DE102015224533A1 - Reactive sealing gas for the targeted adaptation of the cavity internal pressure - Google Patents

Abstract

A method is proposed for producing a micromechanical component with a substrate and with a cap connected to the substrate and enclosing a first cavity with the substrate, a first pressure prevailing in the first cavern and a first gas mixture having a first chemical composition being included , in which
In a first method step, an access opening connecting the first cavity to an environment of the micromechanical component is formed in the substrate or in the cap, wherein
- In a second process step, the first pressure and / or the first chemical composition in the first cavity is set, wherein
In a third process step, the access opening is closed by introducing energy or heat into an absorbent part of the substrate or the cap by means of a laser, wherein in a fourth process step a reactive gas for further adjusting the first pressure and / or the first chemical composition in the first cavern is introduced.

Description

State of the art

The invention is based on a method according to the preamble of claim 1.

Such a method is known from WO 2015/120939 A1 known. If a certain internal pressure in a cavern of a micromechanical component is desired or if a gas mixture with a certain chemical composition is to be trapped in the cavern, the internal pressure or the chemical composition often becomes when the micromechanical component is being capped or during bonding between a substrate wafer and a cap wafer set. When capping, for example, a cap is connected to a substrate whereby the cap and the substrate together enclose the cavern. By adjusting the atmosphere or the pressure and / or the chemical composition of the gas mixture present during the capping, it is thus possible to set the specific internal pressure and / or the specific chemical composition in the cavern.

With the from the WO 2015/120939 A1 Known methods can be adjusted specifically an internal pressure in a cavern of a micromechanical device. With this method, it is possible, in particular, to produce a micromechanical component with a first cavity, wherein in the first cavity a first pressure and a first chemical composition can be set, which differ from a second pressure and a second chemical composition at the time of Capping differ.

In the method for the targeted setting of an internal pressure in a cavern of a micromechanical device according to the WO 2015/120939 A1 In the cap or in the cap wafer or in the substrate or in the sensor wafer, a narrow access channel to the cavern is generated. Subsequently, the cavern is flooded with the desired gas and the desired internal pressure via the access channel. Finally, the area around the access channel is locally heated by a laser, the substrate material liquefies locally and hermetically seals the access channel upon solidification.

The quality of rotation rate sensors depends very sensitively on the internal cavern pressure. Furthermore, as high a quality as possible is required for a high offset performance of rotation rate sensors over their service life, since a deviation of the quality from the value which has been incorporated into the adjustment parameters during the adjustment leads to an offset of the rotation rate sensor. In order to achieve the highest possible and stable quality over the lifetime of the rotation rate sensors, it is therefore essential to stabilize or keep constant the internal pressure of the rotation rate sensor caverns over the service life of the rotation rate sensors. In the case of high-speed rotation rate sensors (i.e., low cavern internal pressure), an increase in internal pressure, which results, for example, from outgassing or from gas diffusion into the cavern, is frequently to be observed after HT storage (storage periods with a comparatively high temperature).

Further methods for the targeted setting of an internal pressure in a cavern of a micromechanical component are made US 8,546,928 B2 . US 2015/0158720 A1 and US 8,513,747 B1 known. A method for determining a leak rate is off US 7,739,900 B2 known.

Disclosure of the invention

The object of the present invention is to provide a method for producing a micromechanical component which is mechanically robust and has a long service life compared with the prior art in a simple and cost-effective manner compared with the prior art. A further object of the present invention is to provide a micromechanical component which is compact in comparison with the prior art, has a mechanically robust and has a long service life. According to the invention, this applies in particular to a micromechanical component with a (first) cavern. Furthermore, it is also possible with the method according to the invention and the micromechanical component according to the invention to realize a micromechanical component in which a first pressure and a first chemical composition can be set in the first cavity and a second pressure and a second chemical composition are set in a second cavity can be. By way of example, such a method is provided for producing micromechanical components, for which it is advantageous if a first pressure is enclosed in a first cavity and a second pressure in a second cavity, wherein the first pressure is to differ from the second pressure. This is the case, for example, when a first sensor unit for rotation rate measurement and a second sensor unit for acceleration measurement are to be integrated in a micromechanical component. For example, in this case the first cavern and the second cavern are separated from each other only by a bonding web. In particular, it is an object of the present invention to enable a high quality over the lifetime of the micromechanical device.

The object is achieved in that in a fourth method step, a reactive gas for further setting of the first pressure and / or the first chemical composition is introduced into the first cavity.

