Method for manufacturing device, device, and deposition apparatus

Abstract

The present invention relates to a method of manufacturing an apparatus (10) comprising a non-twin epitaxial layer (30) of one or more semiconductor materials deposited on a surface (22) of a single crystal sapphire substrate (20) in a deposition apparatus (40). Furthermore, the present invention relates to an apparatus (10) comprising a non-twin epitaxial layer (30) of one or more semiconductor materials deposited on a surface (22) of a single crystal sapphire substrate (20). Furthermore, the invention relates to a deposition apparatus (40) for producing a device (10) according to claim 26, comprising a reaction chamber (42) sealable with respect to the ambient atmosphere (70) for arranging a single crystal sapphire substrate (20), heating means (50) for heating the substrate (20) and deposition means (60) for depositing an epitaxial layer (30) of one or more semiconductor materials on a surface (22) of the substrate (20).

Description

Technical Field

[0001] The present invention relates to a method of manufacturing a device, including depositing an un-twinned epitaxial layer of one or more semiconductor materials on a surface of a single crystal sapphire substrate in a deposition apparatus. In addition, the present invention relates to a device including an un-twinned epitaxial layer of one or more semiconductor materials deposited on a surface of a single crystal sapphire substrate. In addition, the present invention relates to a deposition apparatus for manufacturing the device, the deposition apparatus including a reaction chamber that is sealable relative to an ambient atmosphere for setting the single crystal sapphire substrate, a gas system for providing an adjustable atmosphere in the reaction chamber, a heating tool for heating the substrate, and a deposition tool for depositing an epitaxial layer of one or more semiconductor materials on the surface of the substrate.

Prior Art

[0002] Devices for depositing an epitaxial layer of one or more semiconductor materials on a substrate are the backbone of modern electronics and computer technology. However, the quality of the epitaxial layer depends to a large extent on the surface finish of the substrate used for the epitaxial growth of the semiconductor layer. For example, in the process of continuous miniaturization of electronic devices towards quantum components (such as qubits), it is necessary to have a very low density of structural defects within the deposited epitaxial layer and at the interfaces between it and the upper and lower layers, especially at the interface between it and the underlying substrate.

Summary of the Invention

[0003] Sapphire (Al2O3) is a material that is very suitable for use as a general substrate in microelectronics and nanomanufacturing. However, due to the chemical structure of sapphire as a single crystal based on two elemental components, most of the semiconductor materials used, such as silicon (Si), grow on a given surface of the sapphire substrate in two randomly selected energy-equivalent orientations. Therefore, domains of these orientations with uncontrollable sizes are formed during epitaxial growth, and the boundaries between these domains in turn act as defects and limit the usability of the manufactured device.

[0004] In summary, in order to improve the usability of a device including a semiconductor layer deposited on a single crystal sapphire substrate, it would be advantageous to grow the semiconductor epitaxial layer only in one direction among these energy-equivalent orientations, namely the so-called "non-twinned".

[0005] In view of the above, an object of the present invention is to provide an improved method for manufacturing a device, the device including an epitaxial layer of one or more semiconductor materials deposited on the surface of a single-crystal sapphire substrate in a deposition apparatus, a correspondingly provided apparatus, and a deposition apparatus configured accordingly, wherein the epitaxial layer can be provided as a non-twinned epitaxial layer.

[0006] This object is met by the respective independent claims. In particular, the object is met by a method for manufacturing a device according to claim 1, a device according to claim 26, and a deposition apparatus for manufacturing a device according to claim 27. The dependent claims describe preferred embodiments of the present invention. The details and advantages described with respect to the method according to the first aspect of the present invention also relate to the device according to the second aspect of the present invention and to the deposition apparatus for manufacturing the device according to the third aspect of the present invention, and vice versa, if of technical significance.

[0007] According to a first aspect of the present invention, the object is met by a method for manufacturing a device, the device including a non-twinned epitaxial layer of one or more semiconductor materials deposited on the surface of a single-crystal sapphire substrate in a deposition apparatus. The method according to the present invention includes the following steps:

[0008] a) Providing a miscut angle for the sapphire substrate selected in the range of 0.001° to 1° with respect to the (0001) plane surface of the single-crystal sapphire;

[0009] b) Placing the sapphire substrate provided in step a) in a reaction chamber of the deposition apparatus, subsequently sealing the reaction chamber with respect to the ambient atmosphere, and providing a preparation atmosphere in the reaction chamber;

[0010] c) Heating the sapphire substrate to provide a sapphire substrate having a preparation temperature selected in the range of 1400°C to 2000°C;

[0011] d) Heating the sapphire substrate so that the sapphire substrate has a deposition temperature different from the preparation temperature selected in the range of 300°C to 1400°C;

[0012] e) Depositing an epitaxial layer on the surface of the substrate in the reaction chamber, thereby further heating the substrate to continuously provide the deposition temperature.

[0013] A method according to a first aspect of the present invention allows for an apparatus to fabricate a non-twinned epitaxial layer comprising one or more semiconductor materials. The epitaxial layer is deposited on the surface of a single-crystal sapphire in a deposition apparatus. A deposition apparatus according to the present invention is any apparatus capable of providing an evaporated and / or sublimated material, which is subsequently deposited onto the surface of the sapphire substrate. The evaporated and / or sublimated material is appropriately selected to coat the surface with a corresponding epitaxial layer. In this sense, an epitaxial layer consisting solely of an evaporated and / or sublimated material, as well as an epitaxial layer comprising other material components beside the evaporated and / or sublimated material respectively (e.g., provided by a reaction atmosphere which is also appropriately selected), can be provided by implementing the method of the present invention.

[0014] As described above, simply providing a single-crystal sapphire substrate is not sufficient to ensure the growth of a non-twinned epitaxial layer of one or more semiconductor materials. This is why the method according to the present invention includes the following steps for preparing the surface of the sapphire substrate and subsequently controlling the coating of the surface with an epitaxial layer of one or more semiconductor materials.

[0015] In a first step a) of the method according to the present invention, an actively selected miscut is provided to the sapphire substrate. The miscut is selected with a miscut angle in the range of 0.001° to 1° relative to the (0001) plane surface of the single-crystal sapphire.

