WO2020216776A1

WO2020216776A1 - Micromechanical component with a membrane and a cavity, and method for producing same

Info

Publication number: WO2020216776A1
Application number: PCT/EP2020/061170
Authority: WO
Inventors: Stefan Majoni
Original assignee: Robert Bosch Gmbh
Priority date: 2019-04-26
Filing date: 2020-04-22
Publication date: 2020-10-29
Also published as: DE102019206007A1

Abstract

The invention relates to micromechanical component with a completely grown silicon substrate (10) with a first substrate surface (12a) and a second substrate surface (12b) facing away from the first substrate surface (12a), a medium chamber (40) which is structured into the silicon substrate (10) and which comprises a medium outlet opening (18) structured through the first substrate surface (12a), and a membrane (36) which is formed on the second substrate surface (12b) and which delimits the medium chamber (40). An actuator device (38) is arranged or can be arranged on the membrane (36) such that the membrane (36) can be moved so as to be deformed by the actuator device (38) such that at least one medium present in the medium chamber (40) is pushed out of the medium chamber (40) via the medium outlet opening (18). The invention likewise relates to a method for producing such a micromechanical component.

Description

description

title

MICROMECHANICAL COMPONENT WITH MEMBRANE AND CAVITY AND MANUFACTURING PROCESS FOR IT

The invention relates to a micromechanical component and a

Manufacturing process for a micromechanical component.

State of the art

Manufacturing processes for micromechanical components each with a medium space delimited by a membrane are known from the prior art, in which a recess in the form of the later medium space is structured in a first substrate and then the first substrate on a second substrate with the membrane formed thereon is firmly bonded. Such a method for producing a micromechanical component is disclosed, for example, in DE 10 2014 214 532 B3.

Disclosure of the invention

The invention creates a micromechanical component with the features of claim 1 and a production method for a micromechanical component with the features of claim 7.

Advantages of the invention

The present invention creates micromechanical components in which a medium present in the respective medium space of the micromechanical component comes into contact exclusively with silicon of the silicon substrate of the respective micromechanical component. The silicon of the

However, the silicon substrate of the respective micromechanical component has a reliable resistance to a large number of media, which can be in the form of a fluid / liquid, a gel, a gas and / or as grains / microparticles. Thus, there does not have to be a contamination of the medium space of the respective micromechanical component present medium, damage / decomposition of the respective micromechanical component due to the medium present in its medium space are feared. As will be explained below, those using the present are suitable

Invention created micromechanical components therefore for a variety of purposes for a comparatively long life.

It is expressly pointed out here that the micromechanical components created by means of the present invention can also be produced relatively inexpensively. Furthermore, the micromechanical components can be designed with great design freedom.

In an advantageous embodiment of the micromechanical component, the silicon substrate is completely grown in at least two silicon growth steps, starting from an initial layer made of silicon

Silicon substrate. Such a completely grown silicon substrate has a reliable resistance to a large number of media, such as, for example, oxidative, organic, alkaline and / or acidic media. The silicon substrate encompassed by the embodiment of the micromechanical component described here thus withstands a large number of media present / filled in its medium space for a relatively long time, often (almost) indefinitely.

It is expressly pointed out here that the silicon substrate between its first substrate surface and its second

The substrate surface is free of bond layers. The silicon substrate is thus between its first substrate surface and its second

Substrate surface also free of aluminum / germanium bond layers, compression bond layers, such as in particular gold / gold bond layers, seal glass bond layers and organic bond layers, such as special BCB bond layers. Such bonding layers are chemically attacked by a large number of media. However, since the silicon substrate is free from between its first substrate surface and its second substrate surface

Bond layers, there does not have to be a contamination of the at least one medium present in its medium space with at least one Bond layer material are still feared with a decomposition of the medium space due to a chemical reaction of the bond layer with the at least one medium present in the medium space.

In a further advantageous embodiment of the micromechanical component, in addition to the medium outlet opening, at least one further opening of the medium space is formed in the silicon substrate such that the medium space can be filled and / or emptied via the at least one further opening, the at least one further opening being through the first substrate surface, the second substrate surface and / or through at least one substrate side surface of the silicon substrate that extends from the first substrate surface to the second substrate surface. Filling or emptying the medium space of the embodiment of the micromechanical component described here is thus easily possible.

In addition, at least one screen structure can be formed on and / or within the at least one further opening. By means of the at least one screen structure, undesired foreign particles can be introduced into the medium space of the embodiment of the described here

micromechanical component can be reliably prevented.

For example, the micromechanical component can be a print head, a

Be an insulin pump, a laboratory chip, a sensor or a probe. The

The micromechanical component according to the invention is thus versatile

trainable / usable. It is pointed out, however, that the exemplary embodiments listed here for the inventive

micromechanical components are not to be interpreted restrictively.