As a result, a method for producing a micromechanical component is provided in a simple and cost-effective manner with which the first pressure in the first cavern, in particular if the first cavern is a rotation sensor sensor cavern, can be kept or stabilized substantially constant over the service life or with the first pressure after a provisional setting of the first pressure can be further reduced. This is achieved, for example, by virtue of the fact that small amounts of gas outgassing from the materials within the first cavern over their lifetime or by gas diffusion, for example through the substrate or through the cap or through a bonding frame or bonding web between the first cavern and the second cavern, enter the first cavern by the reactive gas or react with a previously enclosed in the cavern or before the closing of the access port gas and in this way the total internal pressure of the cavern can be kept substantially constant or reduced. Thus, it can be made possible, for example, that the attenuation and thus the quality, for example of the rotation rate sensor, remains unchanged to a first approximation, in particular if different damping factors for different types of gas are neglected.

A further advantage of the method according to the invention is that with the aid of the reactive gas it can be counteracted that the internal pressure occurring in the cavern during or after the regular bonding process does not correspond to the pressure which is included in the bonding.

According to the invention, it is alternatively or additionally provided that in the fourth method step a getter is introduced into the first cavity for further setting of the first pressure and / or the first chemical composition. According to the invention, it is also provided that the reactive gas essentially comprises the properties of a getter.

In the context of the present invention, the term getter is to be understood as meaning a chemically reactive material which serves to obtain a vacuum as long as possible. According to the invention, it is provided that the material is present in a solid state of matter or in a liquid state of aggregation or in a gaseous state of matter. For example, at the surface of the getter, gas molecules enter into a direct chemical compound with the atoms of the getter material. Alternatively or additionally, however, it is also provided that the gas molecules are retained by sorption on the getter material. In this way, the gas molecules are "captured" in or on the surface of the getter material. In the context of the present invention, a distinction is made between an activated getter and an inactivated getter, wherein the activated getter has a higher capture rate compared to the inactivated getter. In this case, the term capture rate means, for example, a number of gas molecules trapped in or on the surface of the getter material per unit time, for example per second. Furthermore, according to the present invention, a distinction is made between a reversible getter and an irreversible getter. According to the invention, a reversible getter comprises at least partially or predominantly reversible getter material and an irreversible getter comprises at least partially or predominantly irreversible getter material. However, it is also provided according to the invention that both a reversible getter and an irreversible getter each comprise at least partially reversible getter material and at least partially irreversible getter material. According to the invention, a reversible getter material is to be understood as meaning a getter material which essentially captures or absorbs gas molecules in or on the surface of the getter material at a first time or during a first time period and at a second time or during, respectively For a second period of time trapped gas molecules from or released from the surface of the getter material substantially again. For example, in accordance with the invention, "substantially capturing" is understood to mean that the capture rate is greater than a release rate or that a first sum of adsorption rate and absorption rate is greater than a desorption rate. According to the invention, "substantially let go or release" is understood, for example, to mean that the capture rate is less than the release rate or that the first sum is less than the desorption rate. By adsorption rate is meant, for example, a number of gas molecules trapped on the surface of the getter material per unit time, for example per second. By absorption rate is meant, for example, a number of gas molecules trapped in the surface of the getter material or in the volume of the getter material per unit time, for example per second. In this case, the term "release rate" or "desorption rate" is to be understood as meaning, for example, a number of gas molecules released or released from the surface of the getter material per unit time, for example per second. According to the invention, a reversible getter can be essentially regenerated or set into an initial state with high absorption readiness and / or readiness for adsorption. According to the invention Under absorption readiness or adsorption readiness to understand the provision of a high absorption rate or adsorption rate in the presence of corresponding gas molecules.

According to the invention, a particle or particle is preferably to be understood as meaning an atom or an assembly of atoms, such as, for example, one or more molecules. In the context of the present invention, the particle is in a gaseous, liquid or solid state or is part of a gaseous, liquid or solid phase and comprises at least one phase interface with its surroundings. In particular, particles according to the invention are understood to mean a small body on the scale of the micromechanical component, i. a body which has a maximum extension of 1/10 of a maximum extent of the micromechanical device.

In the context of the present invention, the term "micromechanical component" should be understood to mean that the term encompasses both micromechanical components and microelectromechanical components.

The present invention is preferably provided for the production of or for a micromechanical component with a cavern. However, for example, the present invention is also applicable to a micromechanical device having two caverns or more than two, i. three, four, five, six or more than six, caverns provided.

