WO2000031767A1

WO2000031767A1 - Micromechanical electrostatic relay

Info

Publication number: WO2000031767A1
Application number: PCT/DE1999/003744
Authority: WO
Inventors: Susanna Kim Hesse; Hans-Jürgen GEVATTER; Helmut Schlaak; Martin Hanke
Original assignee: Tyco Electronics Logistics Ag
Priority date: 1998-11-25
Filing date: 1999-11-25
Publication date: 2000-06-02
Also published as: DE19854450C2; DE19854450A1

Abstract

The inventive micromechanical electrostatic relay has at least one base substrate (1) with a flat base electrode, and an armature tongue (21) that has been relieved from an armature substrate (2), with a flat armature electrode. A wedge-shaped air gap (10) is formed between the base substrate (1) and the armature tongue. An electret layer (15, 25) is also configured on at least one of the substrate surfaces (11; 31), this electret layer being made up of a plurality of programmable, non-volatile storage locations (EEPROMs). A switching characteristic in the form of a make-contact, a break-contact or a changeover switch can be obtained in this manner.

Description

description

Micromechanical electrostatic relay

The invention relates to a micromechanical electrostatic relay with a solid body as the base substrate,

a flexible anchor tongue made of solid material f, which is connected on one side to the base substrate, forms a wedge-shaped working air gap with the open end and can be rolled off on the base substrate when actuated,

a flat base electrode formed on the base substrate,

an armature electrode formed on the armature tongue and opposite the base electrode,

- At least one fixed contact arranged on the base substrate and

- At least one movable contact arranged on the anchor tongue and opposite the fixed contact.

Such a micromechanical relay is basically already described in DE 42 05 029 Cl. Due to the wedge-shaped air gap between the base electrode and the armature electrode, when the voltage is applied between the two electrodes, the armature tongue rolls off on the base electrode, causing the narrow distance between the two electrodes to move further from the clamping point to the free, contacting end (traveling wedge principle) . In this way it is possible, on the one hand, to ensure the insulation strength between the fixed contact and the movable contact in the open state with a sufficient contact spacing, and on the other hand to make the armature respond electrostatically with a relatively low switching capacity. However • with such a purely electrostatic switching principle, relatively high switching voltages are required; in addition, the contact forces that can be achieved are still relatively low. In addition, with this principle, normally closed contacts or changeover contacts are very difficult to implement.

_From US 5 544 001, an electrostatic relay is also already known, in which a movable tongue can be switched between two stationary electrodes and the stationary electrodes are additionally provided with electrets. However, the stationary electrodes are arranged there at a relatively large distance from the movable tongue, so that in the respective switching positions they can only contact the counter electrodes at an acute angle and can touch them at most over part of their surface. This also applies, although it is already provided there that the air gap between the armature tongue and the stationary electrodes by stepped design or by inclined

Course of the stationary electrodes in the clamping area of the armature tongue should be smaller than at its contacting end; because even in this case there is a considerable distance from the stationary electrodes or electrets in the area of the fixed section of the armature tongue, so that a flat contact with the stationary electret is not possible at least over a substantial part of the length of the armature tongue.

In addition, known electrets, as are also used in the electrostatic relay mentioned, have the disadvantage that they are formed by introducing charge carriers into a dielectric layer, it being difficult to produce a homogeneous charge distribution and to keep them stable over the life . In such electrets, the dielectric must be charged during the manufacture of the individual layers. The compensation of charge losses due to surface effects in later operation or a change in the electret voltage are not possible.

The aim of the present invention is therefore to develop an electrostatic relay of the type mentioned at the outset in such a way that with relatively low switching voltages an improved tes switching behavior is obtained with a desired jump _S chaltcharakteristik and with sufficiently high contact forces. It should be possible chaltcharakteristik a desired _S, how to adjust or NC, NO and changer and the respective switching thresholds even after manufacturing for a specific application also to change again.

According to the invention, a relay for achieving this goal has the structure mentioned at the beginning and, moreover, at least one electret charge layer which is arranged on the base substrate and is incorporated into the surface of the wedge-shaped air gap and which by a plurality of programmable, non-volatile charge storage cells, so-called EEPROMs, is formed.