Executing a corresponding manufacturing method for a micromechanical component also creates the advantages explained above, the manufacturing method comprising the steps of: forming a completely

grown silicon substrate with a first substrate surface and a second substrate surface directed away from the first substrate surface, structuring of a medium space in the silicon substrate, for which a medium outlet opening is structured through the first substrate surface, and Forming a membrane on the second substrate surface, which delimits the medium space, wherein an actuator device can be or will be arranged on the membrane in such a way that during subsequent operation of the micromechanical component formed with the actuator device, the membrane is set into a deforming movement by means of the actuator device that at least one medium present in the medium space is pressed out of the medium space via the medium outlet opening.

In an advantageous development of the manufacturing method, in addition to the medium outlet opening, at least one further opening of the

The medium space in the silicon substrate is designed so that the medium space can be filled and / or emptied via the at least one further opening, the at least one further opening through the first substrate surface, the second substrate surface and / or through at least one extending from the first substrate surface to the Second substrate surface extending substrate side surface of the silicon substrate runs. The micromechanical component with the medium space that can be easily filled and / or emptied can thus be produced with comparatively little effort.

Preferably, the silicon substrate is based on a

Starting layer made of silicon completely formed in at least two silicon growth steps. Silicon growth methods which can be used as the at least two silicon growth steps are known from the prior art. The silicon substrate is therefore comparatively easy to manufacture.

In an advantageous embodiment of the production method, at least one intermediate silicon growth step and a final silicon growth step are carried out as the at least two silicon growth steps, the following method steps being carried out one after the other:

Structuring the medium outlet opening through the surface of the

Starting layer present or later from the starting layer

thinned back first substrate surface, covering a partial area of a side of the starting layer facing away from the first substrate surface with a first etch stop layer, executing the at least one intermediate Silicon growth step by adding silicon on top of the first

The side of the starting layer facing away from the substrate surface or an intermediate product grown starting from the starting layer is grown, with a partial area of the side of the intermediate product facing away from the first substrate surface being covered with a further etch stop layer after each intermediate silicon growth step carried out, and with etching stop walls being formed , which connect the first etch stop layer and the at least one further etch stop layer to one another in such a way that the first etch stop layer, the at least one further etch stop layer and the etch stop walls form an etch stop delimitation which surrounds a volume filled with silicon except for at least one etch opening, and the membrane is formed by Carrying out the last silicon growth step by growing silicon on the side facing away from the first substrate surface starting from the starting layer in the at least one intermediate silicon growth step en intermediate product is grown up. As will be explained in more detail below, the embodiment of the manufacturing method described here can be carried out comparatively easily. As a starting material for those described here

Embodiment of the production method, an SOI wafer (silicone on isolator wafer) or a silicon substrate / silicon wafer can optionally be used.

Preferably, after the formation of the membrane, the medium space is structured into the silicon substrate, which has grown completely in the at least two silicon growth steps starting from the starting layer, by etching the volume surrounded by the etch stop delimitation, and then the inner walls of the medium space from the first etch stop layer, which at least one further etch stop layer and the etch stop walls are exposed. The structuring of the medium space in the fully grown silicon substrate is thus easy to carry out, wherein, as will be explained in more detail below, advantageous shapes of the medium space can be implemented by means of the first etch stop layer, the at least one further etch stop layer and the etch stop walls. For example, the first etch stop layer, the at least one further etch stop layer and the etch stop walls can be formed from silicon oxide, with that of the first etch stop layer, the at least one further

Etch stop layer and the etch stop walls surrounding silicon by means of

Xenon difluoride and / or sulfur hexafluoride is etched. The structuring of the medium space in the completely grown silicon substrate is therefore possible without any problems, without undesired areas of the silicon substrate being etched at the same time.

If the first etch stop layer, the at least one further etch stop layer and the etch stop walls are formed from silicon oxide, the

Inner walls of the medium space are preferably exposed by the first

Etch stop layer, the at least one further etch stop layer and the

Etch stop walls are removed in a gas phase etching process. Silicon oxide can be removed easily and reliably using a gas phase etching process. Thus, during a later operation of the micromechanical component produced by means of the embodiment of the production method described here, there is no need to fear contamination of the at least one medium present in its medium space with silicon dioxide.

Preferably, at least two intermediate silicon growth steps are carried out before the last silicon growth step. As will be explained in more detail below, various advantageous shapes of the medium space can be formed in this way without any problems.

As an advantageous further development, between the at least two performed intermediate silicon growth steps, at least one screen structure can be formed on and / or within the at least one further opening by growing silicon on the side of the intermediate product facing away from the first substrate surface. The formation of the at least one screen structure on and / or within the at least one further opening is thus easily possible. In addition, further design elements can be formed by the mentioned or further intermediate silicon growth steps, such as for example at least one support structure and / or at least one structure for preventing the propagation of pressure waves. Brief description of the drawings

Further features and advantages of the present invention are explained below with reference to the figures. Show it:

Fig. La to le schematic cross-sections through intermediate products for

Explaining a first specific embodiment of the manufacturing method for a micromechanical component;

2 shows a schematic illustration of a first specific embodiment of the micromechanical component;

3 shows a schematic cross section through an intermediate product for explaining a second embodiment of the

Manufacturing process;

4 shows a schematic illustration of a second specific embodiment of the micromechanical component;

5 shows a schematic illustration of a third specific embodiment of the micromechanical component;

6 shows a schematic illustration of a fourth specific embodiment of the micromechanical component;

7 shows a schematic illustration of a fifth specific embodiment of the micromechanical component;

Fig. 8a to 8c schematic cross sections through intermediate products for

Explaining a third embodiment of the manufacturing method;

9 shows a schematic illustration of a sixth embodiment of the micromechanical component; 10 shows a schematic illustration of a seventh specific embodiment of the micromechanical component;

11 shows a schematic illustration of an eighth embodiment of the micromechanical component;

12a to 12d are schematic cross-sections through intermediate products for

Explaining a fourth embodiment of the manufacturing method;

13 shows a schematic illustration of a ninth specific embodiment of the micromechanical component; and

14 shows a schematic illustration of a tenth embodiment of the micromechanical component.

