Gas inlet element for a CVD reactor and CVD reactor with a gas inlet element

Abstract

The invention relates to a device for feeding a plurality of reactive gases to a process chamber (31) of a CVD reactor. The gas inlet element has a plurality of gas inlet zones (51 to 56) arranged vertically one above the other, each gas inlet zone (51 to 56) having at least one gas distribution element (2), and a gas inlet channel (10, 11, 12, 13, 14) opening into each gas distribution element (2). Each gas distribution element (2) additionally has passage openings through which a gas inlet channel (10, 11, 12, 13, 14) passes, said gas inlet channel leading to a gas distribution element (2) lying below the gas inlet channel.

Description

Description Gas inlet device for a CVD reactor and CVD reactor with a gas inlet device field of technology

[0001] The invention relates to a device for feeding several reactive gases into a process chamber of a CVD reactor with several vertically arranged gas inlet zones, wherein each gas inlet zone has a gas distribution volume into which one of the reactive gases can be fed by a gas supply line, and which can exit from the gas distribution volume into the process chamber through gas outlet openings arranged in a gas outlet wall, wherein the gas supply line, at least to the gas inlet zones arranged below an uppermost gas inlet zone, is formed by mutually aligned gas inlet channels which are surrounded by end faces which abut the underside of a base of a vertically above it gas inlet zone. State of the art

[0002] DE 102018130139 A1 describes a gas inlet device made of quartz by selective laser etching, comprising several gas inlet elements arranged one above the other, each gas inlet element being formed by a quartz body and having gas outlet openings. A base is located in the center of the gas inlet device, through which gas channels run. One of these gas channels opens into each gas inlet element. A small-diameter bore is located in the center of each gas inlet element.

[0003] US patent 2017 / 0314131 A1 describes a gas inlet device with multiple circumferentially arranged gas inlet zones through which different gases can be fed into a process chamber. 31379PCT drg / 28.11.2025 In the center of the gas inlet zone is a bore with a small diameter.

[0004] US 2013 / 0319333 A1 describes a gas inlet device with multiple sectors, each individually connected to supply lines.

[0005] DE 10 2019 131 794 A1 and EP 2 560 193 A1 each describe a gas inlet device with cooling channels arranged in a gas outlet wall.

[0006] A gas inlet device of the type described above is positioned in the center of a CVD reactor to feed process gases from gas outlet openings located in a gas outlet wall of the gas inlet device into a process chamber surrounding the gas inlet device. The process chamber is bounded below by a susceptor and above by a process chamber ceiling. A heating device is located below the susceptor to heat it to a process temperature that can exceed 1000°C. The susceptor has bearing positions arranged circularly around the gas inlet device. These bearing positions are typically circular disk-shaped bodies that are driven to rotate about their axis. Each of these circular disk-shaped bodies usually carries a circular disk-shaped substrate.In currently manufactured CVD reactors, the diameter of the process chamber is designed to accommodate substrates with a diameter of 10 mm or even 20 mm. The gas inlet in these reactors has a diameter of less than 100 mm. The gas inlet inlets described in the aforementioned publications have even smaller diameters of less than 50 mm. A process chamber designed to coat larger substrates, for example, with a diameter of 300 mm, requires differently dimensioned gas inlet inlets. 31379PCT drg / 28.11.2025 Summary of the invention

[0007] The invention is based on the objective of further developing a gas inlet device of the type described above for process chambers with a large process chamber diameter.

[0008] The problem is solved by the invention specified in the claims. The dependent claims not only represent advantageous further developments of the invention specified in the main claim, but also independent solutions to the problem.

[0009] A gas inlet element according to the invention preferably has a diameter greater than 100 mm, and particularly preferably a diameter greater than 150 mm. The gas inlet element according to the invention is essentially similar in design to the gas inlet element described in the prior art mentioned above. However, the essential difference is that the diameter of the cavity is now large enough to accommodate a cooling device. Preferably, the diameter of the cavity of the gas inlet element is greater than one-third of the diameter of the gas outlet wall, i.e., the outer diameter of the gas inlet element. However, the diameter of the cavity can be less than nine-tenths of the diameter of the gas inlet element. The diameter is sufficiently small to allow enough space around the cavity for gas inlet channels and at least one gas distribution chamber.