Preferably, the access opening is closed by introducing energy or heat into a portion of the substrate or cap that absorbs this energy or heat, using a laser. In this case, energy or heat is preferably introduced in succession in each case in the absorbent part of the substrate or the cap of a plurality of micromechanical components, which are produced jointly on a wafer, for example. However, it is alternatively also provided a temporally parallel introduction of the energy or heat into the respective absorbent part of the substrate or the cap of a plurality of micromechanical components, for example using a plurality of laser beams or laser devices. Alternatively, it is also provided according to the invention that the access opening is closed by means of an oxide reseal process or an oxide reclosure process. In the case of the oxide reseal process or in the oxide reclosure process, for example, a laser reseal process or laser reclosure process alternative closure process in which the subsequent opening of the cavern is hermetically sealed with an oxide cover, which at low ambient pressure is grown up.

Advantageous embodiments and modifications of the invention are the dependent claims, as well as the description with reference to the drawings.

According to a preferred development, it is provided that the cap encloses a second cavity with the substrate, wherein a second pressure prevails in the second cavity and a second gas mixture with a second chemical composition is enclosed.

According to a preferred development, it is provided that in a fifth method step at least one bond, in particular at least one chemical bond, is brought about between at least one first particle A of the reactive gas and at least one second particle B of a further gas. In this way, it is advantageously possible to use the reactive gas to bind second particles B of a further gas, which enters the first cavity, for example, after closing the access opening.

According to a preferred development it is provided that the at least one bond is brought about due to interactions, in particular of electrostatic interactions, between electrons of the at least one first particle A and the at least one second particle B. This advantageously allows a chemical bond between the at least one first particle A and the at least one second particle B.

• – AB_X oder
• – AB oder
• – A_XB ist,

wobei x > 1 ist. Hierdurch wird vorteilhaft eine Stabilisierung des Innendruckes bzw. des ersten Druckes über die Lebenszeit des mikromechanischen Bauelements und/oder ein gezieltes Einstellen des Innendruckes bzw. der Drehratensensorgüte bim Bondprozess bei geringen Drücken und/oder das Erzeugen eines Hochgüte Systems unter Verwendung eines Standard Bondverfahrens und/oder ein hochempfindlicher und selektiver Gassensor ermöglicht.According to a preferred development, it is provided that a new particle C is produced by means of the bond in such a way that the chemical composition of the new particle C

• - AB _X or
• - AB or
• - A is _X B,

where x> 1. This advantageously stabilizes the internal pressure or the first pressure over the lifetime of the micromechanical component and / or a targeted setting of the internal pressure or the rotation rate sensor quality bim bonding process at low pressures and / or generating a high-quality system using a standard bonding process and / / or a highly sensitive and selective gas sensor.

According to a preferred embodiment, it is provided that the new particle C is prepared such that the new particle C in a solid state or in a liquid state or in a gaseous state. In the event that the new particle C is in a solid or in a liquid state, it is advantageously possible, for example, for the micromechanical component to be used as an extremely sensitive gas sensor, in which the reactive gas reacts with the further gas to form a solid in this way no longer contributes to cavern gas pressure. This change in pressure can be determined very precisely by changing the quality of the micromechanical component. Depending on the reaction possibilities of the closing gas or of the reactive gas, the gas sensor produced in this way is selective to certain types of gas. In addition, in the event that the new particle C is in a solid or in a liquid state, for example, it is advantageously possible to produce a high-quality system by means of a standard bonding process, since the new particle C in the solid or in the liquid state is essentially not at first pressure contributes. In the case where the new particle C is in a gaseous state of aggregation, it is advantageously possible, for example, to stabilize the first pressure over the lifetime of the micromechanical component and / or to set the first pressure or yaw rate during the bonding process at low pressures.

According to a preferred embodiment, it is provided that the further gas comprises hydrogen. This advantageously makes it possible, in particular if hydrogen is found in the cavern or in the first cavern in a residual gas analysis, to selectively adjust the quality via the pressure during bonding, if a reactive closing gas or reactive gas is used to set this pressure, which is used with Hydrogen reacts. In this way, during bonding or later released hydrogen is bound by the reactive sealing gas or the reactive gas in the cavern or first cavity and the internal pressure, for example, remains stable at the value that was set during bonding. By means of this method, the quality of the system can also be raised far, if the reactive gas reacts with the released hydrogen to a non-gaseous end product.

According to a preferred development, it is provided that the fourth method step is carried out in time before the third method step. This advantageously makes it possible for the reactive gas to be introduced into the first cavity before closing the access opening.

According to a preferred development, it is provided that the fifth method step is carried out after the fourth method step. Thus, it is advantageously possible that the binding is brought about within the first cavern.

According to a preferred development, it is provided that the fifth method step is carried out after the third method step. Thus, it is advantageously made possible that the first pressure can be kept substantially stable over the service life of the micromechanical component when the access opening is closed or can be reduced.

