Method for manufacturing a micromechanical component and micromechanical component

Abstract

The present invention relates to a method for manufacturing a micromechanical component for a sensor device or a microphone device, comprising the following steps: forming a support structure (10) on a substrate surface (12a) of a substrate (12) using a first sacrificial material, the support structure having a first sacrificial material layer (14), a plurality of etched holes (16) structured through the first sacrificial material layer (14) and a plurality of support pillars (18) extending into the substrate (12); etching at least one cavity (22) spanned by the support structure (10) into the substrate surface (12a); forming a film (30) on or above the first sacrificial material layer (14) of the support structure (10) using at least one semiconductor material; depositing a layer stack (34) including at least one sacrificial layer (36a, 36b) and at least one counter electrode (38); and releasing the film (30) by at least partially removing at least the support structure (10) and at least one sacrificial layer (36a, 36b).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a micromechanical component for a sensor device or microphone device. Additionally, this invention relates to a micromechanical component for a sensor device or microphone device. Background Technology

[0002] As known from the prior art, such as DE 10 2012 217 979 A1, a diaphragm made of at least one semiconductor material is used as a pressure-sensitive element of a sensor or microphone, wherein the diaphragm itself or an electrode attached to the diaphragm interacts with a fixed counter electrode. Typically, in this case, at least one portion of the diaphragm's surface facing away from the counter electrode is exposed. Summary of the Invention

[0003] The present invention realizes a method for manufacturing a micromechanical component for a sensor device or a microphone device, and a micromechanical component for a sensor device or a microphone device.

[0004] Advantages of the present invention This invention provides a micromechanical component having a diaphragm capable of functioning as a pressure-sensitive element or an acoustic wave-sensitive element, which is better protected against mechanical damage or contamination compared to existing technologies. Because the diaphragm, on the side of the micromechanical component implemented by this invention, spans at least one free space etched into the substrate surface on the side away from the at least one interacting electrode, the substrate surface helps to reliably protect the diaphragm from mechanical damage. Simultaneously, it can be easily ensured that particles of a defined size cannot penetrate the cavities etched into the substrate surface with a high probability, thereby advantageously ensuring the diaphragm deflection necessary for the correct functioning of the micromechanical component and / or a sensor device or microphone device incorporating the micromechanical component. Therefore, this invention provides a micromechanical component and / or a sensor device or microphone device incorporating the micromechanical component, whose corresponding diaphragm can be used more reliably for pressure measurement or for acoustic-to-electronic signal conversion. Similarly, the micromechanical component implemented by this invention has an increased lifespan compared to existing technologies.

[0005] In an advantageous embodiment of the manufacturing method, in order to form a support structure on the substrate surface of a substrate by a first sacrificial material, the following steps are performed: structuring a plurality of trenches into the substrate surface of the substrate; depositing the first sacrificial material on the substrate surface having a plurality of trenches structuring into the substrate surface such that a plurality of support pillars (Stützpfosten) extending into the substrate are formed by the first sacrificial material filling the plurality of trenches; the substrate surface is at least partially covered by a subsequent first sacrificial material layer composed of the first sacrificial material; structuring a plurality of etch holes through the first sacrificial material layer; and etching cavities into the substrate surface through the plurality of etch holes in the first sacrificial material layer.

[0006] The method steps described herein can be readily implemented using standard semiconductor technology processes. The support structure formed by the method steps described herein is reliably applicable to realizing at least one cavity etched into the substrate surface and spanned by a film, particularly to realizing a cavity spanned by a film having an extension dimension greater than or equal to 5 μm perpendicular to the substrate surface.

[0007] Preferably, before forming the film, the first sacrificial material layer is at least partially covered by a second sacrificial material layer, the second sacrificial material layer being composed of the first sacrificial material and / or the second sacrificial material, and wherein, during film formation, the second sacrificial material layer is at least partially covered by the film. In this way, the etched holes structured into the first sacrificial material layer can be covered by the second sacrificial material layer, eliminating concerns about film material intruding into the etched holes during film formation.

[0008] In one advantageous embodiment, the support structure is formed of silicon oxide as the first sacrificial material. Therefore, silicon oxide, a material already commonly used in semiconductor technology, can also be used to form the support structure and / or the second sacrificial material layer. This facilitates the implementation of the above-described method steps and the subsequent sacrificial layer etching process.

[0009] As an advantageous extension, prior to forming the film, silicon-rich silicon nitride, silicon carbide, and / or alumina can be locally deposited on a first sacrificial material layer made of silicon oxide, on a second sacrificial material layer made of silicon oxide, and / or in at least one opening structured by the first and / or second sacrificial material layers made of silicon oxide. As explained in more detail below, at least one lateral etch-limiting portion and / or at least one electrically insulating portion can be formed from silicon-rich silicon nitride, silicon carbide, and / or alumina in this way, which exhibits high etch resistance to some etch media commonly used for etching silicon oxide.