[0010] Due to the larger outer diameter of the gas outlet wall compared to the prior art, the circumferential length of the gas distribution chamber is also increased. Therefore, in a further development of the invention, which has an independent character, several gas channels are provided, arranged at uniform angular distributions around a center, and the following... 31379PCT drg / 28.11.2025 Each gas inlet leads into one of the gas distribution chambers. The gas inlet element can have a head with gas distribution lines arranged in a ring around a central point. Each gas inlet zone can be assigned a gas distribution line. The gas distribution lines can be channels arranged concentrically around the center of the head. These channels are connected to the gas channels running through the gas distribution elements, for example, via angled supply lines.

[0011] Each of the vertically stacked gas distribution elements can be manufactured by selective laser etching (SLE). The distribution elements are ring-shaped quartz parts, each with gas distribution chambers open to one broad side, preferably the upper broad side. The gas distribution chambers can be ring-shaped or limited to certain circumferential angles. Several gas inlet channels open into each of the gas distribution chambers. The uppermost gas distribution element contains through-openings that form sections of a gas inlet channel. Each of these through-openings has an end face that, in the assembled state, rests against a mounting surface of the head. A supply line opens into each of the through-openings. The number of these through-openings decreases stepwise with increasing distance from the head.One of the through-openings of the uppermost gas distribution element opens into a free space of the gas distribution element immediately below, allowing the process gas flowing through the through-opening to enter a gas distribution chamber of the gas distribution element. The end faces of the gas channels of the lower gas distribution elements rest against the undersides of the bases of the gas distribution elements, forming a gas inlet channel comprised of several gas distribution elements. The gas distribution chamber of each gas distribution element is connected to an associated gas distribution line via several supply lines. The latter is supplied by a gas mixing system containing reactive gases. The undersides of the bases can be aligned in a single plane. 31379PCT drg / 28.11.2025 The undersides of the floors can also be structured. The end faces of the gas channels can therefore lie in a common plane or in several spaced-apart planes.

[0012] According to a variant of the invention, a gas inlet zone consists of several gas distribution elements extending in a common plane. These gas distribution elements are no longer ring-shaped but each extends only over a sector of a circle. Each of these gas distribution elements is then connected to the gas distribution lines only by an associated supply line. A gas inlet channel opens into each of these gas distribution elements. In this variant, the gas distribution chamber of a gas inlet zone is formed by a plurality of gas distribution chambers that are separated from one another, with the gas distribution elements having side walls that are in contact with each other. The gas distribution elements can extend over the same arc angle. For example, the gas distribution elements can be arranged in a threefold symmetry or in a multiple symmetry.This results not only in horizontal separation joints, where the stacked gas distribution elements are firmly connected, but also in vertical separation joints where side walls abut each other. Adjacent gas distribution elements can also be permanently connected at these points.

[0013] In both variants, each gas distribution element forms a rear wall that is curved and defines an inner cavity. This cavity can accommodate a cooling device. The cooling device can have a first chamber into which a coolant is fed and a second chamber from which the coolant can be drawn off. The two chambers are fluidically connected. One of the chambers can be a radially outer chamber. The other chamber can be a radially 31379PCT drg / 28.11.2025 The cooling device may have two inner chambers. A partition may be arranged between the two chambers. The cooling device may have coaxial walls, relative to an axis of the gas inlet element, that delimit the two chambers. A radial inner wall of the chamber may surround an inner cavity, giving the cooling device a ring shape. A supply line may be provided, extending within the head of the gas inlet element. A coolant may be fed into one of the two chambers via this supply line. The other chamber may be connected to an outlet, also extending within the head of the gas inlet element.

[0014] The gas inlet device can be bounded at the bottom by a base plate. The base plate can incorporate a gas distribution element located at its lowest point. If the gas inlet device has several gas distribution elements extending in a plane along a circular arc, the gas distribution elements of the lowest gas inlet zone can be arranged above a base element that has a circular disk shape and supports the gas distribution elements. The base plate can close the cavity at the bottom. It can have an opening, for example, for the passage of purge gas. This opening can be located in the center of the base plate.