A further subject of the present invention is a micromechanical component having a substrate and having a cap connected to the substrate and enclosing a first cavity with the substrate, a first pressure prevailing in the first cavity and a first gas mixture having a first chemical composition being included wherein the substrate or cap comprises a closed access opening, wherein a reactive gas is included for further adjusting the first pressure and / or the first chemical composition in the first cavity. As a result, a compact, mechanically robust and cost-effective micromechanical component with set first pressure is provided in an advantageous manner. The stated advantages of the method according to the invention also apply correspondingly to the micromechanical component according to the invention.

According to a preferred development, it is provided that a new particle produced by at least one bond, in particular by at least one chemical bond, between at least one first particle A of the reactive gas and at least one second particle B of a further gas is enclosed in the first cavity.

• – AB_X oder
• – AB oder
• – A_XB ist,

wobei x > 1 ist.According to a preferred embodiment, it is provided that the chemical composition of the new particle

• - AB _X or
• - AB or
• - A is _X B,

where x> 1.

According to a preferred development, it is provided that the cap encloses a second cavity with the substrate, wherein a second pressure prevails in the second cavity and a second gas mixture with a second chemical composition is enclosed. As a result, advantageously, a compact, mechanically robust and cost-effective micromechanical Component provided with set first pressure and second pressure.

According to a preferred embodiment, it is provided that the first pressure is less than the second pressure, wherein in the first cavern a first sensor unit for rotation rate measurement and in the second cavern, a second sensor unit for acceleration measurement is arranged. This advantageously provides a mechanically robust micromechanical component for rotation rate measurement and acceleration measurement with optimum operating conditions for both the first sensor unit and for the second sensor unit.

Another object of the present invention is a use of a micromechanical device as a gas sensor, wherein the micromechanical device comprises a membrane. According to a preferred embodiment, it is provided that the membrane is arranged between the first cavern and the surroundings of the micromechanical component. According to a preferred embodiment, it is provided that the membrane is formed semipermeable. According to a preferred development, it is provided that the membrane is not permeable to the first particle and is permeable to the second particle.

Brief description of the drawings

1 shows a schematic representation of a micromechanical device with open access opening according to an exemplary embodiment of the present invention.

2 shows a schematic representation of the micromechanical device according to 1 with locked access opening.

3 shows a schematic representation of a method for producing a micromechanical device according to an exemplary embodiment of the present invention.

4 shows a schematic representation of a micromechanical device according to another exemplary embodiment of the present invention.

Embodiments of the invention

In the various figures, the same parts are always provided with the same reference numerals and are therefore usually named or mentioned only once in each case.

In 1 and 2 is a schematic representation of a micromechanical device 1 with opened access opening 11 in 1 and with locked access opening 11 in 2 according to an exemplary embodiment of the present invention. In this case, the micromechanical component comprises 1 a substrate 3 and a cap 7 , The substrate 3 and the cap 7 are connected to each other, preferably hermetically, and together enclose a first cavern 5 , For example, the micromechanical component 1 formed such that the substrate 3 and the cap 7 additionally enclose together a second cavern. The second cavern is in 1 and in 2 but not shown.

For example, prevails in the first cavern 5 , especially at as in 2 illustrated locked access opening 11 , a first print. In addition, a first gas mixture having a first chemical composition in the first cavern 5 locked in. Furthermore, in the second cavern, for example, there is a second pressure and a second gas mixture with a second chemical composition is enclosed in the second cavern. The access opening is preferred 11 in the substrate 3 or in the cap 7 arranged. In the present embodiment, the access opening 11 exemplary in the cap 7 arranged. According to the invention, however, it may alternatively be provided that the access opening 11 in the substrate 3 is arranged.

For example, it is provided that the first pressure in the first cavern 5 is lower than the second pressure in the second cavern. For example, it is also provided that in the first cavern 5 one in 1 and 2 not shown first micromechanical sensor unit for rotation rate measurement and in the second cavity a in 1 and 2 not shown second micromechanical sensor unit are arranged for acceleration measurement.