[0010] In another advantageous embodiment of this manufacturing method, in order to release the diaphragm, at least one first etch medium inlet extending through the layer stack, at least one second etch medium inlet extending only a portion of the layer stack, and / or a channel extending through the substrate are formed, and at least a support structure and at least one sacrificial layer are at least partially removed by means of at least one etch medium guided through at least one first etch medium inlet and / or through at least one second etch medium inlet and / or through at least one channel. The method steps described herein can be implemented using standard semiconductor technology processes, as explained below. Alternatively, at least one channel extending through the substrate into free space can also be formed to supply pressure to the diaphragm.

[0011] Preferably, the maximum gap width (between the membrane and the substrate) perpendicular to the substrate surface in free space is greater than or equal to 5 μm. This measured gap width provides sufficient volume for membrane warping and prevents particles from adhering to the membrane.

[0012] Preferably, multiple trenches are etched into the substrate on the side of free space that is away from the film and adjacent to the substrate. These trenches are remnants, traces, or molds of trenches previously etched into the substrate. Based on these remnants, traces, or molds in the substrate, it can be reliably seen after performing the sacrificial layer etching process that the corresponding micromechanical component was manufactured using one of the manufacturing methods described above. Attached Figure Description

[0013] Other features and advantages of the invention are described below with reference to the accompanying drawings. The drawings show: Figures 1A to 1H A schematic diagram showing intermediate products and micromechanical components is provided to illustrate a first embodiment of a method for manufacturing micromechanical components for sensor devices or microphone devices. Figure 2 A schematic diagram of a micromechanical component is shown to illustrate a second embodiment of the manufacturing method; Figure 3 A schematic diagram of a micromechanical component is shown to illustrate a third embodiment of the manufacturing method; Figures 4a to 4f show schematic diagrams of intermediate products to illustrate other embodiments of the micromechanical components. Detailed Implementation

[0014] Figures 1A to 1H A schematic diagram showing intermediate products and micromechanical components is provided to illustrate a first embodiment of a method for manufacturing micromechanical components for sensor devices or microphone devices.

[0015] With the help of this manufacturing method Figure 1A In the illustrative reproduction of the method steps, a support structure 10 is formed on the substrate surface 12 of a substrate 12 using a first sacrificial material. The support structure 10 is formed having a first sacrificial material layer 14 and a plurality of support pillars 18 made of the first sacrificial material, the first sacrificial material layer at least partially covering the substrate surface 12a, the first sacrificial material layer having a plurality of etched holes 16 structured through the first sacrificial material layer 14, and the support pillars extending into the substrate 12. For example, the support structure 10 is formed entirely of silicon oxide as the first sacrificial material. The substrate 12 is preferably a semiconductor substrate, such as, in particular, a silicon substrate. However, instead of silicon or as a supplement to silicon, the substrate 12 may also include at least one other semiconductor material, at least one metal, and / or at least one electrically insulating material.

[0016] In the embodiment of the manufacturing method described herein, in order to form the support structure 10 on the substrate surface 12a by means of a first sacrificial material, a plurality of trenches 20 are first structured into the substrate surface 12a of the substrate 12. The plurality of trenches 20 can be etched into the substrate surface 12a, for example, by means of a plasma etching process / trench etching process. The trenches 20 are preferably structured into the substrate surface 12a at a trench depth perpendicular to the orientation of the substrate surface 12a, the trench depth being between 1 μm and 20 μm (micrometers), preferably between 5 μm and 10 μm (micrometers). As explained in more detail below, the trench depth of the trenches 20 determines the subsequent support pillar height of the support pillar 18. However, the values ​​given herein for the trench depths of the trenches 20 should be interpreted illustratively only, as the trenches 20 can be etched to any depth.

[0017] Then, a first sacrificial material is deposited on a substrate surface 12a having a plurality of trenches 20 structured into the substrate surface, such that the first sacrificial material (completely) filling the plurality of trenches 20 forms a plurality of support pillars 18 extending into the substrate, and additionally, the substrate surface 12a is at least partially covered by a subsequent first sacrificial material layer 14 composed of the first sacrificial material. The support pillars 18 may have a support pillar height between 1 μm and 20 μm (micrometers) oriented perpendicular to the substrate surface 12a. Preferably, the support pillar height of the support pillars 18 is between 5 and 10 μm (micrometers). However, the support pillar heights given herein for the support pillars 18 should not be interpreted restrictively. The support pillar heights of the support pillars 18 determine the maximum extension scale perpendicular to the substrate surface 12a of at least one subsequently formed cavity 22. Subsequently, a plurality of etched holes 16 are structured through the first sacrificial material layer 14.