[0016] When cutting the substrate from a bulk single crystal, the cutting plane can be slightly away from the crystal plane, where, according to the present invention, the (0001) plane of the sapphire crystal is used as a reference plane. According to this so-called miscut angle, the prepared surface of the substrate will be terraces, whose terrace width and terrace orientation depend on the cutting direction and can thus be controlled at will. In other words, the miscut angle is the angle at which the single crystal is cut from the bulk substrate, where depending on the miscut angle, the pre-prepared surface will have a terrace width and terrace orientation depending on the cutting direction.

[0017] In addition to the absolute value of the miscut, its orientation is also important because the orientation direction of the step on the surface relative to the periodic arrangement of the crystal it forms defines a symmetry breaking, which allows for a choice between different, energetically equivalent in-plane surface reconstruction orientations. In the method according to the present invention, the crystallographic direction in the (0001) plane of the single-crystal sapphire is used to define the orientation of the miscut angle because the (0001) plane optimally maps the hexagonal symmetry of the single-crystal sapphire.

[0018] After the sapphire substrate with the defined misorientation angle is prepared, in step b) of the method according to the invention below, it is placed in the reaction chamber of the deposition equipment. The reaction chamber is sealable relative to the ambient atmosphere, thus allowing the remaining steps of the method according to the invention to be continued in a controlled environment, in particular relative to the atmosphere present on the surface of the sapphire substrate to be coated. In particular, step b) also includes providing a preparation atmosphere which is suitably selected for the following measures for preparing the surface of the sapphire substrate, in particular with regard to the pressure and / or composition of the preparation atmosphere.

[0019] Preferably, the reaction chamber encloses all the tools required for the preparation of the surface of the sapphire substrate and the subsequent coating of the sapphire substrate. In this way, the reaction chamber can be kept sealed relative to the ambient atmosphere, and the contamination of the manufactured device due to interaction with the environment can be minimized.

[0020] As described above, after providing the defined selected misorientation for the sapphire substrate in step a), the surface of the sapphire substrate is provided with steps. Since sapphire is a material comprising two different elemental components, namely Al2O3, the steps will include an alternating arrangement of surfaces composed of the two elemental components. Since the choice of the corresponding orientation in which one or more semiconductor materials will grow on the steps will be strongly influenced by the actual elemental composition of the surface of the substrate, depositing the epitaxial layer directly on the further untreated step surface of the sapphire substrate will result in domains of these orientations of the grown epitaxial layer.

[0021] Therefore, in order to further prepare the surface of the sapphire substrate, in step c) of the method according to the invention below, the substrate is heated to provide a preparation temperature for the substrate, in particular its surface, selected in the range of 1400 °C to 2000 °C. Any suitable method of heating the substrate can be used, such as direct contact heating or radiative heating.

[0022] The heating provides several advantages. First, impurities on the surface of the substrate can be evaporated. In addition, if a preparation atmosphere containing oxygen is used, the surface can also be oxidized.

[0023] In addition, heating the substrate will also result in an annealing process. In other words, the number of missing or extra atoms on the surface of the substrate can be reduced, and the discontinuities in symmetry present even in the bulk of the substrate surface can also be repaired.

[0024] Finally, in step c) of the method according to the present invention, the temperature of the substrate for heating the substrate is selected in the range of 1400 °C to 2000 °C, and the temperature is high enough so that the most volatile component of the crystal, i.e., oxygen, sublimes from the surface. On the one hand, this exposes a more reactive aluminum reconstruction layer of sapphire on the surface, thus making it easier to deposit the epitaxial layer. On the other hand, when preparing the surface of the sapphire substrate, all the above-mentioned steps caused by a properly selected misorientation have the same termination. Therefore, the selection of the corresponding orientation in which one or more semiconductor materials will grow on the steps is the same for all steps.

[0025] In other words, after step c), the surface of the single-crystal sapphire substrate is properly prepared for depositing a non-twinned epitaxial layer of one or more semiconductor materials. In summary, the preparation is based on the misorientation with respect to the (0001) plane surface of the single-crystal sapphire when actually cutting the sapphire substrate, and subsequent heating of the substrate for annealing the surface and providing a single surface termination on all the formed steps on the substrate surface.

[0026] As described above, in step c), the substrate is heated to provide a preparation temperature that is most suitable for preparing the surface of the sapphire substrate. However, the preparation temperature is suitable for the preparation but not for subsequently depositing the epitaxial layer of the one or more semiconductor materials.

[0027] Therefore, in the next step d) of the method according to the present invention, the substrate is heated again, but to a deposition temperature properly selected for subsequent coating. The deposition temperature is different from the preparation temperature, in particular, much lower than the preparation temperature. Basically, the deposition temperature is selected in the range of 300 °C to 1400 °C. Preferably, the deposition temperature is selected such that, on the one hand, the influence on the substrate due to heating (such as an annealing process or the sublimation of volatile components of the substrate) is minimized, and on the other hand, the mobility of the material deposited on the substrate surface for forming the epitaxial layer is high enough so that the epitaxial layer can grow substantially defect-free.

[0028] After reaching the deposition temperature of the substrate, the actual deposition of an epitaxial layer of one or more semiconductor materials takes place in the last step e) of the method according to the invention by relatively cooling from the preparation temperature and then heating to maintain the deposition temperature, or after cooling to a temperature below the deposition temperature, for example for surface analysis, and then reheating the substrate to the deposition temperature. Basically, any deposition method can be used for said deposition, in fact, the deposition method most suitable for the corresponding one or more semiconductor materials can be used. During the deposition, the substrate is further heated to continuously maintain the substrate at a suitably selected deposition temperature. Thereby, the highest quality of the deposited epitaxial layer can be ensured. Thereby, a non-twinned and substantially defect-free epitaxial layer can be provided.

[0029] In summary, by implementing the method according to the invention, a non-twinned epitaxial layer of one or more semiconductor materials can be provided substantially defect-free on a single-crystal sapphire substrate. Such a layer potentially allows the integration of microelectronic components based on semiconductor layers, such as silicon-based microelectronic circuits, on the sapphire substrate. This allows sapphire to be used as a common substrate for the heterogeneous monolithic integration of various materials.

[0030] The method is further characterized in that in step a), the misorientation angle is selected in the range of 0.01° to 0.1°, particularly in the range of 0.03° to 0.07°, and preferably, the misorientation angle is 0.05°. By selecting the misorientation angle, the height and width dimensions of the steps formed on the substrate surface can be adjusted. The misorientation angle is selected in the range of 0.01° to 0.1°, particularly in the range of 0.03° to 0.07°, and preferably, the misorientation angle is 0.05°, which has been found to be particularly suitable for both providing sufficient steps on the surface to actively break the hexagonal symmetry of the (0001) plane surface of single-crystal sapphire and simultaneously maximizing the dimensions of said steps.