By including an electret layer in the wedge-shaped air gap according to the invention, the switching characteristics of the relay can be adjusted very well to the respective application. Since the electret layer extends into the tip of the wedge-shaped air gap, the electrical charges of the electret become effective from the start of the switching movement at the same time as the control voltage is applied, so that the control voltage itself can be correspondingly lower. Furthermore, it is provided according to the invention that the electret layer is formed in each case by a plurality of charge-storing cells, by means of which a desired homogeneous charge distribution can be set precisely and stably. In contrast to conventional electrets, in which the charge carriers are introduced into a dielectric layer, for example Si0 ₂ or Si0 ₂ -Si ₃ N ₄ composite structures, in the invention the electret function is achieved by introducing charges into an insulator on all sides , electrically conductive storage layer realized. This concept is based on structures that have established themselves in the field of microelectronics as non-volatile, rewritable memory cells (EEPROMs). This principle is adapted to the requirements of the microrelay by appropriately dimensioning the layer thicknesses and the areas of the individual memory cells. The respective electret potential and thus the switching characteristics are specified via the amount of the charge carriers introduced in each case, which can be controlled for the given dimensioning via the charge duration and charge voltage.

The possibility of charging the storage layer after the end of the production process is particularly advantageous in the relay configuration according to the invention. This means that the programming process can also be repeated any number of times (with suitable external wiring), so that the switching behavior can be adapted to the respective requirements in operation at any time. The degrees of freedom in manufacturing technology are thus increased; At the same time, tolerances in the geometry generated during the manufacturing process can be compensated for by the programming process. Charge losses during operation can also be compensated for at any time.

The qualitative and quantitative characteristics of the switching behavior can thus be defined and changed at any time by means of a programming step. For example, it is possible to implement a micro relay family, the individual variants of which initially all have the same structure and thus the same production process, but whose switching properties are only set by the subsequent programming.

Depending on the intended electrical charge density of the electret layer or the charge storage layer, the characteristics of the relay can be selected differently. Thus, the charge density can be chosen so high that the attraction force of the electret exceeds the mechanical prestressing force of the armature tongue with which it is prestressed away from the base substrate due to its basic shape even without activation. In this case, the anchor tongue is at rest was applied to the base substrate and an NC contact is formed. If, however, at a lower charge density this tightening force is less than the biasing force, an _S arises chließer. In a preferred embodiment, an additional cover substrate is arranged above the base substrate in such a way that these two fixed substrates form a wedge-shaped air gap, in which the armature tongue is pivotably arranged and optionally bears on the base electrode or on the cover electrode. In this case, an electret layer is provided on the base substrate and on the cover substrate, these electret layers carrying charges with different signs. In this case, too, the characteristic can be adjusted by coordinating the charge densities in both electret layers. If the charges of different signs in both electret layers are equal in terms of their absolute values, ie their sum is zero, a bistable or, if appropriately fine-tuned, a tristable switching characteristic can be achieved in this way. On the other hand, monostable switching behavior can be achieved by different charge densities in the two electret layers.

In a preferred embodiment of the invention, the air gap surface of the base substrate and optionally of the cover substrate are each curved so that the greatest curvature occurs in the area of the clamping of the anchor tongue and that the distance between the base electrode and the anchor tongue or between the base electrode and the cover electrode of the clamping point of the anchor tongue is steadily increasing towards its free end.

Silicon or a crystalline material with similar properties is preferably used as the material for the base and lid substrates and for the anchor tongue. In addition to crystalline silicon, polysilicon, metals and plastics that can be processed in micromechanics - with a metal coating - are also considered for the anchor tongue. The A- individual memory cells of the electret layer, as he ^¬ believes, consist of a metallic charge storage layer with freely displaceable potential, which in turn is embedded between insulation layers. Only in relation to a charging electrode do these storage cells have a tunnel window, in which a relatively thin tunnel oxide layer allows the passage of charges when a voltage is applied.

A method according to the invention for producing one or more relays of the type mentioned at the outset is that in a crystalline base substrate, by removing the surface, a profile corresponding to the desired wedge-shaped air gap surface is generated and, by selective coating and structuring, at least one insulation layer, a metal layer to form the base electrode and At least one load circuit lead, an electrically conductive electret layer inserted between insulation layers and subdivided into individual charge storage cells, and at least one contact piece are formed such that at least one insulation layer, a metal layer for forming an armature electrode and at least one movable one, on the underside of an armature substrate by selective coating and structuring Contact element and a surface insulation layer are generated that the armature substrate with its structured underside on the st structured top of the base substrate bonded and removed to a desired anchor thickness and that the contour of the anchor tongue is then exposed from three sides. In addition, a cover substrate is preferably coated and structured in a manner analogous to that of the base substrate and then bonded to the anchor substrate with its structured side.

