18c Prior to merging, the electrodes 18a, 18b, and 18c have been veiled with the nonconductive layer 38. In other words, the electrodes have been veiled prior to merging with a nonconductive layer.
  • the concealment can alternatively also take place only at the locations where the mechanical connection of the electrodes should take place, for example at the latching geometries.
  • the insulating layer may also be arranged at additional additional locations.
  • the MEMS converter 40 may be, for example, a sound transducer, such as a loudspeaker or a microphone.
  • a sound transducer such as a loudspeaker or a microphone.
  • the MEMS converter 40 will be described below as a MEMS speaker, the operation may also be transmitted to a MEMS microphone when an applied voltage is detected, that is, measured instead of in the case of a loudspeaker to apply to obtain a movement of the movable member 16.
  • the MEMS loudspeaker 40 may include, for example, the ME S 10, 20, and / or 30.
  • the MEMS converter 40 may also include a pump, a valve, a dosing system, an acceleration sensor, a yaw rate sensor, a micropositioning system, a micro-stabilizer, e.g. B. for image sensors, and / or a micro-switch (such as for high-frequency or high-voltage applications form.
  • the discrete regions 22a and 22b or the corresponding formations of connecting elements can be arranged obliquely in the space, that is to say inclined within the substrate plane, so that only parts of the connecting elements which represent the electrodes 18a and 18c or in the illustrated cross-sectional plane are shown.
  • the substrate 12 may include a plurality of layers 12a, 12b, and 12c.
  • the layer 12a may be referred to as a lid wafer, the layer 12b as a device layer, and the layer 12c as a handle wafer.
  • an insulating or etching stop layer such as Si0 2 or the like may be arranged.
  • the layer 44a may have a thickness of, for example, 1 ⁇ m.
  • a similar layer can be arranged, approximately also comprising Si0 2 and likewise have a layer thickness of about 1 ⁇ .
  • the layers may also have a different layer thickness.
  • movement of the movable member 16 in the substrate plane x / y may cause movement of the fluid surrounding the movable member along the arrow directions of the arrows 46a and / or 46b such that radiation of the fluid pressure along positive and negative thickness direction.
  • the fluid flow By closing one of the openings, the fluid flow can also be provided with a preferred direction.
  • the MEMS converter 40 can also be used as a MEMS pump.
  • the MEMS converter 40 can be used as a valve, dosing system, acceleration sensor, yaw rate sensor, micropositioning system, microstabilizer (for image sensors, for example), microswitches (for example for high-frequency and / or high-voltage applications).
  • the LNED actuator 40 moves laterally in the x / y plane when a control voltage U is applied between the electrodes 18a / 18b and 18c.
  • the layers 12a, 12b, and 12c may also be contacted with a potential, such as grounded, to provide a reproducible movement of the substrate To ensure or enable LNED actor.
  • a below reproduced assignment of the electrical control voltage may be useful or necessary in normal operation.
  • the electrodes 18a and 18b may be grounded, that is, grounded or connected to 0V. The same can apply to the layers 12a, 12b and 12c.
  • a control voltage can be applied, such as an analog audio signal for operation as a MEMS speaker or a corresponding signal for operation as a MEMS pump.
  • Figure 5a shows the provision of a substrate comprising layers 12b and 12c separated by layer 44b.
  • Trenches 48a and 48b which later define the electrode gaps, such as the gaps still to be reduced between the electrodes, can be introduced into the layer 12b. This can be done for example by a DRIE etching with a limitation (stop) on box, the layer 44b.
  • FIG. 5b shows the filling of the trenches 48a and 48b with an insulating material, for example Si0 2 , whereby a main side surface of the layer 12b facing away from the layer 12c can also be covered with the Si0 2 .
  • an insulating material for example Si0 2
  • 5c shows a schematic view of the layer stack in which an etching of a trench 48c, for example a Recess RC trench etching, takes place.
  • the etching of the trench 48c may be performed so that the layer 44b is not reached, that is, the layer 12b is not completely penetrated and the DRIE etching is stopped after a number of process cycles.
  • FIG. 5d shows a schematic view of the layer stack in which an insulating or an etching process of the substrate 12b or 12c inhibiting layer 52 has been deposited in the trench 48c, for example a Si0 2 layer or another electrically insulating layer.
  • FIG. 5 e shows a schematic view of the layer stack in which the previously deposited layer 52 is removed from a bottom of the trench 48 c, for example by a SiO 2 etching at the bottom of the RC trench.
  • 5f shows a schematic side sectional view of the layer stack in which, following the removal of the layer 52 from the bottom of the trench, an isotropic Si etching takes place, so that the layer 12b between the trenches 48a and 48b is removed.
  • the indentation 28b or the overhang 28b can be produced by the remaining material having a reduced extent.