[0031] In addition, the method according to the invention may include providing a vacuum atmosphere having a pressure selected in the range of 10 -8 hPa to 10 -12 hPa as the preparation atmosphere, or the preparation atmosphere includes, preferably consisting of oxygen, particularly composed of O2 and / or O3, having a pressure in the range of 10 4 hPa to 10 -6Pressures selected within the hPa range. Providing the preparation atmosphere as a vacuum atmosphere offers the advantage of a very pure environment during the preparation process on the surface of the sapphire substrate. However, since sapphire is essentially an oxide of aluminum and thus contains oxygen, a preparation atmosphere containing oxygen, especially O2 and / or O3, is also useful as this allows for additional oxidation of the surface. In both ways, a surface of the substrate can be provided that includes a uniform surface termination spanning all steps.

[0032] According to another embodiment of the method of the present invention, in step c) and / or step d) and / or step e), the sapphire substrate is heated by irradiating the sapphire substrate with a laser, especially a laser having a wavelength selected in the range of 1 μm to 20 μm, preferably provided by a CO2 laser source. The laser can advantageously be used to heat the substrate to a desired and defined temperature and is relatively simple to use. The substrate can preferably be irradiated with the laser on the back side to be heated to the desired preparation and / or deposition temperature. Sapphire is transparent at visible light wavelengths and absorbs well at long infrared wavelengths, so a CO2 laser of about 10 μm can be used. Preferably, the temperature can be controlled, for example, by using a pyrometer aimed at the back side of the wafer. Preferably, a single-crystal sapphire substrate can be prepared to have a rough surface on its back side to assist in absorbing laser radiation. Thus, by not performing any further grinding or polishing steps after cutting from a bulk crystal, or by rough grinding or other procedures that produce a surface roughness with a large local deviation from the average surface, the back side of the substrate is roughened on a length scale at or above the heating laser wavelength.

[0033] Furthermore, the method according to the present invention may include providing the preparation temperature to the sapphire substrate for a duration of 200 seconds or longer in step c). The above annealing and sublimation processes during the preparation process on the surface of the sapphire substrate are not instantaneous but require some time. It has been found that a time span of 200 seconds is basically sufficient for the necessary preparation process. On the one hand, the time span is chosen to be as short as possible to provide an efficient process. On the other hand, it needs to be long enough so that uncertainties in the definition of the start and end points of the time span, such as time errors, settling processes, control transients, and transients due to the heat capacity of the substrate, basically do not affect the reproducibility of the heating process. Generally, the necessary duration of the process depends on the actual preparation temperature provided, where a higher preparation temperature allows for a shorter duration.

[0034] The method according to the invention may further be characterized in that, in step c), the preparation temperature is selected in the range of 1600 °C to 1800 °C, preferably, wherein the preparation temperature is 1700 °C. As described above, the preparation temperature must be selected high enough to ensure that the necessary processes occur during the preparation on the substrate surface. It has been found that a preparation temperature selected in the range of 1600 °C to 1800 °C, preferably a preparation temperature of 1700 °C, meets this requirement while limiting the requirements for the heating tool used to heat the substrate in step c) of the method according to the invention.

[0035] In another embodiment of the method according to the invention, in steps d) and e), the deposition temperature is selected in the range of 700 °C to 1200 °C, especially in the region of 900 °C to 1100 °C, preferably, wherein the deposition temperature is 1000 °C, and wherein, in step e), the epitaxial layer comprises silicon (Si), preferably consists of silicon (Si) as a semiconductor material. Silicon is one of the most commonly used semiconductor materials in modern microelectronics. Selecting a deposition temperature in the range of 700 °C to 1200 °C, especially in the range of 900 °C to 1100 °C, preferably, wherein the deposition temperature is 1000 °C, can ensure the deposition of a non-twinned epitaxial layer of silicon on the sapphire substrate with the lowest defect density. In fact, an epitaxial layer comprising silicon, preferably consisting of silicon, can be provided substantially defect-free.

[0036] Furthermore, the method according to the invention may be characterized in that, after providing the preparation atmosphere in step b), the reaction chamber is kept continuously sealed with respect to the ambient atmosphere until the deposition is completely finished in step e). In other words, all steps c) to e) are carried out continuously in the same reaction chamber, and the sealing with respect to the ambient atmosphere remains unchanged throughout the process. Therefore, all steps c) to e) of the method according to the invention are carried out in-situ. Thereby, external influences on the substrate and the subsequently formed device can be avoided, especially contact with the ambient atmosphere.

[0037] Furthermore, the method according to the invention may include that, after step e), the thickness of the epitaxial layer is 50 nm or greater, preferably 3 μm or greater. A wide variety of thicknesses can be provided, especially appropriately selected for the respective purposes of the devices manufactured using the method according to the invention.

[0038] In another embodiment of the method according to the invention, during the deposition of the epitaxial layer in step e), an additional material is deposited into the epitaxial layer for doping the epitaxial layer. By doping a semiconductor material with an additional material, its inherent properties with respect to conductivity or other physical properties can be specifically changed. Therefore, the industrial application possibilities of the devices manufactured in this way can be significantly expanded.

[0039] Furthermore, the method according to the invention may include, in step e), using two or more groups of materials of different semiconductor materials during the deposition of the epitaxial layer, wherein each of the groups of materials includes one or more semiconductor materials, and wherein the two or more groups of materials are used to continuously and / or stepwise and / or repeatedly stepwise modulate the composition of the epitaxial layer. Microelectronic components, such as transistors, typically rely on the interaction of layers of different semiconductor materials. Therefore, by using two or more different groups of materials to deposit the epitaxial layer during step e), the use of the device manufactured by the method according to the invention for a variety of microelectronic components can be provided.

