Method for optimising a CVD reactor and for depositing layers in a CVD reactor, and a method or CVD reactor optimised in this way

Abstract

The invention relates to a method for increasing the efficiency of a CVD reactor (1) and to a coating method carried out or CVD reactor produced using a result of said method, wherein the CVD reactor has a gas inlet element (5) having a plurality of gas inlet zones (6, 7, 8, 9) arranged one above the other, and the height (H1) of the lowest gas inlet zone (6) influences the growth rate of a layer deposited on a substrate in the CVD reactor (1). The aim of the invention is to maximise the growth rate using an optimisation method. For this purpose, a descending branch (15'') of a growth curve should be as linear as possible and have the greatest values.

Description

Description of a method for optimizing a CVD reactor or for depositing layers in a CVD reactor, as well as such an optimized method or CVD reactor. Field of technology

[0001] Die Erfindung betrifft ein Verfahren zum Abscheiden von Verbin- In this process, two reactive gases, for example trimethylgallium and ammonia, are introduced separately into a process chamber through stacked gas outlet openings, along with an inert gas, for example hydrogen. The reactive gases decompose into decomposition products, for example Ga, N, and a carbon compound. The decomposition products Ga and N react on the surface of a substrate or in a pre-flow zone between the gas outlet openings and the substrate to form a reaction product GaN.

[0002] Die Erfindung betrifft darüber hinaus einen zur Durchführung des Ver- Driving-optimized CVD reactor and a method for optimizing the coating process or the CVD reactor. State of the art

[0003] Die Erfindung betrifft einen CVD-Reaktor, wie er beispielsweise in derThe CVD reactor can have a gas inlet device, as described, for example, in DE 10 2008 055 582 A1, DE 10 2013 104 105 A1. 31260PCT – 1.09.2025

[0004] Die JP 7336841 B2 beschreibt eine Vorrichtung und ein Verfahren zum Deposition of layers in which the gas inlet zones of a gas inlet device can have different heights.

[0005] Die US 2012 / 0231609 A1 beschreibt eine Vorrichtung und ein Verfah- for the deposition of III-V semiconductors. The relevance of dynamic pressure downstream of gas inlet zones of a gas inlet organ and vertical diffusion of reactive gases to the substrate are also discussed.

[0006] Ausgangspunkt der Erfindung ist ein CVD-Reaktor bei dem ein an eineThe process chamber, adjacent to the gas inlet element, has at least a first, lowest gas inlet zone and a second gas inlet zone arranged above it. More generally, however, the CVD reactor has a multitude of gas inlet zones arranged one above the other, each with a gas outlet surface. Different reactive gases, along with an inert gas, are fed into the gas inlet zones. The gases flow from the gas outlet surfaces, each with a multitude of gas outlet openings, into the process chamber. A feed zone adjoins the gas inlet element in the direction of process gas flow. Downstream of the feed zone in the direction of flow is a growth zone. One or more substrates, on which a layer is to be deposited, are located in the growth zone.During the deposition of III-V layers, a reactive gas containing an element of group V is introduced into the process chamber through the lowest gas inlet zone and, if applicable, also through an uppermost gas inlet zone—that is, the respective gas outlet surfaces adjacent to a process chamber ceiling or floor. This gas is typically AsH3, PH3, or NH3; hydrogen is used as an inert gas. A second gas outlet surface of a second gas inlet zone, which may be a middle gas inlet zone, introduces a reactive gas of a different type. 31260PCT – 1.09.2025 Elements of Group III, for example Ga, In, Al, in the form of a metal-organic compound, are fed into the process chamber. Summary of the invention

[0007] Der Erfindung liegt die Aufgabe zugrunde, basierend auf den oben ge- They cited findings to specify a method by which the efficiency of a CVD reactor can be systematically increased.

[0008] Der Erfindung liegt darüber hinaus die Aufgabe zugrunde, einen CVD-to specify a reactor whose components are dimensioned to operate more efficiently compared to state-of-the-art CVD reactors, and to specify a method with which layers can be deposited more efficiently compared to the state of the art.

[0009] Gelöst wird die Aufgabe durch die in den Ansprüchen angegebene Er- invention, wherein the dependent claims represent not only advantageous further developments, but also independent solutions of the invention.

[0010] Gemäß einem ersten Aspekt der Erfindung wird vorgeschlagen, die The aim is to minimize the height of the lowest gas inlet zone, i.e., the distance between the lowest gas outlet openings of the gas outlet surface of the second gas inlet zone and the process chamber floor, through which, for example, the third component flows into the process chamber during the deposition of a third-to-five compound. Based on the following considerations prior to the invention, threshold values ​​dependent on the material pairings are to be defined, specifying the boundary conditions within which the optimization of the distance is to be carried out. 31260PCT – 1.09.2025

[0011] Grundlage für die Erfindung ist die Erkenntnis, dass das Einspeisen ei-The reactive gas containing a group V element is designed to prevent the group III element from depositing as a metallic layer in the feed zone on the bottom of the process chamber by means of the lowest gas outlet surface. The lowest gas flow of the first reactive gas thus forms a diffusion barrier for a reaction product of the second reactive gas. On the other hand, reaction products of both the first and second reactive gases, such as Ga and N or As, are to be transported to the substrate in the growth zone to be deposited there as a crystalline layer. The second reactive gas, for example TMGa, decomposes into decomposition products during horizontal transport due to heating of the process chamber by a heating device.In the process chamber, a first decomposition product is formed by the decomposition of the first process gas, and a second and third decomposition product are formed by the decomposition of the second process gas. While the second decomposition product, for example, Ga, should be transported to the surface of the substrate, it is essential to prevent the third decomposition product, which may be a carbon compound, from being transported to the substrate, since carbon and the element from group III are incorporated into the same lattice sites in the crystal. The incorporation of carbon, however, should be avoided. The diffusion barrier therefore has the task of inhibiting the transport of the element from group III to the bottom of the process chamber in the pre-combustion zone and the transport of the third decomposition product, in particular carbon, in the growth zone.At the same time, the transport of the second decomposition product, especially Ga, should be as large as possible to achieve a high growth rate. The growth rate is a parameter that determines the efficiency of a CVD reactor.

[0012] Das durch das Gaseinlassorgan in die Prozesskammer einströmende Process gas is heated by means of a heating device located below a 31260PCT – 1.09.2025 The process chamber floor is located at the susceptor, which is heated to a process temperature, and then brought to a reaction temperature at which the decomposition products are formed. Since the binding energy in the V molecule is greater than in the III molecule, the first reactive gas must be supplied in excess. During the transport of the two reactive gases, the gas-phase concentration of the reaction products, and especially of the first and second reaction products, initially increases in the direction of flow. Simultaneously, the mass flow of the second reaction products, which is essentially limited by diffusion through the lowest barrier layer, also increases towards the process chamber floor, so that the availability of the reaction products forming the layer initially increases in the direction of flow.The availability curve thus initially rises and reaches a maximum due to the deposition of a parasitic coating in the pre-deposition zone, and then falls due to the deposition of the layer on the substrate and the associated depletion in the growth zone. The availability curve or growth curve therefore has a rising flank, a peak, and a falling flank.

[0013] Das in der Wachstumszone angeordnete Substrat liegt auf einem Lager-The space can be formed by a substrate holder that is driven by rotation around a vertically extending axis. This rotation is achieved by providing a gas cushion that supports the substrate holder and sets it in motion. As a result of this rotation, a linearly sloping flank leads to the homogeneous deposition of a layer. If the sloping flank above the substrate, i.e., the growth zone, is not perfectly straight, the edge of the substrate may have a different layer thickness than the central area of ​​the substrate. 31260PCT – 1.09.2025

[0014] Die Verfahrensparameter eines Verfahrens zum Abscheiden derartigerLayers are thus limited by at least the following properties: the transport of the second decomposition product to the surface of the process chamber floor, the transport of the third decomposition product to the substrate surface, and the minimum distance of the peak of the availability curve located in the upstream zone from the boundary of the growth zone. The position of the peak is determined, among other things, by the values ​​of the gas fluxes through the various gas outlet surfaces of the gas inlet zones. However, the ratio of the gas fluxes cannot be set arbitrarily. In order to achieve flow stability, i.e., to avoid the formation of vortices, the maximum difference in the mean flow velocity of the gas fluxes exiting from adjacent gas outlet surfaces must not exceed a maximum value. This is typically 20% of the flow velocity.

[0015] Da die Gase, die durch die voneinander verschiedenen Gasaustrittsflä-Since gases with different molar masses flow into the process chamber, the dynamic pressure between the vertically stacked gas inlet zones is more relevant than the mean flow velocity to prevent turbulence, backflow, or flow perpendicular to the main flow (i.e., in the vertical direction). This dynamic pressure, where P is the density and U is the mean flow velocity, should differ as little as possible immediately downstream of the gas outlet surfaces. The upper limit for the deviation of the dynamic pressure between two gas outlet surfaces should not exceed 30% of the mean value of all gas outlet surfaces. In specific cases, the dynamic pressure can be a maximum of 31260PCT – 1.09.2025 50% deviates from an average value across the entire cross-section of the process chamber in the area immediately downstream of the gas outlet surfaces.

