WO2024132143A1

WO2024132143A1 - Deposition system and method of coating a surface of a substrate

Info

Publication number: WO2024132143A1
Application number: PCT/EP2022/087419
Authority: WO
Inventors: Wolfgang Braun; Dong Yeong Kim
Original assignee: MAX-PLANCK-Gesellschaft zur Förderung der Wissenschaften e.V.
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2024-06-27

Abstract

The present invention relates to a deposition system (200) for coating a surface (22) of a substrate (20) with a layer (40) comprising one or more layer materials (42), comprising a reaction chamber (10) enclosing a reaction volume (12) sealable with respect to the ambient atmosphere (120), a gas system (16) with one or more atmosphere ports (18) for providing an adjustable reaction atmosphere (122) within the reaction volume (12), arrangement means (24) for arranging the substrate (20) within the reaction volume (12), and substrate heating means (30) for 10 heating the substrate (20). Further, the present invention relates to a method of coating a surface (22) of a substrate (20) with a layer (40) comprising one or more layer materials (42) in said deposition system (200).

Description

Deposition system and method of coating a surface of a substrate

The present invention relates to a deposition system for coating a surface of a substrate with a layer comprising one or more layer materials, comprising a reaction chamber enclosing a reaction volume sealable with respect to the ambient atmosphere, a gas system with one or more atmosphere ports for providing an adjustable reaction atmosphere within the reaction volume, arrangement means for arranging the substrate within the reaction volume, and substrate heating means for heating the substrate. Further, the present invention relates to a method of coating a surface of a substrate with a layer comprising one or more layer materials in a deposition system according to one of the preceding claims.

In systems for thermal laser epitaxy (TLE), a laser beam irradiates a source material in a controlled atmosphere provided in a reaction chamber to evaporate and/or sublimate material from provided source elements for depositing said evaporated and/or sublimated material as a layer on a substrate likewise provided in the reaction chamber.

In contrast to that, in systems for chemical vapor deposition (CVD), the substrate is exposed to one or more gas phase precursors, which react and/or decompose on the heated substrate surface to produce the desired deposit.

Both of the aforementioned methods for coating a substrate, namely TLE, and CVD, respectively, have their own advantages but also disadvantages.

TLE is extremely well suited for producing ultra-pure layers of materials which can be provided as solid sources, in particular metals. This holds also true for compound materials, for which all elemental parts can be provided as solid sources or at least as process gases. Further, TLE is rather insensitive to the pressure within the reaction chamber, which can be selected from pressures ranging from UHV, even 10’¹² hPa or less, than up to ambient pressure and beyond, for instance 10⁴ or even higher. Also, the actual temperature of the substrate can be selected in an extremely wide range, from below room temperature, if actively cooled, up to 2000 °C and beyond. However, TLE is less efficient for high-volume production as it requires the frequent exchange or refill of source material. In addition, some elemental source materials such as, e.g., As or carbon, do not evaporate or sublimate as single atoms, but in molecules or even chunks, which may lead to problems when depositing homogeneous epitaxial layers. Finally, elements that are gaseous under standard conditions such as oxygen or nitrogen, form very stable molecules that are hard or almost impossible to decompose in a pure TLE system.

On the other hand, CVD is widely used, for instance in semiconductor device manufacturing, for high-volume production, as it is rather straightforward to implement, has a high throughput and is capable of producing highly perfect crystalline and epitaxial layers. However, to fabricate abrupt interfaces is difficult with CVD, since the switch from one precursor gas mixture to another leads to intermixing. Also growing structures at low temperatures has its difficulties in CVD systems, as low surface temperatures of the substrate restrict the surface mobility of the adatoms, which is indeed the desired effect, but are often also insufficient to fully decompose the precursor materials, leading to unwanted impurity incorporation. In addition, many elements are difficult to synthesize as the core of a suitable precursor, in particular if certain temperature ranges for a mixed synthesis with other precursors need to be met, let alone possible reactions between these different precursors. On top of that, many precursors are extremely toxic, causing health and environmental safety concerns. In view of the above, it is an object of the present invention to provide an improved deposition system, and an improved method of coating a surface of a substrate which do not have the drawbacks of the state of the art. In particular, it is an object of the present invention to provide an improved deposition system, and an improved method of coating a surface of a substrate, which allow the fabrication of layers on substrates with high purity of a range of materials extended compared to the state of the art, whereby further a high-volume production is made possible.

This object is satisfied by the respective independent patent claims. In particular, this object is satisfied by a deposition system according to claim 1 , and by a method of coating a surface of a substrate according to claim 23. The dependent claims describe preferred embodiments of the invention. Details and advantages described with respect to the deposition system according to the first aspect of the invention also refer to the method according to the second aspect of the invention and vice versa, if of technical sense.

According to the first aspect of the invention, the object is satisfied by a deposition system for coating a surface of a substrate with a layer comprising one or more layer materials, comprising a reaction chamber enclosing a reaction volume seal- able with respect to the ambient atmosphere, a gas system with one or more atmosphere ports for providing an adjustable reaction atmosphere within the reaction volume, arrangement means for arranging the substrate within the reaction volume, and substrate heating means for heating the substrate.

The deposition system according to the present invention is characterized in that the deposition system comprises two or more source devices, each source device being configured to provide a respective source material to form at least part of the one or more layer materials, and wherein one or more of the two or more source devices is a thermal laser evaporation (TLE) source comprising a source element providing the respective source material and a laser source for providing a source laser for evaporating and/or sublimating the source material, and wherein one or more of the two or more source devices is a chemical vapor deposition (CVD) source comprising an inlet opening for providing a gas stream of a precursor gas comprising the respective source material in the reaction volume.

The deposition system according to the present invention comprises at least the essential building blocks of deposition systems known in the state of the art. Namely, the deposition system comprises a reaction chamber enclosing a reaction volume for the deposition reaction, and accordingly arrangement means for arranging and positioning the substrate to be coated in the reaction volume. The reaction chamber is sealable with respect to the ambient atmosphere for excluding harmful influences of the ambient environment on the layer to be deposited onto the surface of the substrate. Further, a gas system as part of the deposition system allows to actively adjust and select a reaction atmosphere within the reaction volume, whereby atmosphere ports of the gas system are fluidly connected to the reaction volume for providing said reaction atmosphere within the reaction volume. The reaction atmosphere is preferably selected suitable for the layer to be deposited onto the surface of the substrate, for instance for providing an elemental component of one of the one or more layer materials of the layer.

