Sensor device with a breathable cover and corresponding manufacturing method

Abstract

Embodiments of the present disclosure relate to a sensor device with a breathable cover and a manufacturing method thereof. The sensor device comprises a sensor chip with a MEMS structure and a breathable cover, wherein the MEMS structure is arranged on the main surface of the sensor chip, the breathable cover is arranged above the main surface of the sensor chip, and the breathable cover covers the MEMS structure and forms a cavity above the MEMS structure.

Description

Technical Field

[0001] The present disclosure relates to a sensor device having a gas-permeable cover and a corresponding manufacturing method. Background Art

[0002] The sensor device may have a MEMS (micro-electromechanical system) structure to detect physical quantities, such as pressure, acceleration, light, gas, etc. The measurement results provided by the sensor device may be distorted in various ways, for example due to dirt particles on the sensitive MEMS structure or thermomechanical stresses between components of the sensor device. Sensor device manufacturers are constantly working on improving their products. In particular, it is desirable to develop a sensor device that takes the above-mentioned problems into account and provides improved measurement results. It may also be desirable to provide a method for manufacturing such a sensor device. Summary of the invention

[0003] A number of different aspects relate to a sensor device. The sensor device comprises a sensor chip having a MEMS structure, wherein the MEMS structure is arranged at a main surface of the sensor chip. The sensor device also comprises a gas permeable cover arranged above the main surface of the sensor chip, the gas permeable cover covering the MEMS structure and forming a cavity above the MEMS structure.

[0004] A number of different aspects relate to a method for manufacturing a sensor device. The method includes producing a semiconductor wafer having a plurality of sensor chips, wherein each sensor chip has a MEMS structure arranged at a main surface of the semiconductor wafer. The method also includes forming a plurality of gas permeable covers above the main surface of the semiconductor wafer, wherein each gas permeable cover covers one of the MEMS structures and forms a cavity above the MEMS structure. The method also includes separating the semiconductor wafer into a plurality of sensor devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The device and method according to the present disclosure are explained in more detail below with the aid of the drawings. The elements shown in the drawings are not necessarily drawn to scale relative to each other. The same reference numerals may identify the same components.

[0006] Figure 1 contains Figures 1A to 1F , which schematically illustrates a method for manufacturing a sensor device 100 according to the present disclosure.

[0007] Figure 2 A side cross-sectional view of a sensor device 200 according to the present disclosure is shown.

[0008] Figure 3 A side cross-sectional view of a sensor device 300 according to the present disclosure is shown.

[0009] Figure 4 A side cross-sectional view of a sensor device 400 according to the present disclosure is shown.

[0010] Figure 5 A side cross-sectional view of a sensor device 500 according to the present disclosure is shown.

[0011] Figure 6 A side cross-sectional view of a sensor device 600 according to the present disclosure is shown.

[0012] Figure 7 A side cross-sectional view of a sensor device 700 according to the present disclosure is shown.

[0013] Figure 8 contains Figures 8A to 8E , which schematically illustrates a method for manufacturing a sensor device 800 according to the present disclosure.

[0014] Fig. 9 A flow chart of a method for manufacturing a sensor device according to the present disclosure is shown. DETAILED DESCRIPTION

[0015] The accompanying drawings described below illustrate sensor devices and methods for manufacturing sensor devices according to the present invention. Here, the described devices and methods can be presented in a general manner in order to qualitatively describe aspects of the present disclosure. The described devices and methods may have other aspects, which may not be shown in the corresponding drawings for simplicity. However, the corresponding examples can be expanded with aspects described in combination with other examples according to the present disclosure. Therefore, the embodiments for a specific figure can be equally applicable to the examples of other figures.

[0016] exist Figure 1A In the side cross-sectional view of , a sensor chip 2 having an upper main surface 4 and an opposite lower main surface 6 can be provided. One or more MEMS structures 8 can be arranged on the upper main surface 4. Furthermore, electrical contacts 12 of the sensor chip 2 and a passivation layer 10 can be arranged at the upper main surface 4. The MEMS structure 8 can be surrounded by one or more trenches 14.