[0040] Furthermore, the method according to the invention is characterized in that the deposition equipment uses one or more of the following deposition methods:

[0041] - Thermal Laser Epitaxy (TLE)

[0042] - Pulsed Laser Deposition (PLD)

[0043] - Physical Vapor Deposition (PVD)

[0044] - Electron Beam Physical Vapor Deposition (EBPVD)

[0045] - Sputtering Deposition

[0046] - Molecular Beam Epitaxy (MBE)

[0047] - Chemical Vapor Deposition (CVD)

[0048] - Metal-Organic Chemical Vapor Deposition (MOCVD)

[0049] The list is not exhaustive, and other suitable deposition methods may also be used in individual deposition equipment. In particular, for the corresponding one or more semiconductor materials used to deposit the epitaxial layer in step e) of the method according to the invention, the most suitable deposition method can be selected.

[0050] Furthermore, the method may include providing a deposition atmosphere suitable for depositing the epitaxial layer in step e) in the reaction chamber after step c) and before step e). Some of the one or more semiconductor materials used to deposit the epitaxial layer may require a special deposition atmosphere. This may be the case if the corresponding semiconductor material is a compound material containing a compound element that cannot be provided as a solid target but only in its gaseous form. For example, for nitrides such as GaN or InN as semiconductor materials, a deposition atmosphere containing nitrogen can be used. In general, by providing the deposition atmosphere, the variety of semiconductor materials available for use in the method according to the invention can be expanded.

[0051] The method according to the invention may include, by the deposition atmosphere, including at 10-6 from 1 to 10 1 hPa, especially in the range of 10 -4 to 10 1 h Pa, especially 10 -4 to 10 -2 hPa, the pressure selected within this range is further enhanced. In particular, for each device to be manufactured, especially for each epitaxial layer of one or more semiconductor materials to be deposited in step e), the most suitable pressure of the deposition atmosphere can be selected. Thereby, the final quality of the manufactured device can be improved.

[0052] In another enhanced embodiment of the method according to the present invention, the deposition atmosphere includes a process gas selected from the group consisting of oxygen (O), ozone (O3), plasma-activated oxygen (O), nitrogen (N), plasma-activated nitrogen (N), phosphorus (P), sulfur (S), selenium (Se), mercury (Hg), NH3, N2O, CH4, and combinations thereof. The list is not closed, and other suitable process gases can also be used in each deposition device. Therefore, a wide range of semiconductor materials that require an appropriately selected deposition atmosphere can be provided for the epitaxial layers of the manufactured devices.

[0053] Furthermore, the method according to the present invention is characterized in that one of the one or more semiconductor materials is an elemental semiconductor. Elemental semiconductors are the simplest semiconductor materials because they consist of a single chemical element, and thus only a single material source is required during the deposition of the epitaxial layer in step e) of the method according to the present invention. In addition, elemental semiconductors such as silicon are particularly widely used semiconductor materials in modern microelectronics.

[0054] The method according to the present invention can be further enhanced by: as the elemental semiconductor, one of the following metalloids is selected from the group consisting of silicon (Si), germanium (Ge), diamond-like carbon (C), arsenic (As), boron (B), sulfur (S), selenium (Se), and tellurium (Te). The list is not closed, and other suitable elemental semiconductors can also be used. Thereby, a wide range of semiconductor materials can be provided that are selected for the purpose of the manufactured device.

[0055] Alternatively or additionally, the method according to the present invention may include that one of the one or more semiconductor materials is silicon carbide (SiC). SiC is used, for example, in semiconductor electronic devices that operate at high temperatures or high voltages or both. Therefore, by using silicon carbide as one of the one or more semiconductor materials, devices can be manufactured by the method according to the present invention that is suitable for high temperatures or high voltages.

[0056] Furthermore, the method according to the invention is characterized in that one of the one or more semiconductor materials is a III-V compound semiconductor comprising one or more group III elements and one or more group V elements, wherein the one or more group III elements are selected from the group consisting of boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl), and wherein the one or more group V elements are selected from the group comprising nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The advantage of III-V compound semiconductors compared to elemental semiconductors is that their bandgap can vary with the material composition, typically continuously and / or over a wide range. Thus, the electrical characteristics of a device having an epitaxial layer comprising a III-V compound semiconductor as the semiconductor material can be changed in a targeted manner. Such devices comprising III-V compound semiconductors are mainly used in optical devices such as detectors, light-emitting diodes, or lasers, but are also increasingly used in high-power electronic applications.

[0057] Furthermore, the method according to the invention can be enhanced by the III-V compound semiconductor being a binary compound consisting of one group III element and one group V element, in particular wherein the III-V compound semiconductor is selected from the group comprising GaN, AlN, InN, BN, GaP, AlP, InP, BP, GaAs, AlAs, InAs, BAs, GaSb, AlSb, and InSb. The list is not closed, and other suitable binary III-V compound semiconductors can also be used. Thereby, a wide range of semiconductor materials can be provided, which are appropriately selected for the purpose of the device to be manufactured. Binary compound semiconductors only require two material sources during the deposition of the epitaxial layer in step e) of the method according to the invention, wherein, for example, for nitrides and / or phosphides, one of the material sources can be provided by a suitably selected deposition atmosphere.

[0058] Alternatively, the method according to the invention can be enhanced by the III-V compound semiconductor being a multinary compound consisting of a mixture of three or more group III elements and group V elements, in particular wherein the III-V compound semiconductor is selected from the group comprising InGaN, InGaP, AlGaAs, InGaAs, AlGaSb, InGaSb, and Ga 1- x In x As 1-y P ygroups. The list is not closed, and other suitable ternary III-V compound semiconductors can also be used. Ternary compounds are an option for changing the semiconductor bandgap almost continuously over a wide energy range. Thereby, a wide range of semiconductor materials can be provided, which are appropriately selected for the purpose of the device to be manufactured.

[0059] According to another embodiment, the method according to the invention is characterized in that one of the one or more semiconductor materials is a II-VI compound semiconductor comprising one or more group II elements and one or more group VI elements, wherein the one or more group II elements are selected from the group consisting of beryllium (Be), zinc (Zn), cadmium (Cd) and mercury (Hg), and wherein the one or more group VI elements are selected from the group consisting of oxygen (O), sulfur (S), selenium (Se) and tellurium (Te). Similar to III-V compound semiconductors, II-VI compound semiconductors also have the advantage over elemental semiconductors that their bandgap can vary with the material composition. Thus, the electrical properties of a device having an epitaxial layer comprising a II-VI compound semiconductor as the semiconductor material can be changed in a targeted manner. Such devices comprising a II-VI compound semiconductor generally exhibit a large direct bandgap, which makes them popular in short-wavelength applications in optoelectronics.