Substrate heating means allow heating the substrate to temperatures most suitable for the intended deposition of the layer. Heating the substrate is advantageous independent of the type of the used source device. A suitably selected temperature of the substrate for instance enhances a mobility of the components of the layer deposited onto the surface of the substrate and hence supports the formation of a preferably defect free epitaxial layer. In addition, for the usage of CVD sources the heating of the substrate can be essential, as the thermal energy provided by the substrate might be needed for the breakup of the used precursor gas. In the following, the expressions “precursor gas” and “precursor” are used synonymously with each other. According to the present invention, the deposition system comprises two or more source devices. A source device in the sense of the present invention is a device which can be used in a deposition system for providing a source material to be used for the coating of the substrate within the reaction volume. In other words, the source device provides the source material for instance as evaporated and/or sublimated source material and/or as source material which is embedded into a precursor compound. The source material can be provided by the source devices as elemental component and/or as part of a compound. However, also providing an actual compound material as source material is possible in the scope of the present invention.

The deposition system according to the present invention comprises at least two of said source devices. However, the deposition system is not limited to two source devices but can comprise an arbitrary number of source devices, essentially limited only by the available space within the reaction volume.

According to the present invention, one of the two or more source devices is a thermal laser evaporation (TLE) source, and one of the two or more source devices is a chemical vapor deposition (CVD) source, respectively. However, the deposition system according to the present invention is generally not limited in the respective number of TLE sources and CVD sources, respectively, as long as at least one of each source types is present as source device. In the following, when describing a TLE source and a CVD source, respectively, always a single source and also multiple sources are included.

Each of the two types of source devices comprises the respective building blocks for providing the respective source material within the reaction volume. The TLE source at least comprises a source element providing a source material and a respective laser source for providing the source laser for the evaporation and/or sublimation of the source material. However, also more than one source elements and/or source elements providing more than one source materials are possible, accompanied by more than one accordingly selected laser sources and source lasers, respectively.

On the other hand, the CVD source comprises an inlet opening, which is fluidly connected to the reaction volume. Hence, through the inlet opening a precursor gas encompassing the source material to be provided by the CVD source can be guided into the reaction volume as gas stream. A gas stream in the sense of the present invention is any directed flow of gas. However, also precursor gases providing encompassing more than one source materials and/or a CVD source providing more than one gas streams with different precursor gases, in particular comprising different source materials, are possible.

In summary, in the deposition system according to the present invention the source device for any source material can be selected, in particular whether the respective source material should be provided by the TLE source or by the CVD source. In particular, when using the deposition system according to the present invention, only the TLE source or only the CVD source or both, the TLE source and the CVD source, respectively, can be active at a given time. This allows to combine the advantages of both source types and simultaneously diminish the disadvantages of the respective source types.

As not limiting examples, possible used source devices for a deposition of layers comprising pure aluminum (Al), pure niobium (Nb), graphene or diamond-like carbon (C), carbides, niobium nitride (NbN), and aluminum nitride (AIN), respectively, are described. A layer comprising pure Al as layer material can be deposited in general by using both source types. Al can be readily provided as solid source and hence easily implemented in a TLE source. On the other hand, for providing Al as source element in a CVD source, a metalorganic precursor such as trimethyl aluminum (TMAI) can be used, in which the Al atom is encaged in three methyl (CO3) ligands containing carbon and hydrogen. Although this works well for substrate temperatures above about 400 °C, lower substrate temperatures are excluded as an effective decomposition of the precursor is no longer guarantied. In addition, also for perfect conditions, low concentration carbon contaminations are always a lingering problem in deposition systems only based on CVD sources and operated at limited substrate temperatures when using metalorganic precursors.

In summary, for a layer comprising pure aluminum as a layer material, in the deposition system according to the present invention the TLE source will be used for providing Al as source material, providing the advantages of the TLE method and avoiding the disadvantages of the CVD method.

For pure niobium as layer material, which as a metal can also be easily provided as solid source element and hence is ideally suited for an implementation in a TLE source, a metalorganic precursor is not even developed yet. Hence, also for a layer comprising pure Nb as a layer material, in the deposition system according to the present invention the TLE source will be used for providing Nb as source material.

An opposite example is the deposition of graphene or diamond layers which both are different three-dimensional configurations of carbon. Although carbon may be readily provided as source material by a TLE source, in which solid carbon in the form of graphite is sublimated by the source laser, the sublimated material consists of chunks of carbon, typically small two-dimensional graphene pieces or flakes. When these chunks of carbon meet at the surface of the substrate to be coated, they usually do not match geometrically. Hence, a deposition of a layer with graphene and/or diamond-like carbon in deposition systems based only on TLE sources tends to be difficult and it is challenging to fabricate said layers with high quality. However, by using a CVD source providing methane (CH4) as precursor, in which the single carbon atom is encaged in hydrogens that get released when the molecule hits the hot surface of a heated substrate, a deposition of single carbon atoms on the surface, and hence a deposition of a layer comprising graphene and/or diamond-like carbon with high quality can be readily provided.

In summary, for a layer comprising pure carbon as a layer material, in the deposition system according to the present invention the CVD source will be used for providing CH4 as precursor for providing carbon as source material, providing the advantages of the CVD method and avoiding the disadvantages of the TLE method.

Many other elements, in particular the non-metallic solid elements on the righthand side of the periodic tables such as arsenic (As), sulfur (S) and phosphorous (P) also have the tendency to evaporate or sublimate in molecules, leading to the above-mentioned disadvantages when provided by a TLE source. Hence also for these source materials, CVD sources with suitably selected precursors can be used as source device in the deposition system according to the present invention.

On the other hand, when depositing a layer with a carbide, and hence a binary composite of carbon with another elemental component, using only CVD sources can be challenging as many of the other elemental components, such as for instance metals or semi-conductors like silicon (Si) for silicon carbide (SiC), are difficult to provide by CVD sources with high purity. However, said other elemental components, in particular metals and semi-conducting materials, can readily be provided by TLE sources. Hence, the deposition system according to the present invention can provide its main advantage, namely the combination of a TLE source and a CVD source for a single deposition process. In the above-mentioned example, the TLE source provides evaporated and/or sublimated silicon atoms as source material, and the CVD source provides CH4 as precursor for providing carbon as source material. Both source materials combine at the surface of the heated substrate to the desired layer comprising SiC.

Similar considerations hold also true for example for nitrides, such as for instance AIN or NbN. Despite of the metal part, in said example aluminum and niobium, respectively, can easily be provided by a TLE source, the nitrogen part of said nitrides are difficult to provide as source material by TLE sources, as nitrogen is not solid. However, in TLE sources nitrogen gas can be used as process gas in the process volume, whereby a plasma or other activation source is needed to increase the reactivity of the nitrogen gas. For CVD sources it is the other way around, nitrogen as source material can easily be provided with high reactivity by using ammonia (NH3) as precursor, but, as already described above, the metal components are hard to provide by using for instance a metalorganic precursor, which always is accompanied by carbon contaminations of the layer. In addition, for niobium such a precursor is yet to be developed.