[0017] The sensor chip 2 may be a semiconductor chip, which may be made of silicon, for example. The MEMS structure 8 may be integrated into the sensor chip 2 and may also be referred to as a MEMS unit. In particular, the MEMS structure 8 may be integrated into the semiconductor material of the sensor chip 2. Figure 1A In the figure, a MEMS structure 8 in the form of a membrane is exemplarily shown. More generally, the MEMS structure 8 may include one or more of the following: a bridge, a membrane, a cantilever, a rod, a tongue-like structure, a comb-like structure, etc. The sensor chip 2 may be designed to detect one or more physical quantities, such as pressure, acceleration, temperature, humidity, etc. Examples of sensors are pressure sensors, tire pressure sensors, acceleration sensors, gas sensors, air humidity sensors, etc.

[0018] The passivation layer 10 can be designed to protect the portion of the sensor chip 2 arranged below the passivation layer from external influences. For example, the passivation layer 10 can be made of one or more of the following: nitride, imide or polyimide. The passivation layer 10 can be considered as part of the sensor chip 2, or it can not be considered as part of the sensor chip. The electrical contacts 12 can be electrically coupled to the internal electronic structure of the sensor chip 2 and provide contact connection of the electronic structure. For simplicity, in Figure 1A The electrical connection between the electrical contacts 12 and the electronic structure of the sensor chip 2 is not shown. Figure 1A In the exemplary illustration of FIG. 1 , the electrical contact 12 may be arranged on the passivation layer 10 . In other examples, the electrical contact 12 may be at least partially embedded in the passivation layer 10 .

[0019] The grooves 14 can extend from the upper main surface 4 of the sensor chip 2 into the semiconductor material of the sensor chip 2, respectively. The width of the grooves 14 in the x-direction and / or the y-direction can be in the range of about 5 micrometers to about 20 micrometers, respectively. The depth of the grooves 14 in the z-direction can be in the range of about 80 micrometers to about 120 micrometers. When viewed in the z-direction, the grooves 14 can at least partially surround the MEMS structure 8. Here, when viewed in the z-direction, the individual grooves 14 can be formed in an L-shape, respectively. The L-shapes of the grooves 14 can be staggered with each other and form a staggered overall structure that can surround the MEMS structure 8. Here, in particular, the individual L-shapes cannot touch each other, that is, the staggered overall structure cannot form a closed curve in particular.

[0020] During the manufacturing process of the sensor device to be produced or during the subsequent operation, thermomechanical stresses may occur between the components of the device. For example, such stresses may occur during thermal cycling. The grooves 14 can absorb the thermomechanical stresses or the resulting bending, so that the stress-sensitive MEMS structure 8 is substantially free from mechanical stresses. Therefore, the distortion of the measurement results due to thermomechanical stresses can be avoided or at least reduced by the grooves 14.

[0021] exist Figure 1BIn the side cross-sectional view of the MEMS structure 8, a sacrificial layer 16 can be arranged or deposited above the MEMS structure 8. For example, the sacrificial layer 16 can be made of at least one of the following: photoresist, PMGI (polymethyl glutarimide), etc. The thickness of the sacrificial layer 16 in the z direction can be in the range of about 0.5 microns to about 50 microns. A material layer 18 can be arranged or deposited on the sacrificial layer 16. Generally, the material layer 18 can be made of a structurable material. More precisely, the material layer 18 can be made of a photoformable material, especially a material that can be structured based on a photolithography process. For example, the material layer 18 can be made of at least one of the following: photoresist, polyimide, PBO (polybenzoxazole), etc. First, the material layer 18 can be uniformly deposited above the sacrificial layer 16, and here, the material layer mechanically contacts the sacrificial layer 16 and the passivation layer 10. The deposited material layer 18 can then be structured by a suitable process, in particular by a photolithography process.

[0022] exist Figure 1C In the side cross-sectional view of , the sacrificial layer 16 can be removed, for example, by at least one of the following: a wet chemical process, a wet chemical washing process, an ashing process, etc. After removing the sacrificial layer 16, the structured material layer 18 can form a gas permeable cover 20 arranged above the upper main surface 4 of the sensor chip 2. The term "cover" can optionally be replaced by the term "film" or "diaphragm". The gas permeable cover 20 can cover the MEMS structure 8 and form a cavity 22 above the MEMS structure 8. Figure 1C In the example of FIG. 1 , the groove 14 may be arranged outside the outline of the gas permeable cover 20 when viewed in the z direction. According to the above, the cover 20 may be made of at least one of the following: photoresist, polyimide, polybenzoxazole, and the like.