[0016] Auf der Basis dieser Erkenntnisse wird ein Verfahren vorgeschlagen,in which a CVD reactor has a gas inlet organ adjacent to a process chamber, which has at least a first gas inlet zone and a second gas inlet zone, wherein the first gas inlet zone has a first gas outlet surface adjacent to a process chamber floor with a first height, and the second gas inlet zone has a second gas outlet surface adjacent to the first gas outlet surface with a second height, wherein a first gas flow consisting of an inert gas and a first reactive gas flows into the process chamber through gas outlet openings of the first gas outlet surface and a second gas flow consisting of an inert gas and a second reactive gas flows into the process chamber through gas outlet openings of the second gas outlet surface, wherein a pre-flow zone extending in a flow direction across the process chamber floor adjoins the gas outlet surfaces, wherein the pre-flow zone adjoins a pre-flow zone extending across the process chamber floor and across a storage area,a substrate is located on which a growth zone extending beyond the substrate, the process chamber being heated by a heating device, such that the first reactive gas forms a first decomposition product, in particular an element of group V, and the second reactive gas forms a second decomposition product, in particular an element of group III and a third decomposition product, in particular a carbon compound, and a reaction product of the first and the second decomposition product is deposited on the surface of the substrate as a layer and on the surface of the feed zone as a parasitic coating, the first gas flow forming a barrier in the feed zone and the growth zone which inhibits the deposition of the second decomposition product in the feed zone without reaction with the first decomposition product, i.e. the deposition of, for example, metallic gallium. 31260PCT – 1.09.2025 and in the growth zone inhibits the incorporation of an element of the third decomposition product, in particular carbon, into the layer, wherein a course of an availability of the reaction product in the area of ​​the process chamber floor, which determines a growth rate of the layer or the parasitic coating, rises in the direction of flow in an ascending flank extending in the upstream zone and, after reaching a peak, falls in a descending flank extending over the growth zone.According to the invention, boundary conditions are specified based on experimental experience or on model calculations, whereby these boundary conditions specify at least the transport of the second decomposition product to the surface of the process chamber floor in the feed zone, the transport of the third decomposition product to the surface of the substrate, a minimum distance of the peak of the availability curve from the growth zone, and a maximum difference of a mean dynamic pressure or, optionally, a mean flow velocity of gas flows from adjacent gas outlet zones. In particular, a first threshold value is defined that relates to the maximum permissible transport of the second decomposition product to the surface of the process chamber floor in the feed zone. A second threshold value is defined that relates to the maximum permissible transport of the third decomposition product to the surface of the substrate.A third threshold is defined, relating to a minimum distance between the peak of availability and the growth zone. A fourth threshold is defined, relating to the maximum difference between the mean dynamic pressure or, if applicable, the mean flow velocity of the first gas flow and the mean dynamic pressure or, if applicable, the mean flow velocity of the second gas flow. This creates a multidimensional range of values ​​within which an optimization process can be carried out, taking into account the gas flows and the height of the lowest... 31260PCT – 1.09.2025 The gas release area, i.e., the deposition of, for example, metallic gallium, can be varied. The goal of the optimization process is to achieve the highest possible growth rate in the growth zone, while ensuring that the downward slope of the availability / growth curve is also linear. Another goal is to achieve the lowest possible concentration of the incorporation of the third decomposition product, particularly carbon, into the layer. The threshold values ​​can be independent of the reactive gases of different material pairings. The reactive gases of different material pairings differ, sometimes considerably, in their molar mass, which influences diffusion through the barrier, and in their binding energy or decomposition temperature, which affects the shape of the growth or availability curve.

[0017] Als Materialpaarungen kommen die reaktiven Gase in Betracht, mit de- The following crystals or mixed crystals can be deposited: GaAs, InP, GaAl and GaN.

[0018] Der Schwellwert für den erlaubten Transport des zweiten Zerlegungs- The threshold for the transport of the third decomposition product to the surface of the process chamber floor can be selected such that no metallic layer forms in the feed zone. Furthermore, the threshold can be selected such that the partial pressure of the third decomposition product, for example, a carbon-containing decomposition product, is at a minimum at the substrate surface, or that the vertical gradient of the concentration of the third decomposition product is at a minimum immediately above the substrate surface. Another objective can be to achieve a particularly high local partial pressure of the reactive gas of group V near the substrate. The threshold for the permissible transport of the third decomposition product to the substrate surface can be selected such that a layer with 31260PCT – 1.09.2025 of a carbon concentration not exceeding a limit value. The threshold of the minimum distance of the peak of the availability curve from the growth zone, which must lie in the upstream zone, can be 5 to 10 mm. The threshold of the maximum difference in the mean flow velocities through adjacent gas outlet surfaces or of the mean dynamic pressure downstream of the gas outlet surfaces can be 20%. However, the first and second thresholds can also be determined by a ratio of the mass flow of the first reactive gas through the first gas outlet surface to the mass flow of the second reactive gas through the second gas outlet surface. This ratio is preferably significantly greater than 1.

[0019] Unter diesen Randbedingungen durchgeführte Experimente oder Simu-Relational calculations led to the specification of a minimum value for the distance between the lowest of the second gas outlet openings of the second gas outlet surface, which essentially corresponds to the height of the lowest gas outlet surface. The height of this gas outlet surface, or rather the distance, naturally also depends on the length of the upstream zone measured in the flow direction, the height of the process chamber, and the type of reactive gases. With a material pairing of NH3 as the first reactive gas and TMGa as the second reactive gas, each fed into the process chamber with hydrogen as an inert gas, the optimal distance lies in the range between 6 and 7 mm when the process chamber height is between 25 and 30 mm. Specifically, with a process chamber height of 25.0 to 25.5 mm, the optimal distance lies in the range between 6.4 mm and 7.8 mm. The leading zone has a length of 50 to 80 mm and the growth zone a length of 200 mm.In this configuration, the gas inlet element is located in the center of a circular process chamber. A total of five substrates are positioned at an identical distance from the gas inlet element (31260PCT – 1.09.2025). The experiments revealed that the material of the gas inlet element in the area of ​​the gas outlet openings can also influence the optimal distance or height of the lowest gas outlet surface. For a nickel gas inlet element, the optimal distance is 7.7 mm, and for a quartz gas inlet element, it is 6.5 mm.

[0020] In das Optimierungsverfahren kann darüber hinaus auch die Höhe derThe second gas outlet surface, or the height of a third gas outlet surface of a third gas inlet zone, is included, as well as a third gas flow that passes through the third gas outlet surface. This gas flow consists of an inert gas, in particular hydrogen, and the first reactive gas, for example, a hydride of an element of group 15, such as NH3. This third gas flow inhibits the diffusion of the second decomposition product of the second reactive gas, for example, Ga, to the process chamber ceiling.

[0021] Das Optimierungsverfahren kann darüber hinaus auch die Höhe einerThe fourth gas outlet and a fifth gas outlet are included, with the fourth gas outlet being located above the third gas outlet and the fifth gas outlet being located above the fourth gas outlet. A gas flow consisting of an inert gas and the second reactive gas can enter the process chamber through the fourth gas outlet. Such an arrangement is particularly advantageous when substrates with diameters of 150 mm, 200 mm, and larger are to be coated. This additional zone, through which the second process gas is fed into the process chamber, results in a flatter availability / growth curve in the growth zone. An inert gas and the first reactive gas can again enter through the uppermost gas outlet, namely the fifth gas outlet. 31260PCT – 1.09.2025 The process chamber is fed with gas. However, the total number of gas inlet zones arranged one above the other can also be larger, as described, for example, in the aforementioned DE 102019123023 A1. In this variant of the process, the gas flow ratios are also taken into account in order to maintain flow stability.

[0022] Ein weiterer Parameter kann auch der Totaldruck innerhalb der Pro- The combustion chamber also determines the diffusion constant in the diffusion barrier.

[0023] Ein weiterer Parameter kann die Anzahl der Gasaustrittsöffnungen be- This could be the density of the arrangement of the gas outlet openings, or the diameter of the gas outlet openings of the first gas outlet surface, but also of each other gas outlet surface. The number of gas outlet openings per unit area and their diameter or opening area can be further parameters for optimization.

[0024] Mit einer durch Experimente unterstützten Optimierung wurden fürThe following values ​​were determined for the heights of the gas inlet zones – each with a tolerance of + / -10% from bottom to top: H1 = 3.90 mm, H2 = 3.15 mm, H3 = 8.10 mm, H4 = 1.9 mm, H5 = 8.10 mm.

[0025] In einem CVD-Reaktor mit einem Gaseinlassorgan mit fünf vertikal Layers III-V consisting of Ga, Al, and N were deposited in superimposed gas outlet zones. A gas flow (Q1) of a Group V element was introduced into a process chamber through the lowest gas inlet zone (6), a gas flow (Q2) of a Group III element (NH3) through the gas inlet zone above it (7), a gas flow (Q3) of a Group III element (TMGa, TMAl) through the gas inlet zone above it (8), a gas flow (Q4) of a Group V element (NH3) through the gas inlet zone above it (9), and a gas flow (Q5) of a Group III element (TMGa, TMAl) through the gas inlet zone above it (10).

[0026] Eine GaN-HEMT-Schicht wurden mit folgenden Flüssen der reaktivenGases are separated through the gas inlet zones with a tolerance of + / -10%: (Q1) = 13.5 slm, (Q2) = 5.28E-3 mol / min, (Q3) = 15.75 slm, (Q4) = 5.28E-3 mol / min, (Q5) = 15.75 slm, where the total flux through the respective gas inlet zones, consisting of the flux of the respective reactive gas and an inert gas, has the following values ​​with a tolerance of + / -10%: Gas inlet zone (6) = 16.2 slm, Gas inlet zone (7) = 30.0 slm, Gas inlet zone (8) = 40.1 slm, Gas inlet zone (9) = 19.9 slm, Gas inlet zone (10) = 40.1 slm.

[0027] Die Wachstumsrate betrug hier 6,3 µm / h.

[0028] Eine AlGaN-HEMT-Schicht wurde mit den folgenden Flüssen der reak-The reactive gases were separated through the gas inlet zones with a tolerance of + / -10%: (Q1) = 10.2 slm, (Q2) = 2.58E-3 mol / min, (Q3) = 7.5 slm, (Q4) = 2.58E-3 mol / min, (Q5) = 5.0 slm, where the total flux through the respective gas inlet zones, consisting of the flux of the respective reactive gas and an inert gas, has the following values ​​with a tolerance of + / -10%: Gas inlet zone (6) = 12.6 slm, Gas inlet zone (7) = 21.3 slm, Gas inlet zone (8) = 33.6 slm, Gas inlet zone (9) = 12.9 slm, Gas inlet zone (10) = 39,1 slm.

[0029] Die Wachstumsrate betrug hier 2,7 µm / h. Die Kohlenstoffdotierung be- Here, 8.2 *10 17 cm -3 31260PCT – 1.09.2025

[0030] Eine GaN-Bufferschicht wurde mit den folgenden Flüssen der reaktivenGases are separated through the gas inlet zones with a tolerance of + / -10%: (Q1) = 21.56 slm, (Q2) = 2.05E-3 mol / min, (Q3) = 29.26 slm, (Q4) = 2.05E-3 mol / min, (Q5) = 26.18 slm, where the total flux through the respective gas inlet zones, consisting of the flux of the respective reactive gas and an inert gas, has the following values ​​with a tolerance of + / -10%: Gas inlet zone (6) = 23.4 slm, Gas inlet zone (7) = 36.8 slm, Gas inlet zone (8) = 35.4 slm, Gas inlet zone (9) = 22.2 slm, Gas inlet zone (10) = 38.2 slm.

[0031] Die die Wachstumsrate betrug hier 2,3 µm / h. Die Kohlenstoffdotierung This amounted to 1.25 * 10 16 cm -3 .

