EP2603449A1 - Method for producing a mems apparatus with a high aspect ratio, and converter and capacitor - Google Patents

Abstract

The invention presents a method for producing microstructured apparatuses for microelectromechanical systems (MEMS). In order to increase the maximum aspect ratio conditioned by physical or chemical microstructuring methods, it is proposed to design flat elements of the apparatus, which are structured such that they are movable relative to one another, to be laterally changeable from a first reference position relative to one another (structuring position) to a second reference position (operating position) in a permanent or irreversible manner. As a result, higher trench capacitances can be formed between structured wall sections. The reference position can be changed by means of integrated drives or by supplying energy from the outside and said change is effected in a direction which is substantially different from the measuring direction. In addition to mechanical work and energy from electrical or magnetic fields, heat can be used to shift location in drives as a result of the action of force on an element or induced changes in length. This method makes it possible to produce highly sensitive sensors for very small excitation signals or to produce economical actuators with an extremely high level of efficiency in the form of low-attenuation, area-optimized, highly capacitive converters, as well as variable vertical capacitors with a high capacitance.

Description

 A method of manufacturing a high aspect ratio MEMS device, and transducer and capacitor

The present invention relates to a method for producing high aspect ratio micro-electro-mechanical structures (acronym: MEMS).

Furthermore, the present invention relates to transducers or capacitors having micromechanical structures comprising electrodes separated by trenches.

The actual transducer function of such designed transducer is preferably achieved via the interaction of movable and electrically differently charged, opposing surfaces on the one hand and on the supply lines applied or applied electrical potential difference on the other hand.

In particular, the invention relates to MEMS sensors, in particular for one or more of the measured variables that can be determined by the effect of a path change, such as:

Distance, vibration, acceleration, speed, rotation rate, force, pressure or torque.

The inventive architecture of this sensor makes it possible to supply at least one electrode from a production position to that of another electrode

Work-rest position. The work rest position of two due to the method according to the invention relatively positioned electrodes is increased by an increased

Aspect ratio marked.

Likewise, actuators (encoders) are included with such architecture as, preferably, micromotors (for linear or rotary motion or for vibration generation), micropumps, drives (e.g., for light modulators via arrays), vibrators, switches or relays.

Especially comb structures, as used in already known comb drives (English: Comb-drives) are suitable for the application of the invention.

But even applications without converter function can by the objective

Be detected invention. Thus, the target position determines the target capacity of an integrated or discrete capacitor made in this way. Microstructured trimmer capacitors or fixed capacitance capacitors are other applications of the subject invention. The capacitor thus produced can also be used in circuits as a transducer element in frequency-voltage converters, voltage-frequency converters or analog-to-digital converters and for time measurement. In addition, such elements can be used to compensate for errors due to temperature changes.

The invention is based on a MEMS method according to the prior art and a generic MEMS converter, as in many publications around sensors for the measurement or actuators for the generation of path changes, shifts or accelerations, vibrations or vibrations in different directions but is also revealed by changes or accelerations of different axes.

For sensors, an electrical target signal in the form of an electrical results

Voltage change or electrical current change. This signal can then be amplified via transistor circuits and evaluated via analog-digital circuits and a measure of the mechanical or thermal input variable. The mechanical input may be the result of gravity or some other acceleration, such as vibration or vibration acting on a diaphragm, or pressure.

In microactuators, a mechanical manipulated variable or excitation or a thermally induced change in length is the result of an electrical signal change to the

Electrodes. This manipulated variable can be activated periodically, as is the case with linear or circular oscillators or with micromotors. This can be new

Inertialsysteme are formed, the vibration axes, rocker planes or rotor levels against external force forming an inertia, which in turn is used sensorially. The force is usually the result of the action of an electric or rare magnetic field or the result of a shape-changing

Temperature change of an element due to the thermal power loss in a flow-through actuator, or due to an electrostrictive or magnetostrictive effect.

As restoring forces spring forces are often used, the work on the bias of micro-bending beam or microspiral springs on the restoring forces along the travel must be introduced in addition. In addition, membranes are used as energy storage for restoring forces.

The Coriolis force causes deflections of the oscillating or rotating masses in a direction normal to the direction of oscillation or rotation when a change in the

Swinging axis direction or the position of the vibrating or rotating plane from the outside the inertial system is impressed. These deflections are in turn sensory detected to measure inclinations, yaw rates or angular accelerations.

If the axes of these new inertial systems are changed from the outside in their direction, precession forces also form through the bearing devices of the

Oscillating mechanically coupled and in turn can lead to sensory detectable changes in position of, for example, bending beam. When detecting precession forces, the frequency of the actuator oscillation or the rotational speed of the actuator is only indirectly effective in the magnitude of the amplitude in the measurement, whereas when detecting the Coriolis force in vibration systems, the measurement signal is modulated with the oscillation frequency.

Microelectronic analog circuits or mixed analog-digital microelectronic circuits often have capacitor structures which, due to their very low

Area capacity of typically 1, 75fF ^ m ² or below have a significant space requirement. The capacitance of these capacitor structures is formed for example by two mutually insulated metal layers or by two isolated polysilicon layers or by a diffusion layer of doped silicon and an isolated polysilicon layer. In this case serves as an insulator silicon dioxide. Aluminum is applied for the metal layer.

Device structures in micromechanics may be formed by deep etching techniques, e.g. The reactive silicon ion deep etching (Bosch process) can be produced with a relatively high aspect ratio. The aspect ratio is understood to be the ratio of the depth of a manufactured trench or a recess to the lateral dimension.

A known deep structuring method in the form of a plasma etching process is described for example in DE 42 41 045. With the trench method described therein, trenches with a trench minimum width of 1 μm can already be produced and opened. As with all plasma etching processes, the etching rate, ie the

Speed of material removal depending on the structure distances. With narrow etching openings, the etching rate is significantly lower than can be achieved with wide etching openings. Only at distances above about 10 μηι the etch rate is substantially independent of the structure distances.

In summary, it can be stated that with previously known methods, distances of less than 1 μm are at least not reliably reproducible or not

can be manufactured safely and so far due to the required

Process accuracy was not considered useful. In transducers with micromechanical structures that include electrodes that are separated by trenches, large electrode spacings result in low electrical sensitivity. Low sensitivity means a larger size of the structures because more electrode area is required or larger and low noise amplifier must be used to achieve the required transducer performance.

However, the broader the structures are separated from each other, the deeper and faster they can be structured.

In DE 101 05 187 it is proposed that to increase the aspect ratio of the trenches at least in sections, a further layer is deposited on the side walls of the trenches, whereby smaller trench widths are achieved. In JP 2009 190 150, an oxide film is formed by thermal oxidation, which reduces the trench width. These methods require additional production steps and consequently higher ones

Production times and costs as well as precise monitoring of the process steps result in higher failure rates due to process-related limits.

In DE 101 45 721 an electrode structure designed vertically to the substrate plane is proposed, which allows a mechanical positioning of an exempt finger-operated movable electrode between two further electrodes, whereby the

Finger structure can be guided from a non-immersed position into a dip in the fitted counter-structure with recesses for the finger structures. As a result, electrode distances of 100nm are possible, the cost of structuring and

However, assembly is very high due to the vertical structure of three layered components. In addition, that requires three times the material surface.

US 7,279,761 also shows an approach where comb electrodes from a non

entangled (separate combs) converted into an entangled toothed state and fixed there either by a ratchet or by bistable springs. The introduction of the etched finger structures in the opposite distance gaps is not critical, the sensing axis is parallel to the direction of the positioning axis here.

EP 1 998 345 shows deeply etched offset non-entangled lateral, etched or combed opposing comb structures formed on trench walls. In this case, a comb is movable laterally so that the mutually offset elevations or recesses can be converted into a position with a smaller offset or even in a symmetry position, whereby the capacity increases. The direction of movement is the sensing direction. However, a snap-in function is not provided here.

From WO 02/19509 entangled comb structures are known, where the finger distances of a stationary comb relative to a movable comb are position-dependent, as the interlocking structures of the fingers and spacers are formed as prisms with trapezoidal bases.