For the individual manufacturing steps of the relay, the same or similar etching, coating, structuring and doping methods are used as are used in semiconductor technology or in other areas in micromechanics. The curved profiles for the air gap surfaces of the base _S ubstrats and optionally the lid substrate are obtained preferably by means of gray-scale lithography or sacrificial mask technique before ^¬.

Since a plurality of identical systems are usually obtained on a silicon wafer in a multiple arrangement in such a production method (benefit production), it can be advantageous not to separate the individual relay systems from one another after production, but in the multiple To leave compartment arrangement and to accommodate, for example, in a common housing. The individual relay systems can be controlled individually or in parallel by suitable selection of the connection elements.

Further refinements are mentioned in the subclaims.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. Show it

FIG. 1 shows a switch structure of a micromechanical relay according to the invention,

2 shows the principle of the arrangement of individual memory cells on the base electrode of a relay according to FIG. 1, FIGS. 3 and 4 the model of a charge storage cell of a drive electrode according to FIG. 2 in section and in a top view, FIGS for a relay according to the invention, each in section and in plan view, FIGS. 15A to 15E show a schematic sectional view of a base substrate in different manufacturing process steps,

16A to 16H in a schematic sectional view, the production of one (or two) anchor tongue (s) in several process steps, the connection to a base substrate and the application of an additional cover substrate, FIG. 17 a perspective view of a multiple relay arrangement with a common base substrate, one _V ielzahl of contiguous anchor tongues and a common lid substrate.

Figure 1 shows schematically the structure of a changeover relay according to the invention. It consists of a base substrate 1, an anchor substrate 2 with an anchor tongue 21 and a cover substrate 3, a wedge-shaped air gap 10 being formed between the base substrate 1 and the cover substrate 3 and the anchor tongue 21 being enclosed between these two substrates 1 and 3 . The lid substrate 3 is preferably designed identically to the base substrate 1 and rotated by 180 ° and placed on top of it with the interposition of an armature substrate 2. The surfaces 11 of the base substrate and 31 of the cover substrate facing the air gap 10 are curved so that they have their greatest curvature in the region of the tapering inner air gap end, while this curvature becomes steadily flatter towards the open end of the air gap, the air gap increasing overall open end steadily enlarged. Depending on the respective switching state, the armature tongue 21 can either nestle against the surface of the cover substrate 3 (drawn in solid lines) or against the surface of the base substrate 1 (indicated by dots).

In principle, the substrates 1 and 3 themselves could function as base or cover electrodes with appropriate doping. Likewise, the armature substrate 2 or the armature tongue 21 could directly form an armature electrode. Preferably, however, a base electrode 12 will be provided on the base surface, a cover electrode 32 on the cover surface and metallic anchor electrodes 22 and 23 on the respective surfaces of the armature tongue 21. The metal layers for forming the electrodes can then also form supply lines for the load circuit which are insulated from the electrodes by appropriate structuring. A charging electrode 13 is also produced simultaneously with the base electrode 11 and a charging electrode 33 is produced with the cover electrode 31. Through an iso- lierschicht, 14 and 34, separated from the electrodes 12 and 13 or 32 and 33, then to the base electrode of a La ^¬ dung storage layer 15 disposed on the top electrode, a charge storage layer 35 covered in turn to the outside by a further insulating layer 16 or 36 is. The charge storage layers 15 and 35 are each approximated to the latter in the region of the charging electrodes 13 and 33, so that the insulation layer 14 and 34 respectively forms a tunnel region 17 and 37 of small thickness at this point, in which electrical voltage is applied when a corresponding voltage is applied Charges can be transported into the storage layer 15 or 35.