In summary, also in the example of nitrides, in the deposition system according to the present invention both types of source devices will be used, the CVD source for providing nitrogen as source material using NH3 as precursor, and the TLE source for providing the other elemental part. High quality and essentially defect free, in particular with respect to carbon contaminations, layers with a nitride as layer material can thereby be provided.

In summary, the deposition system according to the present invention comprises at least one TLE source and at least one CVD source. Both types of sources can be used solely or in combination. The selection of the respective used source or sources can be made depending on the source material or source materials to be provided, whereby for each source material the most suitable source type, namely TLE source or CVD source, can be selected. A combination of the advantages and simultaneously an avoidance of the disadvantages of source devices of both types can thereby be provided.

Further, the deposition according to the present invention can be characterized in that the inlet opening comprises an inlet nozzle. Such an inlet nozzle allows forming the gas stream of the precursor gas of the CVD source. A reduction of a diameter of the gas stream and in particular adjusting a direction of the gas stream can be provided by using said inlet nozzle at the inlet opening. A reduction of the needed amount of precursor gas can thereby be provided.

In addition, the deposition system according to the present invention can comprise that the gas stream also encompasses one or more inert carrier gases. Said inert carrier gases do not take part in the intended deposition, but can be used for instance for forming the gas stream, if the amount of precursor gas is too low to effectively be provided as gas stream on its own. Thereby the accessible range of providable abundancies of source materials can be enlarged.

Also, the deposition system according to the present invention can be characterized in that the deposition system comprises two or more CVD sources, wherein the inlet openings of the two or more CVD sources are combined in a gas manifold with a manifold opening for providing a combined gas stream of the mixed gas streams of the two or more CVD sources in the reaction volume. By providing such a gas manifold, the advantages of the availability of two or more CVD sources, for instance the possibility to simultaneously provide two different precursors providing two different source materials, can be provided, without increasing the number of inlet openings needed in the reaction volume and the demands on available space within the reaction volume linked to this. In summary, by implementing a gas manifold, the interior setup within the reaction volume can be simplified. According to an enhanced embodiment of the deposition system according to the present invention, the manifold opening comprises a manifold nozzle. Similar to an inlet nozzle, also a manifold nozzle allows forming the gas stream of the precursor gas of the CVD sources. A reduction of a diameter of the gas stream and in particular adjusting a direction of the gas stream can be provided also by using said manifold nozzle at the manifold opening. A reduction of the needed amount of precursor gases can thereby be provided.

According to another embodiment, the deposition system according to the present invention can comprise that a mean direction of the gas stream is directed towards the surface of the substrate. In other words, the gas stream impinges onto the surface of the substrate to be coated. A good coverage of the whole surface area of the substrate to be coated by the gas stream, and hence by the precursor and consequently by the provided source material, respectively. A uniform deposition of the intended layer on the surface of the substrate can thereby be enhanced.

The deposition system according to the present invention can be enhanced further by that the mean direction of the gas stream and the surface of the substrate form an impinging angle between 60° and 120°, preferably of 90°. Preferably, the gas stream orthogonally impinges onto the surface of the substrate, and hence with an impinging angle of 90°, as in this case a deflection of the gas stream on the surface is radially uniform. However, it has been found that for most of the applications impinging angles between 60° and 120° are sufficient, and in some cases even advantageous, with respect to the quality of the layer deposited onto said surface of the substrate.

According to another enhanced embodiment of the deposition system according to the present invention, the inlet opening and/or the manifold opening is constructed in a showerhead design. In a manifold opening constructed in a showerhead design, in short, a manifold opening constructed as a showerhead, the one or more precursor gas streams are spread within the showerhead and successively uniformly directed towards the surface through a plurality of openings. A very uniform distribution of the gas stream over a large fraction, preferably over the whole, surface area of the substrate to be coated can thereby be provided.

In addition, the deposition system according to the present invention can be enhanced further by that the showerhead design encompasses a pre-distribution volume with a plurality of outlet holes provided in a wall of the pre-distribution volume, wherein the pre-distribution volume is constructed for uniformly distributing the gas stream to the outlet holes, and the plurality of outlet holes is constructed for forming the gas stream into a spray cloud directed towards the surface of the substrate. In this embodiment, the pre-distribution volume is used for spreading the one or more gas streams within the showerhead before actually directing the one or more gas streams towards the surface of the substrate. Preferably, the pre-distribution volume covers within the showerhead at least the same extension as the area of the surface of the substrate to be coated. Subsequently, the spread of one or more gas streams flow through the plurality of outlet holes and hence forms the spray cloud directed towards the surface of the substrate. Preferably, the plurality of outlet holes is uniformly distributed in the wall of the pre-distribution volume for providing the spray cloud with a uniform spatial density.

Further, the deposition system according to the present invention can be characterized in that the CVD source further comprises an outlet opening for providing an exhaust for the gas stream out of the reaction volume, wherein a mean direction of the gas stream at the inlet opening is directed towards the outlet opening and/or wherein a mean direction of the combined gas stream at the manifold opening is directed towards the outlet opening. The source material provided by the CVD source is embedded in a precursor, which forms the gas stream. In some cases, the gas stream additionally comprises also one or more carrier gases. Hence, after deposition of the source material onto the surface of the substrate, there are remnants of the precursor, and if used also the carrier gas, still present in the reaction volume. For preventing contaminations caused by these no longer necessary gases in the reaction chamber, and also to keep the process pressure of the reaction atmosphere constant in a dynamic equilibrium, an outlet opening as part of the respective CVD source can be used. Said outlet can be fluidly connected to a pumping device for actively pumping the unneeded gas components out of the reaction volume. By already directing the incoming flow of gas, namely the gas stream of single CVD sources or the combined gas stream of a gas manifold, towards the outlet opening, an efficiency of said removing of the unwanted gas components can be enhanced.

In addition, the deposition system according to the present invention can be enhanced by that the outlet opening comprises an outlet funnel. Said funnel is a device whose opening cross section decreases along an intended flow direction, namely is large at its beginning within the reaction volume and gets smaller and smaller afterwards. An especially efficient catching of the unwanted gas components can thereby be provided.

According to another enhanced embodiment of the deposition system according to the present invention, the gas stream and/or the combined gas stream is grazing the surface of the substrate, in particular wherein the mean direction of the gas stream and/or the combined gas stream is parallel to the surface of the substrate. As the gas stream is only grazing, in particular also parallel to, the surface of the substrate, a reflection of the gas stream off the substrate is minimized without hindering the provision of the source material out of the precursor. As in TLE sources the respectively provided source material is in most of the cases emitted vertically from the source element of the TLE source, this design of the CVD source allows a spatial separation of the source element of the TLE source and the gas stream of the CVD source. Unwanted interactions between the two source devices, in particular reactions of the components of the gas stream with the source element of the TLE source and/or the already evaporated and/or sublimated source material provided by the TLE source, can thereby be avoided.