From GB 2 387 480 a device is known, the electrodes of a contact switch due to different thermal expansions in a supply and parallel return line of different thickness in current passage due to bending closer each other until they contact safely. In this case, the contact position is further held by a mechanical locking via a hook with a barb, even if the passage of current is terminated. The release of the Wederhakensystems via a second bending device, which is provided on the Wederhaken and has similar structure (with return and return power line of different thermal power loss and thus different extent). A capacitive approach is not described.

On the one hand, to take advantage of this prior art and to overcome the existing disadvantages of the prior art, on the other hand, a method has been sought which incorporates existing technologies such as e.g. around CMOS or BiCMOS semiconductor fabrication techniques, more economically. For this purpose, as far as possible no additional process steps are needed, but nevertheless the sensitivity of

generic transducers are significantly improved. It is another goal to reduce the required material area (chip size) of the converter while still achieving good measurement results. A very high sensitivity of a sensor part should make it possible to save amplifier stages or to use simpler amplifiers for signal conditioning, which in turn reduce the material requirement and thus the production costs.

In summary, the invention is intended to allow sensors, e.g. for accelerations, rotation rates and vibration meters or actuators at low production costs but with high sensitivity or active power, e.g. in actuators, vibrators, relays or switches and the like. It should also be capable of optimizing existing MEMS converters through re-design and re-layout. In addition, capacitors with higher energy storage capacity (capacity) depending used

Silicon surface are made possible by the invention. Wchtig is also a high one

Reliability of the operation of such an actuator or sensor and high yield or low rejects in production.

By the method according to the invention can very small Trenngrabenbreiten

or structure distances are achieved with respect to the structure depth, without requiring additional chemical process steps, as those that are provided for already standardized deep etching. The electromechanical sensitivity of sensors produced thereby and the force effect on actuators is increased. Existing standard processes can be used. Another layer application to the etched structures with its process times, the process risk and additional failures is not required. In general, the micromechanical structures by

Process steps are formed, which are well known from semiconductor technology and are therefore not discussed here. The process allows fabrication in standard wafer fabrication facilities that support, for example, CMOS or BiCMOS processes, and where mask lithography, passivation, etching, metallization, and doping are already in use.

The achievable area capacity with respect to the silicon area used becomes very high in such formed vertical capacitors.

In order to achieve a high aspect ratio, according to the invention, the width of certain separating trench sections, which are basically produced according to a manufacturing process according to the prior art, is reduced by a further method step. This is done by repositioning at least part of completely or almost completely separated structural parts. In the case of structural parts which are not completely separated, holders, preferably in the form of flexible holders, remain between the separating trenches after the release.

The method of the invention allows the fabrication of many microelectromechanical systems where a high aspect ratio of spaced apart structure trenches is advantageous. In order to improve this aspect ratio, it is therefore proposed that at least one structural part of a silicon wafer or of a semiconductor component is almost completely released by chemical and / or physical material removal from an environmental part or another structural part. Ideally, it becomes a reactive one

Ion etching methods such as the DRIE, Deep Reactive Lonic Etching used. However, the parts separated in this way usually remain connected to one another via straddling and elastic connections for keeping and for supply lines. Due to the

Abtragungsprozess properties, such as during etching, a particular Trenngrabenbreite at a given trench depth can not be exceeded. According to the invention, in a further step, the separated inner structural part is changed relative to the outer environmental part or another structural part relatively in the position or orientation, so that the distance between at least two opposite formed wall sections of the ablation separation trenches is reduced. At the same time, of course, the distance is increased at another wall section. The sensing direction of the sensor or the direction of movement of the actuator is due to the invention largely independent of the direction of the positioning path. The trick is that the special

Form design by alternately elevations and recesses in the Ätzgrabenwand, a lateral displacement of the structural parts with the accompanying reduction in distance allows each other. Those migrations, which in the etching against the Recesses are formed, are placed in positions in which migration and migration are positioned opposite each other (but also recesses against recesses). The transverse or shear movement of the spaced

Electrode surfaces lead to new distance ratios in the lateral direction normal to the electrode surface. Thereafter, a fixation, preferably by a

Locking device.

By choosing the sizing of the migrations over the

Wall recesses can be advantageous to adjust the motion damping, which results from the gas located in the etch trench.

The approximated trench wall sections are formed as capacitive electrodes to electrostatically store electrical charge carriers.

For this relative change of the separated components to each other, various methods can be used. Either a force effect or a torque is exerted or transmitted on at least one of the parts separated from one another via devices from outside or via integrated inner devices.

After the position or orientation change of the components for changing the trench spacing, the released structural part is fixed permanently or irreversibly by suitable means. As a result, a high aspect ratio is locally achieved and maintained. The fixation may be such as to preserve the desired transducer functions by not limiting a relative electrode mobility, preferably in a direction or orientation other than that to which fixation is applied.

For material removal, an etching process is ideally used, which is already available for other applications around the circuit. For example, one is

Dry etching process, in particular reactive ion etching advantageous. At present, reactive deep ion etching (DRIE) is best used for these purposes. However, other future advantageous chemical processes are not excluded here.

The fabrication of the structural parts can be well integrated into CMOS process or a BiCMOS process.

According to the invention, there are a wealth of possibilities that allow the relative change in position or orientation change by means of force or torque formation. These include external field sizes. Gravity, preferably

For example, earth gravity, which causes gravity as a result, could cause the internal part position changes relative to one another by tilting a processed wafer from the horizontal position to a vertical position. For example, an external electric field may induce forces or torques on the movably-mounted differently charged structures by an electrically highly charged body to the side of the transducer, causing them to move toward the charged body.

By applying an electrical voltage to the - at Trenngrabenwänden

located electrodes, the resulting electric field the required

Attraction to reach the target position. The feeding of the charge can advantageously take place via separate lines.

The same applies to an external magnetic field. Here, the interaction with an internal magnetic field, for example due to a current flow, must occur through at least one of the separated parts. Externally, the magnetic field is generated by means of a permanent magnet or an electromagnet. For the sake of completeness it should be mentioned that permanent magnetic structures can also be applied to the moving parts in the converter device.

Temperature-induced deformations of suitably constructed bending-elastic compounds due to different thermal expansions, cold contractions can also be used for force effects on the structural parts to be moved to each other.

Also possible, albeit more complex, is the direct coupling of an actuator, for example a button, with a high-friction elastic cap to protect the surface of the MEMS device. This actuator can then pull the structural part directly in the direction of the desired position after placing on the excepted structural part and simultaneous fixation of the environmental part. Even a turn is possible, also in addition. Likewise, the surrounding part can be changed position or orientation while simultaneously fixing the released structural part by means of such an external actuator. Or it can be both the relative position and the orientation of two adjacent

Structures to each other thereby be changed.

The energy conservation law allows the advantageous use of the inertia of the structural part for the position or orientation change. Will the microelectromechanical

Device briefly accelerated in the opposite direction to the direction of positioning or orientation or braked from a uniform motion, for example via a vibrator, or angle accelerated or braked, for example via a

Turntable, the acceleration forces act on the loose or elastic

Compounds attached structural parts, thereby in relative movement to the

reach surrounding parts. Likewise, centrifugal forces (centrifugal forces) can be used. For this purpose, the microelectromechanical device (for example the wafer, or a MEMS converter) is set in rotation about an axis. For this purpose, the cut-out structures are advantageously so with respect to the axis of rotation, that the forces in the radial direction on the released body according to the invention act so that the shift in the working rest position of the structures or rotation is effected in a corresponding orientation position.

Another method of transferring kinetic energy to the movably mounted structural part is the utilization of the vibratory capacity of the structure and its structure

Resonance frequency. About vibrating systems, preferably via vibrators, this is excited to vibrate, which are in the range of a resonant frequency of the structural part.

Equally suitable is the energy transfer by an elastic impact from the outside.

For the above methods, in principle, additional structures are not necessarily required within the microelectromechanical devices. Nevertheless, own drive devices within this can be used for relative positioning or

Orientation change, also supportive, be provided.

These internal drive means are preferably electrostatic comb drive.

But there may also be magnetic drives. To produce the

Magnetic fields, current-carrying lines can be used.