• – in einem ersten Verfahrensschritt 101 die die erste Kaverne 5 mit einer Umgebung 9 des mikromechanischen Bauelements 1 verbindende, insbesondere schmale, Zugangsöffnung 11 in dem Substrat 3 oder in der Kappe 7 ausgebildet. 1 zeigt beispielhaft das mikromechanische Bauelement 1 nach dem ersten Verfahrensschritt 101. Außerdem wird
• – in einem zweiten Verfahrensschritt 102 der erste Druck und/oder die erste chemische Zusammensetzung in der ersten Kaverne 5 eingestellt bzw. die erste Kaverne 5 mit dem gewünschten Gas und dem gewünschten Innendruck über den Zugangskanal geflutet. Ferner wird beispielsweise
• – in einem dritten Verfahrensschritt 103 die Zugangsöffnung 11 durch Einbringen von Energie oder Wärme in einen absorbierenden Teil des Substrats 3 oder der Kappe 7 mithilfe eines Lasers verschlossen. Es ist beispielsweise alternativ auch vorgesehen, dass
• – in dem dritten Verfahrensschritt 103 der Bereich um den Zugangskanal lediglich bevorzugt durch einen Laser lokal erhitzt wird und der Zugangskanal hermetisch verschlossen wird. Somit ist es vorteilhaft möglich, das erfindungsgemäße Verfahren auch mit anderen Energiequellen als mit einem Laser zum Verschließen der Zugangsöffnung 11 vorzusehen. 2 zeigt beispielhaft das mikromechanische Bauelement 1 nach dem dritten Verfahrensschritt 103.

In 3 is a schematic representation of a method for producing the micromechanical device 1 according to an exemplary embodiment of the present invention. This is

• - in a first step 101 the first cavern 5 with an environment 9 of the micromechanical component 1 connecting, in particular narrow, access opening 11 in the substrate 3 or in the cap 7 educated. 1 shows an example of the micromechanical device 1 after the first process step 101 , In addition, will
• In a second process step 102 the first pressure and / or the first chemical composition in the first cavern 5 set or the first cavern 5 with the desired gas and the desired internal pressure over the access channel flooded. Further, for example
• - in a third step 103 the access opening 11 by introducing energy or heat into an absorbent part of the substrate 3 or the cap 7 closed with the help of a laser. For example, it is alternatively provided that
• - in the third step 103 the area around the access channel is preferably locally heated by a laser and the access channel is hermetically sealed. Thus, it is advantageously possible, the inventive method also with other energy sources than with a laser to close the access opening 11 provided. 2 shows an example of the micromechanical device 1 after the third process step 103 ,

Time after the third step 103 can in an in 2 exemplified lateral area 15 at one of the caverns 5 opposite surface of the cap 7 as well as in depth perpendicular to a projection of the lateral area 15 on the surface, ie along the access opening 11 and in the direction of the first cavern 5 , of the micromechanical component 1 mechanical stresses occur. These mechanical stresses, in particular local mechanical stresses, prevail, in particular, at and in the vicinity of an interface between a third process step 103 in a liquid state of aggregation and after the third process step 103 in a solid aggregate state passing and the access opening 11 occlusive material area 13 the cap 7 and one during the third process step 103 in a solid state of matter remaining portion of the cap 7 , Here is in 2 the access opening 11 occlusive material area 13 the cap 7 merely to be regarded as schematic or shown schematically, in particular with regard to its lateral, in particular parallel to the surface extending, extension or shaping and in particular with respect to its perpendicular to the lateral extent, in particular perpendicular to the surface extending, expansion or configuration.

In 4 is shown in a schematic representation of a micromechanical device according to another and according to a third exemplary embodiment of the present invention.

• – AB_X oder
• – AB oder
• – A_XB ist,

wobei x > 1 ist. Schließlich ist beispielsweise vorgesehen, dass das neue Teilchen C derart hergestellt wird, dass das neue Teilchen C in einem festen Aggregatzustand oder in einem flüssigen Aggregatzustand oder in einem gasförmigen Aggregatzustand vorliegt.For example, in a fourth method step, an in 4 schematically illustrated reactive gas 801 for further adjusting the first pressure and / or the first chemical composition into the first cavern 5 is introduced. In addition, it is provided, for example, that in a fifth method step at least one bond, in particular at least one chemical bond, between at least one first particle A of the reactive gas 801 and at least one second particle B of another gas 803 is brought about. In this case, it is provided, for example, that the at least one bond is brought about due to interactions, in particular of electrostatic interactions, between electrons of the at least one first particle A and of the at least one second particle B. Furthermore, it is also provided, for example, that a new particle C is produced by means of the bond in such a way that the chemical composition of the new particle C

• - AB _X or
• - AB or
• - A _X B is

where x> 1. Finally, it is provided, for example, that the new particle C is prepared such that the new particle C is in a solid state or in a liquid state or in a gaseous state.

As in 4 exemplified, is the reactive gas 801 for further adjusting the first pressure and / or the first chemical composition in the first cavity 5 locked in. Here, for example, it is provided that a by at least one bond, in particular by at least one chemical bond, between at least a first particle A of the reactive gas 801 and at least one second particle B of another gas 803 produced new particle C in the first cavern 5 is included.

