WO2024042064A1

WO2024042064A1 - Self-curing concrete as new material for microsystems

Info

Publication number: WO2024042064A1
Application number: PCT/EP2023/073007
Authority: WO
Inventors: Achim Bittner; Alfons Dehé
Original assignee: Hahn-Schickard-Gesellschaft Für Angewandte Forschung E. V.
Priority date: 2022-08-23
Filing date: 2023-08-22
Publication date: 2024-02-29

Abstract

The invention relates to a semiconductor component comprising a MEMS element and/or an electronic circuit, wherein the MEMS element and/or the electronic circuit is formed on or in a base substrate. The semiconductor component is characterised in that it comprises a concrete material. Thus one or more components of the semiconductor component can comprise the concrete material, such as the base substrate, an insulation layer and/or a protective casing. The invention also relates to a method for producing the semiconductor component.

Description

SELF-HARDING CONCRETE AS A NEW MATERIAL FOR MICROSYSTEMS

DESCRIPTION

The invention relates to a semiconductor component comprising a MEMS element and/or an electronic circuit, wherein the MEMS element and/or the electronic circuit is present on or in a base substrate. The semiconductor component is characterized in that it has a concrete material. One or more components of the semiconductor component can include the concrete material, such as. B. the base substrate, an insulating layer and / or a protective cover.

The invention further relates to a method for producing the semiconductor component.

Background and state of the art

It is known that a large number of components can be constructed using semiconductor technology methods. Such components are also referred to as semiconductor components. Semiconductor components can in particular have structures which have sizes and dimensions in the micrometer range. If a mechanical microstructure is combined with an electrical circuit, it is also referred to as a so-called MEMS (microelectromechanical system), MEMS component, MEMS system or MEMS element.

MEMS elements can combine logic elements and micromechanical structures on one chip. Their ability to process and/or generate mechanical and electrical signals makes them ideal for a variety of applications, such as: B. for sensors, actuators, filters and/or oscillators.

Today, MEMS elements form an important technical basis for solutions in microelectronics. Compared to conventional macro systems, they offer advantages primarily in cost savings through low consumption of materials and/or possible parallel production, as well as in efficiency, which is made possible by lower energy and power requirements.

The choice of material for its components is a relevant factor for the functionality and process for producing a semiconductor component. In this regard, various materials have proven themselves in the state of the art and have individual advantages.

Fedder (2003) provides an overview of known materials for micromechanical applications, classifying them into five main categories, namely structural materials, substrate materials, spacer materials, surface materials and active materials. The structural material and the substrate material, which may be one and the same, must be able to withstand different process steps. The relevant properties of the structural material include the elastic modulus, density, residual stress and stress gradients, electrical and thermal conductivity, and the long-term stability of these properties. Spacer materials are typically etched away in whole or in part to expose the microstructure and are often used for this function referred to as sacrificial materials or sacrificial layers. Spacer materials can also be used to make molds for structures. Area or surface materials or insulation materials can be used to protect the substrate or the structural material from certain etching steps. Surface materials are also important to achieve electrical insulation. Active materials are applied to structures to exploit their special physical properties or effects to generate and/or read a signal. Common physical properties and/or effects used are piezoelectric effects.

In the context of microsystem technology, silicon and/or gallium arsenide are particularly frequently used as materials for (base) substrates. The materials mentioned have proven particularly useful in that sensor elements and/or actuator elements can be provided from the material. Furthermore, silicon and gallium arsenide are comparatively inexpensive as semiconductor materials and can be manufactured and/or packaged using established processes. In particular, doping can significantly improve their electrical conductivity. Regarding the possibilities of improving the function of a semiconductor component with regard to the selection and/or processing of semiconductor materials, reference can be made to Rahman (2014).

Other materials, such as B. Quartz, Pyrex, polymers, ceramics and/or plastics can be used as substrates in semiconductor technology and/or microsystem technology. Such materials can also be used as so-called packaging or package substrates to enable MEMS elements to be wrapped and thus ensure particularly good protection.

With regard to the insulation materials or insulation layers, various materials have also proven successful. The dielectric materials used for this are used in particular to enable insulation for electronic contacts and/or to protect the MEMS element and/or an electronic circuit from undesirable electrical effects. A well-known insulation material is silicon dioxide. The selection of dielectric materials can be crucial for the functionality of the semiconductor component, as this can influence, for example, parasitic capacitances and/or inductances. It is particularly relevant to reduce parasitic capacitances in the area of high-frequency applications. In the prior art, the approach is to reduce the permittivity of the dielectric material, for example by using so-called low-k materials (see also Shamiryan et al. (2004)).

To provide a package to protect a MEMS device and/or electronic circuit, encapsulation by a lid substrate (also known as wafer capping) has proven particularly useful. Materials for substrates can also be used, such as: B. Silicon. The cover substrate serves to protect a MEMS element and/or an electronic circuit. For this purpose, the cover substrate is connected to the base substrate, ie the substrate that has the MEMS element and/or the electronic circuit, for example by bonding. This makes it possible to achieve a desired pressure within the encapsulation, e.g. B. a vacuum so that a hermetic or almost hermetic seal can be achieved (see also Heakyoung (2013)). It is known that, in addition to the electrical or dielectric requirements, certain mechanical and/or thermal requirements of the materials for components of the semiconductor component must be met in order to ensure optimal operation. In particular, reliable protection and a long service life of the semiconductor component should also be ensured. The semiconductor component should be able to withstand shocks and not experience any significant expansion due to heat effects, so that no structural changes are caused.

Both the electrical, dielectric and mechanical properties of components of a semiconductor component can be optimized by the chemical structure, the processing-related morphology and by the fillers and/or reinforcing materials used for the materials used.

However, there are also some disadvantages with regard to known materials or manufacturing processes for semiconductor components. For example, in order to carry out processing on components of semiconductor components and/or MEMS elements, chemical reactions often have to be caused in the actual manufacturing process, for example. B. to achieve a hardening of a composition. Such chemical reactions often require the addition of heat (for example using a laser or oven), which makes the process more complex and expensive. Furthermore, it may be that for certain materials and/or components of a semiconductor component and/or a MEMS element there are critical temperatures - for example of approximately 130 ° C - which should not be exceeded in order to avoid undesirable structural changes.