[0032] Durch eine Verdopplung des V / III-Verhältnis von 1678 auf 4980 wurde The carbon doping is reduced to 3.8 *10 15 cm -3 The growth rate in this experiment was 0.7 µm / h. Brief description of the drawings

[0033] Die Erfindung wird nachfolgend anhand beigefügter Zeichnungen er-purified. Figure 1 schematically shows the cross-section through an upstream region of a process chamber 2, Figure 2 schematically shows a transport process of reactive gases or decomposition products in this region, Figure 3 shows a representation according to Figure 2 for a variant of a gas inlet device, 31260PCT – 1.09.2025, Figure 4 schematically shows the top view of a susceptor 17 forming the bottom of a process chamber, Figure 5 schematically shows a cross-section through a CVD reactor 1, Figure 6 shows a SIMS profile of a GaN layer. Description of the embodiments

[0034] Die Figuren 4 und 5 zeigen schematisch den Aufbau eines CVD- Reactor, the efficiency improvement of which is the subject of the invention.

[0035] In einem Gehäuse, das insbesondere aus Edelstahl besteht und welchesA gas inlet element 5, which is gas-tight and evacuatable, is located within the gas-tight and evacuatable chamber. Reactive gases, along with an inert gas, can be fed into this element via supply lines 20. The gas inlet element 5 is essentially cylindrical and has several vertically arranged gas inlet zones 6, 7, 8, 9, 10, as shown in Figure 1. A separate supply line 20 opens into each of the gas inlet zones 6, 7, 8, 9, 10, through which a predetermined mass flow of a gas flow Q1, Q2, Q3, Q4, Q5 is fed into a gas distribution chamber. The cylindrical surface of the gas inlet element 5 forms a gas outlet surface 6', 7', 8', 9', 10' for each of the gas inlet zones 6 to 10. Each of the gas outlet surfaces 6' to 10' has a plurality of evenly distributed gas outlet openings 6'', 7'', 8'', 9'', 10''. The gas outlet surfaces 6' to 10' lie on a common cylindrical surface.

[0036] Die Gasaustrittsflächen 6’ bis 10’ besitzen jeweils eine Höhe H1, H2, H3,H4, H5. The gas outlet surfaces 6' to 10' can have different heights H1 to H5. 31260PCT – 1.09.2025

[0037] Das Gaseinlassorgan 5 ist von einem kreisscheibenförmigen Suszep- The process chamber 2 is surrounded by a gas inlet device 17, which can be rotated about its axis. The susceptor 17 forms a process chamber floor 3 of a process chamber 2, which is arranged circularly around the gas inlet device 5. The process chamber 2 is bounded at the top by a process chamber ceiling 4. The process chamber is surrounded by a gas outlet device 18, with which the inert gas fed into the process chamber 2 through the gas inlet device 5, as well as decomposition products of the reactive gases, can be removed.

[0038] Unterhalb des Suszeptors 17 befindet sich eine Heizeinrichtung 16, mitThe susceptor 17, or process chamber 2, as well as the process chamber ceiling 4, can be heated. Optionally, an additional heating device can be provided above the process chamber ceiling 4 to heat it separately. Alternatively, a cooling device can be provided above the process chamber ceiling 4 to actively cool it.

[0039] Auf einer ringförmigen Fläche um das im Zentrum angeordnete Gas- On the upper surface of the susceptor 17, facing the process chamber 2, several substrates 13 are arranged in the inlet organ 5. Each substrate 13 rests on a storage position 14. The storage position 14 is formed by a substrate carrier, which is a circular disk that can be supported on a gas cushion. The gas cushion can cause the substrate carrier to rotate around a central point M.

[0040] Der sich unmittelbar an das Gaseinlassorgan 5 anschließende BereichThe bottom of the process chamber 3 forms a pre-flow zone 11. The pre-flow zone 11 has a length V, which is in the range of 50 to 80 mm. (See pre-31260PCT – 1.09.2025) Following the running zone 11 is a growth zone 12, in which the substrates 13 or the storage areas 14 are arranged. The length of the growth zone 12 can be 15 to 20 mm or even more. It depends on the diameter of the substrates and essentially corresponds to the diameter of the substrates.

[0041] Die Länge V der Vorlaufzone kann von der Anzahl der Substrate, deren The diameters depend on the diameter of the gas inlet organ 5. In the exemplary embodiment, six substrates are arranged in a circle around the center of the susceptor 17. In other exemplary embodiments, 5, 7 or 8 substrates can also be arranged in a circle on the susceptor 17.

[0042] Die Figur 1 zeigt schematisch den Einlassbereich einer Prozesskam-mer 2, which is bounded above by a process chamber ceiling 4 and below by a process chamber floor 3. Five vertically arranged gas inlet zones 6 to 10 are provided, all of which have a uniform height H1 to H5 for the sake of clarity. In the course of the optimization process according to the invention, at least the height H1 of the first, lowest gas inlet zone 6 is optimized and, in particular, minimized.

[0043] Durch die Gasaustrittsflächen 6’ bis 10’ fließen verschiedene Gas- Flows Q1 to Q5, each consisting of a mixture of an inert gas and a reactive gas. Figure 3 shows an example where the gas inlet zones 6 to 10 have different heights. A first gas flow Q1, a mixture of an inert gas and a gas consisting of an element of group 5, in particular a hydride, flows through the first gas inlet zone 6. NH3 is subsequently mentioned as an example of this gas, and hydrogen as an inert gas. 31260PCT – 1.09.2025

[0044] Durch die zweite Gaseinlasszone 7 strömt ein zweiter Gasfluss Q2, derA mixture of an inert gas and a gas consisting of an element of group III, in particular a metal-organic compound. TMGa is further cited as an example of this gas, and hydrogen as an inert gas.

[0045] Durch die dritte Gaseinlasszone 8 strömt ein dritter Gasfluss Q3, der It can be a mixture of NH3 and hydrogen.

[0046] Durch die vierte Gaseinlasszone 9 strömt ein vierter Gasfluss Q4, der It could be a mixture of TMGa and hydrogen.

[0047] Durch die fünfte Gaseinlasszone 10 strömt ein fünfter Gasfluss Q5, der It can be a mixture of NH3 and hydrogen.

[0048] Die schichtweise in die Prozesskammer 2 einströmenden Gasflüsse Q1 up to Q5 mix during their passage through process chamber 2. The corresponding transport paths perpendicular to the horizontal flow direction are symbolized by arrows in Figures 2 and 3.

[0049] Die Figur 2 zeigt schematisch diesen quer zur horizontalen Strömungs- Directionally directed transport. Ammonia, the reactive gas of the first gas flow, decomposes into NH₃. X in the preliminary zone 11, where NH X(X = 0 to 2) can diffuse towards the bottom of process chamber 3. Trimethylgallium, the reactive gas of the second gas flow, decomposes into Ga and CHX (X = 0 to 3). Ga and CHX diffuse into the lowest flow layer, where the first reactive gas, the inert gas present there, or the first decomposition products of NH3 form a diffusion barrier. 31260PCT – 1.09.2025

[0050] Erfindungsgemäß muss die Diffusionsbarriere so eingestellt sein, dass Elemental Ga is not deposited on the process chamber floor 3 in the pre-flow zone 11, but is transported to the substrate 13 in sufficient quantity. Furthermore, the diffusion barrier must be adjusted so that only a minimal amount of CHX is transported to the substrate 13.

[0051] Die Figur 1 zeigt eine Verfügbarkeitskurve 15, die im Wesentlichen dieThe growth rate represents, on the one hand, a parasitic coating deposited in the pre-zone 11 on the bottom of the process chamber 3 and, on the other hand, a layer deposited on the substrate 13 in the growth zone 12. The availability curve 15 has a rising slope 15''. The increase in the availability of the decomposition products Ga and NH X The effects that cause the deposition of the layers or the parasitic coating are due to the delayed heating of the reactive gases.

[0052] Nach einem Scheitelpunkt 15’ besitzt die Verfügbarkeitskurve 15 eine descending slope 15'''. The decrease in the availability of the decay products is due to the increasing depletion, which in turn is due to the consumption of the decay products Ga and NH. X as a consequence of layer growth.

[0053] Das Abscheiden einer Schicht auf einem auf einem rotierenden Sub-For the substrate 13 to have a layer thickness (layer homogeneity) that is as uniform as possible, the sloping flank 15''' above the substrate 13, i.e., in the growth zone 12, must be as straight as possible. The apex 15' should therefore be located 5 to 10 mm upstream of the upstream edge of the substrate 13 or the growth zone 12. 31260PCT – 1.09.2025

[0054] Die Geschwindigkeiten der Gasflüsse Q1 bis Q5 einander benachbarterGas inlet zones 6 to 10 should differ only slightly from one another to ensure laminar flow within the process chamber. The dynamic pressure immediately downstream of a gas outlet surface 6', 7', 8', 9', 10' should deviate as little as possible from the dynamic pressure downstream of an adjacent gas outlet surface. An upper limit of, for example, 20% can be defined for this deviation to prevent the formation of convection-induced vortices. Alternatively, an average value can be calculated for the mean dynamic pressures downstream of each of the gas outlet surfaces 6', 7', 8', 9', 10'. The mean dynamic pressures downstream of each gas outlet surface should deviate from this average value by a maximum of 30%, or ideally 20%, and in individual cases, no more than 50%. The flow velocity must not fall below a lower limit to avoid the formation of convection-induced vortices.

[0055] Vor dem Hintergrund dieser Randbedingungen kann durch Experi-An optimal value for the growth rate of the layer on the substrate 13 can be determined either by means of a model calculation or by means of a model calculation. The parameters essential for the growth rate are the mass flow of the second reactive gas from the second gas inlet zone 7, i.e., the associated partial pressure of TMGa, the diffusion constant, which is partly determined by the total pressure and the molar mass of the first gas flow Q1 in the diffusion barrier, and the height of the diffusion barrier, which is partly determined by the height H1 of the first gas outlet surface 6' or the first gas outlet zone 6, more precisely by the distance A of the lowest second gas outlet opening 7'' of the second gas outlet surface 7'.

[0056] Die Experimente beziehungsweise die Modellrechnungen werden mitpredefined limit values ​​were applied, namely, for example, a first threshold T1 of a maximum permissible diffusion transport of the second decomposition product, here Ga, to the surface of the process chamber floor 3 in the pre-zone 11, a second threshold T2 of a maximum permissible diffusion transport of the third decomposition product, here CHX, to the surface of the substrate 13, a third threshold T3 of a maximum distance B of the apex 15' of the availability profile 15 from the growth zone 11, and a fourth threshold T4 of a maximum difference between the mean flow velocity V1 of the first gas flow Q1 and the mean flow velocity V2 of the second gas flow.