For example, the cavern internal pressure or the first pressure in the first cavern is provided according to the invention 5 via a chemical reaction of the closing gas or the reactive gas 801 with another component we, for example, another gas 803 to control. According to the invention, this is provided in particular for different objectives, depending on the objective of different requirements both the reactants or to the reactive gas 801 and the other gas 803 and to the reaction products or a new phase comprising the new particle C apply.

• – Zielsetzung 1: Stabilisierung des Innendruckes über Lebenszeit
• – Zielsetzung 2: Gezieltes Einstellen des Innendruckes / der Drehratensensorgüte beim Bondprozess bei geringen Drücken
• – Zielsetzung 3: Erzeugen eines Hochgüte Systems unter Verwendung eines Standard Bondverfahrens
• – Zielsetzung 4: Hochempfindlicher und selektiver Gassensor

For example, the following objectives are foreseen:

• - Objective 1: stabilization of internal pressure over lifetime
• - Objective 2: Selective adjustment of the internal pressure / yaw sensor quality during the bonding process at low pressures
• Objective 3: Create a high quality system using a standard bonding method
• - Objective 4: Highly sensitive and selective gas sensor

Goal 1:

In 4 are different sources of gases or other gases 803 exemplified, wherein the other gases 803 for example, over the lifetime of the micromechanical device 1 the internal pressure of the cavern or the first pressure of the first cavern 5 can change. These other gases 803 For example, they can come from within the cavern, such as outgassing, or, for example, externally into the cavern or into the first cavern 5 penetrate, such as gas diffusion or mini leak paths. This includes the additional gas 803 For example, outgassing and / or gas diffusion into the first cavern 5 into it. It is provided, for example, that the reactive gas 801 is chosen so that the reactive gas 801 with the addition in the cavern or the first cavern 5 over lifetime occurring gases or with the other gases 803 such that the total gas particle number after the reaction is equal to the number of particles of the reactive gas 801 or the first particle before the reaction. This is especially possible because with ideal gases the total particle number defines the pressure which should remain constant over lifetime. For example, it is provided that the reaction or the reaction equation is A + B → AB or A + x * B → AB _x , where
AB and AB _{x are} gaseous or present in a gaseous state. For example, it is also provided that in the first cavern 5 included gas particle number after the reaction substantially the initial or before the reaction in the first cavern 5 present gas particle number of the reactive gas 801 equivalent.

Goal 2:

For example, during and / or after bonding, outgassing occurs in the cavern or in the first cavern 5 leave a different pressure or the first pressure, which differs from a pressure that was set during the bonding process or which in the bonding process in the environment 9 prevailed. This includes the additional gas 803 For example, outgassing during the bonding process. For example, the amount of outgassing fluctuates relatively strongly over the process or the bonding process, which can lead to the quality of micromechanical components 1 fluctuates over a large value range. With the targeted inclusion of a reactive gas 801 , where a low partial pressure is preferred for high quality, for example, the target quality is defined or adjusted. Outgassing during and after the bonding process, for example, completely from the reactive gas 801 bound. In order to achieve the highest possible quality, it is provided, for example, that the partial pressure of the reactive gas is as low as possible, but the reactive gas also has sufficient absorption capacity for outgassing. In order to be able to fulfill both, it is provided, for example, that the reactive gas particle or the first particle A reacts with the outgassing gas particles or with the second particles B such that a reactive gas particle or the first particle A comprises a plurality of particles of the outgassing substance or more second particle B absorbs. For example, it is provided that the reaction or the reaction equation A · x + B → AB _x reads, where AB and AB are _x in gaseous form or are present in a gaseous aggregate state. For example, it is provided here that x> = 1. For example, it is also provided that in the first cavern 5 included gas particle number after the reaction substantially the initial or before the reaction in the first cavern 5 present gas particle number of the reactive gas 801 equivalent.

Goal 3:

For example, during and / or after bonding, outgassing occurs in the cavern or in the first cavern 5 leave a different pressure or the first pressure, which differs from a pressure that was set during the bonding process or which in the bonding process in the environment 9 prevailed. This includes the additional gas 803 For example, outgassing during the bonding process. For example, this results in a significantly lower quality than the process pressure would actually produce when bonding. With the targeted inclusion of a reactive gas 801 , For example, wherein the partial pressure is optimized so that the outgassing particle or the amount of the second particles is consumed as completely as possible by the reaction. In other words, for example, it is provided that as many second particles as possible react with the first particles during the reaction. For example, in particular so that the remaining amount of reactive gas or number of first particles causes the lowest possible pressure or the highest possible quality, a reactive gas 801 used, which is able to bind a plurality of gas particles of the outgassing gas or a plurality of second particles. As a result, for example, the gas particles from outgassing or the second particles are bound as completely as possible and, for example, precipitate out as a solid. In other words, the new particle C is in a solid state of matter. This advantageously achieves that the first Particles and the second particles no longer contribute to the gas pressure or the first pressure. In order to achieve the highest possible quality, it is provided, for example, that the partial pressure of the reactive gas 801 after the reaction as low as possible or lower than the partial pressure of the reactive gas 801 before the reaction in the first cavern 5 or less than the partial pressure of the other gas 803 in the first cavern 5 - Before and / or after the reaction - or less than the partial pressure of the reactive gas 801 in the second cavern and / or in the surroundings 9 or less than the partial pressure of the other gas 803 in the second cavern and / or in the surroundings 9 is. For example, however, it is also provided that the enclosed during bonding reactive gas 801 sufficient absorption capacity for outgassing or other gases 803 Has. In order to be able to fulfill both, provision is made, for example, for the reactive gas particle or the first particle to react with the outgassing gas particles or second particles such that a reactive gas particle or a first particle absorbs a plurality of particles of the outgassing substance or a plurality of second particles. For example, it is provided that the reaction or the reaction equation is A + x.b → AB _x , where AB or AB _{x are} fixed or are present in a solid state of matter. For example, it is provided here that x> = 1. For example, it is also provided that the gas quantity of the reactive gas 801 so on the outgassing during bonding amount of other gas 803 is tuned that in time after the reaction in the first cavern 5 remaining gas particle number is minimal. For example, it is provided here that the reactive gas 801 and / or the further gas is substantially completely converted into a solid.

Goal 4:

For example, a rotation rate sensor via a quality measurement allows a highly sensitive measurement of the internal pressure of the sensor cavern or of the first pressure of the first cavern 5 , This includes the additional gas 803 for example, a gas to be detected. For example, leads into the cavern or into the first cavern 5 entering gas or further gas 803 to a change in the total internal pressure or the first pressure, this or the pressure change can be measured with a very high precision. If, for example, the sensor is provided with a membrane which is only suitable for a gas to be detected or for the additional gas 803 is permeable, is the incoming gas or the other gas 803 directly measurable via the increasing pressure or via the sinking quality. In this case, for example, it is provided that the entering gas or the further gas 803 with the one in the cavern or in the first cavern 5 enclosed reactive gas 801 reacts such that the final product or at least one new particle C comprehensive product precipitates as a solid. This advantageously allows the pressure or the first pressure to drop and the quality to increase. A lower pressure is therefore particularly advantageous over a higher pressure, since the pressure measurement at lower pressures is more precise possible. In other words, an advantage over increasing pressure is that the higher the grade, the more sensitive the pressure measurement. Furthermore, it is provided, for example, that the reactive gas 801 only with the other gas 803 reacts or that the binding can be brought about only between the at least one first particle and the at least one second particle. In other words, for example, it is provided that by the choice of the reactive gas 801 it is ensured that the reactive gas 801 only with a certain type of gas or with the other gas 803 responding. For example, this means that even if other types of gas or third gases inadvertently into the cavern or in the first cavern 5 enter, only the gas to be detected or only the other gas to a decrease in the internal pressure in the first cavern 5 or the first pressure or leads to an increase in the quality. As a result, it is advantageously possible for the sensor to be selective with respect to the type of gas to be detected or relative to the further gas 803 is. In particular, this ensures that the sensor is double-fused by the membrane and by the reactive gas.

For example, it is possible by a temporal superposition of two mutually acting effects, namely an increase in pressure due to an entry of the further gas 803 in the first cavern 5 and a pressure reduction due to the formation of the new particle C, specifically the other gas 803 to detect. This is advantageous even possible if third gases enter the cavern 5 arrive and / or if a reaction of third particles of the third gas with first particles of the reactive gas 801 As a result, the third particles involved in the reaction no longer contribute to the first pressure or to the partial pressure of the third gas.

Furthermore, it is also provided, for example, that after complete saturation of the reactive gas 801 a kind of reset is driven. This advantageously makes it possible for the sensor or the micromechanical component 1 can be used again and again for a long time to detect. For example, it is provided that in the driving of the reset, the sensor is heated up. In other words, during the reset, the temperature of the micromechanical device becomes 1 , in particular with respect to the room temperature, increased. For example, it is provided that the temperature of the micromechanical component is increased to a temperature in a range between 100 ° C and 500 ° C. For example, by the heating of the sensor is the End product or the new Telchen again into the two reactants or the first particle A and the second particle B decomposes. In this case, for example, it is provided that the gas to be detected or the further gas 803 is expelled through the membrane again. For example, it is additionally or alternatively provided that the time after the reaction between the reactive gas 801 and the other gas 803 another reactive gas 801 in the first cavern 5 is introduced or that the fourth process step is performed a further time or more times after the fifth process step. In other words, a renewal of the reactive gas 801 carried out. For this example, it is provided that connections o.ä. to the rotation sensor sensor cavern or the first cavern 5 be connected.