A further difficulty exists with regard to the shaping of components of the semiconductor components, particularly when using materials such as glasses and/or single crystals, which are of high quality, for example, but cannot be optimally designed structurally during a manufacturing process. Other materials, which may be easier to shape, for example polymers and/or ceramics in the context of additive manufacturing, can represent a reduced hermetic seal due to inhomogeneities, which could affect the service life of the semiconductor component.

There is therefore a need in the prior art to provide semiconductor components with improved material properties.

Task of the invention

The object of the invention was to eliminate the disadvantages of the prior art. In particular, it was an object of the invention to provide semiconductor components and methods for their production, which are characterized by optimized functionality, high economic efficiency and process-efficient and cost-effective production.

Summary of the invention

The object of the invention is solved by the independent claims. Advantageous embodiments of the invention are disclosed in the dependent claims. In a first aspect, the invention relates to a semiconductor component comprising a MEMS element and/or an electronic circuit, wherein the MEMS element and/or the electronic circuit is present on or in a base substrate, characterized in that the base substrate comprises a concrete material, the semiconductor component has an insulating layer comprising concrete material for insulating an electrical connection and/or the MEMS component and/or the electronic circuit is at least partially enclosed by a protective cover comprising concrete material.

The inventors have recognized that the use of concrete material can surprisingly significantly improve both the structural and functional properties of a semiconductor component. In particular, it was recognized that a variety of desired effects can be achieved and combined with one another using concrete material, which are of particular advantage in the production of semiconductor components and on the semiconductor components as such.

For this purpose, it is provided according to the invention that at least one component of the semiconductor component comprises a concrete material. Preferably, several components can also comprise a concrete material. Preferably, the base substrate, the insulation layer (also synonymously insulating layer) and/or the protective cover comprises a concrete material.

By using concrete material for the base substrate, for example, a particularly homogeneous surface can advantageously be achieved. Furthermore, the smoothness of the surface of the base substrate can advantageously be adjusted both precisely and easily. In addition, it is advantageous that additional functional materials, such as concrete material, can be added to the base substrate in a process-efficient manner. B. metals for the provision of conductor tracks can be provided. Furthermore, a reliable connection to the MEMS element and/or the electronic circuit is advantageously ensured if this is to be applied to the base substrate.

An insulating layer comprising concrete material also has advantages for the semiconductor component. Concrete material is dielectric, which ensures protection in terms of charge transfer and/or charge equalization. Furthermore, the easy deformability, in particular the simple structuring, of concrete material is particularly useful as an insulating layer, since the structure of the insulating layer allows the electrical and dielectric properties of the semiconductor component to be optimally adjusted. For example, in an insulating layer comprising concrete material, pores can be introduced with little effort, which can be designed to reduce parasitic capacitances.

Concrete material has also proven to be beneficial for providing a protective cover. In particular, the concrete material can ensure that there is a hermetic encapsulation of the MEMS element and/or the electronic circuit. This advantageously prevents material exchange between the environment and internal components of the semiconductor component and ensures long-lasting functionality of the semiconductor component. The use of concrete material has proven to be advantageous not only structurally, but also for processes or methods for producing the semiconductor component or individual components of the semiconductor component

It should be emphasized as particularly advantageous that self-hardening of the concrete material can be used to produce components of the semiconductor component. Self-hardening means in particular that the concrete material can be hardened without additional external energy having to be supplied. This advantageously results in considerable process efficiency, since, on the one hand, simple shaping is achieved and additional effort for the curing reaction can be dispensed with.

The self-hardening of the concrete material is preferably based on cement (as a binder). Hardening, also known as setting, preferably corresponds to a slow chemical-mineralogical reaction of the cement with water, with water also being a preferred component of the concrete material. The cement is preferably a hydraulic binder that only hardens when water is added. The hardening of the concrete material is based, among other things, without being limited to theory, on hydration as a chemical reaction, which will be discussed in more detail below. Cement and water are the components of the concrete material, rather than the aggregates, which are crucial for hardening.

The possibility of using the self-hardening of concrete material also advantageously ensures that no high temperatures occur, which can lead to undesirable structural changes in the semiconductor component. In particular, it is avoided that a temperature has to be applied which could be critical for the functionality of components and/or materials of the semiconductor component and/or the MEMS element, for example a temperature of approximately 130° C.

Another advantage is that concrete material can be combined with a variety of substances to achieve the desired reaction. For example, it is particularly easy to advantageously integrate metals into the concrete material in order to provide conductor tracks for electrical contacting. Furthermore, the property that concrete material is basic can be advantageously used in the context of processing, for example for in-situ conditioning of surfaces. Furthermore, an alkaline environment of the concrete material is advantageous in that a particularly high level of strength can be achieved through the reaction of the cement with water.

According to the invention, it was therefore recognized that a number of advantageous technical effects can be achieved through the use of concrete material to produce a semiconductor component, which have an advantageous effect both on the processing and on the semiconductor component as such.

For the purposes of the invention, a semiconductor component preferably refers to a component that is used for circuits in electrical engineering or electronics, in particular in connection with semiconductor materials. The average person skilled in the art knows that the term semiconductor device can be interpreted broadly. For example, a semiconductor component can have one include an integrated circuit that has transistors and / or diodes or itself be such a component. The integrated circuits are preferably manufactured on base substrates. In addition, components such as transistors, diodes and/or capacitors can be produced by processing the base substrate. Several base substrates can also be used, which can then be divided and form several chips. A semiconductor component can also include or be itself, for example, a circuit board, several processors, semiconductor memories, microcontrollers, converters, microchips, etc. A semiconductor component can preferably be manufactured using methods and/or equipment from semiconductor and/or microsystem technology.

The semiconductor component preferably comprises a base substrate, an insulating layer and/or a protective cover. Furthermore, it is preferred that the semiconductor component has a MEMS element and/or an electronic circuit. The base substrate is preferably to be understood as the carrier of the MEMS element and/or the electronic element. It may also be preferred that the MEMS element and/or the electronic circuit is present within the base substrate. For this purpose, it may be preferred to introduce MEMS structures into the base substrate, for example by using etching processes. Therefore, it may also be preferred that the MEMS element is part of the base substrate.

The insulating layer is preferably a layer that enables electrical insulation, for example of electrical contacts. Dielectric intermediate layers can also preferably be viewed as insulating layers in the context of the invention.