Embodiments of the invention

The figures described below can be interpreted both as representations of the respective micromechanical component and as representations of only one cell of the respective micromechanical component, the respective micromechanical component comprising several such cells and each of the cells of the micromechanical component each having the structures shown in the image . In particular, each of the following

The micromechanical component described have a plurality of such cells, or can be produced with a plurality of such cells.

FIGS. 1 a to 1e show schematic cross-sections through intermediate products to explain a first embodiment of the production method for a micromechanical component.

When carrying out the production method described here, a completely grown silicon substrate 10 with a first substrate surface 12a and a second one directed away from the first substrate surface 12a is produced Substrate surface 12b is formed in that the silicon substrate 10 is completely formed starting from an initial layer 10a of silicon in at least two silicon growth steps or epitaxial steps. At least one intermediate silicon growth step and a final silicon growth step are carried out as the at least two silicon growth steps. Each of the at least two silicon growth steps can be referred to as a silicon epitaxy step.

1 a shows a cross section through the starting layer 10a made of silicon with the first present as the surface of the starting layer 10a

Substrate surface 12a. The starting layer 10a can, for example, be part of an SOI wafer (Silicone On Isolator Wafer), the first substrate surface 12a being aligned with a semiconductor wafer 14 and an insulating layer 16 arranged between the semiconductor wafer 14 and the starting layer 10a made of silicon. The semiconductor wafer 14 can during the

Manufacturing process fulfill the functions of a "handling wafer".

In the embodiment of the production method described here, a medium outlet opening 18 of a later medium space of the

micromechanical component structured by the first substrate surface 12a present as the surface of the starting layer 10a by the

Medium outlet opening 18 is structured by the output layer 10a. The medium outlet opening 18 can, for example, be etched / separated by the starting layer 10. The starting layer 10a formed with the medium outlet opening 18 forms a first supporting wall 19 of the later medium space on its side aligned with the first substrate surface 12a.

In an alternative embodiment of the production method, only the semiconductor wafer 14 (consisting of silicon in this case) can also be used as the starting material. In this case the

The medium outlet opening 18 is structured through the first substrate surface 12a, which is later thinned back (from the starting layer 10a), in that the medium outlet opening 18 is structured in / through the semiconductor wafer 14 and the first substrate surface 12a with the exposed medium outlet opening 18 is formed later for thinning back the semiconductor wafer 14. When The semiconductor wafer 14 can be thinned back, for example, a chemical or physical grinding back of the semiconductor wafer 14 can be carried out.

Subsequently, a partial area of a side 20 of the starting layer 18 facing away from the first substrate surface 12a is coated with a first

Etch stop layer 22 covered. As will become clear from the following description, the first etch stop layer 22 defines the positions and dimensions of inner walls of the later medium space on its to the first

Substrate surface 12a facing side firmly.

A first intermediate silicon growth step is then carried out in that silicon is grown on the side 20 of the starting layer 10a facing away from the first substrate surface 12a. In this way, in the first intermediate silicon growth step, a first silicon region 24 is formed, which at least in regions merges into the starting layer 10a which is only partially covered by the first etch stop layer 22. The first silicon region 24 is thus grown directly / compactly on the starting layer 10a.

After the first intermediate silicon growth step, a partial area of the side 20 of the side facing away from the first substrate surface 12a becomes

Intermediate product covered with a second etch stop layer 26. In addition, etch stop walls (not shown) are formed, via which the first etch stop layer 22 and the second etch stop layer 26 are connected to one another. The etch stop walls can be formed by structuring separating trenches through the first silicon region 24 and filling the separating trenches with at least one etch stop material of the etching stop walls. The intermediate product produced in this way is shown in FIG.

A second intermediate silicon growth step is then carried out, in which silicon is grown on the side 20 of the side 20 which is grown starting from the starting layer 10a and which faces away from the first substrate surface 12a

Intermediate is grown. In this way, a second silicon region 28 is grown on a side of the first silicon region 24 facing away from the starting layer 10a, which is at least regionally in the first silicon region which is only partially covered by the second etch stop layer 26 Silicon area 24 passes over. The second silicon region 28 is thus also grown directly / compactly on the first silicon region 24 and the starting layer 10a. The second silicon region 28 forms a large part of a second supporting wall 30 of the later medium space on its to the second

Substrate surface 12b aligned side.