[0018] After the support structure 10 is formed, at least one cavity 22 spanned by the support structure 10 is etched into the substrate surface 12a. This is achieved using an etching medium guided through a plurality of etch holes 16 in a first sacrificial material layer 14, which has higher etch resistance to the etching medium compared to the substrate 12. Preferably, to etch at least one cavity 22, an isotropic etching step, such as a silicon-plasma etching process, is performed, in which the plurality of etch holes 16 in the first sacrificial material layer 14 serve as etching inlets. In this way, the region of the substrate 12 between the support pillars 18 can be selectively removed. The support pillars 18 can be partially exposed in this manner, however, preferably, the etching of at least one cavity 22 is only performed until the anchorage region 18a of the support pillar 18 still extends into the substrate 12. At least one cavity 22 is preferably etched with a maximum extension scale perpendicular to the substrate surface 12a and smaller than the support pillar height of the support pillar 18.

[0019] After etching at least one cavity 22, the support structure 10 also has advantageous stability. Preferably, the anchoring region 18a of the support structure 18 in the substrate 12 after etching at least one cavity 22 has a height between 0.5 mm and 2 μm (micrometers) oriented perpendicular to the substrate surface 12a, wherein the values ​​should be interpreted illustratively only. Figure 1A The intermediate results are shown after etching at least one cavity 22.

[0020] Optionally, in the manufacturing method described herein, the first sacrificial material layer 14 (before forming the film described later) is at least partially covered by a second sacrificial material layer 24 composed of a first sacrificial material and / or a second sacrificial material. The second sacrificial material layer 24 can be used to seal the etched holes 16 in the first sacrificial material layer 14. Optionally, the second sacrificial material layer 24 can also be formed of silicon oxide. As an advantageous extension, in the manufacturing method described herein, silicon-rich silicon nitride is also deposited (before forming the film described later) as at least an electrically insulating portion 26 and / or as at least a lateral etch-limiting portion 28 on the first / second sacrificial material layer 14 or 24 composed of silicon oxide and / or deposited into the openings structured by the first sacrificial material layer 14 and / or the second sacrificial material layer 24 composed of silicon oxide. However, instead of silicon-rich silicon nitride, silicon nitride, silicon carbide, and / or aluminum oxide can also be used to form at least one electrically insulating portion 26 and / or at least one lateral etch-limiting portion 28. Since silicon-rich silicon nitride, silicon carbide, and aluminum oxide have advantageous low etch rates / high etch resistance to many etch media (such as liquid or gaseous hydrofluoric acid) that are often used to etch silicon oxide, at least one electrically insulating portion 26 and / or at least one lateral etch limit portion 28 can be formed without any problems before removing at least a portion of the support structure 10. Figure 1B Intermediate results are shown following optional method steps for depositing silicon-rich silicon nitride.

[0021] Next, a film 30 is formed on / above the first sacrificial material layer 14 of the support structure 10 using at least one semiconductor material (e.g., doped polysilicon). Figure 1C In this example, during the formation of the diaphragm 30, the second sacrificial material layer 24 is at least partially covered by the diaphragm 30. The number and shape of the support pillars 18 can influence the flexibility of the various diaphragm regions of the diaphragm 30. Preferably, at least one coherent groove 32 is then structured through the diaphragm 30, thereby allowing at least one interface of the first / second sacrificial material layer 14 or 24, at least one electrically insulating portion 26, and / or at least one lateral etched boundary portion 28 to be selectively exposed.

[0022] Figure 1DThe diagram shows an intermediate result after depositing a layer stack 34 on the side of the film 30 facing away from the substrate 12, wherein the layer stack 34 includes at least one sacrificial layer 36a and 36b and at least one counter electrode 38 formed on the side of the at least one sacrificial layer 36a and 36b facing away from the substrate 12. In the embodiment described herein, firstly, a first sacrificial layer 36a, such as a silicon oxide layer, is deposited on the side of the film 30 facing away from the substrate 12. Then, a first electrode material layer 40 is deposited on at least a portion of the surface of the first sacrificial material layer 36a, wherein at least one electrode 42 formed by the first electrode material layer 40 can be mechanically fixed, suspended, or attached to the film 30 and electrically connected to the film 30 by means of the portion of material of the first electrode material layer 40 filling at least one opening structured through the first sacrificial material layer 36a. Optionally, at least one reference electrode 44 can also be formed from the first electrode material layer 40. The first electrode material layer 40 can be, for example, a doped polysilicon layer.

[0023] In the manufacturing method described herein, after depositing and structuring the first electrode material layer 40, a second sacrificial layer 36b, particularly a silicon oxide layer, is deposited, which, after its structuring, is at least partially covered by the second electrode material layer 46. At least one counter electrode 38 is formed from at least one second electrode material layer 46. Optionally, at least one reference counter electrode 48 may also be additionally structured from the second electrode material layer 46, which may form a reference capacitor structure with at least one reference electrode 44 made of the material of the electrode material layer 40. By means of the portion of the material of the second electrode material layer 46 filling at least one opening extending through the second sacrificial material layer 36b, at least one reference electrode 44 can be fixed to at least one portion of the surface of the second electrode material layer 46 such that even if the diaphragm 30 subsequently warps, there is (substantially) no change in the spacing between the at least one reference electrode 44 and its corresponding associated reference counter electrode 48.