[0057] Das Ergebnis einer derartigen Modellrechnung ist ein im WesentlichenThe value of the distance A between the lowest second gas outlet openings 7'', i.e., the gas outlet openings 7'' closest to the first gas inlet zone 6 or the uppermost first gas outlet opening 6''', is dependent on the molar masses of the reactive gases and their reaction rates. This yields the height H1 of the first gas inlet zone 6 or first gas outlet area 6'. The result also includes values, in particular maximum values, for the first gas flow Q1 and the second gas flow Q2, as well as the compositions of the two gas flows Q1 and Q2, namely the ratio of the first reactive gas to the inert gas in the first gas flow Q1 and the ratio of the second reactive gas to the inert gas in the second gas flow Q2. 31260PCT – 1.09.2025

[0058] Die Figur 3 zeigt schematisch ein Ergebnis einer Optimierung eines Sys-tems, in which various reactive gases are fed into the process chamber 2 through five superimposed gas inlet zones 6, 7, 8, 9, 10 in the manner described above, wherein additionally, from a “flow layer” downstream of the fourth gas inlet zone Ga, diffusion occurs both in the direction of the substrate 13 and in the direction of the process chamber ceiling 3.

[0059] Dabei wurden folgende Werte ermittelt: A = 3,9 mm, H2 = 3,15 mm, H3 = 8.1 mm, H4 = 1.9 mm, and H5 = 8.1 mm. The diameters of the gas outlet openings 6", 7", 8", 9", and 10" are 1.1 mm. The diameters of the gas outlet openings 6" of the first gas inlet zone 1 can be slightly larger. Compared to a standard CVD reactor according to the state of the art, a growth increase of 50% can be achieved with these design parameters, so that layers of the same thickness can be deposited in shorter times.

[0060] Bei einem anderen Ausführungsbeispiel, bei dem Substrate mit einemWith diameters of 200 mm arranged on the susceptor 17 and a process chamber height of 25 mm, an optimal distance A of 7.4 mm could be determined, with the center M of the substrate being 160 mm away from the gas outlet surface 6'.

[0061] In einem weiteren Ausführungsbeispiel mit einem Gaseinlassorgan 5 Eight nickel substrates, each with a diameter of 150 mm, are arranged around the gas inlet element 5, with the distance from the center point M of the substrate to the gas outlet surface 6' being 189 mm. The optimal distance Abe is 7.7 mm. The height of the process chamber is 25.3 mm. 31260PCT – 1.09.2025

[0062] In einem weiteren Ausführungsbeispiel mit einem Gaseinlassorgan 5 Eight quartz substrates, each with a diameter of 150 mm, surround the gas inlet organ 5, with the distance from the center point M of the substrate 13 to the gas outlet surface 6' being 189 mm. The optimal distance A is 6.4 mm.

[0063] In einem weiteren Ausführungsbeispiel mit einem Gaseinlassorgan 5Five nickel substrates, each with a diameter of 200 mm, surround the gas inlet element 5, with the distance of the center point M of the substrate being 13173 mm from the gas inlet surface 6'. The optimal distance Abe is 7.7 mm. The process chamber height is 25.3 mm.

[0064] In einem weiteren Ausführungsbeispiel mit einem Gaseinlassorgan aus Five quartz substrates, each with a diameter of 200 mm, surround the gas inlet element 5, with the distance from the center point M of substrate 13 to the gas inlet surface 6' being 173 mm. The optimal distance A is 6.4 mm. The process chamber height is 25.3 mm.

[0065] Die Optimierung der Auslegung der Reaktorgeometrie kann grund- Additionally, this can be done in two ways: via the height H1 of the first gas inlet zone 6, more precisely the distance of the lowest second gas inlet openings 7'' from the process chamber floor 3 and via the length V of the pre-zone; or / and via the height distribution of the other gas inlet zones 7, 8, 9.

[0066] Eine Randbedingung kann unter anderem die Folgende sein: R = A / V, where R should be in the range between 0.02 and 0.04. 31260PCT – 1.09.2025

[0067] Eine weitere Randbedingung kann unter anderem darin bestehen, dassthe gas inlet organ 5 does not have any gas inlet zones 8, 10 through which the first reactive gas flows, whose heights H3, H5 are lower than the height H1 of the first gas inlet zone 6, so that only those gas inlet zones 7, 9 can have a lower height H2, H4 through which another reactive gas, in particular the second reactive gas, flows.

[0068] Eine weitere Randbedingung kann wie folgt formuliert werden, wobei H is the process chamber height, which is in a range between 20 and 30 mm, n is the number of gas inlet zones, where n ≥ 3 and preferably 5, and Hi is the height of a gas outlet surface: (a) H1 ≠ H / n (b) H1 < H / n (c) H2 < H / n (d) H2 ≠ Hn-1 (e) Hn > H / n (f) H4 < H2 or H4 < H1 (g) H2 < H1

[0069] Bei der Erfindung handelt sich um eine Modifikation eines 5-Fach-Ein-The design features alternating Group V and Group III inlets arranged one above the other. The total height of the gas outlet area is 25.15 mm. The base below the lowest gas inlet zone is recessed in a recess. Compared to the conventional equidistant arrangement of the gas inlet levels, each 5 mm wide, in this embodiment the opening height of the lowest level, through which an NH3-H2 mixture flows, is smaller than the average of the opening heights of 5 mm. This overcomes the shortcomings of existing solutions by allowing the use of high NH3 flows, while simultaneously shortening the diffusion paths from the gas stream to the substrate surface and achieving uniform deposition.

[0070] The two gas inlet zones through which the Group III gas mixture flows are located in the second and fourth positions. They each have a lower height than the Group V gas intake zones.This fulfills the requirement of a backflow-free inflow. Due to the relatively high density of the Group V inlet gas mixture resulting from the increased NH3 concentration, an imbalance can occur between adjacent Group V and Group III gas inlet zones with H2 carrier gas and highly diluted Group III feedstocks at similarly high outflow velocities. ) between the adjacent gas inlet zones, leading to a tendency for flow instability to develop. Due to the reduced inlet height of the Group III gas inlet zones compared to the prior art, the gas velocity of the Group III gas mixture is increased at the existing overall flow rate, thereby partially compensating for the density difference. A criterion for maintaining flow stability near the inlet could be, for example, an upper limit on the deviation of the dynamic pressure. 31260PCT – 1.09.2025 between adjacent gas inlet zones by no more than a certain percentage, usually by no more than 30% of the mean of all gas inlet zones, in individual cases by no more than 50% of the mean of all gas inlet zones.

[0071] Bei Verwendung hoher NH3-Flussraten in den Gruppe-V Gaseinlasszo- It was recognized that matching the dynamic pressure by adjusting flow rates and inlet heights is more important for flow stability than matching the momentum flux density q = ρ∙U or the velocity- keit U.

[0072] Außerdem wird durch die höhere Gasgeschwindigkeit der wachstums- The limiting Group III component of mass transport into the reactor chamber is improved. The gas inlet zone G4 (upper Group III inlet) has a particularly low inlet height and a correspondingly high inflow velocity, so that the mass transport of the Group III feedstocks into the outer area of ​​the process chamber is particularly effective.

[0073] Zu den Vorteilen der nicht gleichförmigen Aufteilung der EinlasshöhenOther considerations include: ^Increasing the NH3 flux rate to achieve higher growth rates and thus a higher throughput than the prior art while maintaining the same V / III ratio, or to achieve a higher V / III ratio and thus lower background carbon doping and improved crystal quality at a comparable growth rate. 31260PCT – 1.09.2025^ High exposure to NH3 at the substrate surface, especially near the substrate edge, to achieve a high local V / III ratio and reduced carbon incorporation at the edge. In addition to the increased NH3 flow rate, the reduced inlet height of the lowest gas inlet zone G1 compared to the conventional gas inlet design is crucial for this.^ The reduced inlet height of G1 improves the mass transport of the growth-limiting Group III starting materials from the gas inlet zone G2 (second from the bottom) to the front edge of the substrates.High NH3 flow rates result in a higher density of the gas mixture compared to the carrier gas H2. This reduces the diffusion rate of the group III reactants from gas inlet zone G2 to the substrate surface. The gas flow from gas inlet zone G1 at height h(G1) acts as a diffusion barrier for the transport-limiting group III compounds from gas inlet zone G2 at height h(G2). The maximum of the depletion profile broadens into a shoulder extending onto the substrate, particularly in the configuration with five substrates, each with a diameter of 200 mm, arranged circularly around the gas inlet element, where the substrates are positioned very close to the gas inlet. This results in a loss of the curve's linearity and impairs the uniformity on rotated substrates. A lower inlet height of G1 compensates for this effect, thus achieving the required uniformity of the layer thickness distribution.^ For high NH3 flow rates, especially from the lowest gas inlet zone G1, flow stability can be achieved by adjusting the dynamic pressure 31260PCT – 1.09.2025 within certain thresholds of + / -30% or, in individual cases, up to + / -50% deviation from the mean, by selecting the inlet height of G2 (lower Group III inlet) less than the mean height of 5 mm. This increases the flow velocity, which enters the dynamic pressure term quadratically.