After the second intermediate silicon growth step, etch stop walls 32 are formed which extend through the second silicon region 28. The formation of the etch stop walls 32 can be carried out by structuring separating trenches through the second silicon region 28 and then filling the

Separating trenches are made with at least one etch stop material of the etch stop walls 32. The intermediate product obtained is shown in FIG.

After the formation of the etch stop walls 32, a third etch stop layer 34 is formed on a partial area of the side 20 of the intermediate product directed away from the first substrate surface 12a. The etch stop walls 32 connect the second etch stop layer 26 and the third etch stop layer 34 to one another. The second etch stop layer 26, the third etch stop layer 34 and the etch stop walls 32 define positions and extensions of inner walls of the later

Medium space on its side facing the second surface 12b. As can be seen in Fig. Id, the first etch stop layer 22, the second etch stop layer 26, the third etch stop layer 34 and the etch stop walls 32 are formed such that the first etch stop layer 22, the second etch stop layer 26, the third etch stop layer 34 and the etch stop walls 32 a

Etch stop delimitation 22, 26, 32 and 34 form which surrounds a volume filled with silicon apart from at least one etching opening 35. The etch stop delimitation 22, 26, 32 and 34 defines a shape and a spatial extent of the later medium space.

FIG. 1D also shows the formation of a membrane 36 on the second substrate surface 12b, which is directed away from the first substrate surface 12a, by adding silicon in the last silicon growth step to that of the first

Substrate surface 12a facing away side 20 of the intermediate product grown starting from the starting layer 10a is grown. The silicon of the membrane 36 can in particular directly on the third Etch stop layer 34 are deposited, which ensures that the membrane 36 formed in this way delimits the later medium space.

After the last silicon growth step has been carried out, the completely grown silicon substrate 10 is ready. To protect the second

Substrate surface 12b of the silicon substrate 10 during the further

Manufacturing method, a protective and / or insulating layer 37, such as an oxide layer, can be formed on the second substrate surface 12b of the silicon substrate 10. That won in this way

Intermediate product is shown in Fig. Id.

Optionally, an actuator device 38 can now be arranged / formed on the membrane 36 in such a way that, during later operation of the micromechanical component formed with the actuator device 38, the membrane 36 is set into a deforming movement by means of the actuator device 38 in such a way that at least one is in the subsequent medium space present medium is pressed out of the medium space via the medium outlet opening 18. In the embodiment of FIGS. 1 a to 1e, the actuator device 38 is, for example, a piezoelectric actuator device with at least one piezoelectric functional layer 38a, electrodes 38b and at least one conductor track 38c with at least one contact area 38d. The at least one piezoelectric functional layer 38a can be, for example, a PZT functional layer (lead zirconate titanate). Since the possibility of designing the micromechanical component produced by means of the manufacturing method described here is not limited to a specific type of its actuator device 38, the actuator device 38 is not discussed in more detail here.

The structuring of the medium space 40 in the silicon substrate 10 is also shown graphically in FIG. For this purpose, after the membrane 36 has already been formed, the medium space 40 is structured in the silicon substrate 10, which has grown completely starting from the starting layer 10a, by etching the silicon surrounded by the etch stop delimitation 22, 26, 32 and 34. During the etching of the silicon surrounded by the etch stop delimitation 22, 26, 32 and 34, there are further regions of the silicon substrate 10 which are not to be etched, such as in particular the membrane 36, by means of the at least one Etch stop material of the etch stop limitation 22, 26, 32 and 34 reliably protected. After the silicon surrounded by the etch stop delimitation 22, 26, 32 and 34 has been etched, the inner walls of the medium space 40 are covered by the first etch stop layer 22, the second etch stop layer 26 and the third

Etch stop layer 34 and the etch stop walls 32 exposed. A contamination of at least one medium later filled into the medium space 40 by the at least one etch stop material of the etch stop delimitation 22, 26, 32 and 34 therefore need not be feared when the micromechanical component is in operation.

In an alternative embodiment of that described here

In the manufacturing process, the medium space 40 can first be freely etched before the formation of the actuator device 38 on / in the membrane 36 is started.

The etch stop delimitation 22, 26, 32 and 34 is preferably formed from silicon oxide (as its at least one etch stop material). The components of the etch stop delimitation 22, 26, 32 and 34 can thus each be formed by means of a comparatively low amount of work, such as, for example, by performing a thermal oxidation or by means of an oxide deposition. Another advantage of using silicon oxide as the (only) etch stop material of the etch stop delimitation 22, 26, 32 and 34 is that the silicon surrounded by the etch stop delimitation 22, 26, 32 and 34 in this case is preferably by means of xenon difluoride and / or

Sulfur hexafluoride can be etched, as a result of which the silicon to be etched can be reliably removed, and nevertheless (almost) no etching of the etch stop delimitation 22, 26, 32 and 34 is to be feared. In addition, when using silicon oxide as the (only) etching material, the

Etch stop delimitation 22, 26, 32 and 34 the inner walls of the medium space 40 can be exposed comparatively easily by removing the etch stop delimitation 22, 26, 32 and 34 in a gas phase etching process. As an alternative or in addition to silicon oxide, silicon nitride can also be used as the etch stop material of the etch stop delimitation 22, 26, 32 and 34. In the production method described here, in addition to the medium outlet opening 18, at least one further opening 42 and 44 of the medium space 40, such as a medium supply opening 42 and a medium emptying opening 44, is formed in the silicon substrate 10 in such a way that the medium space 40 over the at least one further Opening 42 and 44 can be filled / emptied. The at least one etching opening 35 can thus be used in many ways. For example, in the embodiment described here, the at least one further opening 42 and 44 runs through at least one extending from the first substrate surface 12a to the second substrate surface 12b

extending substrate side surfaces 12c and 12d of the silicon substrate 10.