[0024] Next, at least a portion of the second electrode material layer 46 is covered by at least one insulating layer 50 and (optionally) by another layer 52, such as another insulating layer. To prevent subsequent under-etching of the second electrode material layer 46 during the sacrificial layer etching process, at least a portion of the second electrode material layer 46 is covered by a layer made of silicon-rich silicon nitride (as the first insulating layer 50). Then, (optionally) another layer 52 made of silicon oxide (as the second insulating layer 52) is deposited on the layer 50 made of silicon-rich silicon nitride. To give the layer stack 34 mechanical strength, preferably, a support layer / reinforcement layer 54 made of polycrystalline silicon (possibly grown at least regionally in an epitaxial reactor and / or LPCVD tube) is also applied on / above layers 50 and 52. Optionally, at least one doped region 55 may also be introduced into the support layer / reinforcement layer 54. However, it should be noted that in Figure 1D The construction of the reproducible, layer-stacked 34 should be interpreted as illustrative only.

[0025] In the manufacturing method described herein, for subsequent release of the diaphragm 30, at least one etch medium inlet 56a and 56b extending through the layer stack 34 are also formed to at least partially remove at least the support structure 10 and at least one sacrificial layer 36a and 36b by means of at least one etch medium guided through at least one etch medium inlet 56a and 56b. At least one etch medium inlet 56a and 56b can also be understood as etch channels, respectively. Figure 1D The intermediate product is shown after the formation of at least one etch medium inlet 56a and 56b, but before etching at least the support structure 10 and at least one sacrificial layer 36a and 36b.

[0026] Exemplarily, in the manufacturing method described herein, in order to release the diaphragm 30, not only is at least one first etch medium inlet 56a formed extending through the layer stack 34, but also at least one second etch medium inlet 56b is formed extending only through a portion of the layer stack 34. The additional construction of the at least one second etch medium inlet 56b enables subsequent etching of at least one sacrificial layer 36a and 36b.

[0027] exist Figure 1EThe intermediate product after the release of the diaphragm 30 is shown. At least the support structure 10, possibly the second sacrificial material layer 24, and at least one sacrificial layer 36a and 36b are at least partially removed by at least one etch medium guided through at least one first etch medium inlet 56a and / or at least one second etch medium inlet 56b. For etching, a vapor-phase etching process containing hydrofluoric acid can be used. It should be clearly noted that by rapidly etching, the diaphragm 30 can be released because the etch medium, such as, in particular, hydrofluoric acid (HF) vapor, can be reliably supplied to the area to be etched via at least one etch medium inlet 56a and 56b. The absence of material within the constructed at least one cavity 22 simplifies the propagation of the etch medium within the cavity 22 and the etching of the support structure 10, even though the support structure is located between the diaphragm 30 and the substrate 12. Conversely, if the volume of at least one cavity 22 is completely filled with at least one first sacrificial material and / or at least one second sacrificial material, the fabrication / etching of the volume between the diaphragm 30 and the substrate 12 or the at least one cavity 22 is significantly more time-consuming.

[0028] like Figure 1E As shown, the removal of at least a portion of the support structure 10 and possibly the second sacrificial material layer 24 creates a free space 57 between the membrane 30 and the substrate 12. For example, the free space 57 may have a maximum gap width σ between 1 μm and 15 μm (micrometers) oriented perpendicular to the substrate surface 12a. This ensures advantageous warpability of the membrane 30. Simultaneously, by constructing the free space 57 between the membrane 30 and the substrate 12, reliable protection of the membrane 30 against mechanical damage or contamination is ensured. In particular, the substrate 12 contributes to the reliable protection of the membrane against mechanical damage. Advantageous possibilities for preventing contamination from entering the free space 57 between the membrane 30 and the substrate 12 will be described below.

[0029] Preferably, the maximum gap width σ of the free space 57, oriented perpendicular to the substrate surface 12a, is greater than or equal to 5 μm (micrometers). Figure 1E It can also be seen that on the side of free space 57 that points away from the diaphragm 30 and is adjacent to the substrate 12, a plurality of trenches 20a etched into the substrate 12 are retained as residual structures 20. The trenches 20a that can be referred to as residual structures 20a are "traces" or emulations of the anchoring regions 18a of the preceding support pillars 18 that extend into the substrate 12 after the support pillars 18 in at least one cavity 22 have been etched. Figure 1EAs shown, at least a portion of the support structure 10 and possibly the second sacrificial material layer 24 are removed in order to create a free space 57 between the diaphragm 30 and the substrate 12, while simultaneously removing at least a portion of at least one sacrificial layer 36a and 36b and creating a cavity 59 in the layer stack 34.