Further, the deposition system according to the present invention can also be enhanced by that the CVD source is at least partly integrated in the gas system.

Also, the gas system is fluidly connected with the reaction volume, in particular for providing the suitably selected reaction atmosphere within the reaction volume. By at least partly integrating the CVD source into the gas system, the fluid connections into the reaction volume necessary for operating the deposition system according to the present invention can be simplified, in particular the number of fluid connections can be lowered. This especially holds true not only for a single CVD source, but also for two or more CVD sources and/or respective gas manifolds.

According to another enhanced embodiment of the deposition system according to the present invention, the one or more atmosphere ports of the gas system are also used as inlet opening and/or manifold opening and/or outlet opening of the CVD source. By using the already present one or more atmosphere ports of the gas system also for the one or more CVD sources, a very simple integration realizable with little effort can be provided. Preferably, one of the atmosphere ports is used as inlet opening and/or manifold opening, and another of the atmosphere ports is used as outlet opening.

Also, the deposition system according to the present invention can be enhanced further by that the source element of the TLE source is arranged within the reaction chamber between the inlet opening and the substrate for an incorporation of the respective source material provided by the TLE source in the gas stream. In other words, the source material provided by the TLE source by evaporation and/or sublimation is not directed towards the surface of the substrate to be coated, but towards the gas stream. This is especially of advantage for CVD sources which provide a gas stream with high pressure and/or high flow velocity. The source material of the TLE source impinges into the gas stream and is carried along with the gas stream, and is ultimately brought to the substrate as part of the gas stream. Simultaneously providing source material from both types of source devices, namely TLE sources and CVD sources, and especially a relative abun- dancy of the different respective source materials can thereby be enhanced.

Additionally, or alternatively, the deposition system according to the present invention can comprise that the source element of the TLE source is arranged within the CVD device upstream of the inlet opening for an incorporation of the respective source material provided by the TLE source in the gas stream. Also, in this embodiment, the source material provided by the TLE source is incorporated into the gas stream and successively carried to the surface of the substrate to be coated together with the precursor used for the source material of the CVD source. For instance, the TLE source can be integrated into a showerhead, in particular into the pre-distribution volume of the showerhead, of the respective CVD source. Even an evaporation and/or sublimation of the respective precursor used by the respective CVD source by integrating a TLE source into the CVD source, is possible. An especially compact design of the deposition system according to the present invention can thereby be provided.

Again additionally, or alternatively, the deposition system according to the present invention can comprise that the source element of the TLE source is arranged within the reaction chamber opposite to the surface of the substrate. An arrangement opposite to the substrate in the scope of the present invention especially is an arrangement of the source element of the TLE source such that a mean direction of evaporated and/or sublimated source material of the TLE source is directed towards the surface of the substrate, preferably with an impingement angle of 90°. An especially good coverage of the whole surface of the substrate to the coated by the source material provided by the TLE source can thereby be provided. Especially for a sole use of the TLE source as source device, this positioning of the source element within the reaction chamber is of advantage.

In addition, the deposition system according to the present invention can be characterized in that the substrate heating means comprise a substrate laser source for providing a substrate laser beam for heating the substrate. One of the advantages of using a substrate laser source for heating the substrate is that only the substrate laser beam has to be provided within the reaction volume. Further heating means, especially electrical heating means, which can cause contaminations of the deposited layer, can be avoided. In addition, as the substrate laser beam can be arbitrarily focused, the temperature of the substrate providable by laser heating is essentially not limited. Temperatures up to 2000 °C and beyond can be provided easily.

According to a further enhanced embodiment of the deposition according to the present invention, the substrate laser source is accordingly selected with respect to a substrate material of the substrate. Different substrate materials can comprise different absorption characteristics, hence by suitably selecting the substrate laser source, an efficiency of the provided heating of the substrate can be enhanced.

In particular, a material of the substrate can be selected from the group of members consisting of: Si, C, Ge, As, Al, O, N, O, Mg, Nd, Ga, Ti, La, Sr, Ta and combinations of the foregoing. By way of example, one of the following compounds SiC, AIN, GaN, AI2O3, MgO, NdGaOs, DyScOs, TbScOs, TiO₂, (LaAI03)o.3(Sr2TaAI0₆)o.35 (LSAT), Ga₂O₃, SrLaAIO₄, Y:ZrO₂ (YSZ) and SrTiO₃ can be used as substrate material. However, the listed materials and compounds are examples only and not limiting.

Many of the materials used for substrates are efficient absorbers for infrared light. Hence, using a substrate laser source providing a substrate laser beam in the infrared range, in particular with a wavelength between 1 pm to 10 pm, preferably a CO2 laser, can be of advantage for a wide variety of possible substrate materials.

In addition, the deposition system according to the present invention can be characterized in that the reaction atmosphere is a vacuum between 10’⁴ and 10’¹² hPa, in particular for pure ideal conditions 10’⁸ to 10’¹² hPa. A vacuum as reaction atmosphere provides an especially clean environment for the intended deposition of the layer onto the substrate. Only the materials provided by the respectively used source devices are present within the reaction volume. Layers with high purity can thereby deposited without contaminations caused by possible gases present in the reaction chamber as reaction atmosphere.

According to an alternative embodiment, the deposition system according to the present invention can comprise that the reaction atmosphere comprises a reaction gas with a pressure selected in the range of 10’⁶ to 10⁴ hPa, in particular in the range of 10’⁴ to 10¹ hPa, especially in the range of 10’⁴ to 10’² hPa, wherein the reaction gas is selected from members of the group comprising oxygen, ozone, plasma-activated oxygen, nitrogen, plasma-activated nitrogen, hydrogen, F, Cl, Br, I, P, S, Se, and Hg, or compounds such as NH3, SFe, N2O, CPU, and combinations of the foregoing. This list is not closed, and also other suitable process gases can be used in the respective deposition system. In particular, the respective reaction gas can be selected with respect to the layer material of the layer to be coated, for instance the reaction gas can comprise one of the components of the layer material. As an example, for a layer comprising sapphire (AI2O3), the needed aluminum can be provided by a TLE source, and the needed oxygen by a reaction atmosphere comprising oxygen, ozone and/or plasma-activated oxygen.

According to another embodiment of the deposition system according to the present invention, the arrangement means comprises an actuator for moving the substrate with respect to the two or more source devices. In other words, the relative position of the surface of the substrate to be coated with respect to the two or more source devices can be actively changed, preferably without breaking the sealing of the reaction chamber with respect to the ambient atmosphere. By changing said relative positioning, the effective amount of the respective source material provided by the two or more source devices at the position of the substrate can be actively adjusted, for instance for changing the growing velocity of the deposited layer.