As an optional addition, a cap (not shown) can be attached to an outer side of the membrane 36 and the actuator device 38 facing away from the medium space 40. The capping can

for example be firmly bonded. In particular, sealing glass bonding and / or eutectic bonding using aluminum and germanium can be carried out as the bonding method for fastening the capping. Optionally, the semiconductor wafer 14 can also be removed.

2 shows a schematic illustration of a first specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 2 can, for example, by means of the previously described embodiment of the

Manufacturing process be made. The micromechanical component has a completely grown silicon substrate 10 with a first substrate surface 12a and a second substrate surface 12b directed away from the first substrate surface 12a. As has already been explained above, the silicon substrate 10 is a silicon substrate 10 that is completely grown in at least two silicon growth steps starting from an initial layer 10a made of silicon.

In addition, the silicon substrate 10 is free of bonding layers between its first substrate surface 12a and its second substrate surface 12b.

A medium space 40 is structured in the silicon substrate 10. The medium space 40 has a structure structured by the first substrate surface 12a Medium outlet opening 18. The medium outlet opening 18 can also be referred to as a nozzle. In addition, a membrane 36, which delimits the medium space 40, is formed on the second substrate surface 12b. An actuator device 38 is arranged on the membrane 36 in such a way that the membrane 36 can be set into a deforming movement by means of the actuator device 38 such that at least one medium present in the medium space 40 can be pushed out of the medium space 40 via the medium outlet opening 18. A bulge of the membrane 36 into the medium space 40 can in particular cause a drop at the medium outlet opening 18. The actuator device 38 is preferably in a direction away from the medium space 40

Arranged on the outside of the membrane 36 so that the actuator device 38 does not come into contact with the at least one medium present in the medium space 40.

Due to the formation of the silicon substrate 10 free of bonding layers between its first substrate surface 12a and its second

Substrate surface 12b need not fear that the at least one medium present in medium space 40 will chemically attack a bond and thus lead to decomposition of the micromechanical component. Likewise, the at least one medium present in the medium space 40 does not have to be contaminated by at least one bonding material

Bond connection are feared. A high demand for purity of the at least one medium present in the medium space 40, such as for a medical / medical technology or a medium

sensor application of the at least one medium is often required, can thus be reliably observed. The micromechanical component is therefore versatile, such as an insulin pump, a laboratory chip, a sensor or a probe. In the embodiment of FIG. 2 this is

micromechanical component a printhead / printhead part, whereby even strongly alkaline or organic inks can be filled into the interior of the medium space 40 without any problems, since an ink filled in the medium space 40 only contacts the inner walls of the medium space 40 made of silicon and thus does not / hardly attack the micromechanical component . The training of the

Medium space 40 made of (pure) silicon also simplifies the application of a continuous protective layer for media that attack silicon, since the Protective layer only has to adhere to silicon and not to a bonding material. .

The medium space 40 has, on its side aligned with the first substrate surface 12a, a first support wall 19, the wall thickness of which, aligned perpendicular to the first substrate surface 12a, is defined by the layer thickness of the previous starting layer 10a. His to the second

On the side facing the substrate surface 12b, the medium space 40 is delimited by a second support wall 30 and the membrane 36, an overhang of the second support wall 30 aligned perpendicular to the second substrate surface 12b relative to the membrane 36 being defined by the layer thickness of the previous second silicon region 28. In addition to the medium outlet opening 18, at least one further opening 42 and 44 of the medium space 40 (as a medium supply opening 42 and as a medium discharge opening 44) is structured in the silicon substrate 10 so that the medium space 40 can be filled via the at least one further opening 42 and 44 / or can be emptied. For example, the at least one further opening 42 and 44 runs through at least one substrate side surface 12c and 12d of the silicon substrate 10 that extends from the first substrate surface 12a to the second substrate surface 12b.

As an optional addition there is a cap 46 on one of the

Medium space 40 facing away from the outside of the membrane 36 and the

Actuator device 38 attached. By way of example, the capping 46 is fastened to the outside of the membrane 36 and the actuator device 38 by means of at least one bond connection 48.

With regard to further properties and features of the micromechanical component of FIG. 2, reference is made to the production method described above.

3 shows a schematic cross section through an intermediate product for explaining a second embodiment of the manufacturing method.