According to FIG. 1, the contact system of the changeover relay consists of a base fixed contact 19, a cover fixed contact 39 and a movable center contact 29 which is arranged on the armature tongue 21. This movable center contact 29 is arranged in a movable contact area 24, which in turn is suspended by spirally or sun wheel-shaped interlocking slots 25 via intermediate movable webs in the armature tongue 21, so that when contact is made, it can be moved out of the plane of the armature tongue 21 and receives the desired contact force in this way (see also FIG. 2). Such a design of an anchor tongue with a movably suspended contact has already been described in DE 44 37 259 Cl. The contact is connected via a conductor track, not shown, to a connection, not shown, in the region of the clamping point of the armature tongue 21. The voltage connection of the relay is also indicated only schematically in FIG. 1. The two fixed electrodes, that is to say the base electrode 11 and the cover electrode 31, are each connected to ground, while a control voltage U _{s is} applied to the armature tongue 21. Depending on the desired switching movement, this control voltage is either positive or negative in coordination with the charge of the two electret layers 15 and 35. When the control voltage U _s is applied, the armature tongue is al acts, whereby it is repelled by the electret charge of one electret layer and attracted by the other electret layer.

FIG. 2 shows the principle of the arrangement of the individual memory cells of an electret layer, as they appear, for example, when the base substrate 1 of FIG. 1 is viewed from above; the substrate itself is not shown in detail. In addition, the contour of the anchor tongue 21 lying on the base substrate is shown in dashed lines in FIG. 2 in order to illustrate the spatial arrangement of the clamping or the contact area and the adaptation of the memory cells to this contact area.

As can be seen in FIG. 2, the individual memory cells 41 are arranged in a matrix-like manner over the entire active surface of the base substrate below the anchor tongue, only the area below the contacting area 24 of the anchor tongue is not occupied by memory cells. A drive electrode or base electrode 11 (FIG. 1) (not shown in FIG. 2) is located below the memory cells and also serves as a control electrode for charging the memory cell. A dotted line in FIG. 2 shows a field of charging electrodes 43 which lie below each memory cell next to a corresponding section of the control electrode and to which a specific voltage is applied via the lead 43a for charging the memory cells.

The structure of the individual memory cells and the charging process will now be explained with reference to FIGS. 3 and 4. Each memory cell 41 accordingly has a charge storage layer 45, which lies between two insulator layers 44 and 46, which consist, for example, of silicon dioxide Si0 ₂ . The charge storage layer 45 is a metallic layer. In a gap in a control electrode 42, which corresponds to the base electrode 12 in FIG. 1, lies the charging electrode 43, which the charge storage layer has in a slight gen distance d _inj faces 47 and forms in this way a do ^¬ nelbereich for charging. This distance d _inj is, for example, 10 to 25 nm, while the normal layer thickness d _{s of} the insulation layer 44 is, for example, 200 to 500 nm. As will be seen from Figure 2, the single ^¬ NEN memory cells 41 are preferably rectangular and arranged such that they have a smaller extension in the longitudinal direction or in the unwinding direction of the anchor tongue than in the transverse direction. In this way, the desired charge distribution and a corresponding switching characteristic can be set particularly well. The dimensions of such a memory cell 41 are preferably in the longitudinal direction of the anchor tongue l _ι = 25 to 50 microns, bι in the transverse direction = 25 to 100 .mu.m. The effective area A _{inj of} the charging _electrode results from their dimensions, which can each be between 5 and 15 _μm in length 1 ₂ and width b ₂ , while the effective area A _{s of} the control electrode takes up approximately the rest of the total area of the memory cell.

In order to introduce charge carriers into the storage layer of a storage cell 41, an electrical control voltage U _{in is} applied between the control electrode 42 and the charging electrode 43. In accordance with the capacitive voltage divider ratio of the arrangement, part of the control voltage drops across the tunnel oxide and determines the constant proportion of the electrical field strength in the tunnel area 47. The Fowler-Nordheim relationship gives the tunnel current density from the total field strength in the tunnel area. As a result of the charge transport into the storage layer 45, an electric field builds up, which counteracts the control field and thus causes a gradual reduction in the current density; the charging process runs into saturation. Accordingly, the total amount of charge introduced into the storage layer, which determines the electret voltage for a given cell area, can be either via the charging time (with a fixed control voltage) or via the control voltage _S (for fixed selected charging time) to be controlled.

FIGS. 5 to 14 show the main process steps for the manufacture of the charge-storing elements 41, each in a top view and in section.

As can be seen in FIGS. 5 and 6, an electrically conductive layer is first applied — insulated from the substrate 1 and structured in such a way that a control electrode 42 and a charging electrode 43 are formed. These two electrodes are interlocked in order to provide the control and charging electrodes for the individual memory cells to be applied later in the manner shown in FIGS. 3 and 4.