[0074] Im folgenden Abschnitt wird die Wirkungsweise und der vorteilhafteThe technical effect of the geometrically modified inlet shown above for three different process regimes in the MOCVD of nitride compound semiconductors is explained based on the respective values ​​used for the gas fluxes and the achieved values ​​for V / III ratio, growth rate, and carbon background doping. 1. Process regime: GaN HEMT, 45 slm NH3. The following table shows the distribution of the total fluxes and the NH3 fluxes for the process conditions of a process step in the fabrication of HEMT structures using the optimized gas inlet organ, as well as the resulting distribution of velocity, momentum flux density, and dynamic pressure. Inlet NH3 Deviation from mean height Total flux Gas inlet zones: Gas inlet h(Gi) area flux rate rate l asszone(mm) share (%) (slm) (slm)v rho*v rho*v**2G5 (top) 8.10 32.2% 40.1 15.75 -27% 10% -6.9%G4 1.90 7.6% 19.9 0 54% -41% 5.6%G3 8.10 32.2% 40.1 15.75 -27% 10% -6.9%31260PCT – 1.09.2025G2 3.15 12.5% ​​30.0 0 40% -47% -12.7%G1 (bottom) 3.90 15.5% 16.2 13.5 -39% 69% 20.8%Total 25.15 146.3 45In process regime 1 for the gas inlet device with the optimized distribution of the inlet heights, almost one-third of the total NH3 flux is introduced through the lowest gas inlet zone G1. In the conventional design with a 5 mm inlet height, an NH3 flux at this height would lead to backflows due to the higher density. The resulting lower diffusion fluxes of the growth-limiting group III species would be accompanied by non-uniform deposition of GaN, particularly near the edge of the substrate. Only the reduction of the inlet heights of G1 and G2 enables uniform deposition.By selecting the gas composition and gas velocities, deviations in dynamic pressure from the mean value between adjacent gas inlet zones are ensured to not significantly exceed ±20%. This guarantees flow stability and separation-free flow at the gas inlet, as verified by three-dimensional fluid mechanics calculations of the flow field for this regime. The following table shows the key process parameters and the resulting V / III ratios and growth rates for process regime 1 using the optimized inlet compared to the conventional 31260PCT – 1.09.2025. The pressure was p = 200 mbar in both cases, and the growth temperature T = 1060°C. Total TMGa flow rate NH3 flow rate NH3 flow rate Flow rate V / III Growth rate (slm) rate (slm) Level G1 (slm) (mol / min) ratio rate (µm / h) optimized inlet 146.3 45.0 13.5 5.28E-03 380 6.3 Conventional Inlet 142.0 36.0 5.4 4.54E-03 354 5.2 For the conventional gas inlet with equally high gas inlet zones, the NH3 flow rate through the lowest gas inlet zone G1 is limited to 5.4 slm for these process conditions. At significantly higher NH3 flows, the flow stability and uniform distribution of the deposition on the substrates are impaired. The optimized inlet allows the NH3 flow to be increased further while maintaining flow stability and uniformity. This allows for higher growth rates and higher production throughput at comparable V / III ratios. Process regime: AlGaN superlattice in HEMT structure for stress relief, 23 slm NH3 Inlet- Top- NH3 Deviation from mean: height area- Total- Flow- Gas inlet- h(Gi) share flow rate rate zone (mm) (%) (slm) (slm)v rho*v rho*v**2G5 (top) 8.10 32.2% 39.1 5.0 -18% -22% -27.6%G4 1.90 7.6% 12.9 0 62% -21% 45.1%G3 8.10 32.2% 33.6 7.5 -30% -8% -27.0%G2 3.15 12.5% 21.3 0 33% -35% -1.5%G1 (bottom) 3.90 15.5% 12.6 10.2 -47% 85% 11.0%. Summe 25.15 119.5 22.7531260PCT – 1.09.2025 In this example from a HEMT structure, a particularly large proportion of the total NH3 flow, almost half, is introduced through the lower gas inlet zone G1 of the gas inlet element with the optimized height distribution. This not only increases the total NH3 flow, allowing for a higher growth rate with a comparable V / III ratio, but also achieves a particularly high local partial pressure of NH3 near the substrate. As a result, even with a comparable total V / III ratio, the unwanted carbon background doping in the layer is lower than with the conventional injector with a uniform height distribution, as shown in the table below. Flow stability is ensured by a deviation of less than 30% from the mean dynamic pressure for the three NH3 gas inlet zones G1, G3, and G5.Further process conditions are pressure p = 50 mbar, growth temperature T = 1060°C, carrier gas H2. TMGa + Carbon - Total NH3 flux - TMAl growth - doping - NH3 flux rate - Level - Flux rate - V / III - Rate - AlGaN - Wafer center (slm) - Rate (slm) - G1 (slm) (mol / min) - Ratio (µm / h) (cm. -3 ) Optimized inlet 119.5 22.75 10.24 2.58E-03 393 2.7 8.2E+16 Conventional inlet 124.8 13.0 6.5 1.41E-03 410 1.5 3.0E+173. Process regime: GaN LED Buffer, 77 slm NH3 Inlet - Top - NH3 Deviation from mean - height - area - Total - Flow rate - Gas inlet zones: Gas inlet h(Gi) share - flow rate - rate z one(mm) (%) (slm) (slm)velocity v rho*v rho*v**2G5 (top) 8.10 32.2% 38.2 26.18 -48% 6% -31.7%G4 1.90 7.6% 22.2 0 82% -40% 34.6%31260PCT – 1.09.2025G3 8.10 32.2% 35.4 29.26 -51% 15% -31.2%G2 3.15 12.5% ​​36.8 0 52% -50% -7.0%G1 (bottom) 3.90 15.5% 23.4 21.56 -35% 69% 35.3%Total 25.15 156 77 In this example of a GaN layer in an LED structure, a low carbon background doping is particularly important, which is achieved, among other things, by a particularly high V / III ratio. The total NH3 flux is 77 slm and corresponds to half of the total flux of carrier gas and NH3 as well as other starting materials. The total NH3 flux is distributed almost evenly between the three gas inlet zones. The maximum deviation of the dynamic pressure from the mean value does not significantly exceed 35% for the individual gas inlet zones.There are two process engineering approaches for selecting the fluxes of the Group III starting materials: one focused on optimizing the growth rate and the other on optimizing the carbon background doping. When optimizing the growth rate, the NH3 flux is doubled compared to the conventional inlet. The MO flux rate, and thus the growth rate, is increased by approximately 50%. This keeps the carbon background doping at a comparable level (increasing the growth rate requires a higher V / III ratio for the same carbon incorporation), as shown in the table below. Further process conditions are: pressure p = 200 mbar, growth temperature T = 1060°C, carrier gas H2. 31260PCT – 1.09.2025. Carbon Total NH3 Flux TMGa Growth Doping Flux Rate NH3 Flux Rate Level Flux Rate V / III Rate GaN Wafer Center (slm) Rate (slm) G1 (slm) (mol / min) Ratio (µm / h) (cm -3) Optimized inlet 119.5 77 21.56 2.05E-03 1678 2.3 1.25E+16 Conventional inlet 124.8 38 5.7 1.27E-03 1335 1.5 1.0E+16 When optimizing the carbon background doping by using the optimized inlet, the NH3 flux is also doubled. However, the TMGa flux rate is only slightly increased, so the growth rate remains the same (a slight increase in the group III flux is necessary because the diffusion rate for the group III compounds is lower in the denser gas mixture with more NH3). Due to the near doubling of the achievable V / III ratio, carbon incorporation is significantly reduced, as shown in the following table. Carbon Total NH3 Flux TMGa Growth Doping Flux Rate NH3 Flux Rate Level Flux Rate V / III Rate GaN Wafer Center (slm) Rate (slm) G1 (slm) (mol / min) Ratio (µm / h) (cm -3) Optimized inlet 119.5 77 21.56 6.9E-03 4980 0.7 3.8E+15 Conventional inlet 124.8 38 5.7 6.51E-03 2605 0.7 7.0E+15 Applying conditions with at least 77 slm NH3 to GaN substrates results in a carbon background doping of on average 1.6 x 10^15 in experiments. Such a low (preferable) value has not yet been published at a growth rate of 0.7 µm / h. The results of the SIMS measurement are shown in Figure 6. 31260PCT – 1.09.2025 For further geometric configurations, simulation calculations of the process chamber were used, which include the coupled calculation of the flow field, the temperature distribution, and the mass transport of the main chemical species. The growth rate distribution on the susceptor and on the substrates results from the diffusion rate to the deposited surface. The carbon incorporation rate is quantitatively determined using a model based on the competitive incorporation between carbon and nitrogen at the group V lattice sites. The cases investigated so far comprise the combinations of inlet heights h(G1) to h(G5) in mm shown in the rows of the tables on the following three pages. The process gas flow rates of H2 and NH3 in slm for the gas inlet zones G1 to G5 are also shown. The total NH3 flow rate is approximately 48 slm. Depending on the case under consideration, 15% to 25% of the total NH3 quantity is received at the lowest inlet G1.The height distribution of the gas inlet zones and the flux distribution of NH3 and H2 across the gas inlet zones G1 to G5 were optimized to achieve a uniform distribution of deposition rates of at most (max – min) / mean = 1.5% and of the carbon background doping of at most (max – min) / mean = 12%. 31260PCT – 1.09.2025. h(G1) h(G2) h(G3) h(G4) h(G5) 5 3.25 7.25 3.25 6.25 4 3.25 7.25 3.25 7.25 4 3.25 8.25 3.25 6.25 4 3.25 9.25 3.25 5.25 3 3.25 7.25 3.25 8.25 3 3.25 9.25 3.25 6.25 3.5 4.25 7.25 2.25 7.75 4.5 2.25 7.25 4.25 6.75 4 3 8 2 8 4.5 2 8 3 7.5 4 3 9 2 7 4 3 10 2 6 3 3 8 2 9 3 3 10 2 7 3.5 2.25 8.25 4 7 3.25 2.5 7.75 5 6.5 3.6 1.8 8.1 3 8.5 4.0 2.0 7.5 3.0 8.0 4.5 2 8 2 8.5 31260PCT – 09 / 01 / 2025 H2 G1 H2 G2 H2 G3 H2 G4 H2 G5 34.07 42.96 14.43 44.57 9.58 19.83 44.13 17.96 45.53 18.15 19.83 44.32 23.00 45.53 12.92 20.03 44.32 28.23 45.73 7.30 5.41 44.90 21.68 46.12 27.50 5.60 44.90 32.34 46.31 16.45 16.15 56.53 19.12 31.38 22.42 21.97 29.59 19.60 57.17 17.28 22.74 43.55 25.71 27.31 26.29 24.11 25.71 26.78 44.76 24.26 25.45 43.55 29.88 27.31 19.42 22.94 43.55 36.96 27.31 14.86 7.54 44.32 30.02 27.70 36.03 7.54 44.32 41.26 27.90 24.59 10.64 30.17 27.89 55.61 21.30 7.54 33.66 23.43 63.95 17.03 13.94 19.90 31.57 45.92 34.28 27.01 25.71 22.61 44.57 25.71 29.33 27.07 28.62 28.48 32.11 31260PCT – 1.09.2025 NH3 G1 NH3 G2 NH3 G3 NH3 G4 NH3 G5 7.22 0.00 20.46 0.00 20.46 9.63 0.00 19.26 0.00 19.26 9.63 0.00 19.26 0.00 19.26 9.63 0.00 19.26 0.00 19.26 12.04 0.00 18.05 0.00 18.05 12.04 0.00 18.05 0.00 18.05 9.63 0.00 19.26 0.00 19.26 10.59 0.00 18.78 0.00 18.78 9.63 0.00 19.26 0.00 19.26 10.59 0.00 18.78 0.00 18.78 8.67 0.00 19.74 0.00 19.74 9.63 0.00 19.26 0.00 19.26 12.04 0.00 18.05 0.00 18.05 12.04 0.00 18.05 0.00 18.05 12.04 0.00 18.05 0.00 18.05 12.04 0.00 18.05 0.00 18.05 12.04 0.00 18.05 0.00 18.05 9.63 0.00 19.26 0.00 19.26 9.63 0.00 19.26 0.00 19.26 31260PCT – 09 / 01 / 2025

[0075] Die vorstehenden Ausführungen dienen der Erläuterung der von der The application covers all inventions that further develop the prior art, at least through the following combinations of features, each of which can also be independently combined, namely:

[0076] Ein Verfahren, das dadurch gekennzeichnet ist, dass Randbedingungena transport of the second decomposition product to the surface of the process chamber floor 3 in the pre-zone 11, a transport of the third decomposition product to the surface of the substrate 13, a second distance B of the apex 15' of the availability in the growth zone and a maximum difference between a mean flow velocity V1 or a dynamic pressure P1 of the first gas flow Q1 and a mean flow velocity V2 or a dynamic pressure P2 of the second gas flow Q2 are specified, and taking these boundary conditions into account, the first distance A as well as the first and the second gas flows Q1, Q2 are varied until the growth rate of the layer reaches a maximum or the incorporation of the third decomposition product into the layer reaches a minimum.