[0023] As Figure 1B As a result of the above-mentioned structuring of the material layer 18 in the gas permeable cover 20, the gas permeable cover 20 may have a plurality of openings 24. Here, the maximum size of each opening 24 may be less than about 5 micrometers. In one example, the minimum size may be about 0.1 micrometer. The gas permeable cover 20 can cover the MEMS structure 8 and thereby prevent particles from reaching the MEMS structure 8 and contaminating it. Since the openings 24 have the mentioned dimensions, particles with a diameter greater than 5 micrometers can in particular be prevented from contaminating the MEMS structure 8. During the manufacture of the sensor device to be produced and during the later operation of the manufactured sensor device, there may be a risk of contamination by foreign particles. By using the cover 20, distortion of the measurement results can be prevented or at least reduced.

[0024] The cover 20 may be gas-permeable, in particular air-permeable, due to the openings 24 formed in the cover 20. If the sensor device to be produced is, for example, a pressure sensor, the openings 24 may enable the MEMS structure 8 to detect the pressure or pressure changes of the gas surrounding the device. Thus, it may also be referred to as a pressure-permeable cover 20.

[0025] Figure 1D The perspective cross-sectional view of FIG. 1 shows an exemplary more specific structure of the breathable cover 20. In particular, the Figure 1C The arrangement is located in a portion between the grooves 14. Figure 1D In the example of the embodiment, the cover 20 can have dozens of openings 24, which can be substantially circular. In other examples, the number and shape of the openings 24 can be selected differently.

[0026] exist Figure 1E In the side cross-sectional view of , an electrical rewiring layer (or redistribution layer) 26 can be formed above the upper side of the sensor chip 2. The rewiring layer 26 can include one or more conductor tracks 28 in the form of metal layers or metal traces, which can extend substantially parallel to the upper side of the sensor chip 2. The conductor tracks 28 can be made of copper or a copper alloy, for example. One or more dielectric layers 30 can be arranged between the conductor tracks 28 to electrically insulate the conductor tracks 28 from each other. The dielectric layer 30 can be made of oxide and / or nitride, for example. The metal layers or conductor tracks 28 arranged on different xy planes can be electrically connected to each other, for example, through a plurality of vias. The conductor tracks 28 of the rewiring layer 26 can realize the function of redistribution or rewiring so that the electrical contacts 12 of the sensor chip 2 are available at other locations on the upper side of the arrangement. Here, the exposed sections of the conductor tracks 28 can form one or more electrical contact areas 32, which can be electrically connected to the electrical contacts 12 of the sensor chip 2.

[0027] exist Figure 1F In the side cross-sectional view, it can be reversed Figure 1E Furthermore, peripheral connection elements 34 can be arranged on the electrical contact surfaces 32 and electrically coupled to them. Figure 1F In the example of , the peripheral connection element 34 can be formed in the form of a solder deposit (or solder element or solder ball). The peripheral connection element 34 can be designed to electrically and mechanically couple the sensor device 100 to a circuit board (not shown). The sensor device 100 can be mounted on the circuit board via the peripheral connection element 34, for example, by means of a soldering process.

[0028] The outline of the sensor chip 2 viewed in the z-direction may be substantially identical to the outline of the sensor device 100. Thereby, a smaller or smallest form factor of the sensor device 100 may be achieved. The sensor device 100 may be a chip-level device, a chip-size device, a chip-scale package (CSP), or a chip-size package. In particular, the sensor device 100 may be a BGA (ball grid array) device, a BGA package, an LGA (land grid array) device, or an LGA package.

[0029] For the sake of simplicity, in the exemplary method of FIG. 1 , only the production of one sensor device 100 is shown and described. In practice, the method of FIG. 1 may be performed at the wafer level or in batch form. Here, one or more of the method steps described may be performed at the wafer level. The sensor device 100 may therefore also be referred to as a wafer-level device or a wafer-level package. For example, in the method performed at the wafer level, a semiconductor wafer having a plurality of sensor chips 2 may also be processed in parallel, that is, a plurality of MEMS structures 8 may be formed in parallel above the corresponding sensor chips 2, a plurality of gas permeable covers 20 may be manufactured above the corresponding MEMS structures 8, and so on. Figures 1A to 1F After the method steps, the semiconductor wafer can be separated into a plurality of sensor devices 100 by a separation process. In this case, for example, a mechanical cutting process and / or a stealth cutting process can be used. It should be noted that all other methods described herein according to the present disclosure can also be performed at least partially on the wafer level.