[0030] Next, as Figure 1F As reproduced in an image, at least one etch medium inlet 56a and 56b is sealed by means of at least one layer 58a and 58b applied to the side of the layer stack 34 away from the substrate 12, such as at least one additional insulating layer 58a and 58b. However, instead of at least one layer 58a and 58b, a eutectic seal, such as a gold-silicon eutectic, may also be used to seal at least one etch medium inlet 56a and 56b. Similarly, a laser resealing process can be implemented to seal at least one etch medium inlet 56a and 56b by using silicon melted / liquefied by a laser as the sealing material.

[0031] As at least one additional insulating layer 58a and 58b, such as silicon oxide layer 58a, aluminum oxide layer (not shown), and / or silicon nitride layer 58b, particularly silicon-rich silicon nitride layer 58b, can be deposited on layer stack 34. The material of at least one additional insulating layer 58a and 58b can also at least partially fill at least one separation trench 60 structured through layer stack 34 to insulate at least one overlaid via 62 through layer stack 34.

[0032] Optionally, at least one printed conductor 64 may be formed, for example, from aluminum and / or from doped silicon on at least one additional insulating layer 58a and 58b, the aluminum optionally having a component made of silicon and / or copper. At least one printed conductor 64 may be electrically attached to at least one plated via 62 and / or at least one doped region 55 in a support layer 54 via at least one opening structured through at least one additional insulating layer 58a and 58b. To connect the electrical contacts of at least one printed conductor 64, at least one bonding pad 68 may be arranged at / on at at least one printed conductor 64, the bonding pad being composed of layers, layer sequences, layer combinations known in semiconductor technology, and / or a layer sequence composed of germanium, aluminum and germanium (optionally having a component made of silicon and copper), and / or a layer sequence composed of gold and germanium (optionally having a component made of silicon and copper). Optionally, a capping layer 70, such as a capping layer 70 composed of silicon oxide, aluminum oxide, silicon carbide, silicon nitride, and / or silicon-rich silicon nitride, may also be deposited and structured on at least one additional insulating layer 58a and 58b, at least one printed conductor 54, and / or at least one bonding pad 68. Figure 1F The intermediate results are shown in the figure.

[0033] Figure 1G The diagram shows an intermediate product after at least one first etch medium inlet 56a has been exposed on the side of the intermediate product pointing away from the substrate 12. Therefore, at least one first etch medium inlet 56a can also be used later during the use of the micromechanical component as a pressure input line, acoustic input line, or media supply (at least a portion thereof) to the free space 57 between the diaphragm 30 and the substrate 12. In contrast, at least one second etch medium inlet 56b remains closed and is thus protected against intrusion of foreign matter or liquids.

[0034] Figure 1H The diagram illustrates a micromechanical component manufactured following a final optional method step, in which the side of the intermediate product facing away from the substrate 12 is secured to an Application-Specific Integrated Circuit (ASIC) 72 or a printed circuit board. The securing of the intermediate product to the ASIC 72 or the printed circuit board can be achieved using a bonding / wafer bonding process with at least one bonding pad 68 secured to the intermediate product and / or at least one separately arranged bonding surface / connection surface (constructed from, for example, the material of at least one bonding pad 68) and at least one additional bonding pad 74 and / or at least one separately arranged bonding surface / connection surface secured to the ASIC 72 or the printed circuit board. Therefore, as... Figure 1H As shown, in the case of this micromechanical component, the pressure supply section, acoustic supply section, or dielectric supply section 76 extending to the free space 57 also extends between the ASIC 72 or printed circuit board and the layer stack 34. However, the spacing between the ASIC 72 or printed circuit board and the layer stack 34, set during bonding, not only serves the pressure supply section, acoustic supply section, or dielectric supply section 76, but also helps to additionally prevent foreign matter from being introduced into the free space and / or free space 57 between the ASIC 72 or printed circuit board and the layer stack 34. It is not shown in the image, but it is also possible, using flip-chip technology, that intermediate products are secured to the ASIC 72 or printed circuit board using solder balls on bonding pads and / or separately arranged bonding / connection surfaces.

[0035] Figure 2 A schematic diagram of a micromechanical component is shown to illustrate a second embodiment of the manufacturing method.

[0036] In the use of Figure 2In the schematic reproduction of the manufacturing method, the support structure 10 is constructed such that the later, intermediate membrane region 30a of the diaphragm 30 is partially mechanically attached to the substrate 12, however (optionally) it can be electrically insulated from the substrate 12 by means of an electrical insulating portion 26. By thinning the substrate 12, the substrate 12 can be implemented as an "additional diaphragm" that can be mechanically and (optionally) electrically insulated from the diaphragm 30. If, in this case, for example, a first pressure exists in the free space 57 and a second pressure, not equal to the first pressure, exists on the outer side of the substrate 12 pointing away from the free space 57, the pressure difference between the first and second pressures can be determined by the mechanical coupling of the diaphragm 30 and the "additional diaphragm" of the substrate 12.