[0060] Furthermore, the method according to the invention can be enhanced by the II-VI compound semiconductor being a binary compound composed of one group II element and one group VI element, in particular wherein the II-VI compound semiconductor is selected from the group consisting of ZnO, ZnS, CdS, ZnSe, CdSe, BeTe, ZnTe and CdTe. The list is not closed, and other suitable binary II-VI compound semiconductors can also be used. Thereby, a wide range of semiconductor materials can be provided, which are appropriately selected for the purpose of the device to be manufactured. Binary compound semiconductors only require two material sources during the deposition of the epitaxial layer in step e) of the method according to the invention, wherein, for example, for oxides and / or sulfides, one of the material sources can be provided by a suitably selected deposition atmosphere.

[0061] Alternatively, the method according to the present invention can be enhanced by a multicomponent compound in which the II-VI compound semiconductor is composed of a mixture of three or more Group II elements and Group VI elements, in particular where the II-VI compound semiconductor is selected from the group consisting of (Zn, Cd)Se, (Be, Zn)Se, (Be, Cd)Se, and Zn(S, Se). The list is not closed, and other suitable multicomponent II-VI compound semiconductors can also be used. Multicomponent compounds are an option for changing the semiconductor bandgap almost continuously over a wide energy range. Thereby, a wide range of semiconductor materials suitable for the purposes of the fabricated device can be provided.

[0062] In a further enhanced embodiment of the method according to the present invention, one of the one or more semiconductor materials is an alloy of two or more semiconductor materials, in particular where the two or more semiconductor materials are selected from the group consisting of elemental semiconductors, III-V compound semiconductors, and II-VI compound semiconductors. In other words, a combination of two or more different semiconductor materials forming the alloy can also be used as part of the epitaxial layer. Thereby, the wide range of possible compositions of the non-twinned epitaxial layer deposited on the sapphire substrate can be further extended.

[0063] According to a second aspect of the present invention, the object is met by a device comprising a non-twinned epitaxial layer of one or more semiconductor materials deposited on the surface of a single-crystal sapphire substrate. The device according to the second aspect of the present invention is characterized in that the device can be obtained by the method according to the first aspect of the present invention. In other words, by implementing the method according to the first aspect of the present invention, the device according to the second aspect of the present invention is manufactured. Therefore, the device according to the second aspect of the present invention provides all the features and advantages described above with respect to the method according to the first aspect of the present invention.

[0064] According to a third aspect of the present invention, the object is met by a deposition apparatus for manufacturing the device according to the second aspect of the present invention, the deposition apparatus comprising: a reaction chamber for setting a single-crystal sapphire substrate and sealable with respect to the ambient atmosphere, a gas system for providing an adjustable atmosphere in the reaction chamber, a heating tool for heating the substrate, and a deposition tool for depositing an epitaxial layer of one or more semiconductor materials on the surface of the substrate. The deposition apparatus according to the third aspect of the present invention is characterized in that the deposition apparatus is configured to perform the method for manufacturing the device according to the second aspect of the present invention.

[0065] The deposition apparatus according to the present invention can be configured to include, but is not limited to, performing a deposition method selected from TLE, PLD, PVD, EBPVD, sputter deposition, MBE, CVD, and / or MOCVD. Each single-crystal sapphire substrate to be coated can be disposed in a reaction chamber of the deposition apparatus, and the reaction chamber is sealable relative to the ambient atmosphere. Subsequently, the substrate can be heated by a correspondingly provided heating tool of the deposition apparatus. The gas system of the deposition apparatus ensures that a suitable adjustable atmosphere exists in the reaction chamber, including both a preparation atmosphere and, when needed, a deposition atmosphere.

[0066] In summary, since the deposition apparatus according to the third aspect of the present invention is configured to perform the method according to the first aspect of the present invention, particularly for manufacturing the device according to the second aspect of the present invention, it also provides, respectively, all the features and advantages described above with respect to the method according to the first aspect of the present invention and the device according to the second aspect of the present invention.

[0067]

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The present invention will be explained in detail below by way of examples with reference to the respective drawings. In particular, it is shown in the figures:

[0069] Figure 1 A method for manufacturing a device according to the present invention,

[0070] Figure 2 The deposition apparatus of the present invention during the execution of the method according to the present invention,

[0071] Figure 3 Two measurements of the device according to the present invention, and

[0072] Figure 4 Two top views of the device according to the present invention.

[0073]

EMBODIMENTS

[0074] Figure 2 The deposition apparatus 40 according to the present invention is depicted in subfigures A and B during different stages of the method according to the present invention as Figure 1 shown. Therefore, Figure 1 and Figure 2 will be described together below.

[0075] The deposition apparatus 40 according to the present invention can be configured to include, but is not limited to, a deposition tool 60 for performing a deposition method selected from TLE, PLD, PVD, EBPVD, sputter deposition, MBE, CVD, and / or MOCVD. Preferably, as Figure 2 shown, the deposition apparatus 40 can be configured as a TLE system 46.

[0076] The deposition apparatus 40 includes a reaction chamber 42. The reaction chamber 42 is sealable relative to the ambient atmosphere 70. The gas system 44 of the deposition apparatus 40 allows an adjustable atmosphere 72, 74 to be provided within the reaction chamber 42. A setting tool (not shown) is used to position the substrate 20 within the reaction chamber 42 for subsequent coating of the surface 22 of the substrate 20.

[0077] In the method according to the invention, the substrate 20 is provided as a single crystal sapphire substrate 20 which has a misorientation angle selected in the range from 0.001° to 1° relative to the (0001) plane surface of the single crystal sapphire, according to step a)A of the method according to the invention. More preferably, the misorientation angle is selected in the range from 0.01° to 0.1°, in particular in the range from 0.03° to 0.07°, and preferably, the misorientation angle is 0.05°. The substrate 20 is disposed in the reaction chamber 42.

[0078] In the following step b)B of the method according to the invention, the reaction chamber 42 is sealed relative to the ambient atmosphere 70 and filled with a suitably selected preparation atmosphere 72, for example, a vacuum atmosphere having a pressure selected in the range from 10 -8 hPa to 10 -12 hPa or an atmosphere comprising preferably oxygen (in particular O2 and / or O3) having a pressure selected in the range from 10 4 hPa to 10 -6 hPa. The preparation atmosphere 72 is provided by the gas system 44 of the deposition apparatus 40.