[0030] Figure 2 The sensor device 200 of FIG. 1 may be at least partially similar to the sensor device 100 of FIG. 1 and have similar components. Figure 2 The breathable cover 20 in the embodiment may be implemented in other ways. Here, the cover 20 may be made of at least one of the following: a semiconductor material, a glass material, or a ceramic material. The cover 20 may be an electrically passive structure and does not have to realize an electrical function. Figure 2 In the example of FIG. 2 , the cover 20 may have substantially the same dimensions in the x-direction and / or the y-direction as the sensor chip 2 . The groove 14 may be arranged within the contour of the gas-permeable cover 20 , viewed in the z-direction.

[0031] Similar to the method of Figure 1, the sensor device 200 can be manufactured in particular at the wafer level. Here, a semiconductor wafer can be provided that can have multiple sensor chips 2 with MEMS structures 8. In addition, a wafer with multiple recesses can be provided, which can be made of at least one of the following: semiconductor material, glass material or ceramic material. In a specific example, the wafer can be a silicon wafer or a glass wafer. The wafer with recesses can be bonded to a MEMS semiconductor wafer, wherein the recess is arranged above the MEMS structure 8 and forms a cavity 22. An opening 24 can be formed in the bottom surface of the recess. The recess and the opening 24 can be made, for example, by an etching process. Finally, the arrangement of the bonded wafers can be separated into multiple sensor devices 200 during the separation process.

[0032] Therefore, the connection between the sensor chip 2 and the cover 20 can be in the form of wafer bonding. Depending on the materials of the sensor chip 2 and the cover 20, different wafer bonding techniques can be used here. In one example, wafer bonding can be involved without the use of an intermediate layer. In this case, direct bonding or anodic bonding can be involved in particular. In another example, wafer bonding with the use of an intermediate layer can be involved. In particular, glass paste bonding, brazing, eutectic bonding, thermocompression bonding or adhesive bonding can be involved. For example, the wafer bonding between the sensor chip 2 and the cover 20 can correspond to silicon-silicon bonding or silicon-glass bonding. It should be noted in this case that for illustrative reasons, Figure 2 The wafer bonding described is not shown in FIG. 2 , but rather a display solution is chosen in which the passivation layer 10 is arranged between the semiconductor material of the sensor chip 2 and the cap 20 .

[0033] In contrast to Figure 1, Figure 2 In the embodiment of the present invention, a redistribution layer 26 can be formed above a main surface 6 of the sensor chip 2, which is opposite to the main surface 4 with the MEMS structure 8. The sensor device 200 can have one or more conductive vias 36, which extend from the upper main surface 4 through the sensor chip 2 to the lower main surface 6, and the conductive vias can electrically couple the electrical contacts 12 of the sensor chip 2 and the redistribution layer 26 to each other. The conductive vias 36 can be TSVs (through silicon vias) in particular.

[0034] Figure 3 The components of the sensor device 300 may be at least partially similar to the sensor devices described previously. Figure 2 On the contrary, Figure 3In the embodiment of the present invention, a rewiring layer 26 may be arranged on a main surface of the gas permeable cover 20 facing away from the sensor chip 2. The sensor device 300 may have one or more conductive vias 38 extending from the top side of the cover 20 to the bottom side of the cover 20, which electrically couple the electrical contacts 12 of the sensor chip 2 and the rewiring layer 26 to each other. If the cover 20 is made of silicon, the electrical vias 38 may be TSVs (Through Silicon Vias).

[0035] The sensor device 300 may have an elastic layer 40 arranged between the sensor chip 2 and the gas permeable cover 20. The elasticity of the elastic layer 40 may be greater than the elasticity of the sensor chip 2. Therefore, the elastic layer 40 may be designed to absorb thermomechanical stresses that may occur, for example, between the sensor chip 2 and the cover 20. In one example, the elastic layer 40 may be made of nitride. In particular, the elastic layer 40 may be provided when it is not effective enough to free the MEMS structure 8 from thermomechanical stresses via the grooves 14. In one example, the sensor chip 2 and the gas permeable cover 20 may mechanically contact the elastic layer 40. The passivation layer 10 described in the previous example may also be present, but for simplicity, it is not shown here. Figure 3 The passivation layer 10 can, for example, be arranged between the semiconductor material of the sensor chip 2 and the elastic layer 40 .