[0037] about Figure 2 Other method steps of the manufacturing method, refer to the previously described, Figures 1A to 1H The implementation method.

[0038] Figure 3 A schematic diagram of a micromechanical component is shown to illustrate a third embodiment of the manufacturing method.

[0039] With the help of Figure 3 Schematic reproduction manufacturing method and Figures 1A to 1H The difference in the implementation is that the pressure supply to the diaphragm 30 is achieved through at least one channel 56c, which extends through the substrate 12 and enables pressure introduction into the free space 57 between the diaphragm 30 and the substrate 12. Instead of or attached to at least one first etching channel / etching medium inlet 56a, the at least one channel 56c can be used as a pressure supply section, acoustic supply section, or medium supply section 76 to the free space 57.

[0040] Alternatively, at least one channel 56c may be configured as a third etch medium inlet 56c for releasing the diaphragm 30, wherein at least the support structure 10 and possibly at least partially the second sacrificial material layer 24 are removed by means of a first etch medium guided through at least one third etch medium inlet 56c and possibly also through at least one first etch medium inlet 56a, and at least at least partially the sacrificial layers 36a and 36b are removed by means of a first etch medium and / or a second etch medium guided through at least one second etch medium inlet 56b.

[0041] In the manufacturing method described herein, the construction of at least one first etching medium inlet 56a can also be omitted. Figure 3 It can also be seen that when structuring at least one channel 56c through the substrate 12, at least one region 78 of at least one sacrificial layer 36a and 36b can be used as a slotting stop structure.

[0042] about Figure 3 Other method steps of the manufacturing method, refer to the previously described, Figures 1A to 1H The implementation method.

[0043] Figures 4a to 4f show schematic diagrams of intermediate products used to illustrate another embodiment of the micromechanical component.

[0044] Figure 4a is Figure 1D Partial segment. As can be seen in Figure 4a, at the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in free space 57, the gap spacing Δ1 oriented perpendicular to the substrate surface 12a is equal to the sum of the following: the maximum extension dimension of at least one cavity 22 oriented perpendicular to the substrate surface 12a, the first layer thickness of the first sacrificial material layer 14, and the second layer thickness of the second sacrificial material layer 24. Therefore, particles / foreign particles intruding into free space 57 through the gap spacing Δ1 at the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can have a maximum size (Größe) equal to the sum of the following: the maximum extension dimension of at least one cavity 22, the first layer thickness of the first sacrificial material layer 14, and the second layer thickness of the second sacrificial material layer 24.

[0045] In contrast, in the example of Figure 4b, the gap spacing Δ2, oriented perpendicular to the substrate surface 12a, at the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in free space 57, is reduced to the sum of the first layer thickness of the first sacrificial material layer 14 and the second layer thickness of the second sacrificial material layer 24. This is achieved by partially omitting the etched hole 16 through the first sacrificial material layer 14 at the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in free space 57. Therefore, particles penetrating into free space 57 through the gap spacing Δ2 at the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can have a size equal to the sum of the first layer thickness of the first sacrificial material layer 14 and the second layer thickness of the second sacrificial material layer 24.

[0046] In the example of Figure 4c, the gap spacing Δ3, oriented perpendicular to the substrate surface 12a, on the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 into the free space 57, is reduced to the first layer thickness of the first sacrificial material layer 14. This is achieved by partially omitting the etched hole 16 through the first sacrificial material layer 14 on the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in the free space 57, and by partially removing the second sacrificial material layer 24 at the same location. In the embodiment of Figure 4c, only particles whose size is at most equal to the gap spacing Δ3 on the subsequent inlet 80 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can intrude into the free space 57.

[0047] Figure 4d is Figure 3 A portion of the fragment. The gap spacing Δ4, oriented perpendicular to the substrate surface 12a, on the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 extending through the substrate 12 in free space 57, is equal to the sum of: the maximum extension dimension of at least one cavity 22 oriented perpendicular to the substrate surface 12a, the first layer thickness of the first sacrificial material layer 14, and the second layer thickness of the second sacrificial material layer 24. Therefore, particles / foreign matter particles intruding into free space 57 through the gap spacing Δ4 on the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can have a maximum size equal to the sum of: the maximum extension dimension of at least one cavity 22, the first layer thickness of the first sacrificial material layer 14, and the second layer thickness of the second sacrificial material layer 24.