[0077] Ein Verfahren, das dadurch gekennzeichnet ist, dass ein erster Schwell-a value T1 of a maximum allowable transport of the second decomposition product to the surface of the process chamber floor 3 in the pre-zone 11 is defined, a second threshold T2 of a maximum allowable transport of the third decomposition product to the surface of the substrate 13 is defined, a third threshold T3 of a minimum second distance B of the apex 15' of the availability trajectory 15 from the growth zone 11 is defined, a fourth threshold T4 of a maximum difference between a mean flow velocity V1 or the dynamic pressure P1 of the first gas flow Q1 and a mean flow velocity V2 or the 31260PCT – 1.09.2025 dynamic pressure P2 of the second gas flow Q2 is defined, and that taking into account the thresholds T1, T2, T3, T4 the first distance A as well as the first and the second gas flows Q1, Q2 are varied until the growth rate of the layer reaches a maximum or the incorporation of the third decomposition product of the layer reaches a minimum.

[0078] Ein Verfahren, das dadurch gekennzeichnet ist, dass durch Modellrech-The following parameters are varied by means of specifications or by conducting experiments: a flow velocity V1 of the first gas flow Q1 averaged over the first gas outlet surface 6', the ratio of the first reactive gas to the inert gas in the first gas flow Q1, a flow velocity V2 of the second gas flow Q1 averaged over the second gas outlet surface 7', the ratio of the second reactive gas to the inert gas in the second gas flow Q2, the length V of the pre-zone 11, the first distance A of the first gas inlet zone 6 nearest the second gas outlet 7'' to the process chamber floor 3, as well as the number and opening area of ​​the gas outlets 6'' in the first gas outlet surface 6', and a minimum value of the first distance A is determined in an optimization process.

[0079] Ein Verfahren, das dadurch gekennzeichnet ist, dass das Gaseinlassor-gan 5 has a third gas inlet zone 8 arranged vertically above the second gas inlet zone 7, with a third gas outlet area 8', through which a third gas flow Q3, containing the first reactive gas, flows into the process chamber 2, wherein the height H2 of the second gas outlet area 7', a height H3 of the third gas outlet area 8' and the third gas flow Q3 or the ratio of the first reactive gas to the inert gas in the third gas flow Q3 are taken into account in the optimization process. 31260PCT – 1.09.2025

[0080] Ein Verfahren, das dadurch gekennzeichnet ist, dass das Gaseinlassor-gan 5 has a fourth gas inlet zone 9 with a fourth gas outlet area 9' vertically above the third gas inlet zone 8, through which a fourth gas flow Q4, containing the second reactive gas, flows into the process chamber 2, and a fifth gas inlet zone 10 with a fifth gas outlet area 10', through which a fifth gas flow Q5, containing the first reactive gas, flows into the process chamber 2, taking into account a height H4 of the fourth gas outlet area 9', the fourth gas flow Q4 or the ratio of the second reactive gas to the inert gas in the fourth gas flow Q4, a height H5 of the fifth gas outlet area 10', the fifth gas flow Q5 or the ratio of the first reactive gas to the inert gas in the fifth gas flow Q5.

[0081] Ein Verfahren, das dadurch gekennzeichnet ist, dass der erste Ab- where A, the first gas flow Q1 and the second gas flow Q2 have been determined according to a method according to one of claims 1 to 6.

[0082] Ein Verfahren, das dadurch gekennzeichnet ist, dass bei einem Total-pressure between 100 mbar and 300 mbar, preferably 200 mbar + / - 20 mbar in process chamber 2, a first gas flow Q1 in the range between 10 sl and 22 sl, a second gas flow Q2 in the range between 2 mmol / min and 6 mmol / min, a susceptor temperature between 1000°C and 1100°C, preferably 1060°C + / -10 K for varying the growth rates between 5 µm / h and 7 µm / h or the incorporation of the third decomposition product into the layer with a concentration of 8E+16 and 3E+17 cm-3, the distance A is varied in a range between 3 mm and 4.5 mm, wherein it is particularly provided that the element of group V is N, As and / or P and the element of group III is Ga, In and / or P. 31260PCT – 1.09.2025

[0083] Ein CVD-Reaktor, der dadurch gekennzeichnet ist, dass der erste Ab- stand A, the number and size of the free areas of the gas outlet openings 6'' in the first gas outlet area 6' and the length V of the pre-zone 11 have been determined according to a method according to one of claims 1 to 6.

[0084] Ein CVD-Reaktor, der dadurch gekennzeichnet ist, dass bei einem Gas-inlet element 5 made of nickel, the distance A is less than 8 mm, or in the case of a gas inlet element 5 made of quartz, the distance A is less than 7 mm, and / or the ratio R of the distance A to the length of the pre-flow zone V is in the range between 0.02 and 0.04, and / or the distance A is less than the heights H3, H5 of other gas outlet surfaces 8', 10' through which a first reactive gas flows, and / or only those gas outlet surfaces 7', 9' have a lower height H2, H4 through which a reactive gas different from the first reactive gas flows, and / or the distance A is less than the quotient of the total height of all gas outlet surfaces 6' to 10' and the number of gas outlet surfaces 6' to 10'.

[0085] Ein Verfahren zum Abscheiden einer Schicht in einem CVD-Reaktor,wherein a gas inlet element 6 has at least five vertically arranged gas outlet zones 6, 7, 8, 9, 10, each with a height H1, H2, H3, H4, H5, and through the lowest gas inlet zone 6 a gas flow (Q1) of an element of group III, through the gas inlet zone 7 above it a gas flow Q2 of an element of group V, through the gas inlet zone 8 above it a gas flow Q3 of an element of group III, through the gas inlet zone 9 above it a gas flow Q4 of an element of group V and through the gas inlet zone 10 above it a gas flow Q5 of an element of group III. The main group is fed into a process chamber 2 in which a substrate 13 to be coated is located, wherein, for the deposition of a GaN-HEMT layer, the heights have the following values ​​with a tolerance of + / - 31260PCT – 1.09.202510%: H1 = 3.90 mm, H2 = 3.15 mm, H3 = 8.10 mm, H4 = 1.9 mm, H5 = 8.The following fluxes of reactive gases flow through the gas inlet zones with a tolerance of + / -10%: Q1 = 13.5 slm, Q2 = 5.28E-3 mol / min, Q3 = 15.75 slm, Q4 = 5.28E-3 mol / min, Q5 = 15.75 slm, where the total flux consisting of the flux of the respective reactive gas and an inert gas through the respective gas inlet zones has the following values ​​with a tolerance of + / -10%: Gas inlet zone 6 = 16.2 slm, Gas inlet zone 7 = 30.0 slm, Gas inlet zone 8 = 40.1 slm, Gas inlet zone 9 = 19.9 slm, Gas inlet zone 10 = 40.1 slm; where, for the deposition of an AlGaN-HEMT layer, the heights have the following values ​​with a tolerance of + / -10%: H1 = 3.90 mm, H2 = 3.15 mm, H3 = 8.10 mm, H4 = 1.9 mm, (H5) = 8.10 mm, and the following fluxes of reactive gases, each with a tolerance of + / -10%, flow through the gas inlet zones: Q1 = 10.2 slm, Q2 = 2.58E-3 mol / min, Q3 = 7.5 slm, Q4 = 2.58E-3 mol / min, Q5 = 5.0 slm.wherein the total flow through the respective gas inlet zones, consisting of the flow of the respective reactive gas and an inert gas, has the following values ​​with a tolerance of + / -10 %: Gas inlet zone 6 = 12.6 slm, Gas inlet zone 7 = 21.3 slm, Gas inlet zone 8 = 33.6 slm, Gas inlet zone 9 = 12.9 slm, Gas inlet zone 10 = 39.1 slm; where, for the deposition of a GaN buffer layer, the heights have the following values ​​with a tolerance of + / -10%: H1 = 3.90 mm, H2 = 3.15 mm, H3 = 8.10 mm, H4 = 1.9 mm, H5 = 8.10 mm, and the following fluxes of the reactive gases, each with a tolerance of + / -10%, flow through the gas inlet zones: Q1 = 21.56 slm, Q2 = 2.05 E⁻³ mol / min, Q3 = 29.26 slm, Q4 = 2.05 E⁻³ mol / min, Q5 = 26.18 slm, where the total flux through the respective gas inlet zones, consisting of the flux of the respective reactive gas and an inert gas, has the following values ​​with a tolerance of + / -10%: Gas inlet zone 6 = 23.4 slm, gas inlet zone 7 =36.8 slm,Gas inlet zone 8 = 35.4 slm, gas inlet zone 9 = 22.2 slm, gas inlet zone 10 = 38.2 slm.31260PCT – 09 / 01 / 2025,

[0086] Eine Vorrichtung, die dadurch gekennzeichnet ist, dass die Höhe H1 the lowest gas outlet zone is chosen such that the growth rate of the GaN layer or a GaAlN layer is greater than 6 µm / h or the carbon background doping is less than 1E-16 cm -3 amounts.