[0036] Figure 4 The sensor device 400 may have components at least partially similar to the sensor devices described previously. Furthermore, the sensor device 400 may have an encapsulation material 42 arranged above the main surface 4 of the sensor chip 2. The gas-permeable cover 20 may be at least partially embedded in the encapsulation material 42, wherein the opening 24 of the cover 20 may remain uncovered by the encapsulation material 42, so that the cover 20 is still gas-permeable. Figure 4 In the example of FIG. 4 , the encapsulation material 42 may cover the side surface of the cover 20, and the encapsulation material 42 may not cover the lower surface of the cover 20. Compared with the previous example, Figure 4 The cover 20 in FIG. 2 can have a smaller size.

[0037] The packaging material 42 can be manufactured by a molding process. In particular, the packaging material 42 can be manufactured based on one or more of the following technologies: compression molding, injection molding, powder molding, liquid molding, etc. The mentioned technologies can be performed in the production of the sensor device 400, especially at the wafer level. The molded connection portion forming the packaging material 42 may include at least one of the following: epoxy resin, filled epoxy resin, glass fiber filled epoxy resin, imide, thermoplastic plastic, thermosetting polymer, polymer mixture.

[0038] The sensor device 400 may have a rewiring layer 26 arranged over the lower main surface of the encapsulation material 42. Figure 4 In the example of , the lower surface of the cover 20 may be partially covered by the redistribution wiring layer 26. The sensor device 400 may have one or more conductive vias 44, which extend from the upper side of the packaging material 42 through the packaging material 42 to the lower side of the packaging material 42. The conductive vias 44 can be made of, for example, "copper pillar bumps" or "pillar bumps", which can be produced, for example, by an electroplating process. In one example, the conductive vias 44 can be encapsulated by the packaging material 42 during the molding process and can be exposed again on their lower side after the packaging material 42 is ground off. The redistribution wiring layer 26 can be electrically coupled to the electrical contacts 12 of the sensor chip 2 via the conductive vias 44. Therefore, with the help of additional peripheral connection elements 34, the internal electronic structures of the sensor chip 2 can be electrically contacted.

[0039] exist Figure 4 In the example of , the breathable cover 20 can be mechanically connected to the passivation layer 10. In this case, the passivation layer 10 can in particular be a polyimide layer. In this case, the mechanical connection can be provided in any manner, for example by an adhesive. Figure 4 In the example of FIG. 5 , the groove 14 viewed in the z-direction may be arranged within the contour of the gas-permeable cover 20 .

[0040] Figure 5 The sensor device 500 may be at least partially connected to Figure 4 Similar to the sensor device 400 of Figure 4 In contrast, the gas-permeable cap 20 can be mechanically connected to the semiconductor material of the sensor chip 2. Thus, the cap 20 and the sensor chip 2 can be connected to one another, for example, via a silicon-silicon connection.

[0041] Figure 6 The sensor device 600 may be at least partially connected to Figure 4 Similar to the sensor device 400 of Figure 4 The difference is that in Figure 6 In the example of FIG. 5 , the groove 14 may be arranged outside the contour of the gas-permeable cover 20 as viewed in the z-direction.

[0042] Figure 7 The sensor device 700 may be at least partially connected to Figure 5 Similar to the sensor device 500 of Figure 5 The difference is that in Figure 7 In the example of FIG. 5 , the groove 14 may be arranged outside the contour of the gas-permeable cover 20 as viewed in the z-direction.

[0043] exist Fig. 8AIn the side cross-sectional view of , the sensor chip 2 may be provided with one or more MEMS structures 8 . Fig. 8A The method steps can be Figure 1A The method steps are similar.

[0044] exist Figure 8B The method steps shown in the side cross-sectional view can be at least partially related to Figure 1B The method steps are similar to those of . The sacrificial layer 16 may be arranged or deposited above the MEMS structure 8 . The sacrificial layer 16 may be made of, for example, at least one of the following: photoresist, PMGI, etc. The sacrificial layer 16 may cover a portion of the passivation layer 10 and the MEMS structure 8 .

[0045] exist Figure 8C In the side cross-sectional view of FIG. 1 , a rewiring layer 26 may be formed over the upper side of the sensor chip 2 and the sacrificial layer 16 . The rewiring layer 26 may be similar to the rewiring layer of the previous example. Figure 8C In the example of FIG. 1 , the dielectric material 30 of the rewiring layer 26 may be deposited and structured over the sacrificial layer 16. When the dielectric material 30 is structured, a plurality of openings 24 may be formed.