[0048] In the example of Figure 4e, the gap spacing Δ5, oriented perpendicular to the substrate surface 12a, on the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in free space 57, or on the inlet of the channel 56c used as the third etching medium inlet 56c, is equal to the sum of the first layer thickness of the first sacrificial material layer 14 and the second layer thickness of the second sacrificial material layer 24. This is achieved by partially omitting the etch hole 16 through the first sacrificial material layer 14 on the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in free space 57. Therefore, the particles that penetrate into free space 57 through the gap spacing Δ5 on the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can have a maximum size equal to the sum of the first layer thickness of the first sacrificial material layer 14 and the second layer thickness of the second sacrificial material layer 24.

[0049] Finally, in the example of FIG4f, the gap spacing Δ6, oriented perpendicular to the substrate surface 12a, at the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 into the free space 57, is reduced to the first layer thickness of the first sacrificial material layer 14. This is achieved by partially omitting the etched hole 16 through the first sacrificial material layer 14 at the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 in the free space 57, and by partially removing the second sacrificial material layer 24 at the same location. In the embodiment of FIG4f, only particles whose size is at most equal to the gap spacing Δ6 at the subsequent inlet 82 of the pressure supply section, acoustic supply section, or dielectric supply section 76 can intrude into the free space 57.

[0050] In order to (additionally) prevent particles / foreign matter particles on the subsequent inlets 80 or 82 of the pressure supply section, acoustic supply section or media supply section 76 from being introduced into the free space 57, it is also possible to construct at least one grid structure in the pressure supply section, acoustic supply section or media supply section 76.

[0051] In all the manufacturing methods described above, standard processes from semiconductor technology can be used to deposit and structure the individual layers. Furthermore, all of these manufacturing methods can be extended by adding a chemical-mechanical polishing step.

[0052] All of the above-described manufacturing methods are advantageously applicable to the manufacture of sensor devices and microphone devices, particularly capacitive pressure sensors in which the diaphragm 30 or the electrode 42 suspended on the diaphragm 30, together with the counter electrode 38, is used for pressure measurement. Similarly, the micromechanical components manufactured using the above methods can be used as at least a portion of a capacitive acoustic transducer for converting sound waves into electrical signals. Because the diaphragm 30 is advantageously protected by the substrate 12, mechanical damage typically does not occur or is minimally occurring on the diaphragm 30, even if the corresponding intermediate products come into contact with other components (e.g., chucks or processing systems) during the manufacturing process.

[0053] Accordingly, Figure 1H , 2 The micromechanical components of diaphragm 30 can be used as at least a part of sensor and microphone devices, such as capacitive pressure sensors or capacitive acoustic transducers for converting sound waves into electrical signals. With this type of capacitive pressure sensor, very low pressures can be measured, especially because diaphragm 30 can be constructed very delicately without concern for premature mechanical damage to the fragile diaphragm 30. The delicate construction of diaphragm 30 can be achieved, for example, by increasing its diaphragm area and / or by reducing its diaphragm thickness. Furthermore, it should be noted that... Figure 1H, 2 The availability of micromechanical components of 3 is not limited to the uses described herein.

[0054] Figure 1H , 2 Each of the micromechanical components in 3 is configured to have: a substrate 12 and a layer stack 34, the substrate having a substrate surface 12a on which a film made of at least one semiconductor material is spread out such that the film 30 spans at least one free space 57 etched into the substrate surface 12a, the layer stack being deposited on the side of the film 30 facing away from the substrate 12, the layer stack having at least one counter electrode 38, wherein a hole 59 is formed in the layer stack 34 between the film 30 and the at least one counter electrode 38, the film 30 being adjacent to the hole. It can be seen from these features that... Figure 1H , 2 The micromechanical components of 3 are manufactured using one of the manufacturing methods described above.

[0055] This can also be seen from the following content. Figure 1H , 2 The micromechanical components of component 3 are manufactured using one of the aforementioned manufacturing methods: the maximum gap width σ of the free space 57, oriented perpendicular to the substrate surface 12a, is greater than or equal to 5 μm (micrometers). Furthermore, it can also be seen from the following... Figure 1H , 2 The fact that the micromechanical components of 3 are manufactured using one of the aforementioned manufacturing methods results in the retention of multiple trenches 20a etched into the substrate 12 as residual structures 20a of the "preceding" trenches on the side of the free space 57 that points away from the diaphragm 30 and is adjacent to the substrate 12. The trenches 20a / residual structures 20a are "traces" / abformung of the anchoring regions 18a of the preceding support pillars 18 that extend further into the substrate 12 after etching at least one support pillar 18 in the cavity 22. Preferably, the trenches 20a have a height between 0.5 μm and 2 μm (micrometers) oriented perpendicular to the substrate surface 12a, wherein these values ​​should not be interpreted restrictively.