An intermediate layer as an insulating layer preferably means a dielectric layer which is present between at least two components and/or at least two sections of the semiconductor component. For example, it may be preferred that the intermediate layer is attached between two substrates in order to enable electrical insulation between these two substrates. The intermediate layer preferably has a flat design, i.e. H. it preferably has a length and/or width that is many times greater than its thickness, preferably by a factor of 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more.

The protective cover preferably serves to enclose the MEMS element and/or the electronic circuit in order to prevent material exchange with the environment. For this purpose, it is preferred that the protective cover is applied at least partially over the MEMS element and/or the electronic circuit, preferably completely.

As explained above, it was recognized according to the invention that the use of a concrete material can offer various advantages both for providing a base substrate, an insulating layer and a protective cover. Such use of concrete material for the production of semiconductor components is not known from the prior art.

The preferred components mentioned can be components of the semiconductor component according to the invention individually or in combination with one another. The semiconductor component preferably comprises a base substrate, a protective cover and/or an insulating layer. Accordingly, it can be preferred that the semiconductor component only has the base substrate, the protective cover or comprises the insulating layer, preferably in combination with a MEMS element and/or an electronic circuit. It may also be preferred that the semiconductor component comprises the base substrate and the protective shell, or the base substrate and the insulating layer, or the protective shell and the insulating layer, or the base substrate and the protective shell and the insulating layer, preferably in combination with a MEMS element and/or an electronic circuit.

In the context of the invention, concrete material preferably means a material which includes concrete in its chemical composition, with concrete preferably being meant as a building material. Concrete includes in particular a binder for creating chemical bonds and an additive for imparting stability and/or strength.

In a preferred embodiment, the semiconductor component is characterized in that the concrete material has a cement, the cement preferably being selected from a group comprising blastfurnace sand, silica fume, pozzolans, fly ash, burnt slate, limestone, calcium sulfate, tar clay cement clinker and / or cement clinker, where preferably the cement clinker has tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminate ferrite, tricalcium aluminate and / or free calcium oxide.

The cement is an essential component of the concrete material and preferably represents a binder with which the setting process results. The setting process refers to the chemical reaction in which the concrete material self-hardens. Cement is in particular a hydraulic binder, i.e. This means that the concrete material can harden both in air and under water and is also durable. During curing, i.e. H. During the setting process, the cement reacts with water to form insoluble, stable compounds. These compounds, which can be present, for example, as calcium silicate hydrates, form fine needle-shaped crystals, which interlock with one another and thus lead to the high strength of the cement and thus the self-hardening of the concrete material. Hydration occurs during self-curing, i.e. H. an accumulation of water molecules.

Cement clinker refers to a solid substance that forms a proportion of cement, in particular Portland cement, where the Portland cement can be provided by cement clinker and lime or anhydrite. Portland cement comprises approximately 58 - 66% calcium oxide, approximately 18 - 26% silicon dioxide, approximately 4 - 10% aluminum oxide and 2 - 5% iron oxide. In particular, the cement clinker is responsible for self-hardening through hydration, which, without wishing to be limited to one theory, in turn results from the chemical structure of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminate ferrite, tricalcium aluminate and / or free calcium oxide. The terms silicate reaction and aluminate reaction are also common in the prior art.

The aforementioned types of cement have proven to be beneficial for quick and reliable self-hardening of the concrete material. In addition, hydroxide ions can form upon contact with water, meaning that the concrete material is basic. The hydroxide ions formed upon contact with water are, for example can be used to adjust the nucleophilicity in order to bring about a desired chemical reaction, particularly during processing.

In a preferred embodiment, the semiconductor component is characterized in that the concrete material is a fiber concrete comprising fibers, the fibers preferably comprising a material selected from a group comprising plastic, steel and/or glass.

Fiber concrete preferably refers to a concrete material that has fibers and therefore contains fiber reinforcement. The fibers can be, for example, plastic, steel and/or glass fibers. In the case of fiber reinforcement, the matrix is preferably selected from a group comprising cement, cement stone and/or mortar.

With the help of introduced fibers, (tensile) stresses in the concrete material can be advantageously absorbed, so that a particularly pronounced strength, stability and/or hardness can be achieved. This is particularly useful for, for example, the base substrate and/or the protective cover to improve the protective function. For example, a protective effect is also provided if the semiconductor component is exposed to mechanical stress such as vibrations or the like.

Further properties for the concrete material and thus for the semiconductor component can advantageously be set using parameters of the fiber. Parameters for the fibers (also known as fiber properties) can be selected from a group comprising fiber materials (preferably plastic, steel and/or glass), fiber sizes (e.g. micro and/or macro fibers) and/or fiber geometries (e.g .straight, hook-shaped, wavy, end-squashed and/or end-compressed). The fiber properties can be used to regulate the mechanical, electrical, optical properties and/or behavior when exposed to foreign substances. Furthermore, the processing properties and/or the usage properties of the concrete material for the semiconductor component can be additionally optimized through the fiber properties.

In a preferred embodiment, the semiconductor component is characterized in that the concrete material has a pore structure, the pore structure preferably having pores with a diameter selected between 1 nm - 200 nm, preferably between 2 - 50 nm, particularly preferably between 5 nm - 40 nm.

The presence of a pore structure for the concrete material is particularly advantageous for the insulating layer of the semiconductor component. This allows parasitic capacitances between two or more conductive sections, e.g. B. conductor tracks or plated-through holes can be reduced. The creation of parasitic capacitances is a well-known problem in semiconductor and microsystem technology. Parasitic capacitances arise, among other things, when two or more conductive areas with different voltages are close together so that the electric field between them stores an electric charge on them. The effect of parasitic capacitance is particularly relevant in high-frequency applications. Advantageously, the material density and thus the dipole density can be reduced by the pore structure of the concrete material, in particular for the insulating layer. This reduces the relative permittivity and therefore also the parasitic capacitance. It is advantageous simple way to create a desired pore structure of the concrete material. In particular, the pore structure can be adjusted easily and precisely by the method with which the concrete material can be applied. The preferred ranges for pore diameters mentioned have proven to be particularly useful for reducing parasitic capacitances.