  • a cavity 54 may remain.
  • 5g shows a schematic side sectional view of the stack in which the RC trench 48c is filled with an etch stop material, such as Si0 2 . This can be done in such a way that a surface of the layer 12 b exposed through the cavity 54, which faces the layer 12 c, is covered by the layer 52.
  • 5h shows a schematic side sectional view of the stack in which the material of the layer 52 is removed in the region between the trenches 48a and 48b and in the area covering the cavity 54.
  • the layer 12b may be partially etched back to create the upper overhang 28a. It becomes clear that the staggered production of the overhangs 28a and 28b can also have different dimensions from one another.
  • FIG. 5i shows a schematic side sectional view of the stack, in which the region exposed in FIG. 5h and the volume of the back-etched layer 12b is filled with the material of the layer 52, that is to say filling with, for example, Si0 2 .
  • 5j shows a schematic side sectional view of the stack, in which open trenches 56a and 56b are etched in a region lying laterally with respect to the trenches 48a and 48b.
  • the open trench 56a and / or 56b may be apertures defining the air chambers and the pumping chambers, respectively.
  • Figure 5k shows a schematic side sectional view of the layer stack exposing elements 18'a, 18'b and 18'c, which later form the electrodes 18a, 18b and 18c, respectively.
  • the elements 18'a, 18'b and / or 8'c can be used as electrodes.
  • 51 shows a schematic side sectional view of the stack in which the cavity 14 is closed by attaching the layer 12 a, wherein the layer 12 a, the layer 12 b and / or the layer 12 c may have optional openings 38 to an influx or outflow of a Allow fluids into or out of the cavity 14.
  • the movable element has two electrodes 8c-1 and 8c-2 which may have a potential difference with respect to the electrodes 18a and 18b.
  • the electrodes 18c-1 and 18c-2 may be formed to always have a same electric potential, such as being electrically connected to each other.
  • the electrodes 18c-1 and 18c-2 may be integral with interconnected elements between which a trench or hole pattern is disposed, such as to facilitate underlying etching. Such an arrangement of two electrodes between the outer electrodes 18a and 18b may allow individual displacement of the movable element along each direction in the substrate plane.
  • the electrodes 18c-1 and 8c-2 only the electrode 18c may be arranged or a different number of electrodes may be arranged, for example more than 2, more than 3 or more than 4.
  • a method of fabricating a MEMS according to the first aspect includes providing a substrate.
  • the substrate can be provided such that a cavity is generated in the further course or that the cavity has already been produced.
  • a cavity may be generated later as some elements are formed and exposed in the substrate.
  • a movable member is disposed in the cavity 14, the movable member having a first electrode, such as electrode 18a, a second electrode, such as electrode 18b, and a third electrode, such as electrode 18c, disposed between the first and second electrodes.
  • the third electrode is electrically isolated with the first and second electrodes at discrete regions, as described in connection with the MEMS 10.
  • the first, second and third electrodes are arranged so that the movable element moves in a substrate plane in response to an electric potential between the first electrode and the third electrode or in response to an electric potential between the second electrode and the third electrode that is, the x / y plane executes.
  • the third electrode is arranged such that a dimension of the third electrode perpendicular to the substrate plane, that is along the z-direction, is less than a dimension of the first electrode 18a and a dimension of the second electrode 18b perpendicular to the substrate plane.
  • a method of manufacturing a MEMS according to the second aspect includes providing a substrate. Furthermore, a first electrode is formed in a cavity of the substrate so that the first electrode is suspended from the substrate. Further, forming a second electrode in the cavity of the substrate so that the second electrode is suspended from the substrate. A third electrode is formed in a cavity of the substrate between the first electrode and the second electrode.
  • the method includes fixing the first electrode, the second electrode, and the third electrode to each other and electrically isolated at discrete regions, such that the first, second, and third electrodes are connected between the first electrode and the third electrode in response to an electrical potential or between the second electrode Electrode and the third electrode perform a movement along a direction of movement in a substrate plane, and so that the first electrode and the second electrode in a state without the electrical potential are under mechanical stress, so that the first and the second electrode of the third electrode due to a separation of the fixation.
  • the intermediates described in connection with FIGS. 5a to 51 can correspond both to the requirements of the first aspect and alternatively or additionally to the requirements of the second aspect. This means that it is possible to dispense with an embodiment of the overhangs 28a and / or 28b and / or that the electrodes 18a and 18b can be formed out of the substrate layer 12b such that the spring elements explained in connection with FIGS. 2a and 2b are formed ,
  • Embodiments relate to LNED-based devices in which a retraction is formed on the bottom and top of the central electrode, the external electrodes acting as an electrical shielding function.
  • Other embodiments relate to loudspeakers and / or micropumps having such a MEMS.