[0046] exist Fig.8D The method steps shown in the side cross-sectional view can be Figure 1C The method steps are at least partially similar. Here, the sacrificial layer 16 can be removed, for example, by at least one of the following: a wet chemical process, a wet chemical washing process, an ashing process, etc. After removing the sacrificial layer 16, a part of the rewiring layer 26 can form a gas-permeable cover 20 arranged above the upper side of the sensor chip 2. Here, the cover 20 can in particular be made of a dielectric material 30 of the rewiring layer 26. The cover 20 can cover the MEMS structure 8 and form a cavity 22 above the MEMS structure 8. By means of the above-mentioned structuring of the dielectric material 30 of the rewiring layer 26, the gas-permeable cover 20 can have a plurality of openings 24. The openings 24 can provide a (fluidic) gas connection between the MEMS structure 8 and the environment of the sensor device. Fig.8D The cover 20 may have a similar structure to the previously described covers. Fig.8D In the example of FIG. 5 , the groove 14 may be arranged outside the contour of the gas-permeable cover 20 as viewed in the z-direction.

[0047] exist Fig. 8E The method steps shown in the side cross-sectional view can be Figure 1F The method steps are at least similar.

[0048] Fig. 9 The method is shown in an overall manner and should describe the main aspects of the method according to the present disclosure. The method may have Fig. 9The methods of Figures 1 and 8 may be viewed as more detailed implementations of the method of Figure 1 .

[0049] At 46, a semiconductor wafer having a plurality of sensor chips may be produced, wherein each sensor chip has a MEMS structure arranged at a main surface of the semiconductor wafer. At 48, a plurality of gas permeable covers may be formed over the main surface of the semiconductor wafer, wherein each gas permeable cover covers one of the MEMS structures and forms a cavity over the MEMS structure. At 50, the semiconductor wafer may be separated into a plurality of sensor devices.

[0050] Example

[0051] A sensor device and a method for producing a sensor device are explained below using examples.

[0052] Example 1 is a sensor device, comprising: a sensor chip having a MEMS structure 8, wherein the MEMS structure is arranged at a main surface of the sensor chip; and a gas permeable cover arranged above the main surface of the sensor chip, the gas permeable cover covering the MEMS structure and forming a cavity above the MEMS structure.

[0053] Example 2 is a sensor device according to Example 1, wherein the gas permeable cover has a plurality of openings, and a maximum dimension of each opening is less than 5 micrometers.

[0054] Example 3 is the sensor device of example 1 or 2, wherein the gas permeable cover is made of at least one of: a photoresist, a polyimide, or a polybenzoxazole.

[0055] Example 4 is the sensor device according to example 1 or 2, wherein the gas permeable cover is made of at least one of the following: a semiconductor material, a glass material, or a ceramic material.

[0056] Example 5 is the sensor device according to any of the preceding examples, wherein in a top view of the major surface of the sensor chip, an outline of the sensor chip is substantially the same as an outline of the sensor device.

[0057] Example 6 is a sensor device according to any of the preceding examples, further comprising: a plurality of trenches, the trenches respectively extending from the main surface of the sensor chip into the semiconductor material of the sensor chip, and in a top view of the main surface of the sensor chip, the trenches surround the MEMS structure.

[0058] Example 7 is the sensor device according to Example 6, wherein the groove is arranged outside the outline of the gas permeable cover in a top view of the main surface of the sensor chip.

[0059] Example 8 is the sensor device according to Example 6, wherein the groove is arranged within the outline of the gas permeable cover in a top view of the major surface of the sensor chip.

[0060] Example 9 is a sensor device according to any one of the preceding examples, the sensor device further comprising: a rewiring layer electrically coupling electrical contacts of the sensor chip with peripheral connection elements of the sensor device, wherein the rewiring layer is arranged above a main surface of the sensor chip, above a main surface of the sensor chip opposite to the main surface of the sensor chip, or above a main surface of the cover.

[0061] Example 10 is the sensor device according to Example 9, wherein the breathable cover is fabricated from a portion of the rewiring layer.

[0062] Example 11 is a sensor device according to any of the preceding examples, the sensor device further comprising: a conductive via extending through the sensor chip, the conductive via electrically coupling an electrical contact of the sensor chip with a peripheral connection element of the sensor device.

[0063] Example 12 is a sensor device according to any of the preceding examples, the sensor device further comprising: conductive vias extending through the gas permeable cover, the conductive vias electrically coupling electrical contacts of the sensor chip with peripheral connection elements of the sensor device.