In a preferred embodiment, the semiconductor component is characterized in that the concrete material has a roughness, the roughness preferably having an average roughness in a range between 0.01 pm and 100 pm, preferably between 1 pm and 50 pm, particularly preferably between 5 pm and 8 p.m.

The term roughness is preferably used to describe the unevenness of a surface, in particular the surface height. The average roughness value preferably refers to a parameter with which the roughness of a surface can be characterized. The lower the average roughness value, the less rough and smoother the surface is. The center rough values mentioned have proven to be advantageous in order to provide surfaces that are sufficiently smooth for the functionality of the semiconductor component. The smooth surface is particularly advantageous for the base substrate and/or for the protective cover.

For the base substrate, the smoothness, in particular due to the preferred average roughness values mentioned, is an advantage in that further coatings can also be applied smoothly. This advantageously eliminates the need for complex process steps, such as: B. planarization, for example to make insulating layers and/or other layers sufficiently smooth.

A smooth surface is required for the protective cover, among other things. advantageous in that when contacting a foreign substance, e.g. B. a liquid, adhesion is prevented. In addition, a connection with the concrete material, such as. B. sticking can be prevented or the protective effect of the protective cover can be increased.

In a preferred embodiment, the semiconductor component is characterized in that the base substrate has the concrete material, wherein the MEMS element and/or the electronic circuit is present on a surface of the base substrate and/or is integrated into the base substrate.

For the purposes of the invention, the base substrate preferably refers to a flat, preferably disk-shaped body whose width and/or length is significantly greater than the thickness of the body. The length and/or width of the base substrate can be higher than the length and/or width by a factor of 1.5, 2, 3, 4, 5 or more. The thickness of the base substrate can be, for example, in the millimeter or submillimeter range. The base substrate preferably serves as a carrier for the MEMS element and/or the electronic circuit.

Preferably the base substrate comprises a concrete material. The surface properties of the base substrate can advantageously be precisely adjusted by using concrete material. In particular, a permanent connection between the base substrate and the electronic circuit and/or MEMS element can advantageously be achieved through adhesion if it is to be attached to the base substrate. In addition, the roughness or Smoothness of the surface can be optimized so that further layers that are applied to the base substrate can also be designed to be essentially homogeneous.

In addition, the ease of processing concrete material makes it possible to easily obtain a desired shape for the base substrate. For example, the base substrate can have a geometric shape that is round or angular in cross section. For this purpose, it may be preferred to introduce the concrete material into a shaping component, the shaping component preferably being able to function as a matrix for the mold. For the shaping of the base substrate, it may also be preferred to specify parameters of a method with which the concrete material is applied and thus directly obtain a shape for the base substrate. The concrete material is preferably applied in a pasty form and the self-hardening of the concrete material is used to determine the shape of the base substrate. Advantageously, the degrees of freedom with which the shape for the base substrate can be determined are easier to determine than for other common materials in semiconductor and/or microsystem technology for base substrates. For example, slopes, depressions and/or cavities can also be introduced particularly easily into the base substrate. The easy formability through the use of concrete material is also available for components such as: B. insulating layers and/or protective covers.

The base substrate can preferably also have a concrete material if the base substrate has an SOI construction. An SOI construction is known in the art as a construction of substrates that have a dielectric oxide layer between two semiconductor layers. It may thus be preferred that the base substrate comprising concrete material has a first concrete material layer, a dielectric layer positioned thereon and, in turn, a second concrete material layer.

The base substrate comprising concrete material can preferably also be present as a circuit carrier, preferably also as an injection-molded circuit carrier (English: Molded Interconnect Device, abbreviated to MID). The base substrate can advantageously be structured with a high degree of design freedom and electrical connections can be integrated, such as. B. conductor tracks and / or plated-through holes, so that a significantly miniaturized semiconductor component can be provided.

The design of the base substrate comprising concrete material as a package substrate is also advantageously possible. A package substrate can advantageously be used to obtain a carrier and at the same time a protective cover for a MEMS element and/or an electronic circuit. For this purpose, it is preferred that the package substrate has notches into which the MEMS element and/or the electronic circuit can be inserted. Above the notches there are preferably covers which at least partially surround the MEMS element and/or the electronic circuit as a protective cover.

The use of concrete material can therefore advantageously imitate known structures for the base substrate and optimize their properties. Furthermore, MEMS structures for the MEMS element can be introduced into the base substrate particularly easily. MEMS structures preferably refer to sections in the micrometer range (e.g. 1 pm - 1000 pm) and serve to provide the MEMS element. MEMS structures are preferably introduced into the base substrate in order to integrate MEMS elements into the base substrate. It may also be preferred to form one or more cavities in the base substrate in order to create a free volume in which the MEMS element and/or the electronic circuit can be introduced. This can advantageously achieve a high level of compactness of the semiconductor component and simultaneous protection of sensitive MEMS elements.

It has proven to be particularly advantageous for the geometric design and/or for the introduction of structures, such as. B. MEMS structures and / or cavities, the use of concrete material for the base substrate has been proven. The effect of self-curing means that structures can be created for the base substrate without having to invest a lot of process effort. For example, preferably no etching process is necessary to design the structures or cavities. Instead, a desired shape and/or structure can preferably be provided by a setting process when the base substrate is provided by means of a corresponding shaping component, for example. B. to achieve hardening and/or strength at room temperature.

Advantageously, by using concrete material for the base substrate, different MEMS structures can be introduced in a simple manner, which serve to provide the MEMS element. The MEMS structures can be selected from a group comprising translatable, rotatable, oscillatable, lamellar and/or meander-like MEMS structures. Many MEMS structures can therefore advantageously be provided to form the MEMS element. For this purpose, there is preferably an electronic contact with the MEMS element in order to generate signals on the MEMS element or to read them from the MEMS element. A large number of MEMS structures can therefore advantageously be introduced into the base substrate comprising concrete material, so that a large number of MEMS elements can be present on or in the base substrate.

In a further preferred embodiment, the semiconductor component is characterized in that the base substrate has a concrete material and an additive, wherein preferably the additive can be activated using an ablation process to form active areas and the active areas can be activated by metallization to provide for the electrical connection of the MEMS -Element and/or the electronic circuit can be used.