He deposition system according to the present invention can be enhanced further by that the actuator is constructed for rotating the substrate with respect to the two or more source devices. In this enhanced embodiment, the mean distance between the surface of the substrate and the respective source devices stays constant, but possible differences of a distance of different parts of the surface of the substrate to said source devices are averaged out. An especial uniform layer can thereby be deposited onto the surface of the substrate.

To increase uniformity, the substrate may be rotated or translated in an essentially linear way. Also, planetary gear motion of a multitude of substrates on an accordingly equipped substrate manipulator may be used to improve the deposition uniformity.

According to a second aspect of the present invention, the object is satisfied by a method of coating a surface of a substrate with a layer comprising one or more layer materials in a deposition system according to the first aspect of the present invention.

The method according to the present invention comprises the steps of a) arranging the substrate within the reaction volume, b) sealing the reaction chamber with respect to the ambient atmosphere, c) filling the reaction volume with the reaction atmosphere, d) heating the substrate, e) operating one or more of the one or more source devices for providing a respective source material for forming the one or more layer materials, and f) depositing the layer onto the surface of the substrate.

The method according to the second aspect of the present invention is intended to be executed by using a deposition system according to the first aspect of the present invention. Hence, the method according to the second aspect of the present invention provides the same features and advantages already described above in detail with respect to the deposition system according to the first aspect of the present invention.

In a first step a) of the method according to the present invention, the substrate to be coated is arranged within the reaction volume, in particular by using the arrangement means of the deposition system according to the present invention. If the arrangement means comprise an actuator, the position of the substrate within the reaction volume, especially with respect to the two or more source devices, can be altered later on.

Subsequently the reaction chamber and in particular the reaction volume is sealed with respect to the ambient atmosphere in step b) of the method according to the present invention. Sealing the reaction volume shields the substrate and also the layer deposited onto the surface of the substrate in the following, against harmful influences caused by the ambient atmosphere.

In addition, the sealing of the reaction volume in step b) allows in the following step c) to fill the reaction volume with the reaction atmosphere. The reaction atmosphere can be a vacuum with pressures of 10’¹² or even lower, but also a suitable reaction gas with pressures ranging from 10’⁶ to 10⁴ hPa. In particular, the respective reaction gas can be suitably selected for providing a component of the layer material of the layer to be deposited onto the substrate.

The next step d) comprises heating the substrate. Heating the substrate means to a suitably selected temperature of the substrate for instance enhances a mobility of the components of the layer deposited onto the surface of the substrate and hence supports the formation of a preferably defect free epitaxial layer. In addition, for the usage of CVD sources the heating of the substrate can be essential, as the thermal energy provided by the substrate might be needed for the breakup of the used precursors.

In the last two steps e) and f) of the method according to the present invention, the actual coating of the surface of the substrate takes place. In step e), one or more of the source devices are operated. In other words, in step e) one or more source materials are provided within the reaction volume, for instance directly as evaporated and/or sublimated elemental component or provided and enclosed in a precursor.

Independent from the type of source device used in step e), the layer is actually deposited onto the surface of the substrate. When using a TLE source directly directed towards the substrate in step e), the respective source material can readily be deposited onto the surface of the substrate. On the other hand, when using a CVD source as one of the one or more source devices, the gas stream comprising the precursor is directed for instance at close to normal incidence towards the surface of the substrate, or at a grazing angle, whereby the precursor is decomposed by the heated substrate and subsequently the provided source material is deposited onto the surface.

In summary, after execution of step f), the surface of the substrate is coated with the layer with the intended composition with respect to the used layer materials. In particular, by using the deposition system according to the first aspect of the present invention when executing the method according to the second aspect of the present invention, for each of the components of the intended layer material the respectively most suitable source device, namely a TLE source or a CVD source, can be selected, whereby only the TLE source or only the CVD source or both, the TLE source and the CVD source, respectively, can be active. A combination of the advantages of both source types and at the same time reduced disadvantages of the respective source types can thereby be provided.

Further, the method according to the present invention can also be characterized in that the reaction chamber stays sealed after the execution of step b) until finishing the execution of step f). By keeping the reaction chamber sealed during the complete execution of the method according to the present invention, in particular up to the end of the execution of step f), harmful influences of the environment, in particular of the ambient atmosphere on the quality of the layer deposited onto the surface of the substrate can be minimized, preferably avoided completely.

In addition, the method can also comprise that steps e) and f) are repeatedly carried out, wherein in each iteration of step e) the provided respective source material and/or the operated source devices of the one or more source devices is changed. In other words, a layer comprising a multilayer structure can be provided as layer by executing this embodiment of the method according to the present invention. In particular, for each of the layers the most suitable source device or source devices, respectively, can be selected. Especially, it is possible that iterations of executions of step e) with only TLE sources used as source devices are alternated with iterations of executions of step e) with only CVD sources used as source devices

According to a further enhanced embodiment of the method according to the present invention, the reaction chamber stays sealed with respect to the ambient atmosphere during the repeated execution of steps e) and f). By keeping the reaction chamber sealed also during the repeated execution of steps e) and f) of the method according to the present invention, in particular up to the end of the execution of step f), harmful influences of the environment, in particular of the ambient atmosphere on the quality of the layer deposited onto the surface of the substrate can be minimized, preferably avoided completely. Also, disruptions of the growth process due to, for instance cooling and subsequent re-heating the substrate, can also be avoided. Instead, the respective deposition processes using different source devices can be performed back-to-back, with no or only a minimal interruption that may be required to change growth parameters, such as for instance chamber pressure, substrate temperature, fluxes of source vapor, flow of precursor gas, and/or flow of carrier gas, between the successive deposition processes.

In the following, some alternative embodiments of the method according to the present invention are described, in which especially step e) is carried out differently. However, said alternatives are related to a single execution of step e). Hence, if the method according to the present invention is carried out with several subsequently executed iterations of step e), each of said iterations of step e) can again be carried out as each of the possible alternatives described in the following.

According to a first alternative embodiment of the method according to the present invention, in an execution of step e) only one or more TLE sources are used for providing the respective source material. This embodiment is suitable especially for layer materials which are readily providable as source materials by a TLE source such as for instance a metal or any other elemental material which can be provided as a solid source element.

According to a second alternative embodiment of the method according to the present invention, in an execution of step e) only one or more CVD sources are used for providing the respective source material. This embodiment is suitable especially for layer materials which are readily providable as source materials by a CVD source such as for instance gaseous elements such as for instance nitrogen, or materials which have the tendency to evaporate or sublimate in molecules such as carbon, arsenic, sulfur or phosphorous.

According to a second alternative embodiment of the method according to the present invention, in an execution of step e) one or more TLE sources and one or more CVD sources are used for providing the respective source material. This embodiment is suitable especially for layer materials which are a compound of one or more source materials readily providable by a TLE source and of one or more source materials readily providable by a CVD source. As already mentioned above, such layer materials are for instance carbides and nitrides, but also sulfides and phosphides.