Heating devices in the form of electrical leakage resistances can lead to the deformation of certain connection structures to the released structural part due to different thermal expansion due to current flow. Installed in different locations or in different positions, this causes a relative displacement or rotation of the connected parts to each other.

The same is possible if thermally induced deformations of suitable separate structures during passage of electricity push away the released structural part.

It can be advantageous to combine different devices for forming a force effect or a torque.

The force effect or the torque should be designed sufficiently such that the effect of counteracting spring forces, in particular spring forces of elastic connections, is exceeded. So the force effect is appropriate so that mechanical energy storage, such as elastic springs, charged or tensioned.

The fixation or securing of the released part after positioning or

Reorientation advantageously takes place mechanically by means of the structuring of catch traps on the microelectromechanical device, preferably assisted by return springs, which, for example, press sliding lugs into latching positions. Federgelagerte teeth, especially with different steep edges in the direction of

Movement, can also be used for Rastverbinden. These are similar structures to those known by cable ties.

If a bending beam is formed at least on one wall of the separating trench walls and then strongly pressed against a protrusion on the opposite wall and consequently bent, the contact angle between the bending beam and the survey can flatten. The consequence is that a lower static friction as an obstacle to the tensioned bending beam is overcome and this can jump as a result in a further intended position behind the survey due to the spring force.

The so-called "ratchet-like" arrangement of bending beam and survey can either be done so that a unidirectional mobility arises. Then, a change, preferably a reduction of a considered Trenngrabenabschnittes take place, but not an increase.

But it can also be provided several locking positions. This allows during the process to control any position from different nominal positions in one or more steps, whereby different transducer characteristics can be set; possibly also reversible. The already mentioned force effects and devices serve again. Additional factors must be taken into account when selecting a specific position, for example the duration of a force, the number of defined force actions, but also the amplitude of the action, within a certain time.

Alternatively, electromechanically acting microactuators may be provided on the device for fixing the positioned or reoriented structure and maintaining the locally high aspect ratio.

Also suitable for locking is thermal deformation of structures, whereby they at least partially intervene in the path. The rear-freedom of movement of the moving part with respect to the other parts is prevented by blocking structures, preferably by locking bolts. But it may also be the total freedom of movement, preferably in those directions or applications for which subsequently no sensitivity is desired, be limited. Targeted bonding, wedging, soldering or destruction of structures formed to obtain a particular relative mobility are other methods of fixation after aspect ratio optimization. Thus, for example, the thermal melting of a current-carrying resistor, the mobility of an exempted and positioned part permanently or irreversibly at least in the direction or the direction of rotation, from which the approach of the separated parts has taken place.

In addition to the method according to the invention for producing microelectromechanical transducers, certain microelectromechanical transducers are also the subject of this invention.

The characteristic of such a converter according to the invention is the presence of parts which are at least partially cut out of one another but after release of such approximated parts that the aspect ratio is increased in a stabilized manner at the specific positions between them. Preferably, at least one part is structured from another. Therefore, a part is the structural part and its associated environmental part. However, it is also possible to structure two elastically connected structural parts at a distance from an environmental part and also to connect them via elastic connections (springs).

Between the parts there are partly bridged dividing trenches. Ideally, these trenches have sections of reciprocating, looped or zigzagged or meandering course. The trench side walls are formed in these sections as electrodes with opposite counterelectrodes, preferably by known doping methods.

Physical considerations and the analysis of currently existing etching processes shows that with the approach method presented here, an aspect ratio can be formed in the work rest position which represents a multiple of current aspect ratios in work rest positions in known MEMS electrodes.

Thus, a feature of the inventive converter type presented here is one

Aspect ratio, which is within a range of 15 to 500,

Preferably, the range is between 20 to 200. In particular, the aspect ratio has a value in a sensor feature-determining dividing trench portion that is at least 25, but preferably as constant as possible over the portion.

Both the depth of the separation trench and the distance due to the partial displacement can be defined very precisely via mask-lithographically defined structures, but the surface structuring of the trench walls can result in certain process-related residual roughness which has an influence on the dielectric strength and the average capacitance, especially at close range.

The regions with the very high aspect ratio according to the invention are e.g. when

Electrodes designed and, to make a large area in a small space,

preferably formed comb-like with interlocking not touching each other surveys. Due to the manufacturing process, structures are provided on the transducer or devices that serve to keep the structure released by the manufacturing process in a work rest position or orientation. The holding serves to keep the mean value of the aspect ratio constant even in sensor or actuator applications, but does not restrict the sensor or actuator characteristics.

In conventional mechanical approaching MEMS methods, the sensory or actuation directional axis is currently used as the approach direction, so that the production tolerances and the mechanical play of detents can also directly influence the transducer size. In the solution presented here, the capacitive transducer sensitivity is within the approximate etch trench portions in FIG

Essentially in the direction of the tangential surface normal of the local Ätgragrabenwände.

The work rest position or orientation thus differs geometrically from the relative production position of the one-piece structured parts prior to separation and during trench formation.

The converter according to the invention thus has separating trench sections with a

Average width, which has a fraction of the average width of all on this converter made dividers. Such a capacitive electrode arrangement in this section results in an advantageously high sensitivity of a sensor formed in this way or high power of an actuator designed in this way.

According to the invention, it may be advantageous for at least one internal drive device to be integrated to increase the aspect ratio. This drive device may be an electrostatic comb drive. It can alternatively be a drive that uses magnetic fields of current-carrying lines.

Likewise, a thermally induced drive can be provided. This can be represented by a built-up in different shape and / or material property component, wherein caused by a flow of current different thermal expansion causes the movement. Formal changes of certain compounds to the released structural part can be enforced, whereby a relative

Objektverschiebung- or rotation of the structural part relative to the environmental part via a power supply is possible. Specially designed Wegdrückelemente between the Trenngrabenabschnitten can for the sake of a reduction on the other side by temperature

Length increase, widened by electrostrictive or magnetostrictive elements.

For effect enhancement, they can also have a similar effect to bimetallic strips. In the form of spirals or arches, a corresponding torque is thermally effected, which can exert pressure or rotation directly on the element to be moved or rotated via a lever, if appropriate current passage for heating or a

Heat is supplied from the outside.

Alternatively or additionally, the internal drive means and facilities for supporting the wrkung external devices for a Kraftwirkungs- or

Torque transmission be provided. Candidates include thermal elements that operate at high ambient temperature or magnetic materials that are attracted or repelled by an external magnetic field, such as iron, nickel or cobalt, or alloys or rare earth metals, and the like. Also, a certain storage of the movable structural part by means of springs cause a very defined resonance property, which can be excited for example by ultrasound, and thereby causes the desired change success.

Supporting devices are also special bearings due to structuring which allow sliding in one direction, rotation about an axis or twisting of a torsional suspension.

Are bending-elastic connections between the structural part and the surrounding part or between two exempted structural parts in a locked deflection, so allows a due to the flexural restoring force in a possible

Cancellation of the lock to bring the moving part back into the production state with a lower aspect ratio. In addition, by the back pressure of

Spring force secured the lock.

The isolated structural part expediently has a limited mobility. Either the shape of the structure or the trench profile or the arrangement and design of the flexurally elastic connections serves this purpose. It is expedient that the component has only two degrees of freedom for movements that are as independent as possible after production. In this case, at least one direction in the way according to the invention

Locking devices available. These serve to permanently or irreversibly block the relative movement of the structural part relative to the environmental part.

Advantageously, bending-elastic connections between the structural part and the surrounding part can be arranged, the rotation in a limited angle allow. In order to prevent an elastic or caused by the bending stiffness turning back, fixing elements may preferably in the form of pawls in

To be provided engaging tooth flanks. With the help of asymmetrical tooth flanks, it is possible to control a screening in only one direction.

To lock the converter according to the invention may also have wedges, glues or solder joints, which prevent the transition from the work rest position back to the production position.

Arretiereinrichtungen in the form of catch traps can be advantageously constructed of springs with hooks and barbs. Thus, at least one of the springs may be formed with hooks on each one of the separated parts of the structure. However, the detent trap constructed in such a way should, if possible, not hinder or possibly minimize any necessary sensory or actuatory movement or rotation.