The additive preferably refers to a further additional substance that is present in or on the base substrate. The additive can preferably be selected from a group comprising aluminosilicates, preferably tectoalumosilicates. It is known that aluminosilicates have a pore structure. The aluminosilicates as an additive, which are preferably incorporated into the concrete material, can be activated by the ablation process, so that a metal, e.g. B. a precious metal can accumulate. Metallization without external current can then preferably be carried out, in which metal is deposited starting within the pores and also in an outer edge region of the pores. A flat metallization layer can therefore be specifically formed on the surface of the base substrate. The ablation method used is preferably a method that makes it possible to activate the additive. Activation preferably refers to a state in which a reaction, for example a binding with a metal, is favored. The ablation process can be carried out, for example, by emitting electromagnetic radiation, in particular by laser beams. The metallization, ie the application of metal, can be carried out, for example, in a chemically reductive metal bath, e.g. B. in a copper bath.

Concrete material is advantageously suitable as a suitable carrier for such an additive in order to carry out metallization using an ablation process, so that an electrical connection can be provided for the MEMS element and/or the electronic circuit.

In a preferred embodiment, the semiconductor component is characterized in that the insulating layer has a concrete material, with the insulating layer preferably being at least partially present on the electrical connection and/or encasing an electrical connection.

The electrical connection can, for example, be selected from a group comprising conductor tracks, conductor track levels and/or plated-through holes. Advantageously, concrete material as a dielectric material can be adapted to the shape of the electrical connection in order to ensure optimal electrical insulation. The concrete material can also preferably be optimally applied to bonding wires in order to enable insulation for electrical contacts between, for example, the MEMS element and the electronic circuit.

In a preferred embodiment, the semiconductor component is characterized in that the insulating layer has a concrete material, the insulating layer preferably having a pore structure.

A pore structure can advantageously improve the functionality of the semiconductor component. As explained above, parasitic capacitances between electrical connections can be reduced, for example, by the presence of a pore structure. This can be justified, among other things, by the fact that the dipole density is reduced by the pore structure comprising pores.

In a preferred embodiment, the semiconductor component is characterized in that the protective cover is selected from a group comprising a protective layer and/or a cover substrate.

The preferred options mentioned, comprising a protective layer and/or a cover substrate, have proven effective in enabling secure hermetic encapsulation of the MEMS element and/or the electronic circuit and thus achieving reliable protection from the environment. It is advantageous to use concrete material both for a protective layer and for a cover substrate.

In a preferred embodiment, the semiconductor component is characterized in that the semiconductor component has a protective layer comprising concrete material, wherein the protective layer is preferably present in a surface-conform manner on the MEMS element and/or the electronic circuit. The protective layer preferably refers to a layer that is applied to components of the semiconductor component, such as. B. the MEMS element and / or the electronic circuit can be applied. The use of concrete material advantageously makes it possible to apply the protective layer particularly precisely, so that local coverings are also possible.

In particular, it is advantageously possible to apply a protective layer comprising concrete material to components of the semiconductor component in a surface-conform manner. A surface-conform protective layer refers in particular to a layer which lies essentially directly and tightly against the underlying components in a shape-preserving manner. Substantially direct and close-fitting preferably means that the majority of the protective layer rests directly, but in some areas includes volumes that are not filled by components, for example in corner areas or below a wire bond.

The surface-conforming protective layer is preferably completely surface-conforming. This means in particular that the protective layer is almost perfectly snug or conforms to the surface and even the smallest structures are coated with a tight fit.

The smallest structures are preferably structures with dimensions of a maximum of 10 nanometers (nm), a maximum of 100 nm, a maximum of 1 micrometer (pm), a maximum of 10 pm or a maximum of 100 pm. By applying a surface-conform protective layer comprising concrete material, on the one hand, a hermetic, space-optimized protective layer can be applied extremely cheaply. On the other hand, a surface-conform protective layer allows a high degree of flexibility with regard to a targeted opening or recess of the protective layer in an interaction area of the MEMS element. The MEMS interaction region preferably means a functional component of the MEMS element, which interacts with an external medium in the desired manner. In the case of an acoustic MEMS transducer, for example, it is a MEMS membrane. In the case of an optical MEMS transducer, for example, it is an optical emitter.

The protective layer, which can preferably be present in a surface-conform manner, preferably has a thickness of approximately 10 nm (nanometers) - 1 mm (millimeters). It may also be preferred that the protective layer can have a thickness of approximately 10 nm - 100 nm, approximately 100 nm - 200 nm, approximately 200 nm - 500 nm, approximately 500 nm - 1 pm (micrometer), approximately 1 pm - 5 pm, approx. 5 pm - 10 pm, approx. 10 pm - 50 pm, approx. 50 pm - 100 pm, approx. 100 pm - 500 pm or from approx. 500 pm - 1 mm. One skilled in the art will recognize that the aforementioned range limits can also be combined to obtain further preferred ranges, such as approximately 100 nm - 1 pm, approximately 500 nm - 5 pm or approximately 200 nm - 10 pm.

The preferred thicknesses for the protective layer advantageously lead to excellent protection of the MEMS element and/or the electronic circuit while at the same time being compact and ensuring high functionality. Furthermore, the preferred thicknesses for the protective layer can be provided easily, inexpensively and quickly using methods proven in the prior art.

Terms such as essentially, approximately, approximately, approximately, etc. preferably describe a tolerance range of less than ± 20%, preferably less than ± 10%, even more preferably less than ± 5% and in particular less than ± 1%. Statements of essentially, approximately, approximately, etc. always reveal and include the exact stated value.

In a preferred embodiment, the semiconductor component is characterized in that the semiconductor component has a cover substrate comprising concrete material, wherein the cover substrate preferably covers the MEMS element and/or the electronic circuit and is cohesively connected to the base substrate.

The cover substrate preferably refers to a substrate with which the MEMS element and/or the electronic circuit can be covered or enclosed. The lid substrate may preferably be an ordinary substrate or an SOI wafer comprising concrete material. A cover substrate comprising concrete material can advantageously be connected to the base substrate in a materially bonded manner, so that a stable connection between the base substrate and the cover substrate is made possible. As a result, components on or in the base substrate are advantageously particularly well protected. A cohesive connection includes connections in which the base substrate and the cover substrate are held together by atomic or molecular forces. Cohesive connections are at the same time non-detachable connections that can only be separated by destroying the connecting means.