The invention will be explained in detail in the following by means of embodiments and with reference to the drawings. In particular, in the figures are shown:

Fig. 1 A schematic view of a first embodiment of the deposition system according to the present invention,

Fig. 2 A schematic view of details of a second embodiment of the deposition system according to the present invention,

Fig. 3 A schematic view of a third embodiment of the deposition system according to the present invention, and

Fig. 4 A schematic view of a fourth embodiment of the deposition system according to the present invention. In the following, the invention is described by referring to four exemplary embodiments of the deposition system 200 according to the present invention. However, each of said examples of the deposition system 200 according to the present invention is constructed for carrying out the method according to the present invention. Hence, in the following, the respective deposition systems 200 and the method according to the present invention are described together.

Figure 1 depicts a possible first embodiment of the deposition system 200 according to the present invention. Said embodiment of the deposition system 200 shares with all other embodiments that the respective deposition system comprises a reaction chamber 10, which encloses a reaction volume 12 and is further sealable with respect to the ambient atmosphere 120 (step b) of the method according to the present invention).

Arrangement means 24 are present within the reaction volume 20 for arranging and positioning a substrate 20 to be coated with a layer 40 within the reaction volume 12. As depicted, the arrangement means 24 can comprise an actuator 26 for moving, preferably rotating, the substrate 20. A uniformity, and hence a quality, of the layer 40 can thereby be improved. Arranging the substrate 20 in the reaction chamber 12 forms the initial step a) of the method according to the present invention.

In addition, the deposition system 200 according to the present invention also comprises substrate heating means 30 for heating the substrate 20, which is especially done in step d) of the method according to the present invention. A suitably selected temperature of the substrate 20 for instance enhances a mobility of the components of the layer 40 deposited onto the surface 22 of the substrate 20 and hence supports the formation of a preferably defect free epitaxial layer 40. In addition, a thermal energy provided by the substrate 20 might be needed for a break up of used precursor gases 102, as it will be described below. Preferably, said substrate heating means 30 can be based on laser heating, comprising in particular a substrate laser source 32 for providing a substrate laser beam 34. As depicted, the substrate laser source 32 can be positioned outside of the reaction chamber 10, whereby coupling means 14 such as for instance chamber windows allow a guidance of the substrate laser beam 34 into the reaction volume 12. As the substrate laser beam 34 can be arbitrarily focused, the temperature of the substrate 20 providable by laser heating is essentially not limited. Temperatures up to 2000 °C and beyond can be provided easily.

Further, the deposition system 200 comprises a gas system 16. One or more atmosphere ports 18 of the gas system 16 are fluidly connected to the reaction volume 12. Thereby, in particular in connection with the provided sealability of the reaction volume 12, a reaction atmosphere 122, accordingly selectable in particular with respect to the intended layer 40 to be deposited, can be provided within the reaction volume 12 by the gas system 16, in particular in step c) of the method according to the present invention.

In particular, the deposition system 200 is characterized in that it comprises at least two source devices 50 for providing a source material 52 to be deposited onto the substrate 20, wherein at least one of the two or more source devices 50 is a TLE source 60, and at least one of the two or more source devices 50 is a CVD source 70. This constructive feature of the deposition system 200 according to the present invention allows combining the advantages of both types of source devices 50, while simultaneously avoiding the disadvantages of both TLE sources 60 and CVD sources 70, respectively.

As depicted in Fig. 1 , the TLE source 60 comprises a source element 62 providing the respective source material 52, which can for instance be arranged within the reaction volume 12 opposite to the surface 22 of the substrate. A source laser 64, depicted as arrow representing the laser beam of the source laser 64 provided by an external laser source, is coupled into the reaction volume 12 through a coupling means 14 and impinges onto the source element 62. Thereby, the respective source material 52 of the TLE source 60 is evaporated and/or sublimated and is subsequently deposited onto the surface 22 of the substrate 20.

On the other hand, the CVD source 70 comprises an inlet opening 72, preferably an inlet nozzle 74, for providing a gas stream 100 in the reaction volume 12, whereby the gas stream 100 comprises at least a precursor gas 102 for providing the respective source material 52 of the CVD source 70. Said gas stream 100 can also comprise carrier gases 104 if needed. In the depicted embodiment, the gas stream 100 provided by the CVD source 70 is directed towards the surface 22 of the substrate 20, indicated by the arrow representing the mean direction 106 of the gas stream 100.

At the substrate 20 the respective source materials 52, independent of whether directly provided by a TLE source 60 or provided as part of a precursor gas 102 of a CVD source 70 which is decomposed for instance by the thermal energy of the heated substrate 20, are combined and form the layer material 42 of the deposited layer 40. Said operation of the respective source devices 50 and the subsequent deposition of the respective provided source materials 52 as layer materials 42 of the layer 40 form the last two steps e), f) of the method according to the present invention.

Not limited to the embodiment described above, the at least one TLE source 60 and the at least one CVD source 70, which are present as source devices 50 in all embodiments of the deposition system 200 according to the present invention, can be operated in step e) of the method according to the present invention alone or in combination. In other words, for each layer material 42 of an intended layer 40 to be deposited onto a substrate 20, the most suitable source devices 50 can be selected. In particular, if for example a layer 40 is to be deposited comprising a layer structure comprising several different layer materials 42 deposited on top of each other, the steps e) and f) of the method according to the present invention can be repeatedly carried out, whereby for each of said repetitions the actually operated source devices 50 can again be accordingly selected with respect to the layer material 42 to be deposited.

Preferably, the reaction chamber 10 stays sealed after sealing it in step b) for the duration of the remaining steps of the method according to the present invention, in particular also for any of the aforementioned repetitions of steps e), f).

In the following, other possible embodiments of the deposition system 200 according to the present invention are described with respect to Figs. 2-3. However, said embodiments essentially differ in that their respective source devices 50 are different. The basic elements of the deposition system 200, such as for instance reaction chamber 10, gas system 16, and arrangement means 24, essentially are the same. Hence, in the following the different source devices 50 of the depicted embodiments of the deposition system 200 are described in detail, whereas for a description of other elements reference is made to the according description of said elements with respect to Fig. 1 .