[0087] Eine Vorrichtung zum Abscheiden einer III-V-Schicht, wobei ein Gas-The inlet organ 6 has at least five vertically arranged gas outlet zones 6, 7, 8, 9, 10, each with a height H1, H2, H3, H4, H5, and through the lowest gas inlet zone 6 a gas flow Q1 of an element of the III main group, through the gas inlet zone 7 above it a gas flow Q2 of an element of the V main group, through the gas inlet zone 8 above it a gas flow Q3 of an element of the III main group, through the gas inlet zone 9 above it a gas flow Q4 of an element of the V main group and through the gas inlet zone 10 above it a gas flow Q5 of an element of the III main group. The main group can be fed into a process chamber 2, in which a substrate 13 to be coated can be accommodated, with the heights having the following values ​​with a tolerance of + / -10%: H1 = 3.90 mm, H2 = 3.15 mm, H3 = 8.10 mm, H4 = 1.9 mm, H5 = 8.10 mm.

[0088] Alle offenbarten Merkmale sind (für sich, aber auch in Kombination un-(mutually) essential to the invention. The disclosure of the application hereby also fully incorporates the disclosure content of the associated / attached priority documents (copy of the prior application), also for the purpose of including features of these documents in the claims of the present application. The dependent claims characterize, even without the features of a referenced claim, independent inventive developments of the prior art, in particular to make divisional applications on the basis of these claims. The invention specified in each claim may additionally encompass one or more of the 31260PCT – 1.09.2025 The invention includes features described above, particularly those identified by reference numbers and / or listed in the reference number list. The invention also relates to designs in which individual features mentioned in the above description are not realized, especially if they are recognizably unnecessary for the intended use or can be replaced by other technically equivalent means. 31260PCT – 1.09.2025 List of reference symbols 1 CVD reactor 16 Heating device 2 Process chamber 17 Susceptor 3 Process chamber floor 18 Gas outlet device 4 Process chamber ceiling 19 Center point 5 Gas inlet device 20 Supply line 6 First gas inlet zone 6' First gas outlet surface 6'' Gas outlet opening 7 Second gas inlet zone 7' Second gas outlet surface A Distance 7'' Gas outlet opening B Distance 8 Third gas inlet zone H1 First height 8' Third gas outlet surface H2 Second height 8'' Gas outlet opening H3 Height 9 Fourth gas inlet zone H4 Height 9' Fourth gas outlet surface H5 Height 9'' Gas outlet opening M Center point 10 Fifth gas inlet zone P1 Dynamic pressure 10' Fifth gas outlet surface P2 Dynamic pressure 10'' Gas outlet opening Q1 First gas flow 11 Pre-flow zone Q2 Second gas flow 12 Growth zone Q3 Third gas flow 13 Substrate Q4 Fourth gas flow 14 Storage area Q5 Fifth gas flow 15 Availability curve R ratio 15' peak S flow direction 15'' rising flank T1 first threshold 15''' falling flank T2 secondThreshold 31260PCT – 1.09.2025 T3 third threshold T4 fourth threshold U flow velocity V length of the upstream zone V1 flow velocity V2 flow velocity W length of the growth zone Ρ Dichte 31260PCT – 1.09.2025

Claims

Claims 1. A method for increasing the efficiency of a CVD reactor (1), wherein a gas inlet element (5) adjoining a process chamber (2) has at least a first gas inlet zone (6) and a second gas inlet zone (7), wherein the first gas inlet zone (6) has a lowest first gas outlet surface (6') adjoining, in particular, a process chamber floor (3) with a first height (H1), and the second gas inlet zone (7) is arranged above the first gas outlet surface (6') and in particular adjoins it and has a second gas outlet surface (7') with a second height (H2), wherein a first gas flow (Q1), which contains a first reactive gas and optionally an inert gas, passes through gas outlet openings (6'') of the first gas outlet surface (6'), and a second gas flow (Q2), which contains a second reactive gas and optionally an inert gas, passes through gas outlet openings (7'') of the second gas outlet surface (7'). Inert gas contains flows into the process chamber (2),wherein the second gas outlet openings (7'') nearest to the first gas inlet zone (6) have a first distance (A) to the process chamber floor (3), wherein a pre-flow zone (11) extending in a flow direction (S) over the process chamber floor (3) adjoins the gas outlet surfaces (6', 7'), wherein the pre-flow zone (11) adjoins a growth zone (12) extending over the process chamber floor (3) and over a storage area (14) on which a substrate (13) is located, wherein the process chamber (2) is heated with a heating device (16) such that the first reactive gas forms a first decomposition product, in particular an element of group V, and the second reactive gas forms a second decomposition product, in particular an element of group III and a third decomposition product, in particular a carbon compound,and a reaction product of the first and the second decomposition product on the surface of the substrate (13) as a layer and on the surface of the 31260PCT – 1.09.2025, The pre-zone (11) is deposited as a parasitic coating, wherein the first gas flow in the pre-zone (11) and the growth zone (12) forms a barrier which, in the pre-zone (11), inhibits the deposition of the second decomposition product without reaction with the first decomposition product, and in the growth zone (12), inhibits the incorporation of an element of the third decomposition product, in particular carbon, into the layer, wherein a profile (15) of an availability (15) of the reaction product, which determines a growth rate of the layer or the parasitic coating, rises in the flow direction (S) in the region of the process chamber floor (3) in an ascending flank (15'') extending in the pre-zone (11) and, after reaching a peak (15'), falls in a descending flank (15''') extending over the growth zone (12), characterized bythat boundary conditions for the transport of the second decomposition product to the surface of the process chamber floor (3) in the feed zone (11), for the transport of the third decomposition product to the surface of the substrate (13), for a second distance (B) of the peak (15') of the availability profile (15) in the growth zone, and for a maximum difference between a mean flow velocity (V1) or a dynamic pressure (P1) of the first gas flow (Q1) and a mean flow velocity (V2) or a dynamic pressure (P2) of the second gas flow (Q2) are specified, and taking these boundary conditions into account, the first distance (A) as well as the first and the second gas flows (Q1, Q2) are varied until the growth rate of the layer reaches a maximum or the incorporation of the third decomposition product into the layer reaches a minimum.

2. Method according to claim 1, characterized in that,that a first threshold (T1) of a maximum permitted transport of the second Zerle- 31260PCT – 1.09.2025, a threshold value (T2) of a maximum allowable transport of the third decomposition product to the surface of the process chamber floor (3) in the pre-flow zone (11) is defined, a second threshold value (T2) of a maximum allowable transport of the third decomposition product to the surface of the substrate (13) is defined, a third threshold value (T3) of a minimum second distance (B) of the peak (15') of the availability profile (15) from the growth zone (11) is defined, a fourth threshold value (T4) of a maximum difference between a mean flow velocity (V1) or dynamic pressure (P1) of the first gas flow (Q1) and a mean flow velocity (V2) or dynamic pressure (P2) of the second gas flow (Q2) is defined, and taking into account the threshold values ​​(T1, T2, T3, T4), the first distance (A) as well as the first and second gas flows (Q1, Q2) are varied.until the growth rate of the layer reaches a maximum or the incorporation of the third decomposition product of the layer reaches a minimum.

3. Method according to claim 1 or 2, characterized in that the following parameters are varied by model calculations or by carrying out experiments: a flow velocity (V1) of the first gas flow (Q1) averaged over the first gas outlet surface (6'), the ratio of the first reactive gas to the inert gas in the first gas flow (Q1), a flow velocity (V2) of the second gas flow (Q1) averaged over the second gas outlet surface (7'), the ratio of the second reactive gas to the inert gas in the second gas flow (Q2), the length (V) of the upstream zone (11),The first distance (A) of the first gas inlet zone (6) to the second gas outlet opening (7'') nearest to the process chamber floor (3), as well as the number and opening area of ​​the gas outlet openings (6'') in the first gas outlet area (6'), and a minimum value of the first distance (A) are determined in an optimization process. 31260PCT – 1.09.2025 4. A method according to one of the preceding claims, characterized in that the gas inlet element (5) has a third gas inlet zone (8) arranged vertically above the second gas inlet zone (7) with a third gas outlet surface (8') through which a third gas flow (Q3), containing the first reactive gas, flows into the process chamber (2), wherein the height (H2) of the second gas outlet surface (7'), a height (H3) of the third gas outlet surface (8') and the third gas flow (Q3) or the ratio of the first reactive gas to the inert gas in the third gas flow (Q3) are taken into account in the optimization process. Method according to claim 4, characterized in that the gas inlet element (5) has a fourth gas inlet zone (9) vertically above the third gas inlet zone (8) with a fourth gas outlet surface (9') through which a fourth gas flow (Q4), which contains the second reactive gas, flows into the process chamber (2),and has a fifth gas inlet zone (10) with a fifth gas outlet surface (10') through which a fifth gas flow (Q5), containing the first reactive gas, flows into the process chamber (2), taking into account a height (H4) of the fourth gas outlet surface (9'), the fourth gas flow (Q4) or the ratio of the second reactive gas to the inert gas in the fourth gas flow (Q4), a height (H5) of the fifth gas outlet surface (10'), the fifth gas flow (Q5) or the ratio of the first reactive gas to the inert gas in the fifth gas flow (Q5).