  • Embodiments also relate to components based on LNED and having an aspect ratio of the LNED gap due to the sen and due to a subsequent merging of the electrodes, an aspect ratio of more than 30 is generated. For example, aspect ratios having a value in a range of at least 50, of at least 100, of at least 200, at least 400, or even higher.
  • the aspect ratio of at least 50 may have an upper limit of 10,000 or more
  • the aspect ratio of at least 100 or at least 200 may have an upper limit of 7,000 or more
  • / or the aspect ratio of at least 400 may have an upper limit of 3,500 or more
  • LNED actuators may be used for MEMS-based acceleration sensors, gyroscopes, and gyroscopes, and generally for all MEMS in which a microcomponent is to be mechanically moved in the substrate plane and encapsulated by a lid and bottom substrate.
  • Figure 6a shows a schematic side sectional view of a layer stack or wafer bond comprising layers 12c and 12b.
  • the layer 12b may at least partially but also be completely enveloped by the layer 44b, so that the layers 12b and 12c are spaced apart from one another by the layer 44b and may be electrically insulated from one another.
  • FIG. 6b shows a schematic plan view of the layer stack from FIG. 6a.
  • FIG. 6c shows a schematic plan view of a layer stack which, for example, can be obtained from the layer stack according to FIG. 6a and in which the layer 12c is likewise enveloped by a material of the layer 44b. On one of the side facing away from the layer 12b, this envelope may have an opening 58.
  • FIG. 6d shows a schematic plan view of the layer stack from FIG. 6c.
  • 6e shows a schematic side sectional view of a layer stack which can be formed from the layer stack according to FIG. 6c, for example by etching trenches 48a to 48d into the layer 12b.
  • the trenches may have a depth of, for example, 725 ⁇ .
  • FIG. 6f shows a schematic plan view of the layer stack from FIG. 6e.
  • the trenches 48a to 48d may form structures of the electrodes 18a to 18c. Some or all of the trenches 48a-48d may be fluidly connected to one another and form a common trench.
  • FIG. 6g shows a schematic side sectional view of a layer stack that can be formed from the layer stack according to FIG.
  • a plasma-enhanced (PE) deposition of undoped silicon dioxide (undoped silicon glass - USG) on a front side of the wafer can take place.
  • PE plasma-enhanced
  • FIG. 6h shows a schematic plan view of the layer stack from FIG. 6g.
  • Fig. 6i shows a schematic side sectional view of a layer stack that may be formed from the layer stack of Fig. 6g, such as by partially removing the layer 12c through the opening 58 to form a trench 48e.
  • the opening 58 is already shown in Fig. 6c, it can also be produced later.
  • the trench may be formed as far as the layer 44, which may include Si0 2 .
  • FIG. 6j shows a schematic plan view of the layer stack from FIG. 6i, the appearance of FIG. 6h corresponding to FIG.
  • FIG. 6k shows a schematic side sectional view of a layer stack which can be formed from the layer stack according to FIG. 6i, for example by the layer 44 being removed in regions such that the electrodes 18a to 18c are exposed and the layer stack at least partially or completely outer peripheral surfaces of the layer 44 is released, the layer 44 is still disposed between the layers 12b and 12c. It may be a release, d. h., exposing the moving elements.
  • FIG. 61 shows a schematic plan view of the layer stack from FIG. 6k, which shows a spacing of the electrodes 18a to 18c in accordance with the state of the MEMS 20 of FIG. 2a.
  • FIG. 6m shows a schematic side sectional view of a layer stack which can be formed from the layer stack according to FIG. 6k, for example by the electrodes 18a to 18c being moved towards one another and fixed. The fixation can be done by arranging the layer 38. Alternatively, the layer 38 can also be arranged at a different time, for example earlier, and the fixation can be obtained by another concept described herein.
  • the layer 38 can be arranged, for example, by means of an atomic layer deposition method (Atomic Layer Deposition - ALD). Alternatively or additionally, the layer 38 can also be arranged as a spray paint.
  • FIG. 6n shows a schematic plan view of the layer stack from FIG. 6m, which shows the MEMS 20 in the state according to FIG. 2b.
  • FIG. 6o shows a schematic side sectional view of a layer stack which can be formed from the layer stack according to FIG. 6m.
  • the layer 12b may be covered with an insulating layer, such as the layer 38, whereby recesses 62 may be produced which allow the layer 12b to be contacted by the layer 38.
  • FIG. 6p shows a schematic plan view of the layer stack from FIG. 6o.
  • FIG. 6q shows a schematic side sectional view of a layer stack which can be formed from the layer stack according to FIG. 6o, for example by arranging the layer 12a.
  • a wafer bonding can be used.