In the production method shown schematically by means of FIG. 3, the medium space 40 becomes at one of the medium outlet opening 18 Adjacent area is expanded by an exit opening antechamber 50 designed as a recess in the first support wall 19, in that the first support wall 19 by means of an additional intermediate silicon growth step, which is carried out before the first intermediate silicon growth step, by a growth directly on the starting layer 10a further silicon area 52 is reinforced. An etch stop layer 54 and etch stop walls 56, which define the subsequent shape of the exit opening vestibule 50, can also be seen.

With regard to further properties and features of the manufacturing method of FIG. 3, reference is made to the manufacturing method of FIGS. La to le.

4 shows a schematic illustration of a second specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 4 can be produced, for example, by means of the production method explained with reference to FIG. 3. The outlet opening antechamber 50 formed on an area of the medium chamber 40 adjacent to the medium outlet opening 18 offers volume for an advantageous eddy current in front of that of the medium outlet opening 18. In addition, the outlet opening antechamber 50 enables the formation of a very short medium outlet opening 18 without restricting the stability of the first supporting wall 19 of the medium chamber 40 . In contrast to the embodiment of FIG. 2, the micromechanical component of FIG. 4 also has a medium outlet opening 18 with a smaller length perpendicular to the first substrate surface 12a. A desired diameter and an advantageous shape of the medium outlet opening 18 can thus be adhered to more easily and more accurately in the production of the micromechanical component of FIG. 4, whereby a desired drop size of a drop emerging from the medium outlet opening 18 or a defined tear-off of the drop can be better guaranteed and bubbles and drying residue on the

Medium outlet opening 18 can be suppressed more reliably. Using the

Forming the exit opening antechamber 50 as a recess in the first support wall 19 by means of the additional intermediate silicon growth step ensures at the same time that the first support wall 19 continues to have advantageous stability. With regard to further properties and features of the micromechanical component of FIG. 4, reference is made to the embodiments described above.

5 shows a schematic illustration of a third specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 5 differs from the previously described embodiment only by a funnel-shaped design of its medium outlet opening 18 with a diameter that decreases in the direction of the first substrate surface 12a. The funnel-shaped design of the medium outlet opening 18 is e.g. can be implemented using a KOH / potassium hydroxide etching process or a conical trench etching (tapered trench etching).

With regard to further properties and features of the micromechanical component of FIG. 5, reference is made to the embodiments described above.

6 shows a schematic illustration of a fourth specific embodiment of the micromechanical component.

In the micromechanical component shown schematically in FIG. 6, there is a further opening 42 and 44 at its at least one

Throttle valve 58 designed as constrictions at the respective further openings 42 and 44. For this purpose, in an area of the medium space 40 adjacent to the medium outlet opening 18 or the outlet opening antechamber 50, an antechamber 60 of the medium chamber 40 is created as an (additional) recess in the first support wall 19 by means of an additional intermediate silicon growth step which is carried out prior to the first intermediate silicon growth step by another

Silicon area 62 is reinforced. The silicon of at least one

Throttle valve 58 is deposited in the first intermediate silicon growth step, using previously formed etch stop layers and Etch stop walls an etching of the silicon of the at least one throttle valve 58 is prevented during the structuring of the medium space 40.

By means of the at least one throttle valve 58, a transmission of vibrations from the membrane 36 of the illustrated cell via the at least one medium filled in the medium space 40 to a membrane 36 of an adjacent cell (not illustrated) can be prevented. In this way, crosstalk between cells of a micromechanical component formed with a plurality of cells, which could lead to an undesired increase in the size of a droplet emerging from the medium outlet opening 18 of a cell, can be reliably prevented.

With regard to further properties and features of the micromechanical component of FIG. 6, reference is made to the embodiments described above.

7 shows a schematic illustration of a fifth specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 7 has, as a supplement to the embodiment described above, at least one screen structure 64 and / or within its at least one further opening 42 and 44. The at least one screen structure 64 is preferably on and / or within the at least one further opening 42 and 44

formed by growing silicon on the side of the intermediate product facing away from the first substrate surface 12a between the at least two intermediate silicon growth steps carried out.

With regard to further properties and features of the micromechanical component of FIG. 7, reference is made to the previously described embodiments.

FIGS. 8a to 8c show schematic cross-sections through intermediate products to explain a third embodiment of the production method. The micromechanical component shown schematically by means of FIGS. 8a to 8c differs from the embodiment of FIG. 2 in that the at least one further opening 42 and 44 runs through the second substrate surface 12b. As a further development of the embodiment of FIGS. 1 a to 1e, a capping 46 is firmly bonded to the outside of the membrane 36 and the actuator device 38 facing away from the medium space 40, in which a medium storage space 66 and a medium outflow space 68 are structured so that the at least one further Opening 42 and 44 in the medium storage space 66 or in the medium outflow space 68 opens. This is shown schematically in Fig. 8a.

8b shows the structuring of the medium space 40 and the gas phase etching, both processes being carried out after the solid bonding of the capping 46 via the medium storage space 66, via the at least one further opening 42 and 44 and via the medium drainage space 68. Then, as shown in FIG. 8c, a silicon protective layer 70 is deposited in order to protect the bond connections 48 from being wetted with the at least one medium before the at least one medium is filled into the medium space 40. The silicon protective layer 70 can be applied, for example, by sputtering. The protrusions 72 shown of the capping 46 can then be removed by sawing or grinding back.