[0079] As Figure 2 shown in sub - figure A, in order to prepare the surface 22 of the substrate 20, in a subsequent step c)C of the method according to the invention, the substrate 20 is heated to a preparation temperature selected in the range from 1400 °C to 2000 °C. To ensure effective preparation of the surface 22 of the substrate, a heating duration of 200 seconds or more for the substrate 20 is provided. In particular, the preparation temperature is selected in the range from 1600 °C to 1800 °C, and preferably, the preparation temperature is 1700 °C. As shown, the heating tool 50 for heating the substrate may be a substrate heating laser 52 which provides a laser beam incident on the substrate 20, in particular on the back surface of the substrate 20. Since the substrate 20 is single crystal sapphire, a laser beam having a wavelength selected in the range from 1 μm to 20 μm can be used. Preferably, the substrate heating laser 52 includes a CO2 laser source.

[0080] The heating provides several advantages. First, impurities on the surface 22 of the substrate 20 can be evaporated. Additionally, if a preparation atmosphere 72 containing oxygen is used, the surface can also be oxidized. Further, heating of the substrate 20 also results in an annealing process. Finally, the most volatile component in the crystal, namely oxygen, sublimes from the surface 22 of the substrate 20. This exposes a more reactive aluminum reconstruction layer of sapphire on the surface 22, thus making the deposition of the epitaxial layer easier. Additionally, the entire surface 22 of the sapphire substrate 20 has the same reconstruction and thus termination. Therefore, a non-twinned growth of one or more semiconductor materials for forming the epitaxial layer 30 can be provided (see Figure 2 subfigure B).

[0081] In summary, after step c), the surface 22 of the single-crystal sapphire substrate 20 is properly prepared for the deposition of a non-twinned epitaxial layer 30 of one or more semiconductor materials. The preparation is based on the misorientation of the (0001) planar surface of the single-crystal sapphire substrate 20 during the cutting of the sapphire, and subsequent heating of the substrate 20 to anneal the surface 22, thereby providing a single surface termination for the surface on the entire surface 22 of the substrate 20.

[0082] After the substrate 20 is prepared in steps a)A to c)C of the method according to the invention, the substrate 20 is in most cases still at the preparation temperature, which is usually not perfect or even not suitable for subsequently coating the surface 22 with the epitaxial layer 30. Therefore, in the next step d)D of the method according to the invention, the temperature of the substrate 20 is changed to a more suitable deposition temperature different from the preparation temperature. Depending on the expected one or more semiconductor materials for the epitaxial layer 30, the deposition temperature can be selected in the range of 300 °C to 1400 °C. For example, for silicon as the semiconductor material, it can be in the range of 700 °C to 1200 °C, particularly in the range of 900 °C to 1100 °C, preferably 1000 °C. Again, preferably, the source heating laser 52, particularly a CO2 laser, can be used to heat the substrate 20. For example, if a specific gradient of defects such as dislocations is prepared, or a heterostructure of different layers 30 of the semiconductor material is prepared, the deposition temperature can also be changed subsequently during the deposition process.

[0083] The heating in step d)D is kept activated in the subsequent step e)E of the method according to the invention to continuously provide the surface 22 of the substrate 20 during the deposition of the epitaxial layer 30, as Figure 2As shown in sub - figure B. Since the deposition apparatus 40 shown is a TLE system 46, the corresponding deposition tool 60 includes a source heating laser 66, as indicated by the arrow, representing the laser beam provided by the source heating laser 66 for evaporating and / or sublimating the source material 64 provided as source 62 within the reaction chamber 42. The evaporated and / or sublimated source material 64 impinges on the surface 22 prepared in the first steps a) to c) of the method according to the invention, thereby forming a non - twinned epitaxial layer 30. By continuously providing the substrate 20 at the deposition temperature of the substrate 20, the high quality of the deposited epitaxial layer 30 can be ensured. Thus, a non - twinned and substantially defect - free epitaxial layer 30 can be provided.

[0084] Preferably, throughout the method according to the invention, i.e., from the sealing in step b)B until the end of the coating of the substrate 20 in step e)E, the reaction chamber 42 remains sealed relative to the ambient atmosphere. Thereby, any harmful effects of the contact of the epitaxial layer 30 with the ambient atmosphere can be avoided.

[0085] The sealing of the reaction chamber 42 during the execution of the method according to the invention also allows the reaction chamber 42 to be filled with a deposition atmosphere 74 after step c)C, the deposition atmosphere 74 being suitable for the intended epitaxial layer 30 to be deposited on the surface 22 of the substrate 20. The deposition atmosphere 74 can include, for example, process gases selected from the group consisting of oxygen (O), ozone (O3), plasma - activated oxygen (O), nitrogen (N), plasma - activated nitrogen (N), phosphorus (P), sulfur (S), selenium (Se), mercury (Hg), NH3, N2O, CH4, and combinations thereof. Additionally, or alternatively, the deposition atmosphere 74 can include a pressure selected in the range of 10 -6 to 10 1 hPa, particularly in the range of 10 -4 to 10 1 hPa, particularly in the range of 10 -4 to 10 -2 hPa.

[0086] In Figure 2 sub - figure B, the epitaxial layer 30 is only schematically depicted. The epitaxial layer 30 can have a thickness of, for example, 50 nm or greater, preferably 3 μm or greater. Additionally, additional materials can be deposited into the epitaxial layer 30 for doping the epitaxial layer 30. Alternatively or additionally, sub - layers comprising different semiconductor materials can be used to continuously and / or stepwise and / or repeatedly stepwise modulate the composition of the epitaxial layer 30.

[0087] In addition, a variety of different semiconductor materials can be used to form the epitaxial layer 30. The range of possible materials includes elemental semiconductors such as silicon or germanium, group III-V compound semiconductors such as GaN, GaAs or InGaN, and / or group II-VI compound semiconductors such as ZnO, CdSe or (Zn, Cd)Se. In addition, combinations and / or alloys of the above can be used.

[0088] In summary, by implementing the method of the present invention and / or by using the deposition apparatus 40 of the present invention, a non-twinned epitaxial layer 30 of one or more semiconductor materials can be provided substantially defect-free on the single-crystal sapphire substrate 20. Such an epitaxial layer 30 potentially allows the integration of semiconductor layer-based microelectronic components, such as silicon-based microelectronic circuits, on the sapphire substrate 20. This allows the use of sapphire as a common substrate 20 for heterogenous monolithic integration of different materials.