As mechanical actuators micro-rotors, electromechanical microactuators can serve. But also thermally variable structures can be used by means of sliding bolts driven transversely to the movement paths of the released and positioned or reorientierten structural part for blocking the way.

It is advantageous if at least one bending beam at least on one wall of the

Trenngrabenwände is arranged and the counter wall has at least one elevation, preferably with tooth flanks. Then, the spring stiffness of the bending beam and the sliding friction between the bending beam surface and the surface of the survey can serve to increase the work required to overcome it.

This combination of bending beam and survey is conveniently arranged as a pawl. This has a "ratchet-like inhibitory effect". A mechanical one

Limiting the bending path of the bending beam and its orientation with respect to the shape of the survey allows blocking the movement in the opposite direction. The tooth flanks are preferably designed asymmetrically.

It can be advantageous to have a plurality of latching positions in order to set different transducer properties during or after production.

As a possible microelectromechanical transducers according to the invention designed high-sensitive, or very small sensors for travel, vibration, acceleration, speed, rotation rate, force, pressure or torque, or for such physical quantities that can be transformed into this. As an application for actuators micromotors for linear or rotary motion, and vibrators (vibrators) are provided. Also micropump, microdrives preferably for light modulators on mirrors (arrays)), or also mechanical micro-switches or relays may have the features according to the invention.

An adjustable capacitor is also designed according to or with the described properties.

Such microelectromechanical converters are advantageous as part of an integrated microelectronic circuit which has further circuit parts, such as those for amplification and signal processing or signal conversion.

The present invention will be described in more detail with reference to the following drawings, in which:

 1 shows a sketch of a first possible embodiment of a characteristic part of a microelectromechanical transducer 1 with two relatively movable structural elements 2, 3 in a production position prior to positioning in the work rest area.

 Fig. 1 a shows the section A-A 'with the production-related condition, also of the

 Structure depth 19 dependent distances 4.

 FIG. 2 shows a sketch of the first possible embodiment from FIG. 1 according to FIG

 Positioning from the production situation into the work rest position.

 Fig. 2a shows the section B-B 'with reduced distances 7, but also enlarged

 Intervals 8.

 Fig. 3 shows a sketch of a second possible embodiment of a

 microelectromechanical device 1 or a part of a

 Microelectromechanical transducer with two (to three) relative to each other movable structural elements 2, 3 in the production position before positioning in the Arbeitsruhelage.

 FIG. 4 shows a sketch of the embodiment from FIG. 3 after positioning in FIG

 Work rest.

 FIG. 5 shows a sketch of an alternative electrode structure design in FIG

 Production situation before the approach of the electrodes 5.

Fig. 6 shows the structure of Fig. 5 after positioning in the working recumbent and with approximated electrodes 5. Fig. 6a shows an alternative with reverse

 Change of position in the work-rest position after the positioning.

Fig. 7 shows a possible single-stage irreversible latching device prior to positioning in the work rest

Fig. 8 shows a latching device of Fig. 7 after positioning 9 shows a possible multi-stage, at least temporarily irreversible, latching device in the production position before the positioning.

10 shows the multi-stage latching device from FIG. 9 in the second latching position and with the tensioned counter-spring 6.

Description of the embodiments

The comb-like structuring of a device 1 according to the invention shown in FIG. 1 has certain distances 4 and a specific depth 19 after a typically used dry reactive ion deposition, from which a certain aspect ratio (structure depth to structure distance) is predetermined. Ideally, a trench width is produced by the etching masks, which represents a good compromise between etching time and etch-related area loss.

The device 1 here consists of two components 2, 3 having mutually toothed tongues. The surfaces of these tongues have elevations. These

Elevations are determined by design and mask lithography. The technology-related minimum etch width for the desired etch depth 19 may also be considered a larger

Trench width 4 to be set. Here are three surveys per tongue shown as an example. The projections of adjacent tongues are arranged offset from one another, with one tongue belonging to component 2 and the other to component 3. Component 2 here is the optional structural part. Component 3 may also be an optional structural part, or an environmental part, which is firmly connected to a housing, for example. By the release, the parts 2, 3 are moved relative to each other. When the structural part 2 in FIG. 1 is moved downwards in the direction 9, the elevations on the opposite tongues reach an antiparallel or mirrored position. The result is sketched in FIG. The small distances 4 change on the one hand to larger distances 8 and on the other hand to smaller distances 7. This is even more clearly visible in the sectional images Fig. 1 a and Fig. 2a. Since the surfaces of these tongues, in particular the elevations are designed such that they can carry charge carriers, resulting in capacity surfaces. Supply line for the application or removal of charge carriers or

Test leads for detecting the potential difference are provided (not shown here). The potential surfaces 5 are substantially in the starting position (after the etching process) according to FIG. 1, 1a for the elevations and recesses at the same distance from each other. This produces approximately a capacitance which is proportional to the area of electrode surfaces A 5 opposite and indirectly proportional to the distance d 4.

C = prop. A / d (1.1) Formula 1.1. reflects the relationship before the movement. Strictly speaking, in the present example, there are two times six faces Ai, the sum of these faces determining the total capacitance C _v .

C _v = prop. 12A ^ d (1.2)

Moving in the direction 9 as shown in FIG. 2 by one way, a partial capacitance changes advantageously to Ci> C _v due to the approximation by di, that of FIG

Survey height corresponds.

C, = prop. Ai / fd-di) (2.1)

However, another fractional capacity disadvantageously changes to C ₂ <C _V

C ₂ = prop. Ai / fd + di) (2.2)

The sum in the example here after the change of location of the structural part:

C _n = prop. (6Ai / (d-di) + 4A ₁ / (d + d ₁ ) (2.3)

In Fig.1 and Fig.2, di = d / 2. The following is an enlarged capacity of:

Cno.5 = prop. (12A _! / D + 8 / 3Ai / d) = prop. 14.66 ai / d (2.4)

Thus, over 22% (C _n o.5 / C _v = 14.66 / 12) increase in capacitance is achieved by halving the spacing of individual electrode spacings, as shown here. At five

Surveys on two tongues each would yield 26% for the same dimensions and 30% for 10 surveys on two tongues, and theoretically 33% for 100 surveys on two tongues.

For example, higher elevations of 90% of the size compared to 4 would result in five times the total capacity.

Co.1 = prop. (6 ^ / (0, 1 d) + 4A ₁ / (1, 1 d) (2.5)

C "o.i = prop. (öOAi / d) + 40/11 A ^ d) = prop. 63.63 A ^ d (2.6)

This gives over 500% Increase the capacity if the distance of individual electrode distances is reduced to one tenth. This is not shown in FIG. 1 or FIG. 2. In the target position according to FIG. 2 of the structural part 2 and of the further part, also surrounding part 3, the direction 9 or the opposite direction is blocked or greatly restricted for movements, mobility in directions perpendicular thereto 10, however, remains largely intact, in particular for sensors or actuators.

In addition to the above-mentioned increase in capacity from the process according to the invention, the result for the product is also an increase in sensitivity. Since the change delta C occurs quadratically over the distance change delta d in the derivative of the function, the sensitivity also increases quadratically. In the example of FIG. 2, the sensitivity to FIG. 1 is almost 50% greater. For a 1/10 pitch reduction structure, the theoretical increase in sensitivity would be more than 25 times (!) Over the prior art. Thus, a 25-factor amplifier can be saved, or the gain can be reduced. Much smaller sensors can thus provide the same sensor performance. The power consumption of actuators can also be reduced.

Fig. 3 shows the microstructure of Fig. 1 in a second embodiment. The

Embodiment according to FIG. 3 differs from that according to FIG. 1 in that the surrounding part 3 is present on two sides of the released part. This reduces the required length of tabs per area of semiconductor base material (e.g., silicon), resulting in more favorable mechanical properties.

The movement of the centrally located structural part 2 after the etching production is again in the direction 9 relative to the surrounding parts 3 in the position shown in FIG. 4. Again surveys are transferred to the entangled tongues from an asymmetry position in a symmetry position, and then locked accordingly. The locking elements are not shown in Fig. 1 - 6 for clarity. In Fig. 7 - 10 simple examples are outlined.