FIGS. 7 and 8 show as the next step the application of the tunnel oxide 47, which _forms the first part of the insulating layer 44 (FIG. 3) with the thickness d _ιnD . The charging electrode 43 and the control electrode 42 are completely covered by this first oxide layer 47.

In the next step, which can be seen in FIGS. 9 and 10, the insulating layer 44 is reinforced to the entire thickness d _{s in} such a way that the tunnel windows 44a remain free, in which the tunnel oxide layer 47 is exposed.

In the next step, which is shown in FIGS. 11 and 12, the storage layer, structured according to the individual storage cells 45, is then applied. This storage layer also extends into the tunnel window 44a, where it lies directly on the oxide layer 47.

The final step, which is shown in FIGS. 13 and 14, comprises the application of the insulating cover layer 46, which electrically insulates the entire storage layer, that is to say all the storage cells, from the outside. It was still adds that only a broken-off part of the substrate coating and the substrate itself are shown in abbreviated form in FIGS. 6, 8, 10, 12 and 14. The size relationships result from FIG. 2, where it is clear that the individual storage cells 41 have a smaller extent 1 in the longitudinal direction or in the unwinding direction of the anchor tongue and their greater extent b transversely to this unrolling direction.

FIGS. 15A to 151 and 16A to 16M show the essential manufacturing steps for a relay according to FIG. 1. A longitudinal section through the respective substrate is shown, only the most important process steps being listed. For example, intermediate steps such as masking or applying additional layers that are necessary in terms of production technology with adhesion promoters, diffusion barriers, etc. are not dealt with. Process steps of this type are known to those skilled in the processing of silicon wafers or similar substrates in semiconductor technology or in micromechanical process technology.

FIG. 15A basically shows a section through a silicon substrate 100, which serves as a starting substrate for a base substrate 1 or a lid substrate 3. This substrate 100 is first removed on the surface in order to obtain the curved surface 101 required for the wedge-shaped working air gap. As can be seen from FIG. 15B, two mirror-inverted substrate systems are manufactured at the same time for manufacturing reasons, namely an electrode surface 101a in the left half of the substrate and a mirrored electrode surface 101b in the right half of the substrate. This base electrode profile is preferably generated using gray-tone lithography; However, other processing methods would also be conceivable, such as sacrificial layer technology or other etching processes from semiconductor processing. An insulation layer 102 according to FIG. 15C, a metal layer 103 (FIG. 15D) for forming the drive electrode or control electrode 42 and the charging electrode 43 and for forming load circuit leads (not shown in any more detail) are then applied and structured in succession. Thereafter, according to FIG. 15E, a thin insulation layer 107 is applied to form the tunnel section 17 and, according to FIG. 15F, a thick insulation layer 104 is applied and structured in the region of the charging electrode 13 or 43.

According to FIG. 15G, a metallization layer 105 is then applied as a charge-storing layer and structured to form the individual memory cells 41. According to FIG. 15H, an uppermost insulation layer 106 is finally applied and structured in order to be able to galvanically reinforce the stationary contact pieces 109 according to FIG. 151.

FIGS. 16A to 16M schematically show the further extraction of an anchor tongue 21 from an anchor substrate 200 and its connection to a base substrate and a cover substrate 300. First, a plate-shaped armature substrate 200 is provided on the underside of the wafer with an insulation layer 201 (FIG. 16B), and a metal layer 202 (FIG. 16C) is applied to this insulation layer and structured to form an armature electrode 22 (FIG. 1) and load circuit leads .

According to FIG. 16D, a further insulation layer 203 is then applied and structured, so that, according to FIG. 16E, movable contacts 209 can be formed on the metal layer 202 by galvanic amplification.

The thus obtained and structured armature substrate 200 is then anodically or eutectically or otherwise bonded to a base substrate 100, which is designed according to FIG. 151 (see FIG. 16F). 16G, the armature substrate is then removed to a desired thickness of the armature tongue 21. etched. Such a thickness is on the order of 10 µm, for example. The anchor tongue layer 210 obtained in this way could, if only one opener or closer should be produced, be separated in the middle in the area 211, so that two anchor tongues 21, which are denoted in brackets and arranged in mirror-inverted fashion, would be obtained.