Claims

1. A method for manufacturing micromechanical components, the method comprising the following steps: A support structure (10) is formed on the substrate surface (12a) of the substrate (12) by a first sacrificial material, wherein, The support structure (10) is formed having a first sacrificial material layer (14) made of the first sacrificial material and a plurality of support pillars (18) made of the first sacrificial material, the first sacrificial material layer at least partially covering the substrate surface (12a), the first sacrificial material layer having a plurality of etched holes (16) structured through the first sacrificial material layer (14), and the support pillars extending into the substrate (12). At least one cavity (22) spanned by the support structure (10) is etched into the substrate surface (12a) using an etching medium guided by a plurality of etch holes (16) in the first sacrificial material layer (14), which has higher etch resistance to the etching medium compared to the substrate (12). A film (30) is formed on or above the first sacrificial material layer (14) of the support structure (10) by at least one semiconductor material. A layer stack (34) is deposited on the side of the film (30) that is away from the substrate (12), the layer stack (34) including at least one sacrificial layer (36a, 36b) and at least one counter electrode (38) formed on the side of the at least one sacrificial layer (36a, 36b) that is away from the substrate (12). The diaphragm (30) is released by at least partially removing at least the support structure (10) and the at least one sacrificial layer (36a, 36b).

2. The manufacturing method according to claim 1, wherein, In order to form the support structure (10) on the substrate surface (12a) of the substrate (12) using the first sacrificial material, the following steps are performed: Multiple trenches (20) are structured into the substrate surface (12a) of the substrate (12); The first sacrificial material is deposited on a substrate surface (12a) having a plurality of trenches (20) structured into the substrate surface, such that a plurality of support pillars (18) extending into the substrate (12) are formed by the first sacrificial material filling the plurality of trenches (20), and the substrate surface (12a) is at least partially covered by a subsequent first sacrificial material layer (14) composed of the first sacrificial material; The plurality of etched holes (16) are structured through the first sacrificial material layer (14). The cavity (22) is etched into the substrate surface (12a) through a plurality of etch holes (16) in the first sacrificial material layer (14).

3. The manufacturing method according to claim 1 or 2, wherein, Before the membrane (30) is formed, the first sacrificial material layer (14) is at least partially covered by a second sacrificial material layer (24), which is composed of the first sacrificial material and / or the second sacrificial material, wherein, during the formation of the membrane (30), the second sacrificial material layer (24) is at least partially covered by the membrane (30).

4. The manufacturing method according to claim 1 or 2, wherein, The support structure (10) is formed of silicon dioxide as the first sacrificial material.

5. The manufacturing method according to claim 4, wherein, Prior to the formation of the membrane (30), silicon-rich silicon nitride, silicon carbide and / or aluminum oxide are locally deposited on a first sacrificial material layer (14) made of silicon oxide, on a second sacrificial material layer (24) made of silicon oxide, and / or deposited in at least one opening, the at least one opening being structured by the first sacrificial material layer (14) made of silicon oxide and / or the second sacrificial material layer (24) made of silicon oxide.

6. The manufacturing method according to claim 1 or 2, wherein, In order to release the membrane (30), at least one first etch medium inlet (56a) extending through the layer stack (34), at least one second etch medium inlet (56b) extending only through a portion of the layer stack (34), and / or a channel (56c) extending through the substrate (12) are formed, and at least the support structure (10) and the at least one sacrificial layer (36a, 36b) are at least partially removed by means of at least one etch medium guided through the at least one first etch medium inlet (56a) and / or through the at least one second etch medium inlet (56b) and / or through the at least one channel (56c).

7. The manufacturing method according to claim 1 or 2, wherein, In order to supply pressure to the diaphragm (30), at least one channel (56c) is formed extending through the substrate (12) into the free space (57).

8. The manufacturing method according to claim 1, wherein, The micromechanical components are configured for use in sensor devices.

9. The manufacturing method according to claim 1, wherein, The micromechanical component is configured for use in a microphone device.

10. A micromechanical component manufactured by the manufacturing method according to any one of claims 1 to 9, the micromechanical component comprising: A substrate (12) having a substrate surface (12a) on which a film (30) made of at least one semiconductor material is spread out such that the film (30) spans at least one free space (57) etched into the substrate surface (12a). A layer stack (34) is deposited on the side of the film (30) facing away from the substrate (12), the layer stack having at least one counter electrode (38), wherein, A cavity (59) is constructed in the layer stack (34) between the diaphragm (30) and the at least one counter electrode (38), with the diaphragm (30) adjacent to the cavity. In this context, on the side of the free space (57) that is away from the diaphragm (30) and adjacent to the substrate (12), a plurality of trenches are etched into the substrate (12), wherein the trenches are traces or molds of the anchoring region (18a) of the preceding support post (18) that extends into the substrate (12) after the support post (18) in the at least one cavity (22) is etched.

11. The micromechanical component according to claim 10, wherein, The maximum gap width (σ) of the free space (57) oriented perpendicular to the substrate surface (12a) is greater than or equal to 5 μm.

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