Also in this embodiment in Fig. 3, and Fig. 4, a unidirectional direction 9 is provided for the approach of the electrode surfaces and a preferably bidirectional direction 10 for the transducer function.

Alternative structures to FIGS. 1-4 are shown in FIGS. 5 and 6. The structuring in Fig. 5 is designed in a staircase. By moving in the direction of 9, or by simultaneous movement of both parts 2, 3 to each other in directions 9, 9 ', the opposing electrode surfaces approach. The result in FIG. 6 shows the parts 2, 3 brought together in the working rest position. The process-related distance 4 of the oppositely directed step-like profiled tongues is determined by the

Merging in direction 9 to a distance 7 approximated. After locking the movement in the direction 9, the mobility in the direction 10 is sufficiently maintained for the function of the transducer. Part 3 is here to better distinguish from Part 2 hatched drawn. The five stages of the two oblique tongues are in Fig. 6 to the rest position with a capacity of

C = prop. A / d (6.1). The output capacitance after the etching process is essential by the

Stair edges determined that bring the charge carriers with different polarity closest to each other. In a first approximation, one can approximate the tongue length times the tongue width equal to the component depth t as an effective capacitor area A _w , the effective capacitor spacing d _w is a value which lies between the distance of the edges and the etching width, in a first estimate, the half diagonal between the trench-limiting electrode surfaces are assumed:

C _v i = prop. (10 * d / sqrt2 * t) / (d / sqrt2) = prop. 10 * Ai / d (5.1)

So, in a first approximation, the capacity of a pair of tongues before approach is proportional to the sum of all step surfaces and indirectly proportional to the distance. This value corresponds to the value as it can be achieved from the prior art in a first approximation.

The capacity after a change to, for example, a distance equal to 1/10 of the

Production distance is, results

C _n i_o.i = prop. (10 ^ / (0.1 d) = prop. 100 * Ai / d = C _v * 10 (6.2)

The capacity here is 10 times, ie a value increase that is twice as high as in the examples from FIGS. 1 to 4.

However, the change in sensitivity is more complex here, since here the staircase surfaces undergo a change in the distance parallel to the long side of the sketch sheet and a change in area parallel to the short side of the sketch sheet.

Based on a further example in Fig. 6a, the advantage for the damping will be explained. After positioning in the near position of the parts by the objective method in the direction 9 or 9 and 9 ', a further movement for this direction is locked by suitable measures, the mobility in the direction of the sensing axis 10 (here orthogonal to the positioning) remains within the remaining free space received. It can be seen here that an outward movement can also lead to an inner approximation of the sensor surfaces. The electrode surfaces define substantially communicating spaces, e.g. with gas, usually with air, according to the

Ambient air pressure are filled. A room type Vi is limited by the vertical here drawn areas of overlap of the overlapping length l, 23, the second type of room V ₂ is limited by the area of overlap the length g, 24. The grave distances along this overlap lengths I, g are conditioned at 23 gradually smaller than the 24th

The trench depth is constant. Thus, the compressible / displaceable volume Vi if t is the depth, I the overlap area 23 and si the distance of

Overlap areas.

V ₂ = ~ t * g * s ₂ (6a.2)

For V ₂ , the same applies to the side surface t * g and the distance s ₂ . By the

Size determination of L and g can be taken a direct influence on the spatial relationships \: ν ₂ taken. l + g = L (6a.3) thus becomes

V ₂ = ~ t * (Ll) * s ₂ (6a.4)

The step width corresponds to the depth t of the component, L is the length of the steps and the height H of the steps results from the distance difference:

H = s ₂ -S! (6a.5) thus becomes

V ₂ = ~ t * (Ll) * (H + s ₁ ) (6a.6)

In the working position both Vi and V _{2 are} spatially varied. If you leave a change to z. B. si / 2, so the volume Vi is halved. The amount of air must therefore be compressed and displaced accordingly. However, V ₂ has a constant proportion and a variable part

V ₂ = ~ t * (Ll) * H + t * (Ll) * Si (6a.7) For ease of explanation, assume that Ll is the same distance as si and H and L are three times as large as Si. Then the volume V2v is before the

compression:

V _2v = ~ t * (Si) * 3s., + T * (Si) * Si = ~ 4t * (s.,) ² (6a.8) and thereafter

V _2n = ~ 3.5 t * ( _Sl ) ² (6a.9)

The relative change of the second volume here is 12.5%. For V _! applies

V _1v = ~ 2 * t * S _! ² (6a.10)

Vm = ~ t * _Sl ² (6a.11)

The pressure change for the gas volume in V _2n is thus lower than for the volume V _{1 n} and thus the total pressure change is advantageously reduced by the pressure compensation. This results in a reduced attenuation compared with the prior art.

Nonlinearities in the capacitance changes may be due to differential arrangements, e.g. As shown in Fig. 4, are well linearized, the lower part must be mirrored.

In the basic version, for example, 250μηι deep etching (with the aspect ratio 1: 20) and then move the parts to each other, to 500 nm distance between the

Electrodes is reached. This would result in an aspect ratio of 500 (!).

To fix the parts, the circuit must have locking devices as described. Two examples of such devices are outlined in FIGS. 7-10.

Fig. 7 shows a latch 11 in the formed during the process embodiment with latching elements 14 in the form of hooks with springs, the hooks are chamfered in the direction of movement. As a result, they slide under pushing away the lateral springs to the

Counterhook over and are returned to the hook by the spring tension. Additional bending springs 6 tension the latching device and press the hooks against each other, the contacting side has no bevelled edge here. The

Movement of the parts 12 and 13 is unidirectional only apart to an end position as in Fig. 8. The parts 12 and 13 are rigidly connected in the device according to the invention with the structural parts 2, 3 respectively formed in these parts. Agility along the direction 10 is maintained by the device within certain limits.

The use of multiple locking stages provides a way to set and fix a target capacity in stages. Figures 9 and 10 illustrate a possible latch, which is a latching device 15 with several rest positions and teeth with

different flanks 16 uses. The rack moves against the bending beam, pin 17 with beveled end, by the orthogonal to the direction of movement designed rear sides of the teeth and the beam, or bolts, the respective position is fixed. A solution of the lock can only by transverse movements, or forces across the

Movement direction of the rack done, for example, by a movement of the beam or bolt in the direction of the 18th

The foregoing description of the embodiments according to the present invention is for illustrative purposes only, and not for the purpose of limiting the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope of the invention and its equivalents.

LIST OF REFERENCE NUMBERS

1 microelectromechanical device, MEMS converter (part)

 2 (optional) structural part

 3 (remaining) surrounding part (detail) or second structural part

 4 minimum due to the structure depth production-related or chosen larger Trenngrabenbreite (4 ')

 5 capacitive electrodes (surface)

 6 bend-elastic connection

 7 reduced distance due to the changed relative (here lateral)

 structure position

 7 'reduced distance due to the movement of two interfaces to each other

8 increased distance due to the changed relative (here lateral)

 structure position

 8 'increased distance due to the movement of two interfaces away from each other

9 Direction of a permanent or irreversible change of position (lateral, axial or tangential (in particular for rotational movements), also opposing movement (9 ')

 10 optional sensing direction or optionally forced actuator movement direction (linear with lateral range of motion, circular in angular clearance, or blocked without range of motion)

 11 fixing device (locking catch)

12 with 2 (3) stably connected or formed part of 11 13 with 3 (2) stably connected or formed part of 11

 14 snap-in elements with springs and hooks

 15 Fixation device with several locking positions

 16 elevations, in particular teeth with different flank pitches

 17 locking tongue, (also locking pin or locking bar)

 18 direction for one (optional unlocking)

 19 structure depth

 20 dividing trench within a section

 21 dividing trench walls

 22 distance-reducing path for certain detent position

 23 Overlap width of the compression capacity in the working position

 24 Overlap width of shearing capacity in the working position

A-A "section 1

 B-B "section 2

The invention is defined in particular by the claims. specific

Embodiments and developments thereof are listed below.