[0089] In Figure 3 and Figure 4 shows the actual measurement results of a non-twinned epitaxial layer 30 of silicon on a single-crystal sapphire substrate 20 fabricated by implementing the method of the present invention (see Figure 1 ) in a deposition apparatus 40 according to the present invention (see Figure 2 , particularly subfigure B).

[0090] Due to the uniform selection of only one of the two possible rotation domains of the sapphire surface 22 of the sapphire substrate 20, during the deposition of the epitaxial layer 30, silicon nucleates and grows only in one direction without twins and associated defects. This is verified by the x-ray analysis of such a silicon layer on sapphire (0001) shown in subfigure A of Figure 3 . Two x-ray diffraction scans are shown in the upper panel of the epitaxial layer 30 of silicon and in the lower panel of the underlying sapphire substrate 20. As shown, the silicon peak repeats only every 120°, which is the case only when there is a single in-plane orientation of (111)-oriented silicon. For a twinned layer, six peaks would be measured for each rotation instead of three.

[0091] Figure 3 Subfigure B of depicts the x-ray θ-2θ scan of the same sample, which sample contains an epitaxial layer 30 of silicon on a sapphire substrate 20. The uniform (111) orientation of the epitaxial layer 30 including silicon is confirmed by the x-ray θ-2θ scan. Only the (111) and (333) reflections associated with silicon are parallel to the α-A2O3 (0006) and (000.12) planes perpendicular to the surface 22 in the growth direction of the epitaxial layer 30 (except for misorientation).

[0092] Figure 3 The two measurement results shown together confirm that the silicon epitaxial layer 30 is non-twinned and has only a single orientation with respect to the substrate 20.

[0093] In Figure 4 a top view of two samples of the epitaxial layer 30 on the sapphire substrate 20 is shown. The difference between the two samples is the respective thickness of the epitaxial layer 30, i.e., 300 nm in subfigure A and 1.3 μm in subfigure B.

[0094] The corresponding silicon epitaxial layer 30 still has some defects due to its 32.8% imperfect lattice mismatch with the substrate 20. This means a close match of three Al2O3 lattice constants to two silicon lattice constants (ideally 33.333…%). However, these defects seem to disappear significantly as the thickness of the epitaxial layer 30 increases.

[0095] As described above, Figure 4 subfigure A of

[0096] shows the epitaxial layer 30 with a thickness of approximately 300 nm, about 1 / 3 of the distance of the image size tickmark at the top and left of the image. At this stage, the surface of the epitaxial layer 30 is still quite rough, where the lowest regions may reach down to or very close to the surface 22 of the substrate 20. Figure 4 However, the thicker epitaxial layer 30, as shown in subfigure B of

[0097] shows a closed surface of the epitaxial layer 30. The depicted thickness of the epitaxial layer 30 is approximately as thick as the distance of the horizontal scale. As shown by the numbers on the scale, the highest and lowest points in the scan now only span 1 / 20 of the total thickness of the epitaxial layer 30. Flat terraces extend several micrometers in the horizontal direction. For even thicker layers, further smoothing and improvement of the surface crystal quality occur, particularly allowing the use of layers and devices fabricated according to the present invention in silicon-based devices and nanostructures.

[0098] 10: Device

[0099] 20: Substrate

[0100] 22: Surface

[0101] 30: Epitaxial layer

[0102] 40: Deposition equipment

[0103] 42: Reaction chamber

[0104] 44: Gas system

[0105] 46: TLE system

[0106] 50: Heating tool

[0107] 52: Substrate heating laser

[0108] 60: Deposition tool

[0109] 62: Source

[0110] 64: Source material

[0111] 66: Source heating laser

[0112] 70: Ambient atmosphere

[0113] 72: Preparation atmosphere

[0114] 74: Deposition atmosphere

[0115] A: Step a)

[0116] B: Step b)

[0117] C: Step c)

[0118] D: Step d)

[0119] E: Step e)

Claims

1. A method of manufacturing a device (10), the device including a non-twinned epitaxial layer (30) of one or more semiconductor materials deposited on a surface (22) of a single-crystal sapphire substrate (20) in a deposition apparatus (40), the method comprising the steps of: a) providing a sapphire substrate (20) having a misorientation angle selected in the range of 0.001° to 1° relative to the (0001) plane surface of the single-crystal sapphire; b) disposing the sapphire substrate (20) provided in step a) in a reaction chamber (42) of the deposition apparatus (40), subsequently sealing the reaction chamber (42) relative to the ambient atmosphere (70), and providing a preparation atmosphere (72) in the reaction chamber (42); c) heating the sapphire substrate (20) to provide a sapphire substrate (20) having a preparation temperature selected in the range of 1400°C to 2000°C; d) heating the sapphire substrate (20) to provide a sapphire substrate (20) having a deposition temperature selected in the range of 300°C to 1400°C, different from the preparation temperature; and e) depositing an epitaxial layer (30) on the surface (22) of the substrate (20) in the reaction chamber (42), thereby further heating the substrate (20) to continuously provide the deposition temperature.

2. The method according to claim 1, Among them, in step a), the misorientation angle is selected in the range of 0.01° to 0.1°, particularly in the range of 0.03° to 0.07°, preferably, wherein the misorientation angle is 0.05°.

3. The method according to claim 1 or 2, Among them, Provide a vacuum atmosphere with a pressure selected within the range of 10 -8 hPa to 10 -12 hPa as the preparation atmosphere (72), or the preparation atmosphere (72) includes oxygen, preferably consists of oxygen, especially consists of O2 and / or O3, and has a pressure selected within the range of 10 4 hPa to 10 -6 hPa.

4. The method according to any one of claims 1 to 3, Among them, in step c) and / or step d) and / or step e), by irradiating the sapphire substrate (20) with a laser, preferably provided by a CO2 laser source, particularly a laser having a wavelength selected in the range of 1μm to 20μm, to heat the sapphire substrate (20).

5. The method according to any one of claims 1 to 4, Among them, in step c), providing the preparation temperature to the sapphire substrate (20) for a duration of 200 seconds or longer.

6. The method according to any one of claims 1 to 5, Among them, in step c), the preparation temperature is selected in the range of 1600°C to 1800°C, preferably, wherein the preparation temperature is 1700°C.