With regard to further properties and features of the production method of FIGS. 8a to 8c, reference is made to the embodiments described above.

9 shows a schematic illustration of a sixth specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 9 can be produced, for example, by means of the production method of FIGS. 8a to 8c. With regard to further properties of the micromechanical component of FIG. 9, reference is therefore made to the statements relating to those described above

Embodiments referenced. 10 shows a schematic illustration of a seventh specific embodiment of the micromechanical component.

In the embodiment of FIG. 10, too, at least one screen structure 74 is formed on and / or within the at least one further opening 42 and 44. The at least one screen structure 74 can be produced together with the membrane 36 in the last silicon growth step. (The at least one screen structure 74 can be designed as a "membrane with holes".)

With regard to further properties and features of the micromechanical component of FIG. 10, reference is made to the embodiments described above.

11 shows a schematic illustration of an eighth specific embodiment of the micromechanical component.

In the micromechanical component shown schematically by means of FIG. 11, its medium space 40 is also delimited by a damper membrane 76 in addition to the membrane 36. The damper membrane 76 can be used to ensure that pressure waves generated by the actuator device 38 with deformation of the membrane 36 in the at least one in the

Medium space 40 present medium are attenuated and not transferred to at least one neighboring cell.

Preferably, the damper membrane 76 is a polyimide membrane. The polyimide of the damper membrane 76 can in this case after the formation of the

Actuator device 38 are deposited and structured.

With regard to further properties and features of the micromechanical component of FIG. 11, reference is made to the previously described embodiments.

FIGS. 12a to 12d show schematic cross sections through intermediate products for explaining a fourth embodiment of the production method. In the production method of FIGS. 12a to 12d, as a further development, in addition to the openings 18, 42 and 44, a separate etching opening 78 of the later medium space 40 is formed. Also, the second

Substrate surface 12b is covered with a thick etch protection layer 80, such as an oxide layer, except for the etching opening 78 / an area surrounding the etching opening 78 (see FIG. 12a).

Then, as is shown schematically in FIG. 12b, the

Medium space 40 structured in the silicon substrate 10. After structuring the medium space 40 and the gas phase etching, the etching opening 78 is closed (see FIG. 12c). This can be done for example by means of a local melting of silicon, e.g. by means of a laser sealing process (laser reseal), or by means of a material deposition.

An etch port seal 78a remains.

As can be seen in FIG. 12 d, the bond connections 48 for fastening the capping 46 are made on a direction away from the medium space 40

Outside of the membrane 36 and the actuator device 38 only after

Structuring the medium space 40 and the gas phase etching formed. There is thus no risk that the bond connections will be attacked when structuring the medium space 40 or during gas phase etching.

With regard to further properties and features of the production method of FIGS. 12a to 12d, reference is made to the embodiments described above.

13 shows a schematic illustration of a ninth specific embodiment of the micromechanical component.

The micromechanical component shown schematically in FIG. 13 can be manufactured, for example, by means of the manufacturing method of FIGS. 1 a to 1e and 12a to 12d described above. With regard to the properties and features of the micromechanical component of FIG. 13, reference is made to the previously described embodiments. 14 shows a schematic illustration of a tenth embodiment of the micromechanical component. In contrast to the previously described embodiments, in the micromechanical component of FIG. 13 the at least one further opening 42 and 44 runs through the first substrate surface 12a. The at least one screen structure 82 at the at least one further opening 42 and 44 can be through the

Output layer 10a be structured.

With regard to further properties and features of the micromechanical component of FIG. 14, reference is made to the embodiments described above. The manufacturing methods explained above thus allow great design freedom when forming the respective micromechanical component, in particular when forming its medium space 40. In contrast to methods with bonding steps according to the prior art, when the medium space 40 is modified, the conventional need to structure another wafer is eliminated and for bonding the further wafer to an intermediate product.

Claims

Expectations

1. A micromechanical component comprising: a completely grown silicon substrate (10) with a first substrate surface (12a) and a second substrate surface (12b) directed away from the first substrate surface (12a); a medium space (40) structured in the silicon substrate (10) with one structured by the first substrate surface (12a)

Medium outlet opening (18); and a membrane (36) which is formed on the second substrate surface (12b) and delimits the medium space (40); wherein an actuator device (38) can be arranged or arranged on the membrane (36) in such a way that the membrane (36) can be caused to deform by means of the actuator device (38) in such a way that at least one medium present in the medium space (40) passes through the Medium outlet opening (18) can be pushed out of the medium space (40).

2. Micromechanical component according to claim 1, wherein the silicon substrate (10) is a silicon substrate (10) that is completely grown in at least two silicon growth steps starting from an initial layer (10a) made of silicon.

3. Micromechanical component according to claim 1 or 2, wherein the

Silicon substrate (10) between its first substrate surface (12a) and its second substrate surface (12b) is free of bonding layers.