[0064] Example 13 is a sensor device according to any of the preceding examples, the sensor device further comprising: a packaging material arranged over the major surface of the sensor chip, wherein the gas permeable cover is at least partially embedded in the packaging material.

[0065] Example 14 is a sensor device according to Example 13, the sensor device further comprising: conductive vias extending through the packaging material, the conductive vias electrically coupling electrical contacts of the sensor chip with peripheral connection elements of the sensor device.

[0066] Example 15 is a sensor device according to any of the preceding examples, wherein the gas permeable cover is mechanically connected to the semiconductor material of the sensor chip.

[0067] Example 16 is the sensor device according to any one of Examples 1 to 14, wherein the gas permeable cover 20 is mechanically connected to the polyimide layer disposed over the major surface of the sensor chip.

[0068] Example 17 is a sensor device according to any one of the preceding examples, the sensor device further comprising: an elastic layer arranged between the sensor chip and the breathable cover, wherein the sensor chip and the breathable cover are in mechanical contact with the elastic layer, and the elasticity of the elastic layer is greater than the elasticity of the sensor chip.

[0069] Example 18 is a sensor device according to any one of the preceding examples, wherein the sensor chip 2 is designed to detect a pressure signal.

[0070] Example 19 is a method for manufacturing a sensor device, wherein the method includes: producing a semiconductor wafer having a plurality of sensor chips, wherein each sensor chip has a MEMS structure arranged at a main surface of the semiconductor wafer; forming a plurality of breathable covers above the main surface of the semiconductor wafer, wherein each breathable cover covers one of the MEMS structures and forms a cavity above the MEMS structure; and separating the semiconductor wafer into a plurality of sensor devices.

[0071] Example 20 The method according to Example 19, wherein forming multiple breathable covers and cavities includes: producing a wafer having multiple recesses, wherein the wafer is made of at least one of the following: a semiconductor material, a glass material, or a ceramic material; and bonding the wafer to a semiconductor wafer, wherein the recesses are arranged above the MEMS structure and form cavities.

[0072] Example 21 is a method according to Example 19, wherein forming multiple breathable covers and cavities includes: forming multiple sacrificial layers above the MEMS structure; forming multiple material layers above the multiple sacrificial layers; structuring the material layers to form breathable covers; and removing the sacrificial layers to form cavities.

[0073] Example 22 is the method according to Example 21, wherein structuring the material layer includes a photolithography process.

[0074] Example 23 is a method according to Example 19, wherein forming multiple breathable covers and cavities includes: forming multiple sacrificial layers above the MEMS structure; forming a rewiring layer above the multiple sacrificial layers, wherein the breathable covers are formed; and removing the sacrificial layers, wherein the cavities are formed.

[0075] Although specific embodiments are shown and described herein, it will be apparent to those skilled in the art that various alternative and / or equivalent implementations may replace the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptation or variation of the specific embodiments discussed herein. Therefore, it is intended that the present disclosure be limited only by the claims and their equivalents.

Claims

1. A sensor device, comprising: A sensor chip (2) having a MEMS structure (8), wherein the MEMS structure (8) is arranged at a main surface (4) of the sensor chip (2); and A gas-permeable cover (20) is arranged above the main surface (4) of the sensor chip (2), the gas-permeable cover covers the MEMS structure (8) and forms a cavity (22) above the MEMS structure (8).

2. The sensor device according to claim 1, wherein the gas-permeable cover (20) has a plurality of openings (24), and the maximum dimension of each opening (24) is less than 5 micrometers.

3. The sensor device according to claim 1 or 2, wherein the gas-permeable cover (20) is made of at least one of the following: photoresist, polyimide or polybenzoxazole.

4. The sensor device according to claim 1 or 2, wherein the gas-permeable cover (20) is made of at least one of the following: a semiconductor material, a glass material or a ceramic material.

5. The sensor device according to any of the preceding claims, wherein in a top view of the main surface (4) of the sensor chip (2), an outline of the sensor chip (2) is substantially identical to an outline of the sensor device.

6. The sensor device according to any one of the preceding claims, further comprising: A plurality of trenches (14) extend from the main surface (4) of the sensor chip (2) into the semiconductor material of the sensor chip (2) and surround the MEMS structure (8) in a top view of the main surface (4) of the sensor chip (2).