For example, it is also provided that as many reactive gas particles or first particles as possible react with the Detektiergasteilchen or with a second particle or bring about a bond. As a result, a particularly high sensitivity of the sensor is advantageously achieved.

For example, it is provided that the reaction or the reaction equation x · A + B → A _x B is wherein A is _X B or AB are fixed or are present in a solid state. For example, it is provided here that x> = 1. For example, it is also provided that during the heating up or during the reset or while driving the reset, the reaction or the reaction equation is A _x B → (heat) → A + x · B. For example, it is also provided that the reactive gas 801 with the other gas 803 reacts and that thereby the total pressure in the first cavern 5 or the first pressure is effectively reduced.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• WO 2015/120939 A1 [0002, 0003, 0004]
• US 8546928 B2 [0006]
• US 2015/0158720 A1 [0006]
• US 8513747 B1 [0006]
• US 7739900 B2 [0006]

Claims (11)

Method for producing a micromechanical component ( 1 ) with a substrate ( 3 ) and one with the substrate ( 3 ) and with the substrate ( 3 ) a first cavern ( 5 ) enclosing cap ( 7 ), whereas in the first cavern ( 5 ) there is a first pressure and a first gas mixture is included with a first chemical composition, wherein - in a first process step ( 101 ) one the first cavern ( 5 ) with an environment ( 9 ) of the micromechanical device ( 1 ) connecting access opening ( 11 ) in the substrate ( 3 ) or in the cap ( 7 ) is formed, wherein - in a second process step ( 102 ) the first pressure and / or the first chemical composition in the first cavern ( 5 ), wherein - in a third process step ( 103 ) the access opening ( 11 by introducing energy or heat into an absorbent part of the substrate ( 3 ) or the cap ( 7 ) is closed by means of a laser, characterized in that in a fourth process step, a reactive gas ( 801 ) for further setting the first pressure and / or the first chemical composition in the first cavern ( 5 ) is introduced. Process according to claim 1, wherein in a fifth process step at least one bond, in particular at least one chemical bond, between at least one first particle (A) of the reactive gas ( 801 ) and at least one second particle (B) of another gas ( 803 ) is brought about. Method according to one of the preceding claims, wherein the at least one bond due to interactions, in particular of electrostatic interactions, between electrons of the at least one first particle (A) and the at least one second particle (B) is brought about. Method according to one of the preceding claims, wherein the bond is used to produce a new particle (C) such that the chemical composition of the new particle (C) is - AB _X or - AB or - A _X B, where x> 1. A process according to any one of the preceding claims, wherein the new particle (C) is prepared such that the new particle (C) is in a solid state or in a liquid state or in a gaseous state. Micromechanical device ( 1 ) with a substrate ( 3 ) and one with the substrate ( 3 ) and with the substrate ( 3 ) a first cavern ( 5 ) enclosing cap ( 7 ), whereas in the first cavern ( 5 ) is a first pressure and a first gas mixture is included with a first chemical composition, wherein the substrate ( 3 ) or the cap ( 7 ) a locked access opening ( 11 ), characterized in that a reactive gas ( 801 ) for further adjusting the first pressure and / or the first chemical composition in the first cavern ( 5 ) is included. Micromechanical device ( 1 ) according to claim 6, wherein a by at least one bond, in particular by at least one chemical bond, between at least a first particle (A) of the reactive gas ( 801 ) and at least one second particle (B) of another gas ( 803 ) prepared new particle (C) in the first cavity ( 5 ) is included. Micromechanical device ( 1 ) according to claim 6 or 7, wherein the chemical composition of the new particle (C) - AB _X or - AB or - A _X B, where x> 1. Micromechanical device ( 1 ) according to claim 6, 7 or 8, wherein the cap ( 7 ) with the substrate ( 3 ) enclosing a second cavern, wherein in the second cavern, a second pressure prevails and a second gas mixture is included with a second chemical composition. Micromechanical device ( 1 ) according to claim 6, 7, 8 or 9, wherein the first pressure is less than the second pressure, wherein in the first cavern ( 5 ) is arranged a first sensor unit for rotation rate measurement and in the second cavern, a second sensor unit for measuring acceleration. Use of a micromechanical component ( 1 ) according to claim 6, 7, 8, 9 or 10 as a gas sensor, wherein the micromechanical component ( 1 ) comprises a membrane.

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