4. Micromechanical component according to one of the preceding claims, wherein in addition to the medium outlet opening (18) at least one further opening (42, 44) of the medium space (40) in the silicon substrate (10) is designed so that the medium space (40) over the least a further opening (42, 44) can be filled and / or emptied, and wherein the at least one further opening (42, 44) through the first

Substrate surface (12a), the second substrate surface (12b) and / or through at least one substrate side surface (12c, 12d) of the silicon substrate (10) extending from the first substrate surface (12a) to the second substrate surface (12b).

5. Micromechanical component according to claim 4, wherein at least one

Sieve structure (64, 74, 82) is formed on and / or within the at least one further opening (42, 44).

6. Micromechanical component according to one of the preceding claims, wherein the micromechanical component is a print head, an insulin pump, a laboratory chip, a sensor or a probe.

7. Manufacturing process for a micromechanical component with the following steps:

Forming a fully grown silicon substrate (10) having a first substrate surface (12a) and one of the first

Substrate surface (12a) facing away second substrate surface (12b);

Structuring of a medium space (40) in the silicon substrate (10), for which a medium outlet opening (18) through the first

Substrate surface (12a) is structured; and

Formation of a membrane (40) on the second substrate surface (12b), which delimits the medium space (40), wherein an actuator device (38) can be or will be arranged on the membrane (36) in such a way that during a later operation of the actuator device (38) formed micromechanical component, the membrane (36) is caused to deform by means of the actuator device (38) in such a way that at least one medium present in the medium space (40) passes through the

Medium outlet opening (18) is pushed out of the medium space (40).

8. The manufacturing method of claim 7, wherein in addition to the

Medium outlet opening (18) and at least one further opening (42,

44) of the medium space (40) in the silicon substrate (10) is formed in such a way that the medium space (40) can be filled and / or emptied via the at least one further opening (42, 44), and the at least one further opening (42 , 44) through the first substrate surface (12a), the second substrate surface (12b) and / or through at least one substrate side surface (12c, 12d) of the silicon substrate (10) extending from the first substrate surface (12a) to the second substrate surface (12b) runs.

9. Manufacturing method according to claim 7 or 8, wherein the silicon substrate (10) is completely formed starting from an initial layer (10a) made of silicon in at least two silicon growth steps.

10. The manufacturing method according to claim 9, wherein at least one intermediate silicon growth step and a final silicon growth step are carried out as the at least two silicon growth steps, and the following method steps are carried out in succession:

- Structuring the medium outlet opening (18) through the surface of the starting layer (10a) or later from the

Starting layer (10a) thinned back first substrate surface (12a);

- Covering a partial area of a side (20) of the starting layer (10a) facing away from the first substrate surface (12a) with a first etch stop layer (22);

- Carrying out the at least one intermediate silicon growth step by adding silicon to the side (20) of the starting layer (10a) facing away from the first substrate surface (12a) or a

starting from the starting layer (10a) grown

Intermediate is grown, being executed after each Intermediate silicon growth step, a partial area of the side (20) of the facing away from the first substrate surface (12a)

Intermediate product is covered with a further etch stop layer (26, 34), and etch stop walls (32) are formed which connect the first etch stop layer (22) and the at least one further etch stop layer (26, 34) to one another in such a way that the first etch stop layer (22 ) which form at least one further etch stop layer (26, 34) and the etch stop walls (32) form an etch stop delimitation (22, 26, 32, 34) which surround a volume filled with silicon except for at least one etching opening (35); and

- Forming the membrane (36) by performing the last silicon growth step by placing silicon on top of the first

Substrate surface (12a) facing away side of the intermediate product grown from the starting layer (10a) in the at least one intermediate silicon growth step is grown.

11. Manufacturing method according to claim 10, wherein after the formation of the membrane (36) of the medium space (40) in the starting from the

Starting layer, the silicon substrate completely grown in the at least two silicon growth steps is structured by etching the volume surrounded by the etch stop delimitation (22, 26, 32, 34), and then the inner walls of the medium space (40) from the first etch stop layer (22), the at least one further etch stop layer (26, 34) and the etch stop walls (32) are exposed.

12. The manufacturing method according to claim 11, wherein the first etch stop layer (22), the at least one further etch stop layer (26, 34) and the

Etch stop walls (32) are formed from silicon oxide, and wherein the first etch stop layer (22), the at least one further

Etch stop layer (26, 34) and the etch stop walls (32) surrounding silicon is etched by means of xenon difluoride and / or sulfur hexafluoride.

13. Manufacturing method according to claim 11 or 12, wherein the first

Etch stop layer (22), the at least one further etch stop layer (26, 34) and the etch stop walls (32) are formed from silicon oxide, and wherein the inner walls of the medium space (40) are exposed by the first Etch stop layer (22), the at least one further etch stop layer (26, 34) and the etch stop walls (32) are removed in a gas phase etching process.

14. Production method according to one of claims 10 to 13, wherein at least two intermediate silicon growth steps are carried out before the last silicon growth step.

15. Manufacturing method according to claim 8 and claim 14, wherein between the at least two executed intermediate silicon

At least one screen structure (64) is formed on and / or within the at least one further opening (42, 44) by growing silicon on the side (20) of the intermediate product facing away from the first substrate surface (12a).