7. The method according to any one of claims 1 to 6, Among them, in steps d) and e), the deposition temperature is selected in the range of 700°C to 1200°C, particularly in the range of 900°C to 1100°C, preferably, wherein the deposition temperature is 1000°C, and wherein, in step e), the epitaxial layer (30) includes silicon (Si), preferably consisting of silicon (Si) as the semiconductor material.

8. The method according to any one of claims 1 to 7, Among them, after providing the preparation atmosphere (72) in step b), the reaction chamber (42) is kept continuously sealed relative to the ambient atmosphere (70) until the deposition in step e) is completely finished.

9. The method according to any one of claims 1 to 8, Among them, After step e), the thickness of the epitaxial layer (30) is 50 nm or greater, preferably 3 μm or greater.

10. The method according to any one of claims 1 to 9, Among them, During the deposition of the epitaxial layer (30) in step e), additional material is deposited into the epitaxial layer (30) for doping the epitaxial layer (30).

11. The method according to any one of claims 1 to 10, Among them, During the deposition of the epitaxial layer in step e), two or more material groups of different semiconductor materials are used, where each of the material groups includes one or more semiconductor materials, and where the two or more material groups are used to continuously and / or stepwise and / or repeatedly stepwise modulate the composition of the epitaxial layer (30).

12. The method according to any one of claims 1 to 11, Among them, The deposition apparatus (40) uses one or more of the following deposition methods: - Thermal Laser Epitaxy (TLE) (46) - Pulsed Laser Deposition (PLD) - Physical Vapor Deposition (PVD) - Electron Beam Physical Vapor Deposition (EBPVD) - Sputtering Deposition - Molecular Beam Epitaxy (MBE) - Chemical Vapor Deposition (CVD) - Metal Organic Chemical Vapor Deposition (MOCVD).

13. The method according to any one of claims 1 to 12, Among them, After step c) and before step e), a deposition atmosphere (74) suitable for depositing the epitaxial layer (30) in step e) is provided in the reaction chamber (42).

14. The method according to claim 13, Among them, The deposition atmosphere (74) includes a pressure selected in the range of 10 -6 to 10 1 hPa, particularly in the range of 10 -4 to 10 1 hPa, especially in the range of 10 -4 to 10 -2 hPa.

15. The method according to claim 13 or 14, Among them, The deposition atmosphere (74) includes a process gas selected from the group consisting of oxygen (O), ozone (O3), plasma-activated oxygen (O), nitrogen (N), plasma-activated nitrogen (N), phosphorus (P), sulfur (S), selenium (Se), mercury (Hg), NH3, N2O, CH4, and combinations thereof.

16. The method according to any one of claims 1 to 15, Among them, One of the one or more semiconductor materials is an elemental semiconductor.

17. The method according to claim 16, Among them, As the elemental semiconductor, one of the following metalloids is selected from the group consisting of silicon (Si), germanium (Ge), diamond-like carbon (C), arsenic (As), boron (B), sulfur (S), selenium (Se), and tellurium (Te).

18. The method according to any one of claims 1 to 17, Among them, One of the one or more semiconductor materials is silicon carbide (SiC).

19. The method according to any one of claims 1 to 18, Among them, One of the one or more semiconductor materials is a III-V compound semiconductor, the III-V compound semiconductor including one or more group III elements and one or more group V elements, where the one or more group III elements are selected from the group consisting of boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl), and where the one or more group V elements are selected from the group consisting of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).

20. The method according to claim 19, Among them, The III-V compound semiconductor is a binary compound composed of a group III element and a group V element. In particular, the III-V compound semiconductor is selected from the group consisting of GaN, AlN, InN, BN, GaP, AlP, InP, BP, GaAs, AlAs, InAs, BAs, GaSb, AlSb, and InSb.

21. The method according to claim 19, Among them, The III-V compound semiconductor is a multi-component compound composed of a mixture of three or more group III elements and group V elements. In particular, the III-V compound semiconductor is selected from the group consisting of InGaN, InGaP, AlGaAs, InGaAs, AlGaSb, InGaSb, and Ga 1-x In x As 1-y P y of the group.

22. The method according to any one of claims 1 to 21, Among them, One of the one or more semiconductor materials is a II-VI compound semiconductor comprising one or more group II elements and one or more group VI elements, wherein the one or more group II elements are selected from the group consisting of beryllium (Be), zinc (Zn), cadmium (Cd), and mercury (Hg), and wherein the one or more group VI elements are selected from the group consisting of oxygen (O), sulfur (S), selenium (Se), and tellurium (Te).

23. The method according to claim 22, Among them, The II-VI compound semiconductor is a binary compound composed of a group II element and a group VI element. In particular, the II-VI compound semiconductor is selected from the group consisting of ZnO, ZnS, CdS, ZnSe, CdSe, BeTe, ZnTe, and CdTe.

24. The method according to claim 22, Among them, The II-VI compound semiconductor is a multi-component compound composed of a mixture of three or more group II elements and group VI elements. In particular, the II-VI compound semiconductor is selected from the group consisting of (Zn, Cd)Se, (Be, Zn)Se, (Be, Cd)Se, and Zn(S, Se).

25. The method according to any one of claims 16 to 24, Among them, One of the one or more semiconductor materials is an alloy of two or more semiconductor materials. In particular, the two or more semiconductor materials are selected from the group consisting of elemental semiconductors, III-V compound semiconductors, and II-VI compound semiconductors.

26. An apparatus (10) comprising a non-twinned epitaxial layer (30) of one or more semiconductor materials deposited on a surface (22) of a single-crystal sapphire substrate (20), Among them, The apparatus (10) can be obtained by the method according to any one of claims 1 to 25.

27. A deposition apparatus (40) for manufacturing the apparatus (10) according to claim 26, comprising: A reaction chamber (42) that can be sealed relative to the ambient atmosphere (70) for setting the single-crystal sapphire substrate (20); A gas system (44) for providing an adjustable atmosphere in the reaction chamber (42); A heating tool (50) for heating the substrate (20); and A deposition tool (60) for depositing an epitaxial layer (30) of one or more semiconductor materials on the surface (22) of the substrate (20); Wherein the deposition apparatus (40) is configured to perform the method according to any one of claims 1 to 25 for manufacturing the apparatus (10) according to claim 26.

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