In Fig. 2, in particular a special embodiment of a CVD source 70, especially of the inlet opening 72 of said CVD source 70, is depicted. Said inlet opening 72 is constructed in a showerhead 90 design. As shown, a showerhead 90 comprises a pre-distribution volume 92 for spreading the incoming gas stream 100, again comprising a precursor 102 providing the source material 52 and a carrier gas 104. A plurality of outlet holes 94 (for better visibility, only three of them are marked with reference signs) is provided in a wall 96 of the pre-distribution volume 92. During operation of the CVD source 70 as source device 50 of the deposition system 200, the gas stream 100 enters the pre-distribution volume 92, spreads, and subsequently flows, preferably in equal amounts and/or with equal flow rates, through preferably all outlet holes 94 into the reaction volume 12. Thereby, the gas stream 100 is formed as a distributed spray cloud 98 with a mean direction 106 towards the surface 22 of the substrate 20. An especially uniform coating of the substrate 20 with the layer 40 can thereby be provided.

As an additional feature, the depicted embodiment of the deposition system 200 further comprises an additional TLE source 60 as source device 50, which is integrated into the depicted CVD source 70. A source element 62 comprising a respective source material 52 of the TLE source 60 is arranged within the pre-distribution volume 92, and a source laser 64 is coupled into the pre-distribution volume 92 by accordingly provided coupling means 14. By this construction, the source material 52 provided by the TLE source 60 is evaporated and/or sublimated directly into the gas stream 100 of the CVD source 70. In other words, the gas stream 100 not only contains the precursor gas 102 providing the source material 52 of the CVD source 70, but also atoms or molecules of the source material 52 provided by the TLE source 60, and the transport of the source materials 52 provided by both types of source devices 50 is provided together. In addition, and not depicted, a TLE source 60 can already be used for evaporating and/or sublimating the precursor 102 of the CVD source 70.

Figure 3 depicts again an embodiment of the deposition system 200 according to the present invention, in which the TLE source 60 and the CVD source 70 are separated. Similar to Fig. 1 , the TLE source 60 is arranged such that its source element 62 is arranged opposite to the substrate 20. For details with respect to this arrangement, see the according description above with respect to Fig. 1 . Different to Fig. 1 , the CVD source 70 provides a gas stream 100, which comprises a mean direction 106 essentially parallel to the surface 22 of the substrate 20. In other words, the gas stream 100 comprising the precursor gas 102 providing the source material 52 of the CVD source 70 and a carrier gas 104 grazes along the surface 22 of the substrate 20. For that, the CVD source 70 not only comprises an inlet opening 72, but also an outlet opening 76, whereby said openings 72, 76 are arranged opposite to each other with respect to the substrate 20. For an even better collection of the incoming remnants of the decomposed precursor 102 and of the carrier gas 104, the outlet opening 76 can be constructed as and/or with an outlet funnel 78.

As depicted, the CVD source 60 preferably can also be at least partly be integrated into the gas system 16. In particular, the atmosphere ports 18 of the gas system 16 can also be used by the CVD source 70, in particular as inlet opening 72, and outlet opening 76, respectively.

As another, not depicted possible embodiment of a CVD source 70, the inlet opening can provide the gas stream 100 normal to the substrate 20. On the substrate 20, the remnants of the gas stream are deflected radially outwards from the rim of the substrate 20, where a plurality of suitably arranged outlet openings 76 or a single continuous outlet opening 76 are arranged. In fact, this design is used in in many modern deposition systems 200 which are solely based on CVD sources 70. Also, an opposite flow direction of the gas stream 100, namely parallel to the substrate 20 starting at the rim of the substrate 20 and outwards normal to the substrate 20 at or close to the center of the substrate 20, is possible. However, in the latter embodiment a rotation substrate 20 is of advantage for averaging out any unevenness and irregularity in the distribution of the gas stream 100.

In Fig. 4, a possible embodiment of the deposition system 200 similar to the one shown in Fig. 3 is depicted. Again, a flow of gas generally parallel to the surface 22 of the substrate 20 is provided by CVD sources 70. However, in this embodiment, the flow of gas originates not from a single CVD source 70, but from at least two CVD sources 70. The respective gas streams 100 from the different CVD sources 70, which especially can differ with respect to the used precursors 102, carrier gases 104, and, most important, provided source materials 52, are combined in a gas manifold 80, and subsequently provided into the reaction volume 12 by a common manifold opening 82, in particular a manifold nozzle 84. On the other side of the substrate 20, a shared outlet opening 76 of one of the CVD sources 70 is arranged. Again, both, the manifold opening 82 and the outlet opening 76, can be constructed as part of the gas system 16, in particular using the already present atmosphere ports 18 of the gas system 16. Providing several different source materials 52 of CVD sources 70 in a single gas stream 100 can thereby be provided.

Another difference is the placement of the source element 62 of the used TLE source 60. In the depicted embodiment of the deposition system 200, the source element 62 is arranged within the reaction volume 12 between the inlet opening 72 and the substrate 20. Thereby, the source material 52 provided by the TLE source 60 is evaporated and/or sublimated directly into the gas stream 100 of the CVD sources 70. Hence, similar to the embodiment of Fig. 2, the source materials 52 of both types of source devices 50, namely TLE source 60 and CVD sources 70, are transported together in the gas stream 100. This is especially suitable for high pressure environments.

List of references

10 Reaction chamber

12 Reaction volume

14 Coupling means

16 Gas system

18 Atmosphere port

20 Substrate

22 Surface

24 Arrangement means

26 Actuator

30 Substrate heating means

32 Substrate laser source

34 Substrate laser beam

40 Layer

42 Layer material

50 Source device

52 Source material

60 TLE source

62 Source element

64 Source laser

70 CVD source

72 Inlet opening

74 Inlet nozzle 76 Outlet opening

78 Outlet funnel

80 Gas manifold

82 Manifold opening

84 Manifold nozzle

90 Showerhead

92 Pre-distribution volume

94 Outlet hole

96 Wall

98 Spray cloud

100 Gas stream

102 Precursor gas

104 Carrier gas

106 Mean direction

120 Ambient atmosphere

122 Reaction atmosphere

200 Deposition system

Claims

Max-Planck-Gesellschaft zur F rderung der M29077PWO - To/Pr Wissenschaften e.V. Claims

1 . Deposition system (200) for coating a surface (22) of a substrate (20) with a layer (40) comprising one or more layer materials (42), comprising a reaction chamber (10) enclosing a reaction volume (12) sealable with respect to the ambient atmosphere (120), a gas system (16) with one or more atmosphere ports (18) for providing an adjustable reaction atmosphere (122) within the reaction volume (12), arrangement means (24) for arranging the substrate (20) within the reaction volume (12), and substrate heating means (30) for heating the substrate (20), wherein the deposition system (200) comprises two or more source devices (50), each source device (50) being configured to provide a respective source material (52) to form at least part of the one or more layer materials (42), and wherein one or more of the two or more source devices (50) is a thermal laser evaporation (TLE) source (60) comprising a source element (62) providing the respective source material (52) and a laser source for providing a source laser (64) for evaporating and/or sublimating the source material (52), and wherein one or more of the two or more source devices (50) is a chemical vapor deposition (CVD) source (70) comprising an inlet opening (72) for providing a gas stream (100) of a precursor gas (102) comprising the respective source material (52) in the reaction volume (12).