The cover substrate can preferably have essentially the same structure as the base substrate. In particular, it may be preferred that the cover substrate is essentially flat, i.e. H. a length and/or width of the cover substrate is many times higher than a height of the cover substrate, preferably at least by a factor of 1, 5, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. Furthermore, the cover substrate and/or the base substrate can preferably have a cavity, with the cover substrate and the base substrate preferably being connected to one another in such a way that a cavity is formed within the semiconductor component, in which the MEMS element and/or the electronic circuit are preferably placed is present. A connection of the base substrate to the cover substrate can preferably take place at lateral regions of the base and cover substrates, which enclose one or both cavities. In this way, a cost-effective, compact and robust semiconductor component can advantageously be provided using simple means, within which a MEMS element and/or an electronic circuit can be placed in a protected manner.

Due to the easy formability of concrete material, it is also advantageously possible to introduce structures such as slopes, notches, depressions, grooves or other structures on the cover substrate. In this way, an optimal adaptation to a storage space for the semiconductor component can advantageously be achieved. The use of concrete material therefore provides significantly improved design freedom for the semiconductor component as a whole.

In a preferred embodiment, the semiconductor component is characterized in that the MEMS element is selected from a group comprising an acoustic MEMS transducer, optical MEMS transducer, MEMS sensor, in particular MEMS gas sensor and/or MEMS filter. Reliable operability and optimal usability can advantageously be guaranteed for a large number of MEMS elements if at least one component of the semiconductor component comprises a concrete material. For example, it may be preferred that the MEMS structures comprise a concrete material to provide the MEMS element. It may also be preferred that one or more insulating layers comprise a concrete material, which in particular enables secure electronic insulation. In addition, it may be preferred that the protective cover comprises a concrete material, thereby enabling reliable protection for the MEMS element.

A MEMS transducer preferably refers to a MEMS converter, i.e. H. a MEMS element capable of converting energy from one form to another. In particular, in a MEMS transducer, the input signal differs from the output signal in terms of the type of signal.

Preferably, the MEMS converter is selected from a group comprising an acoustic MEMS converter and/or an optical MEMS converter.

An acoustic MEMS transducer is set up to interact with a volume flow of a fluid, with the MEMS structures being designed to interact with the volume flow or to record or generate pressure waves. The fluid can be either a gaseous or a liquid fluid.

An acoustic MEMS converter refers to a MEMS converter that uses an acoustic signal, preferably sound pressure waves, during a conversion of a form of energy and/or a type of signal. In an acoustic MEMS converter, either the input signal or the output signal is an acoustic signal. For example, an acoustic MEMS transducer can be a MEMS speaker or a MEMS microphone. For example, a MEMS speaker is configured to generate an acoustic signal based on an electrical signal. A MEMS microphone, for example, is set up to generate an electrical signal based on an acoustic signal.

An optical MEMS converter refers to a MEMS converter in which the input signal or the output signal is an optical signal. An optical signal preferably means light, which can have a wavelength in the visible or non-visible range. For example, an optical MEMS converter can convert light as an input signal into an electrical signal. For example, in an optical MEMS converter, light may fall on an electrode surface and electrons may be emitted from the electrode surface. It may also be the case, for example, that in an optical MEMS converter the resistance of a material changes when it is illuminated. Furthermore, such a functional principle can exist that an output voltage that is proportional to the radiation intensity is generated. Likewise, for example, in an optical MEMS converter, light can be emitted based on an electrical quantity, such as. B. with an OLED, LED, electroluminescent lamp etc.

In further preferred embodiments, the MEMS element is a MEMS sensor, in particular a MEMS gas sensor and/or a MEMS filter. A MEMS sensor can, for example, comprise a capacitively or optically readable, piezoelectric, piezoresistive and/or magnetic beam and/or a capacitive, piezoelectric, piezoresistive and/or optical microphone or membrane in order to measure a physical, chemical and/or biological quantity capture.

The MEMS sensor is preferably a MEMS gas sensor. A MEMS gas sensor is preferably able to detect a gas as such and/or a concentration of a gas. A MEMS gas sensor can, for example, be based on the principle of photoacoustic spectroscopy. In photoacoustic spectroscopy, intensity-modulated infrared radiation with frequencies in the absorption spectrum of a molecule to be detected in a gas is preferably used. If this molecule is present in the beam path, modulated absorption occurs, leading to heating and cooling processes whose time scales reflect the modulation frequency of the radiation. The heating and cooling processes lead to expansions and contractions of the gas, causing sound waves at the modulation frequency. These can be measured using, for example, sound detectors and/or flow detectors. The power of the sound waves is preferably directly proportional to the concentration of the absorbing gas.

In a further preferred embodiment, the MEMS sensor is a MEMS filter, preferably a MEMS frequency filter, in particular a SAW or BAW filter. A SAW filter is preferably a surface acoustic wave filter (also AOW filter), which in particular represents a bandpass filter for electrical signals. BAW filters (English: bulk acoustic wave) are preferably similar electronic filters with bandpass characteristics. However, in contrast to the SAW filter, these preferably have a base substrate in which the acoustic waves are propagated.

In preferred embodiments, the semiconductor component comprises a MEMS element. In further preferred embodiments, the semiconductor component comprises an electronic circuit. In further preferred embodiments, the semiconductor component comprises a MEMS element and an electronic circuit.

In a preferred embodiment, the semiconductor component is characterized in that the electronic circuit is selected from a group comprising a computing unit, a processor, a microprocessor, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a programmable logic circuit ( PLD), a Field Programmable Gate Array (FPGA) and/or a programmable logic circuit.

In a further aspect, the invention relates to a method for producing a semiconductor component comprising the following steps: a) provision of a base substrate, b) attachment of a MEMS component and/or an electronic circuit on or in the base substrate, characterized in that the base substrate is a concrete material comprises, an insulating layer comprising a concrete material for insulating an electrical connection is applied and/or a protective cover comprising concrete material is applied, which at least partially encloses the MEMS component and/or the electronic circuit.

The average person skilled in the art will recognize that technical features, definitions, advantages and preferred embodiments for the semiconductor component according to the invention also apply to a method for producing the semiconductor component and vice versa.