Among other things, the invention relates to a process for the preparation

micro-electro-mechanical devices (1) with a high aspect ratio, characterized in that the method comprises the following steps:

 At least one structural part (2) of a silicon wafer or of a semiconductor component with a thickness which is small in relation to the areal extent is produced by chemical and / or physical material removal with a technology-related

 Aspect ratio with respect to an environmental part (3) or another

 Free structural part, wherein elastic-elastic connections (6) between the structural part (2) and its surrounding material can remain,

 • there is a method step for reducing the distance (4 to 7)

 between at least two mutually opposite and preferably as capacitive electrodes (5) formed wall sections of Abtragungs- separating trenches (20) by mechanical relative predominantly lateral position or orientation change of the exposed structural part (2) relative to the

 Surrounding part (3) or another structural part of the semiconductor surface by means of internal and / or external devices, the force or a

 Apply or transmit torque to at least one of the separated parts (2, 3),

 • after reducing the distance (4) in a given

 Trenngrabenabschnitt (20) is at least one released structural part (2) permanently or irreversibly by a device (12, 15) against an increase in the

Distance (7) of the approximate wall sections secured. In such a method, a CMOS can be used for the production of the structural parts (2, 3)

Process or a BiCMOS process can be used.

The force effect or the torque can be caused by direct coupling of at least one actuator, preferably at least one button with elastic cap high friction, wherein the one or more buttons after placement on at least one free structure part (2) and simultaneous fixing of the surrounding part (3) the structural part (2) or several such parts - or vice versa, the ambient part (3) with simultaneous fixation of at least one isolated structural part (2) - the environmental part (3) - directly into the

Direction (9) of the target position or target orientation pulls or turns as required.

Alternatively, the force effect or the torque can be achieved by using the inertia of at least one structural part (2), wherein preferably the

microelectromechanical device (1) briefly accelerated in the opposite direction to the direction (9) for positioning or to the direction of rotation (9) for orientation or

is angularly accelerated.

Alternatively, the force effect can also be caused by the use of centrifugal force, wherein preferably the microelectromechanical device (1) is set in rotation, and the arrangement of the released structural parts (2) takes place such that the radially acting forces are the required movements or rotations of these parts (FIG. 2) in the nominal position or

Promote target orientation.

But it can also be generated by an elastic impact from the outside.

In another alternative, the force or torque through the

Applying an electrical voltage to the electrodes (5) provided on the separation trench walls (21) is triggered via the electric field forming, preferably via separate supply lines.

In the method according to the invention, combinations of various

Devices of the types described for the formation of the force or the

Torque can be used. The force or the torque can also be against spring forces, in particular against spring forces of elastic

Connections (6) take place.

In the method according to claim 9 can continue by the force or the

Torque at least one bending beam (6, 17), at least on one wall of the

Trenngrabenwände (21) is provided so strong against at least one elevation (16) is pressed and bent on the opposite wall, due to the contact angle and the additional spring force acting between the bending beam and survey static friction is overcome and the beam (17) jumps into a further position behind the survey (16).

In this case, the arrangement of bending beam (17) and elevation (16), for example, carried out so that a unidirectional mobility arises, which allows only a change, preferably a reduction of a considered Trenngrabenabschnittes (20).

In the method according to the invention of one of the two last-mentioned types, a plurality of latching positions can be provided on a fixing device (15), wherein during the positioning method a position is controlled from the different setpoint positions in one step or several steps in order to set certain transducer properties.

In a further aspect, the invention relates to a microelectromechanical transducer (1) with respect to an environmental part (3) at least one at least partially

free-standing preferably held by elastic connections structural part (2) and electrodes (5) on opposite preferably meandering or zigzag or looped or reciprocating preferably parallel Trenngrabenwänden (21), the sections between at least two such separated parts (2, 3)

are arranged, characterized in that this converter (1)

 An aspect ratio in the work rest position within a section of the separation trench (20) which is in the range from 15 to 500, preferably in the range from 20 to 200, in particular has a preferably constant value over the section that is at least 25 times the structure depth ( 19) opposite the separating trench width (7), and

 A device (11, 15) which holds or fixes at least one released structural part (2) with respect to a further structural part (3) in a work rest position or work rest orientation, whereby the relative position and

 Orientation of these made of one piece separated structural parts (2, 3) is unlike that which existed before or during the preparation of the separation trench.

This microelectromechanical converter (in the following short: converter) can

Trenngrabenabschnitte (20) having a smaller width (7) than the

Average width, preferably a fraction of the average widths of all on this converter (1) made dividing trenches in the working rest position.

In the transducer according to the invention, at least one bending beam (17), at least on a wall of the Trenngrabenwände (21), be provided and at least one elevation, preferably with tooth flanks (16), be provided on the opposite wall, said

Spring stiffness of the bending beam (17) and the sliding friction between the Bending beam surface and the surface of the elevation increased work to

Overcoming the transition require.

In the converter (1) according to the invention, an actuating element on a joint or pivot bearing or a bending beam (17) and at least one elevation (16) ratchet-like, preferably arranged as a pawl, or preferably a mechanical restriction of the actuating element in one direction or the bending path of the Bending beam may be provided as a blocking element, including the orientation of the actuating element or the bending beam in combination with the shape of the survey, which is preferably asymmetrically toothed, in one direction has sliding and non-slidable in another direction angle of attack for blocking.

Furthermore, in the case of the converter (1) according to the invention, a plurality of latching positions can be provided on the locking device, which stabilizes at least one structural part (2) with respect to another structural part or the surrounding part (3) either permanently but detachably or irreversibly in a proximity position of the electrodes (5).

The transducer according to the invention of one of the types described can be a sensor for travel, acceleration, force, vibration, speed, rate of rotation, pressure or torque, or an actuator in the form of a micromotor for linear or a micromotor for rotary motion, or a vibrator, a micro-pump, a micro-drive preferably for light modulators on mirrors (arrays)), or a mechanical micro-switch or a relay.

The converter may be part of an integrated microelectronic circuit.

In summary, the invention relates, inter alia, to the following aspects:

A. A method for producing micro-electro-mechanical devices (1) with a high aspect ratio, in which at least one structural part (2) of a silicon wafer or a semiconductor device with a thickness in relation to the surface thickness by chemical material removal preferably reactive deep ion etching (DRIE) and / or physical removal of material with a technology-related aspect ratio compared to an environmental part (3) or a further structural part is released, with flexible elastic connections (6) between the structural part (2) and its surrounding material can remain, the relative movement of the parts (2,3 ) allow in at least one degree of freedom, characterized in that by means of internal and / or external devices, a force and / or torque on at least one of the separated parts (2, 3) to reduce the local

Separation trench distance (4 to 7) is exercised or transmitted, that the resulting lateral and relative movement and / or

 Direction of rotation (9) of the parts (2,3) to each other, in particular caused

 Transverse movement or shearing motion, mostly independent of the

 Orientation of those normal vectors of at least parts of opposing and offset formed wall portions of Abtragungs-separating trenches (20), which are formed as capacitive electrodes (5) in the form of migrations, and that upon reaching a target position with a reduced local

Separating trench spacing (7) at least one released structural part (2) permanently or irreversibly by a device (12, 15) against an increase of the distance (7 ^' ) or against a decrease of the distance (8 ^' ) is secured, whereby a movement in Axle or direction of rotation (9) is inhibited.

 B. A method according to aspect A, wherein the force or torque formation for relative position change or orientation change due to one or more of the following causes:

 Mass attraction (gravitation) between the earth mass and the mass of at least one released structural part (2) by orientation to one another,

 Forces between electric charges (electric field), preferably caused by a highly electrically charged body is positioned in the direction of that side of the at least one loaded with structural parts (2), in which the structural part (2) or the structural parts translationally relative to the environmental part (3) is to be moved to the target position, or whereby a

 Torque due to a suitably arranged elastic or

 torsionally capable suspension of the at least one structural part (2) is generated, whereby this is rotated to the desired orientation position, or by generating these forces by applying an electrical voltage to the electrodes (5) provided on the separation trench walls (21), preferably via separate supply lines,

 • Magnetic forces through permanent and / or electromagnetism

 preferably by the interaction with a field due to a

 Current flow through at least one of the separated parts (2, 3) on the one hand and the magnetic field from an external

 Permanent magnets or an external electromagnet on the other hand,

• Length change due to electrical or magnetostriction of

 Structural connectors,

 • thermally induced change in length or deformations due to

 different thermal expansions of material structures of a

 corresponding formation between the separated parts (2, 3) for the relative orientation and / or positional shift due to a change in temperature of the environment.