6. Method for depositing a layer in a CVD reactor, wherein a gas inlet element (5) adjoining a process chamber (2) has at least a first gas inlet zone (6) and a second gas inlet zone (7), wherein the first gas inlet zone (6) has a first gas outlet surface (6') adjoining a process chamber floor (3) 31260PCT – 1.09.2025 with a first height (H1),and the second gas inlet zone (7) has a second gas outlet surface (7') adjacent to the first gas outlet surface (6') with a second height (H2), wherein a first gas flow (Q1), containing a first reactive gas and optionally an inert gas, flows into the process chamber (2) through gas outlet openings (6'') of the first gas outlet surface, and a second gas flow (Q2), containing a second reactive gas and optionally an inert gas, flows into the process chamber (2) through gas outlet openings (7'') of the second gas outlet surface (7'), wherein a pre-zone (11) extending in a flow direction (S) over the process chamber floor (3) adjoins the gas outlet surfaces (6', 7'), wherein the second gas outlet openings (7'') closest to the first gas inlet zone (6) have a first distance (A) to the process chamber floor (3) have, wherein the pre-run zone (11) extends over the process chamber floor (3) and over a storage area (14) on which a substrate (13) is located,extending growth zone (12) adjoins the process chamber (2) with a heating device (16) so that the first reactive gas decomposes a first decomposition product, in particular an element of the V main group, and the second reactive gas decomposes a second decomposition product, in particular an element of the III main group. a main group and a third decomposition product, in particular a carbon compound, is formed, and a reaction product of the first and the second decomposition product is deposited on the surface of the substrate (13) as a layer and on the surface of the pre-decomposition zone (11) as a parasitic coating, wherein the first gas flow forms a barrier in the pre-decomposition zone (11) and the growth zone (12), which in the pre-decomposition zone (11) inhibits the deposition of the second decomposition product without reaction with the first decomposition product, and in the growth zone (12) inhibits the incorporation of an element of the third decomposition product, in particular carbon, into the layer,wherein a course (15) of a growth rate of the layer or parasitic coating 31260PCT – 1.09.2025, determining availability of the reaction product in the region of the process chamber floor (3) in the flow direction (S) increases in an ascending flank (15'') extending in the feed zone (11) and, after reaching a peak (15'), decreases in a descending flank (15''') extending over the growth zone (12), characterized in that the first distance (A), the first gas flow (Q1) and the second gas flow (Q2) have been determined according to a method according to one of claims 1 to 6.7.A method for depositing a layer in a CVD reactor, wherein a gas inlet element (5) adjoining a process chamber (2) has at least a first gas inlet zone (6) and a second gas inlet zone (7), wherein the first gas inlet zone (6) has a first gas outlet surface (6') adjoining a process chamber floor (3) with a first height (H1), and the second gas inlet zone (7) has a second gas outlet surface (7') adjoining the first gas outlet surface (6') with a second height (H2), wherein a first gas flow (Q1) comprising a first reactive gas, which is a hydride of an element of group V, passes through gas outlet openings (6'') of the first gas outlet surface, and a second gas flow (Q2) comprising a second reactive gas, which is a organometallic compound of an element of the III.-Main group is, includes, flows into the process chamber (2), wherein a pre-flow zone (11) extending in a flow direction (S) over the process chamber floor (3) is connected to the gas outlet surfaces (6', 7'), wherein the second gas outlet openings (7'') nearest to the first gas inlet zone (6) have a first distance (A) to the process chamber floor (3), wherein the pre-flow zone (11) adjoins a growth zone (12) extending over the process chamber floor (3) and over a storage area (14) on which a substrate (13) is located, which is formed by a susceptor (17) 31260PCT – 1.09.2025. with a heating device (16) is heated to a susceptor temperature, such that the first reactive gas is a first decomposition product, namely an element of the V main group, and the second reactive gas is a second decomposition product, namely an element of the III.The main group, and a third decomposition product, namely a carbon compound, is formed, and a reaction product of the first and the second decomposition product is deposited on the surface of the substrate (13) as a III-V layer, characterized in that, at a total pressure between 100 mbar and 300 mbar, preferably 200 mbar ± 20 mbar in the process chamber (2), a first gas flow (Q1) in the range between 10 slm and 22 slm, a second gas flow (Q2) in the range between 2 mmol / min and 6 mmol / min, a susceptor temperature between 1000°C and 1100°C, preferably 1060°C ± 10 K, the growth rates are varied between 5 µm / h and 7 µm / h, or the third decomposition product is incorporated into the layer at a concentration of 8E+16 and 3E+17. cm-3 or in a range between 8E+16 and 3E+17 cm-3, the distance (A) is varied in a range between 3 mm and 4.5 mm, in particular providing that the element of the V.The element of main group N, As and / or P and the element of the III main group Ga, In and / or P is .

8. CVD reactor (1) for carrying out a method according to claim 6 or 7, wherein a gas inlet element (5) adjoining a process chamber (2) has at least a first gas inlet zone (6) and a second gas inlet zone (7), wherein the first gas inlet zone (6) has a first gas outlet surface (6') adjoining a process chamber floor (3) with a first height (H1), and the second gas inlet zone (7) has a second gas outlet surface (7') adjoining the first gas outlet surface (6') with a second height (H2), with gas outlet openings (6'') of the first gas outlet surface for the first gas flow (Q1) to pass through, and with gas outlet openings (7'') of the second gas outlet surface (7') for the 31260PCT – 1.09.2025. second gas flow (Q2), wherein the second gas outlet openings (7'') nearest to the first gas inlet zone (6) have a first distance (A) to the process chamber floor (3), wherein a pre-flow zone (11) extending in a flow direction (S) over the process chamber floor (3) adjoins the gas outlet surfaces (6', 7'), wherein the pre-flow zone (11) adjoins a growth zone (12) extending over the process chamber floor (3) and over a storage area (14) on which a substrate (13) is located, with a heating device (16) with which the process chamber (2) can be heated, characterized in that the first distance (A), the number and size of the free areas of the gas outlet openings (6'') in the first gas outlet surface (6') and the length (V) of the pre-flow zone (11) are determined according to a method according to one of the claims 1 to 6 have been determined.9.CVD reactor according to claim 8, characterized in that, in the case of a gas inlet element (5) made of nickel, the distance (A) is less than 8 mm, or in the case of a gas inlet element (5) made of quartz, the distance (A) is less than 7 mm, and / or that the ratio (R) of the distance (A) to the length of the pre-flow zone (V) is in the range between 0.02 and 0.04, and / or that the distance (A) is less than the heights (H3, H5) of other gas outlet surfaces (8', 10') through which a first reactive gas flows, and / or that only those gas outlet surfaces (7', 9') have a lower height (H2, H4) through which a reactive gas different from the first reactive gas flows, and / or that the distance (A) is less than the quotient of the total height of all gas outlet surfaces (6' to 10') and the number of gas outlet surfaces. (6' to 10').

10. Method for depositing a layer in a CVD reactor, wherein a gas inlet device (6) has at least five vertically stacked 31260PCT – 1.09.2025. Gas outlet zones (6, 7, 8, 9, 10) each have a height (H1, H2, H3, H4, H5) and through the lowest gas inlet zone (6) a gas flow (Q1) of an element of the III main group, through the gas inlet zone above it (7) a gas flow (Q2) of an element of the V main group, through the gas inlet zone above it (8) a gas flow (Q3) of an element of the III main group, through the gas inlet zone above it (9) a gas flow (Q4) of an element of the V main group and through the gas inlet zone above it (10) a gas flow (Q5) of an element of the III main group.The main group is fed into a process chamber (2) containing a substrate (13) to be coated, wherein, for the deposition of a GaN-HEMT layer, the heights have the following values ​​with a tolerance of + / -10%: (H1) = 3.90 mm, (H2) = 3.15 mm, (H3) = 8.10 mm, (H4) = 1.9 mm, (H5) = 8.10 mm and the following fluxes of the reactive gases, each with a tolerance of + / -10%, flow through the gas inlet zones: (Q1) = 13.5 slm, (Q2) = 5.28 E-3 mol / min, (Q3) = 15.75 slm, (Q4) = 5.28 E-3 mol / min, (Q5) = 15.75 slm, where the flux of the respective reactive gas and an inert gas is determined by the flux of the respective reactive gas and an inert gas. The total gas flow through the respective gas inlet zones, each with a tolerance of + / -10%, has the following values: Gas inlet zone (6) = 16.2 slm, Gas inlet zone (7) = 30.0 slm, Gas inlet zone (8) = 40.1 slm, Gas inlet zone (9) = 19.9 slm, Gas inlet zone (10) =. 40,1 slm;where, for the deposition of an AlGaN-HEMT layer, the heights have the following values ​​with a tolerance of + / -10%: (H1) = 3.90 mm, (H2) = 3.15 mm, (H3) = 8.10 mm, (H4) = 1.9 mm, (H5) = 8.10 mm, and the following fluxes of reactive gases, each with a tolerance of + / -10%, flow through the gas inlet zones: (Q1) = 10.2 slm, (Q2) = 2.58 E⁻³ mol / min, (Q3) = 7.5 slm, (Q4) = 2.58 E⁻³ mol / min, (Q5) = 5.0 slm, where the total flux through the respective gas inlet zones consists of the flux of the respective reactive gas and an inert gas. The gas intake zones each have the following values ​​with a tolerance of + / -10%: Gas intake zone (6) = 12.6 slm, Gas intake zone (7) = 21.3 slm, Gas intake zone (8) = 33.6 slm, Gas intake zone (9) = 12.9 slm, Gas intake zone (10) = 39,1 slm;where, for the deposition of a GaN buffer layer, the heights have the following values ​​with a tolerance of + / -10%: (H1) = 3.90 mm, (H2) = 3.15 mm, (H3) = 8.10 mm, (H4) = 1.9 mm, (H5) = 8.10 mm, and the following fluxes of the reactive gases flow through the gas inlet zones, each with a tolerance of + / -10%: (Q1) = 21.56 slm, (Q2) = 2.05 E⁻³ mol / min, (Q3) = 29.26 slm, (Q4) = 2.05 E⁻³ mol / min, (Q5) = 26.18 slm, where the total flux through the respective gas inlet zones, consisting of the flux of the respective reactive gas and an inert gas, is also within a tolerance of + / -10%. % have the following values: Gas inlet zone (6) = 23.4 slm, Gas inlet zone (7) = 36.8 slm, Gas inlet zone (8) = 35.4 slm, Gas inlet zone (9) = 22.2 slm, Gas inlet zone (10) = 38,2 slm.

11. Device for depositing a GaN layer or an AlGaN layer, wherein a gas inlet element (6) has at least several vertically arranged gas outlet zones (6, 7, 8, 9, 10) each with a height (H1, H2, H3, H4, H5), characterized in that the height (H1) of the lowest gas outlet zone is selected such that the growth rate of the GaN layer or a GaAlN layer is greater than 31260 PCT – 1.09.20256 µm / h or the carbon background doping is less than 1E+16 cm-3.

12. Device for depositing a III-V layer, wherein a gas inlet organ (6) has at least five vertically arranged gas outlet zones (6, 7, 8, 9, 10) each with a height (H1, H2, H3, H4, H5) and through the lowest gas inlet zone (6) a gas flow (Q1) of an element of the III main group, through the gas inlet zone (7) above it a gas flow (Q2) of an element of the V.Main group, through the gas inlet zone (8) above, a gas flow (Q3) of an element of the III main group, through the gas inlet zone (9) above, a gas flow (Q4) of an element of the V main group, and through the gas inlet zone (10) above, a gas flow (Q5) of an element of the III main group can be fed into a process chamber (2) in which a substrate (13) to be coated can be accommodated, wherein the heights have the following values ​​with a tolerance of + / -10%: (H1) = 3.90 mm, (H2) = 3.15 mm, (H3) = 8.10 mm, (H4) = 1.9 mm, (H5) = 8.10 mm.

13. A III-V layer deposited on a substrate according to a method of the preceding claims, characterized in that the carbon background doping in the III-V layer is less than 1E+16 cm-3 or less than 4E+16 cm-3.

14. Method, CVD reactor or apparatus, characterized by one or more of the characterizing features of one of the preceding claims.31260PCT – 1.09.2025.

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