The preferred method for producing the semiconductor component advantageously achieves a significant process improvement, since in particular the self-hardening of the concrete material can be used. Self-curing can, for example, take place at room temperature. It is therefore not necessary to integrate further process steps in order to harden the concrete material and thus carry out the final shaping. This advantageously saves both the complexity of the process and the costs, since, for example, concrete material is more cost-effective than using a heating oven to carry out drying and/or curing. For example, it may be that the concrete material is introduced in a pasty state, taking into account a desired shape, in order to then dry independently.

Concrete material solidifies not only through drying itself, but through the chemical process of setting. The cement and water in the concrete material can preferably form a cement paste that crystallizes and bonds firmly with other components of the concrete. In the concrete material, the evaporation of water is preferably not relevant for curing and only occurs partially. Instead, water remains in the concrete material as a result of the setting process and is important for strength. During the setting process, curing takes place based on the binder, which in the case of concrete material is cement. In particular, given the fact that the dimensions of semiconductor components in semiconductor and/or microsystem technology are many times smaller than the usual use of concrete material, the self-curing of the concrete material can be used efficiently in order to advantageously obtain quickly finished semiconductor components, in particular in the context of mass production. It is particularly advantageous that concrete material can be used as part of processing at temperatures that are below a critical temperature, which could have a detrimental effect on components of the semiconductor component. In particular, a sufficiently reliable shaping of components of the semiconductor component, e.g. B. MEMS structures for providing the MEMS element. Furthermore, the self-curing of the concrete material can advantageously take place at temperatures that are below temperature ranges that could be critical for components and/or materials of the semiconductor component. Self-curing is advantageously possible at temperatures between 20°C - 100°C, preferably between 20°C - 80°C, particularly preferably between 30°C - 60°C. In particular, self-curing can advantageously take place at room temperature. It is particularly advantageous that an external energy supply is not necessary for hardening and/or solidification.

In addition, it is advantageous that the concrete material can be combined with a variety of functional materials, in particular to cause a chemical reaction that can lead to components of the semiconductor component, such as. B. metallization for creating electrical connections. The property that the concrete material is basic applies to be taken into account here, which can, however, also be used advantageously, since hydroxide ions are present as active ions and enable rapid binding and/or reaction.

Advantageously, concrete material can also be processed particularly easily, for example in order to obtain a desired shape and/or structure. This makes it particularly easy to form MEMS structures in the base substrate in order to provide the MEMS element. In particular, shapes and/or structures can be set using a method with which the concrete material for a component of the semiconductor component can be produced.

In a preferred embodiment, the method is characterized in that the concrete material is applied and/or processed by a method selected from a group comprising film casting, injection molding, additive manufacturing, embossing and/or joining, preferably by a selection of parameters of the method Pore structure and/or roughness can be adjusted.

Concrete material can advantageously be used in a number of manufacturing processes that are used in the context of semiconductor and/or microsystems technology to produce semiconductor components. The methods mentioned have proven themselves in the state of the art and ensure optimal operation and essentially error-free production of semiconductor components. The methods mentioned can also advantageously be used to reliably adjust the shape and/or structure of the concrete material for one or more components of the semiconductor component.

Film casting refers to a primary molding process that can be used to produce thin and/or large-area films comprising concrete material. The concrete material preferably flows from a storage container with an adjustable slot on the bottom, pressure-free and bubble-free, under a drum (drum casting) or an endless copper strip (strip casting). The concrete material can preferably also be spread evenly with an adjustable blade.

Process parameters can be monitored particularly easily and reliably during film casting. Films comprising concrete material, which were provided by film casting, are advantageously characterized by a very homogeneous surface free of air bubbles and shrinkage.

Injection molding is also a primary molding process. The concrete material is injected under pressure into a mold, the injection molding tool, using an injection molding machine. In the injection molding tool, the concrete material returns to its solid state through cooling or a crosslinking reaction and is removed as a finished part after the injection molding tool is opened.

Additive manufacturing includes manufacturing processes in which the material comprising concrete material is applied layer by layer to provide three-dimensional objects. The layer-by-layer structure is computer-controlled according to one or more predetermined dimensions and/or shapes. Physical and/or chemical hardening and/or melting processes take place during construction. During embossing, the surface of the concrete material is processed using dies in order to obtain desired structures, such as pores, reliefs, depressions, cavities, etc. Embossing can preferably also be used to correct dimensional and/or shape deviations of a component of the semiconductor component to correct.

Joining refers to general processes with which at least two components of the semiconductor component can be permanently connected (joined). In the context of semiconductor and/or microsystem technology, this includes in particular welding, soldering, gluing and/or assembly and connection techniques, such as: B. Bonding.

While in the prior art concrete materials are mostly only used for macroscopic components, it was recognized according to the invention that, in particular with the aforementioned primary molding processes, extremely delicate structures can also be provided, which allow the production of a semiconductor component comprising structures and/or components in the micrometer range.

In a preferred embodiment, the method is characterized in that the concrete material is applied in a paste-like form, preferably using self-hardening of the concrete material through an exothermic reaction.

A pasty form of the concrete material means that the concrete material is present as a paste, i.e. as a solid-liquid mixture. The concrete material as a paste can be characterized by the solids content and/or the viscosity. The concrete material in the form of a paste preferably comprises a solids content between 30% - 80%, preferably between 50% - 70%. The solids content is particularly preferably more than 50%. Preferably, the concrete material in its pasty state has a viscosity between 1 - 3000 mPa s (millipascal times second), preferably between 1 - 1000 mPa s, particularly preferably between 1 - 500 mPa s, very particularly preferably between 1 - 200 mPa s. In particular, the paste is characterized by the fact that it is preferably non-flowable, but is spreadable.

The self-curing of the concrete material is preferably used to provide the semiconductor component and/or components of the semiconductor component. In particular, hydration occurs, i.e. H. the attachment of water molecules. In particular, the hydration of calcium oxide, magnesium oxide and/or cement to calcium hydroxide, magnesium hydroxide and/or calcium silicate hydrates is relevant for the use of concrete material. Without being limited to theory, the setting process on which the self-hardening of the concrete material is based is an exothermic reaction.

In a preferred embodiment, the method is characterized in that the base substrate has a material comprising concrete and the base substrate has an additive, the additive preferably being activated using an ablation process so that active areas are formed and the active areas are made available by metallization an electrical connection of the MEMS component can be used, wherein the electrical connection, preferably a conductor track, is preferably introduced by a galvanic process.