To obtain a changeover relay according to FIG. 1, however, the upper side of the armature tongue layer 210 is structured further, namely by applying a further insulation layer 205 according to FIG. 16H, by applying and structuring a metal layer 206 for a further armature drive electrode 23 (FIG. 1) and, if appropriate, for load circuit leads and by applying and structuring a further insulation layer 207 (FIG. 16J). Then by galvanic

Reinforcing the metal layer 206, movable contact pieces 208 are formed (FIG. 16K), and finally two anchor tongues 21 are obtained by laterally structured, three-sided exposure, as is shown in FIG. 16L (but only in section). Finally, a lid substrate

300, which is designed like the base substrate 100 according to FIG. 151, is bonded from above with the structured surface down to the armature substrate 200. In this way, according to FIG. 16M, a relay is formed with two opposing armatures 21, the base fixed contacts 19 and the cover fixed contacts 39 of both systems being connected via the metal layers 103. If the systems were to be switchable separately, these layers would have to be separated or insulated accordingly in the course of production.

In practice, the processing of the individual substrates is carried out not only with two anchor tongues according to FIGS. 15 and 16, but in multiples, so that a matrix arrangement with a large number of relay systems is obtained. Such a multiple is shown in FIG. 17, wherein a common base substrate 100 and a common cover substrate 300 form an armature substrate 200 with a large number of armature tongues 21. conclude. The individual switching units, each with an armature tongue 21, can be controlled or designed separately or in parallel by appropriate design of the feed tracks.

The individual relay system or the relay multiple arrangement is accommodated in a conventional manner in a housing, which is not specifically shown. Such a housing is preferably hermetically sealed and can, for example, be evacuated or filled with a protective gas (N ₂ or SF ₆ ). It is also expedient to manufacture the housing from metal for the purpose of electrostatic shielding.

All representations in the exemplary embodiments are greatly enlarged, the proportions not being to scale in all cases; in particular, some layer thicknesses are exaggerated for the sake of clarity. Typical dimensions of an anchor tongue are, for example: length 1500 to 2000 μm width approximately 1000 μm thickness 10 μm.

Claims

claims

1. Micromechanical electrostatic relay with

- A solid body as the base substrate (1; 100), - A flexible anchor tongue (21) which has been machined from solid material and which is connected on one side to the base substrate (2; 200), with this a wedge-shaped working air gap which widens continuously towards the open end (10) and can be rolled off on the base substrate (1) when actuated,

- a flat base electrode (12) formed on the base substrate (1; 100),

an armature electrode (22, 23) formed on the armature tongue (21) and opposite the base electrode (12),

- At least one fixed contact (19) arranged on the base substrate (1) and

- At least one movable contact (29) arranged on the armature tongue (21) and opposite the fixed contact, characterized by at least one electret charge layer (15) which is arranged on the base substrate (1) and is incorporated into the surface of the wedge-shaped air gap a plurality of programmable, non-volatile charge storage cells (EEPROMs) (41) is formed.

2. Relay according to claim 1, so that the individual memory cells (41) in the rolling direction of the armature tongue (21) have a smaller extent than in the direction perpendicular thereto.

3. Relay according to claim 1 or 2, characterized in that the individual memory cells (41) each have an extension in the rolling direction of the armature tongue between 25 microns and 50 microns and in the perpendicular direction between 25 microns and 100 microns.

4. Relay according to one of claims 1 to 3, characterized in that the individual memory cells (41) each have a metallic charge storage layer (45) which is embedded between two insulation layers (44,46), one of the insulation layers Separates charge storage layer (45) from a control electrode (42) and an additional charging electrode (43) is provided, which is separated from the charge storage layer (45) only by a tunnel insulation layer (47), the thickness (d _inj ) of which is only a fraction of the thickness (d _s ) of the insulation layer (44) separating the control electrode (42) from the charge storage layer (45).

5. Relay according to claim 4, characterized in that the tunnel insulation layer has a layer thickness (d _in j) between 10 and 25 nm and the insulation layer between the charge storage layer (45) and the control electrode (42) has a layer thickness (d _Ξ ) between 200 and 500 nm.

6. Relay according to claim 4 or 5, so that the control electrode (42) and the charging electrode (43) are formed by structuring from one and the same metal layer (103).

7. Relay according to one of claims 4 to 6, so that the control electrode (42) also serves as the base electrode (12) or cover electrode (32) for the switching drive of the relay.