  • the layer 12a may be spaced from the layer 12b by the insulating layer 52, and may include openings 64a and / or 64b that facilitate contacting underlying layers 12b, see opening 64a, and / or fluidly contacting the MEMS with the substrate Environment, see opening 64b. Further steps may be taken to deposit or partially or completely remove layers.

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Abstract

Un MEMS comprend un substrat pourvu d'une cavité, et un élément mobile disposé dans la cavité et comprenant une première électrode, une deuxième électrode et une troisième électrode disposée entre les première et deuxième électrodes et fixée en étant isolées électriquement de celles-ci dans des zones discrètes. L'élément mobile est conçu pour effectuer un mouvement le long d'une direction de déplacement dans un plan de substrat en réponse à un potentiel électrique entre la première électrode et la troisième électrode ou en réponse à un potentiel électrique entre la deuxième électrode et la troisième électrode. La dimension de la troisième électrode perpendiculairement au plan du substrat est inférieure à la dimension de la première électrode et la dimension de la deuxième électrode perpendiculairement au plan du substrat.
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DE102019203914B3 (de) 2019-03-21 2020-07-30 BTU Cottbus-Senftenberg MEMS mit großer fluidisch wirksamer Oberfläche
EP3739904A1 (fr) * 2019-05-14 2020-11-18 FRAUNHOFER-GESELLSCHAFT zur Förderung der angewandten Forschung e.V. Système de transducteur acoustique et dispositif acoustique
US20220380200A1 (en) * 2019-11-13 2022-12-01 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Mems device, assembly comprising the mems device, and methods for operating the mems device
DE102020201197A1 (de) 2020-01-31 2021-08-05 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein MEMS mit hohem Aspektverhältnis
DE102021204653A1 (de) * 2021-05-07 2022-11-10 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. In-plane MEMS-Varaktor
DE102022210972A1 (de) 2022-10-18 2024-04-18 Robert Bosch Gesellschaft mit beschränkter Haftung Verfahren zur Herstellung einer mikromechanischen Schichtstruktur mit hohem Aspektverhältnis und mikromechanische Schichtstruktur

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4906840A (en) 1988-01-27 1990-03-06 The Board Of Trustees Of Leland Stanford Jr., University Integrated scanning tunneling microscope
US5075548A (en) 1989-07-17 1991-12-24 Olympus Optical Co., Ltd. Tunnel current probe moving mechanism having parallel cantilevers
JP3151956B2 (ja) * 1992-09-04 2001-04-03 株式会社村田製作所 加速度センサ
AU2002222123A1 (en) 2000-12-11 2002-06-24 Rad H Dabbaj Electrostatic device
JP2005004077A (ja) * 2003-06-13 2005-01-06 Ricoh Co Ltd 光変調装置およびその駆動方法
CN101772383B (zh) * 2007-07-31 2011-11-02 皇家飞利浦电子股份有限公司 具有高k电介质的cmut
WO2009073743A1 (fr) * 2007-12-03 2009-06-11 Kolo Technologies Inc. Transducteur ultrasonore micro-usiné capacitif avec rétroaction de tension
DE102010029936A1 (de) * 2010-06-10 2011-12-15 Robert Bosch Gmbh Bauelement mit einer mikromechanischen Mikrofonsruktur
FR2963099B1 (fr) * 2010-07-22 2013-10-04 Commissariat Energie Atomique Capteur de pression dynamique mems, en particulier pour des applications a la realisation de microphones
EP2664058B1 (fr) 2011-01-14 2017-05-03 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Composant micro-mécanique
CN103288034A (zh) * 2012-03-01 2013-09-11 北京大学 一种离面静电驱动器及其制作方法
DE102013216898B4 (de) * 2013-08-26 2023-02-09 Robert Bosch Gmbh Mikromechanisches Bauelement und Verfahren zur Herstellung eines mikromechanischen Bauelements
JP2016018049A (ja) * 2014-07-07 2016-02-01 キヤノン株式会社 可変形状ミラー及びその製造方法
DE102014225934B4 (de) 2014-12-15 2017-08-03 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Elektrostatisch auslenkbares mikromechanisches Bauelement und Verfahren zu seiner Herstellung
DE102015206774B4 (de) 2015-04-15 2018-10-25 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Mikromechanische Vorrichtung mit einem aktiv biegbaren Element
DE102015210919A1 (de) * 2015-06-15 2016-12-15 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. MEMS-Wandler zum Interagieren mit einem Volumenstrom eines Fluids und Verfahren zum Herstellen desselben

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US20190382257A1 (en) 2019-12-19
WO2018162417A1 (fr) 2018-09-13
US11186478B2 (en) 2021-11-30
DE102017203722A1 (de) 2018-09-13
KR20190126370A (ko) 2019-11-11
CN110621612A (zh) 2019-12-27
DE102017203722B4 (de) 2021-11-25

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