The additive can preferably be selected from a group comprising aluminosilicates, preferably tectoalumosilicates. When activated, the additive has a state in which: a reaction or type of reaction can occur at a higher rate or yield. The use of an ablation procedure has proven to be a particularly reliable method for activating the additive. By activating the additive, a reliable connection to the material for metallization can advantageously be made possible, for example in order to provide electrical connections, preferably conductor tracks. The metallization is preferably carried out using a galvanic process.

The galvanic process can be used to dissolve a metal using an electric current through a bath containing an electrolyte, starting from a positive pole (anode) and transferring it to the negative pole (cathode). The metal ions dissolved in the bath are deposited on the activated areas by reduction, for which purpose electrical contact with the negative pole is preferably provided. Alternatively, the metal ions can already be contained in the electrolyte as a solution. Using a galvanic process, the metal ions are advantageously deposited particularly evenly, so that electrical connections that are homogeneous in terms of structure can be created.

In a further aspect, the invention relates to the use of a concrete material for producing a semiconductor component.

The inventors have recognized that concrete material can be used in the context of semiconductor and/or microsystem technology, which has an advantageous effect on the structure and manufacturing process of semiconductor components. One or more components of the semiconductor component can have concrete material, such as. B. the base substrate, an insulating layer and / or a protective cover. Concrete material is also extremely suitable for being integrated into state-of-the-art processes for producing components of the semiconductor component. The use of concrete material in the production of a semiconductor component therefore achieves a significant improvement over the prior art. Such use of concrete materials was previously unknown in the prior art.

BIBLIOGRAPHY

Fedder, Gary K. "MEMS fabrication." International Test Conference, 2003. Proceedings. ITC 2003. IEEE Computer Society, 2003.

Rahman, Md Atikur. "A review on semiconductors including applications and temperature effects in semiconductors." American Academic Scientific Research Journal for Engineering, Technology, and Sciences 7.1 (2014): 50-70.

Shamiryan, Denis, et al. "Low-k dielectric materials." Materials today 7.1 (2004): 34-39.

Park, Heakyoung. "Sealing dispensing requirements to meet MEMS packaging and throughput impact." Additional Papers and Presentations 2013. DPC (2013): 000535-000570.

Claims

PATENT CLAIMS

1 . Semiconductor component comprising a MEMS element and/or an electronic circuit, wherein the MEMS element and/or the electronic circuit is introduced on or in a base substrate, characterized in that the base substrate comprises a concrete material, the semiconductor component comprises an insulating layer comprising concrete material for insulation an electrical connection and / or the MEMS component and / or the electronic circuit is at least partially enclosed by a protective cover comprising concrete material.

2. Semiconductor component according to the preceding claim, characterized in that the concrete material has a cement, the cement preferably being selected from a group comprising blastfurnace sand, silica fume, pozzolans, fly ash, burnt slate, limestone, calcium sulfate, tar clay cement clinker and / or cement clinker, where preferably the cement clinker has tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminate ferrite, tricalcium aluminate and / or free calcium oxide.

3. Semiconductor component according to one or more of the preceding claims, characterized in that the concrete material is a fiber concrete comprising fibers, the fibers preferably comprising a material selected from a group including plastic, steel and / or glass.

4. Semiconductor component according to one or more of the preceding claims, characterized in that the concrete material has a pore structure, the pore structure preferably having pores with a diameter selected between 1 nm - 200 nm, preferably between 2 - 50 nm, particularly preferably between 5 nm - 40 nm.

5. Semiconductor component according to one or more of the preceding claims, characterized in that the concrete material has a roughness, the roughness preferably having an average roughness in a range between 0.01 pm and 100 pm, preferably between 1 pm and 50 pm, particularly preferably between 5pm and 8pm.

6. Semiconductor component according to one or more of the preceding claims, characterized in that the base substrate has a concrete material and an additive, wherein preferably the additive can be activated using an ablation process to form active areas and the active areas can be used by metallization to provide the electrical connection of the MEMS element and/or the electronic circuit. Semiconductor component according to one or more of the preceding claims, characterized in that the insulating layer has a concrete material, wherein preferably the insulating layer is at least partially present on the electrical connection and / or encases an electrical connection. Semiconductor component according to one or more of the preceding claims, characterized in that the insulating layer has concrete material, the insulating layer preferably having a pore structure. Semiconductor component according to one or more of the preceding claims, characterized in that the semiconductor component has a protective layer comprising concrete material, the protective layer preferably being present in a surface-conform manner on the MEMS element and/or the electronic circuit. Semiconductor component according to one or more of the preceding claims, characterized in that the semiconductor component has a cover substrate comprising concrete material, wherein preferably the cover substrate covers the MEMS component and is cohesively connected to the base substrate. Semiconductor component according to one or more of the preceding claims, characterized in that the MEMS element is selected from a group comprising acoustic MEMS transducers, optical MEMS transducers, MEMS sensors, in particular MEMS gas sensors and/or MEMS filters and/or the electronic circuit is selected from a group comprising a computing unit, a processor, a microprocessor, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a programmable logic circuit (PLD), a field programmable gate array (FPGA) and / or a programmable logic circuit. Method for producing a semiconductor component according to one or more of claims 1 - 11 comprising the following steps: a) providing a base substrate, b) attaching a MEMS component and / or an electronic circuit on or in the base substrate, characterized in that the base substrate comprises a concrete material, an insulating layer comprising a concrete material is applied to insulate an electrical connection and/or a protective cover comprising concrete material is applied, which at least partially encloses the MEMS component and/or the electronic circuit. Method according to the previous claim, characterized in that the concrete material is applied and / or processed by a method selected from a group comprising film casting, injection molding, additive manufacturing, embossing and / or joining, preferably by a selection of parameters of the method a pore structure and /or a roughness can be adjusted. Method according to one or more of claims 12 - 13, characterized in that the concrete material is applied in a pasty form, self-hardening of the concrete material being preferably used by an exothermic reaction. Method according to one or more of claims 12 - 14, characterized in that the base substrate has a material comprising concrete and the base substrate has an additive, the additive preferably being activated with an ablation process so that active areas are formed and the active areas through metallization can be used to provide an electrical connection of the MEMS component, wherein the electrical connection, preferably a conductor track, is preferably introduced by a galvanic process.