7. The sensor device according to claim 6, wherein, in a plan view of the main surface (4) of the sensor chip (2), the groove (14) is arranged outside the contour of the gas-permeable cover (20).

8. The sensor device according to claim 6, wherein, in a plan view of the main surface (4) of the sensor chip (2), the groove (14) is arranged within the contour of the gas-permeable cover (20).

9. The sensor device according to any one of the preceding claims, further comprising: a redistribution layer (26) which electrically couples the electrical contacts (12) of the sensor chip (2) to peripheral connection elements (34) of the sensor device, The rewiring layer (26) is arranged above the main surface (4) of the sensor chip (2), above a main surface (6) of the sensor chip (2) opposite to the main surface (4) of the sensor chip (2), or above a main surface of the cover (20).

10. The sensor device according to claim 9, wherein the gas-permeable cover (20) is produced from a portion of the rewiring layer (26).

11. The sensor device according to any one of the preceding claims, further comprising: A conductive via (36) extends through the sensor chip (2), the conductive via electrically coupling an electrical contact (12) of the sensor chip (2) to a peripheral connection element (34) of the sensor device.

12. The sensor device according to any one of the preceding claims, further comprising: Conductive vias (38) extend through the gas-permeable cover (20) and electrically couple electrical contacts (12) of the sensor chip (2) to peripheral connection elements (34) of the sensor device.

13. The sensor device according to any one of the preceding claims, further comprising: An encapsulation material (42) is arranged above the main surface (4) of the sensor chip (2), wherein the gas-permeable cover (20) is at least partially embedded in the encapsulation material (42).

14. The sensor device according to claim 13, further comprising: Conductive vias (44) extend through the encapsulation material (42), the conductive vias electrically coupling electrical contacts (12) of the sensor chip (2) with peripheral connection elements (34) of the sensor device. 15 . The sensor device as claimed in claim 1 , wherein the gas-permeable cap ( 20 ) is mechanically connected to the semiconductor material of the sensor chip ( 2 ). 16 . The sensor device according to claim 1 , wherein the gas-permeable cover ( 20 ) is mechanically connected to a polyimide layer arranged over the main surface ( 4 ) of the sensor chip ( 2 ).

17. The sensor device according to any one of the preceding claims, further comprising: An elastic layer (40) is arranged between the sensor chip (2) and the air-permeable cover (20), wherein the sensor chip (2) and the air-permeable cover (20) are in mechanical contact with the elastic layer (40), and the elasticity of the elastic layer (40) is greater than the elasticity of the sensor chip (2).

18. The sensor device according to any of the preceding claims, wherein the sensor chip (2) is designed to detect a pressure signal.

19. A method for manufacturing a sensor device, wherein the method comprises: Producing a semiconductor wafer having a plurality of sensor chips (2), wherein each sensor chip (2) has a MEMS structure (8) arranged at a main surface (4) of the semiconductor wafer; forming a plurality of gas-permeable covers (20) above the main surface (4) of the semiconductor wafer, wherein each gas-permeable cover (20) covers one of the MEMS structures (8) and forms a cavity (22) above the MEMS structure (8); and The semiconductor wafer is separated into a plurality of sensor devices.

20. The method of claim 19, wherein forming a plurality of air-permeable covers (20) and cavities (22) comprises: Producing a wafer having a plurality of recesses, wherein the wafer is made of at least one of: a semiconductor material, a glass material, or a ceramic material; as well as The wafer is wafer bonded to the semiconductor wafer, wherein the recess is arranged above the MEMS structure (8) and forms the cavity (22).

21. The method of claim 19, wherein forming a plurality of air-permeable covers (20) and cavities (22) comprises: forming a plurality of sacrificial layers (16) above the MEMS structure (8); forming a plurality of material layers (18) above the plurality of sacrificial layers (16); structuring the material layer (18) wherein the air-permeable cover (20) is formed; as well as The sacrificial layer (16) is removed, wherein the cavity (22) is formed.

22. The method according to claim 21, wherein structuring the material layer (18) comprises a photolithographic process.

23. The method of claim 19, wherein forming a plurality of air-permeable covers (20) and cavities (22) comprises: forming a plurality of sacrificial layers (16) above the MEMS structure (8); forming a rewiring layer (26) over the plurality of sacrificial layers (16), wherein the gas-permeable cover (20) is formed; as well as The sacrificial layer (16) is removed, wherein the cavity (22) is formed.

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