C. A method according to aspect A, wherein the force or the torque by mechanical energy supply in one form or more forms from the group: Vibration excitation, acceleration or angular acceleration against inertia, rotation to form centrifugal forces, impulse or

 Drehimpulsübertragung is achieved, wherein the micro-electro-mechanical device (1) from the outside preferably via vibrating systems, preferably excited by vibrators to vibrate, and / or by a rotating

 Device is rotated, and / or receives a pulse about a shock.

D. Method according to one of the aspects A to C, in which the force effect by internal drive devices, preferably

 • electrostatic comb drives, or

 • Using drives, the magnetic fields of current-carrying lines, is effected, or

 the path is effected by deformations, wherein at least two - in particular elastic - connections to the exposed structural part (2) are heated with different thermal expansion when heated, different in magnitude or direction and with current flow, preferably by amount different due to a different cross-section or different thermal power dissipation ,

 E. Method according to one of the aspects A to D, in which the fixing or securing of the released part (2) after positioning or reorientation takes place mechanically by means of the structuring of simple or staggered catch catches (11, 15) preferably supported by restoring springs, or

 electromechanically by microactuators, or due to thermal deformation of structures, which thereby at least partially in the

 Intervene route, and these structures stop at least the freedom of movement back, due to blocking structures preferably locking pin (17) or resiliently mounted gears, especially those with different edges.

 F. Method according to one of the aspects A to E, in which by at least one

 Measure from the group: targeted gluing, wedging, soldering of structures, or destroying parts thereof, wherein the structures or structural parts serve to maintain mobility, - is preferably used for the destruction of the thermal melting of a current-carrying resistor, and in each of these measures the mobility of the released and positioned part (2) permanently or irreversibly at least in the opposite direction to the direction (9) or the direction of rotation from which the approach of the separated parts (2, 3) is carried out is prevented.

 G. Microelectromechanical transducer (1) with a relative to

Surface area of small thickness and at least one with respect to an environmental part (3) at least partially released preferably held by elastic connections structural part (2) which opposite electrodes (5) on preferably parallel separating trench walls (21), the preferably meandering or zigzag-shaped or looped or running back and forth, characterized in that this transducer (1)

 An aspect ratio in the work rest position within a section of the separation trench (20) which is in the range of 15 to 500, preferably in the range of 20 to 200, in particular has a value preferably as constant as possible over this section which is at least 25 times the structure depth ( 19) opposite the separating trench width (7), and

 • has a capacitive transducer sensitivity within this section whose direction (10) is at least approximately normal to the tangential surfaces of the opposing trench walls in the considered section with the trench width (7), and

 • means which are suitable for permanently or permanently fixing at least one movement of an exposed structural part (2) relative to a further structural part (3) in one direction (9) or direction of rotation, and

 • The converter for at least one further, of direction (9) independent

 Direction (10) allows mobility between the structural parts (2, 3), the relative position and orientation of these one-piece separated structural parts (2, 3) being different from that which existed before or during the manufacture of the separation trench; remaining directions of mobility are unlike those that existed prior to positioning and activation or use of the means for fixation.

Microelectromechanical transducer (1) according to aspect G, the

 At least one internal drive device from the group comprises:

 electrostatic comb drives, piezo elements, drives using the magnetic fields of current-carrying lines, drives due to

 Deformations due to different thermal expansion due to different shape and / or material property preferably at

 Achieve current flow, preferably changes in shape of certain compounds to the isolated structural part (2) or as Wegdrückelemente preferably curved or spiral formed with lever arm

 Elements whose path widened between separation trench portions (20) on another side to an increased distance (8), whereby the distances between the electrodes (5) on the other side to the reduced distance (7) are reduced, or

• Support devices for external devices for force or torque transmission, in particular thermally variable elements, magnetic elements or special oscillatory suspensions or torsional axes of rotation, or bearings for targeted rectilinear sliding or rotational movements of isolated bodies. I. microelectromechanical transducer (1) according to one of the aspects G or H, the bending-elastic connections (6) between the structural part (2) and the

 Surrounding part (3), which are in the operating state in tensioned deflection.

J. microelectromechanical transducer (1) according to one of the aspects G to I, in which the isolated structural part (2) has limited mobility in two independent directions (9, 10), due to the shaping of a

 Structural part (2) and the surrounding part (3) to each other and / or flexurally elastic connections (6), wherein the path locking devices (11, 15) which permanently or irreversibly the relative movement of the structural part (2) for movement in one direction (9 ) with respect to the surrounding part (3).

K. microelectromechanical transducer (1) according to one of the aspects G to I, in which bending-elastic connections (6) between the structural part (2) and the surrounding part (3) are arranged such that a relative rotation between the parts (2, 3) is allowed at a restricted angle, and

 Fixing elements (11, 15) preferably in the form of pawls with

 Tooth flanks preferably only a rotation in a rotational direction (9) due to asymmetrical tooth flanks allows.

 L. Mikroelektromechanischer transducer (1) according to one of the aspects G to K, which has at least one wedge, an adhesive and / or a solder joint, the

 Locking the mobility of the structural parts (2,3) relative to each other in the direction (9) or direction of rotation to structural part positioning in the

 Work rest position is used.

 M. microelectromechanical transducer (1) according to one of the aspects G to K, the simple or staggered detents (11, 15), preferably formed from springs with hooks and barbs (14), wherein at least one of the springs with hooks (14) is formed on each one of the separated parts (2, 3) of the structure, and wherein after the entanglement, a degree of freedom preferably due to the execution of bending beam-like feed of the hook or due

 Independent cantilever bearing for the actuator or sensory

 Movement or rotation is preferably maintained in a direction of hooking (9) independent direction (10) or direction of rotation.

 N. microelectromechanical transducer (1) according to one of the aspects G to K, the mechanical actuators, preferably in the form of micro-seals,

 electromechanical microactuators or thermal variable structures, which block structures preferably insert sliding bolts in the transverse to the movement paths of the released and positioned or re-oriented structural part (2).

O. Microelectromechanical transducer (1) according to one of the aspects G to N, the at least one individual component or at least one component of an integrated circuit of the three components • sensor for one or more of the group sizes: path,

 Acceleration, force, vibration, speed, yaw rate, pressure and torque, or

 Actuator in the form of one of the devices of the group: micromotor for linear motion, micromotor for a rotating movement, vibrator, micropump, micro-drive preferably for light modulators on arrays), mechanical micro-switch and relay or

 • Adjustable capacitor is.