8. Relay according to claim 1 to 7, characterized in that the base substrate (1) has a flat surface (11) and that the armature tongue (21) from the base substrate (1) is biased away in a continuously curved basic shape.

9. Relay according to claim 1 to 7, so that the armature tongue (21) has a flat basic shape and that the base substrate (1) has a surface (11) which is continuously curved away from the armature tongue (21).

10. Relay according to one of claims 1 to 9, characterized in that the electrical charges of the electret layer (15, 35) generate a tightening force between the base substrate (1) and the armature tongue (21) which is less than that of the base substrate (1 ) directed biasing force of the armature tongue (21), so that a normally open contact is formed.

11. Relay according to one of claims 1 to 9, characterized in that the electrical charges of the electret layer (15, 35) generate a pulling force between the base substrate (1) and the armature tongue (21) which is greater than that away from the base substrate. Tete biasing force of the armature tongue (21), so that an NC contact is formed.

12. Relay according to one of claims 1 to 11, characterized in that in addition a cover substrate (3; 300) over the base substrate (1) is arranged to form a continuously wedge-shaped air gap (10) and one of the armature electrode (22, 23) flat opposite Cover electrode (32) carries that the armature tongue (21) between the two substrates (1, 3; 100, 300) is clamped and in a first

Switch position to the cover substrate (3; 300) and a second switch position to the base substrate (1; 100) and • that on the base substrate 81) and the cover substrate (3) each have an electret layer (15, 35) with charges of different polarity is arranged.

13. Relay according to claim 12, so that the sum of the electrical charges in both electret layers (15, 35) is equal in amount.

14. Relay according to claim 12, so that the sum of the electrical charges in the two electret layers (12, 32) is different according to the amount.

15. Relay according to one of claims 1 to 14, characterized in that the wedge-shaped air gap (10) between the base substrate (1), the anchor tongue (21) and optionally the cover substrate (3) forming curved surfaces in each case in the vicinity of the clamping of the Anchor tongue (21) have an area of greatest curvature.

16. Relay according to one of the claims Ibis 15, so that the armature tongue (21) has at least one contact section (24) carrying the movable contact (29), which is movable via flexible straps out of the armature plane, in the region of its movable end section.

17. Arrangement of a plurality of relays according to one of claims 1 to 16, so that all relays are connected at least via their basic substrates (1) to a one-piece carrier substrate (100) in a multiple arrangement.

18. The arrangement according to claim 17, characterized in that on the carrier substrate (100) control lines are provided for each individual relay.

19. The arrangement as claimed in claim 17, so that control lines for the parallel control of a plurality of relays are provided on the carrier substrate (100).

20. A method for producing one or more relays according to one of claims 1 to 19, characterized in that in a crystalline base substrate (100) by removal of the surface a profile corresponding to the desired wedge-shaped air gap (101) is generated and that by selective coating and structuring at least the following layers are applied: a) an insulation layer (102), b) a metal layer (103) for forming a base electrode (12), a charging electrode (13) and at least one load circuit feed, c) a thin insulation layer (107) for Generation of a tunnel section (17), d) a thick insulation layer (104) in the area of the drive electrode, e) a charge-storing metal layer (105), f) a surface insulation layer (106) that on the underside of an armature substrate (200) by se - Lective coating and structuring of at least one insulation layer (201), a metal layer (202) to form an anchor Electrode (22) and at least one movable contact element (209) and a surface insulation layer (203) are generated that the armature substrate (200) with its structured underside bonded to the structured top of the base substrate (100) and removed to a desired anchor thickness and that the contour of the anchor tongue (21) is then exposed from three sides.

21. The method according to claim 20, characterized in that a crystalline lid substrate (300) is coated in an analogous manner as the Ba ^¬ sissubstrat (100) and structured, and that this lid substrate (300) is bonded with its structured side to the armature substrate (200) .

22. The method according to claim 20 or 21, so that the curved air gap surface (101) of the base substrate (1) and / or the cover substrate (3) is produced by gray-tone lithography.

23. The method according to any one of claims 20 to 22, characterized in that after the connection of the armature substrate (200) with the base substrate (100) and optionally with the cover substrate (300), a charging voltage (U _iri j) between the control electrode (12; 32nd ; 42) and the charging electrode (13; 33; 43) is applied, and that a predetermined electric charge is generated in the individual memory cells (41) by adjusting the charging voltage and / or the charging time.