2. Deposition system (200) according to claim 1 , wherein the inlet opening (72) comprises an inlet nozzle (74).

3. Deposition system (200) according to claim 1 or 2, wherein the gas stream (100) also encompasses one or more inert carrier gases (104).

4. Deposition system (200) according to one of the preceding claims 1 to 3 wherein the deposition system (200) comprises two or more CVD sources (70), wherein the inlet openings (72) of the two or more CVD sources (70) are combined in a gas manifold (80) with a manifold opening (82) for providing a combined gas stream (100) of the mixed gas streams (100) of the two or more CVD sources (70) in the reaction volume (12).

5. Deposition system (200) according to claim 4, wherein the manifold opening (82) comprises a manifold nozzle (84).

6. Deposition system (200) according to one of the preceding claims 1 to 5, wherein a mean direction (106) of the gas stream (100) is directed towards the surface (22) of the substrate (20).

7. Deposition system (200) according to claim 6, wherein the mean direction (106) of the gas stream (100) and the surface (22) of the substrate (20) form an impinging angle between 60° and 120°, preferably of 90°.

8. Deposition system (200) according to claim 6 or 7, wherein the inlet opening (72) and/or the manifold opening (82) is constructed in a showerhead (90) design.

9. Deposition system (200) according to claim 8, wherein the showerhead (90) design encompasses a pre-distribution volume (92) with a plurality of outlet holes (94) provided in a wall (96) of the pre-distribution volume (92), wherein the pre-distribution volume (92) is constructed for uniformly distributing the gas stream (100) to the outlet holes (94), and the plurality of outlet holes (94) is constructed for forming the gas stream (100) into a spray cloud (98) directed towards the surface (22) of the substrate (20).

10. Deposition system (200) according to one of the preceding claims 1 to 9, wherein the CVD source (70) further comprises an outlet opening (76) for providing an exhaust for the gas stream (100) out of the reaction volume (12), wherein a mean direction (106) of the gas stream (100) at the inlet opening (72) is directed towards the outlet opening (76) and/or wherein a mean direction (106) of the combined gas stream (100) at the manifold opening (82) is directed towards the outlet opening (76).

1 1 . Deposition system (200) according to claim 10, wherein the outlet opening (76) comprises an outlet funnel (78).

12. Deposition system (200) according to claim 10 or 1 1 , wherein the gas stream (100) and/or the combined gas stream (100) is grazing the surface (22) of the substrate (20), in particular wherein the mean direction (106) of the gas stream (100) and/or the combined gas stream (100) is parallel to the surface (22) of the substrate (20).

13. Deposition system (200) according to one of the preceding claims 10 to 12, wherein the CVD source (70) is at least partly integrated in the gas system (16).

14. Deposition system (200) according to claim 13, wherein the one or more atmosphere ports (18) of the gas system (16) are also used as inlet opening (72) and/or manifold opening (82) and/or outlet opening (76) of the CVD source (70).

15. Deposition system (200) according to one of the claims 10 to 14, Wherein the source element (62) of the TLE source (60) is arranged within the reaction chamber (10) between the inlet opening (72) and the substrate (20) for an incorporation of the respective source material (52) provided by the TLE source (60) in the gas stream (100).

16. Deposition system (200) according to one of the preceding claims 1 to 15, wherein the source element (62) of the TLE source (60) is arranged within the CVD device upstream of the inlet opening (72) for an incorporation of the respective source material (52) provided by the TLE source (60) in the gas stream (100).

17. Deposition system (200) according to one of the preceding claims 1 to 16, wherein the source element (62) of the TLE source (60) is arranged within the reaction chamber (10) opposite to the surface (22) of the substrate (20).

18. Deposition system (200) according to one of the preceding claims 1 to 17, wherein the substrate heating means (30) comprise a substrate laser source (32) for providing a substrate laser beam (34) for heating the substrate (20).

19. Deposition system (200) according to claim 18, wherein the substrate laser source (32) is accordingly selected with respect to a substrate (20) material of the substrate (20).

20. Deposition system (200) according to one of the preceding claims 1 to 19, wherein the reaction atmosphere (122) is a vacuum between 10’⁴ and 10’¹² hPa, in particular for pure ideal conditions 10’⁸ to 10’¹² hPa.

21 . Deposition system (200) according to one of the preceding claims 1 to 19, wherein the reaction atmosphere (122) comprises a reaction gas with a pressure selected in the range of 10’⁶ to 10⁴ hPa, in particular in the range of 10’⁴ to 10¹ hPa, especially in the range of 10’⁴ to 10’² hPa, wherein the reaction gas is selected from members of the group comprising oxygen, ozone, plasma-activated oxygen, nitrogen, plasma-activated nitrogen, hydrogen, F, Cl, Br, I, P, S, Se, and Hg, or compounds such as NH3, SFe, N2O, CH4, and combinations of the foregoing.

22. Deposition system (200) according to one of the preceding claims 1 to 21 , wherein the arrangement means (24) comprises an actuator (26) for moving the substrate (20) with respect to the two or more source devices (50).

23. Deposition system (200) according to claim 22, wherein the actuator (26) is constructed for rotating the substrate (20) with respect to the two or more source devices (50).

24. Method of coating a surface (22) of a substrate (20) with a layer (40) comprising one or more layer materials (42) in a deposition system (200) according to one of the preceding claims, comprising the steps of a) arranging the substrate (20) within the reaction volume (12), b) sealing the reaction chamber (10) with respect to the ambient atmosphere (120), c) filling the reaction volume (12) with the reaction atmosphere (122), d) heating the substrate (20), e) operating one or more of the one or more source devices (50) for providing a respective source material (52) for forming the one or more layer materials (42), and f) depositing the layer (40) onto the surface (22) of the substrate (20).

25. Method according to claim 24, wherein the reaction chamber (10) stays sealed after the execution of step b) until finishing the execution of step f).

26. Method according to claim 24 or 25, wherein steps e) and f) are repeatedly carried out, wherein in each iteration of step e) the provided respective source material (52) and/or the operated source devices (50) of the one or more source devices (50) is changed.

27. Method according to claim 26, wherein the reaction chamber (10) stays sealed with respect to the ambient atmosphere (120) during the repeated execution of steps e) and f).

28. Method according to one of the preceding claims 24 to 27, wherein in an execution of step e) only one or more TLE sources (60) are used for providing the respective source material (52).

29. Method according to one of the preceding claims 24 to 27, wherein in an execution of step e) only one or more CVD sources (70) are used for providing the respective source material (52).

30. Method according to one of the preceding claims 24 to 27, wherein in an execution of step e) one or more TLE sources (60) and one or more CVD sources (70) are used for providing the respective source material (52).