Claims

Claims: 1. A process for the preparation of microelectromechanical devices (1) with high  Aspect ratio, characterized in that the method comprises the following steps:  At least one structural part (2) of a silicon wafer or of a semiconductor component with a thickness that is small in relation to the areal extent is formed by chemical and / or physical material removal with a technology-related aspect ratio with respect to an environmental part (3) or a further structural part (3) through the formation of ablation Separating trenches (20) are free, whereby bending-elastic connections (6) can remain between the structural part (2) and its surrounding material,  There is a method step for reducing the distance (4 to 7) between at least two opposing wall sections of the ablation separation trenches (20) which are preferably designed as capacitive electrodes (5) by a mechanical relative predominantly lateral position or orientation change of the with respect to the environmental part (3) or one of the further structural parts (3) of a semiconductor surface by means of inner and / or outer devices which exert a force or torque on at least one of the separated parts (2, 3) transfer, • after reducing the distance (4 to 7) in a given  Separation trench portion (20) is secured at least one released structural part (2) permanently or irreversibly by means (12, 15) against an increase in a distance (7'nach 4 ') of the approximate wall sections. 2. The method of claim 1, wherein the at least two opposing and preferably as capacitive electrodes (5) formed wall portions of the Abtragungs-separating trenches (20) have elevations and in the step of reducing the distance (4 to 7) elevations of opposite wall sections get into an antiparallel or mirrored position. 3. The method of claim 2, wherein distances (4) from opposite wall portions of the Abtragungs-separating trenches (20), which are each arranged between the elevations, in the step of reducing the  Distance (4 to 7) between the surveys to larger distances (8) to be changed. 4. The method of claim 3, wherein for improving the damping properties of microelectromechanical devices (1) a certain ratio of Area sizes of arranged between the surveys wall sections of Abtragungs-separating trenches (20) is selected to area sizes of the surveys. Method according to one of the preceding claims, in which an etching method, preferably a dry etching process, in particular reactive ion etching, preferably reactive ion etching (Deep Reactive Lonic Etching, DRIE) is used for material removal. Method according to one of the preceding claims, in which the force effect or torque formation for relative position change or Orientation change is due to  - An external gravitational field, preferably by the force of the  Erdgravition on the mass of the at least one released structural part (2) when fixing the surrounding part (3), or vice versa to the mass of  Environmental parts (3) when fixing the at least one structural part (2), or - An external electric field, preferably formed by a highly electrically charged body, which is positioned in the direction of that side of the at least one structural part (2), in which the at least one structural part (2) in translation relative to the surrounding part (3) are moved to the desired position should, or by which one  Torque due to a suitably arranged elastic or torsional suspension of the at least one structural part (2) is generated, whereby this and any other structural parts are rotated to the desired orientation position, or an external magnetic field, preferably by the interaction with a field due to a current flow through at least one of the separated parts (2, 3) on the one hand and the magnetic field of an external permanent magnet or an external electromagnet on the other hand,  - A change in temperature of the environment, which deformations due  causes different thermal expansion or cold-contractions a corresponding formation of the bending-elastic compounds (6), or - A change in length due to electrical or magnetostriction of  Structural connection parts, in particular the bending-elastic compounds (6). Method according to one of claims 1 to 5, wherein the force or the torque by using vibration and resonance, wherein the microelectromechanical device (1) is preferably excited from the outside via oscillating systems, preferably via vibrators to vibrate, which stimulate at least one released structural part (2) in particular by means of bending-elastic compounds (6) to resonant vibrations, the relative movements of the at least one exposed structural part ( 2) over the residual structure. Method according to one of claims 1 to 5, in which  - The force is caused by internal drive devices, preferably by electrostatic comb drives or by drives that use magnetic fields current-carrying lines, or  - The path is effected by deformations, wherein at least two - in particular elastic - connections to the exposed structural part (2) are heated in amount or direction of different thermal expansion when heated with current flow, wherein the thermal expansion preferably different by amount due to a different cross-section or different thermal Power loss is, or  - The path is caused by deformations of separate structures, at  Passage of current due to their thermally induced deformation of the isolated structural part (2) push away. Method according to one of claims 1 to 8, wherein the fixing or securing of the isolated part (2) after positioning or reorientation mechanically by means of the structuring of detents (11, 15), preferably supported by return springs, or electromechanically by microactuators, or due to thermal deformation of structures, which thereby at least partially engage in the path, and wherein the structures at least the freedom of movement back by blocking structures, preferably locking pin (17) or resiliently mounted gears, especially those with different edges stop. 10. The method according to any one of claims 1 to 9, which comprises at least one measure from the group: targeted bonding, wedging, soldering structures, or destroying parts thereof, wherein the structures or structural parts serve to maintain mobility, - preferably wherein for Destroying the thermal melting of a current-carrying resistor is used - and in each of these measures the mobility of the isolated and positioned part (2) permanently or irreversibly at least in the opposite direction to the direction (9) or to the direction of rotation, from the approach of the separated parts ( 2, 3), is prevented. 1. microelectromechanical transducer (1) with at least one opposite to a  Surrounding part (3) by the formation of separation trenches (20) at least partially released, preferably held by elastic connections structural part (2) and electrodes (5) on opposite, preferably meandering or zigzag or looped or reciprocating, preferably parallel Trenngrabenwänden (21 ), which are arranged in sections between at least two such separated parts (2, 3), characterized in that this converter (1)  An aspect ratio in the work rest position within a section of the separation trench (20) which is in the range of 15 to 500, preferably in the range of 20 to 200, in particular has a value preferably as constant as possible over this section which is at least 25 times the structure depth ( 19) opposite the separating trench width (7), and  • a device (11, 15), which the at least one isolated structural part (2) relative to a further structural part (3) in a work rest position or  Rest-rest orientation holds or fixed, whereby thereby the relative situation and  Orientation of these made of one piece separated structural parts (2, 3) is unlike that which existed before or during the preparation of the separation trench. 2. microelectromechanical transducer (1) according to claim 1 1, the  • at least one internal drive device from the group comprises: electrostatic comb drives, piezo elements, drives, the magnetic fields  Use current-carrying lines, drives due to deformations, due to different thermal expansion due to different shape and / or material property obtain preferably current flow, preferably changes in shape of certain compounds to the isolated structural part (2) or as Wegdrückelemente preferably curved or spiral formed with lever arm elements whose Widened between separating trench portions (20) on another side to an increased distance (8), whereby the  Distances between the electrodes (5) on the other side to the reduced distance (7) can be reduced, or  • Support facilities for external equipment to the force effect or  Has torque transmission, in particular thermally variable elements, magnetic elements or special oscillatory suspensions or  torsional axes of rotation, or bearings for targeted rectilinear sliding or for rotational movements of isolated bodies. 3. microelectromechanical transducer (1) according to any one of claims 11 or 12, the  bend-elastic connections (6) between the structural part (2) and the Surrounding part (3), which are in the operating state in deflection, preferably with a certain spring tension. 14. microelectromechanical transducer (1) according to one of claims 1 1 to 13, wherein the isolated structural part (2) dimensionally limited mobility due to the shape of a structural part (2) and the surrounding part (3) to each other and / or 5 bending-elastic compounds (6), preferably in two preferably  Independent directions (9, 10), the path at least against movement in one direction (9) process-related locking means (11, 15) which permanently or irreversibly block the relative movement of the structural part (2) relative to the surrounding part (3).  10  15. microelectromechanical transducer (1) according to one of claims 11 to 14, wherein the bending-elastic connections (6) in such a way between the structural part (2) and the  Surrounding part (3) are arranged so that a relative rotation between the parts (2, 3) is possible in a limited Wnkel, and fixing elements (11, 15) i5 preferably in the form of pawls with tooth flanks preferably only one  Rotation in one direction of rotation (9) due to asymmetrical tooth flanks allows. 16. microelectromechanical transducer (1) according to any one of claims 11 to 15, the  Rastfallen (11, 15), preferably formed from springs with hooks and 20 barbs (14), wherein at least one of the springs with hooks (14) on each one of the separated parts (2, 3) of the structure is formed, and wherein after the entanglement, a degree of freedom for the actuator or sensory movement or rotation preferably in one for Verhakungsrichtung (9) independent direction (10) or direction of rotation is maintained.  25  17. microelectromechanical transducer (1) according to any one of claims 11 to 16, the  mechanical actuators, preferably in the form of micro-mirrors, electromechanical microactuators or thermal variable structures, which blocking structures, preferably sliding bolts in the transverse to the  30 movement paths of the released and positioned or re-oriented structural part  (2) bring in. 18. microelectromechanical transducer (1) according to any one of claims 11 to 17, the  has at least one wedge, an adhesive and / or a solder joint, the lock 35 of the mobility of the structural parts (2, 3) relative to each other in the direction (9) or Direction of rotation to structural part positioning in the work rest position is used. 19. microelectromechanical transducer (1) according to any one of claims 11 to 18, the • a sensor for travel, acceleration, force, vibration, speed, yaw rate, pressure or torque,  An actuator in the form of a micromotor for linear or rotary motion, a vibrator, a micropump, a microdrive, preferably for light modulators on arrays), a mechanical microswitch or a relay,  • or is an adjustable capacitor. 20. Use of the microelectromechanical transducer (1) according to any one of claims 1 1 to 19, for an integrated microelectronic circuit.