[0015] Each gas distribution element can have a back wall that is thicker than the gas outlet wall. The back wall can have bores that form the gas inlet channels. The back wall can also have a section of reduced width. In this section, the back wall forms a cavity into which a gas inlet channel of an inlet zone located above it opens. The gas flowing from this gas inlet channel enters the chamber and exits the chamber through the gas outlet openings located in the gas outlet wall. 31379PCT drg / 28.11.2025

[0016] The gas distribution chamber can be divided into two chambers, either concentric or separated by side walls. An arc-shaped partition with openings, forming a pressure barrier, can extend between the two chambers. Gas can flow through these openings from an inner chamber to an outer chamber.

[0017] The invention further relates to a CVD reactor comprising a housing, a process chamber arranged within the housing, and a gas inlet element with at least one of the previously described features. The process chamber is bounded at the top by a process chamber ceiling. At the bottom, the process chamber is bounded by a susceptor. The susceptor has pockets, each containing a substrate carrier. The substrate carriers can be circular disk-shaped bodies. Nozzles can be arranged in the bottoms of the pockets through which a gas can be injected into the pockets. This gas can be used to set the substrate carrier into rotation. Each substrate carrier can hold one substrate.

[0018] Below the susceptor is a heating element; this can be an IR heater, an RF heater, or a resistance heater, which heats the susceptor to a process temperature. Reactive gases, for example, containing elements from groups III, V, II, VI, or IV, are introduced to deposit layers onto the substrates. This is done together with a carrier gas, for example, hydrogen.

[0019] The gas distribution elements described above are preferably manufactured by selective laser etching. In the variant of the invention in which the gas distribution elements extend only over a circular sector, the device can 31379PCT drg / 28.11.2025 The gas distribution elements can be kept relatively small for manufacturing, which is cost-effective. Dividing the gas distribution body of a gas inlet zone into several individual, arc-shaped gas distribution elements thus leads to a reduction in manufacturing costs.

[0020] The arrangement of the gas distribution body around a large central cavity also leads to cost reductions, as less material is consumed. Crucially, however, the cavity allows for the accommodation of a central cooling unit. Brief description of the drawings

[0021] Exemplary embodiments of the invention are explained below with reference to the accompanying drawings. These show: Fig. 1 shows a side view of a first embodiment of a gas inlet device, Fig. 2 shows the gas inlet device in a top view. Fig. 3 shows the section along line III-III in Figure 2, Fig. 4 shows the section along line IV-IV in Figure 2 in a perspective view, Fig. 5 shows the section along line VV in Figure 4, wherein a gas inlet channel 10 extends from a supply line 22 arranged in the gas inlet head 20 through several gas distribution bodies of the gas inlet zones 51 to 55 and into a gas distribution chamber 31379PCT drg / 28.11.2025 mer 5 of a gas distribution body of the lowest gas inlet zone 56 opens, Fig. 6 shows a section similar to that of figure 5, but through a gas inlet channel 11, which opens into the gas distribution chamber 5 of a gas distribution body arranged above it in the gas inlet zone 55, Fig. 7 shows a section similar to that of figure 5, but through a gas inlet channel 12, which opens into a gas distribution chamber 5 of a gas distribution body arranged above it in the gas inlet zone 54, Fig. 8 shows a section similar to that of figure 5, but through a gas inlet channel 13, which opens into a gas distribution chamber 5 of a gas distribution body arranged above it in the gas inlet zone 53, Fig. 9 shows a section similar to that of Figure 5, but through a gas inlet channel 14, which opens into a gas distribution chamber 5 of a gas distribution body arranged above it in the gas inlet zone 52, Fig. 10 shows a section similar to that of Figure 5, but through a gas inlet channel 15, which opens into a gas distribution chamber 5 of a gas distribution body arranged above it in the gas inlet zone 51, Fig. 11 shows the section along line XI-XI in Figure 1, Fig. 12 shows the section along line XII-XII in Figure 10, 31379PCT drg / 28.11.2025 Fig. 13 shows the section along line XIII-XIII in Figure 10, Fig. 14 shows a perspective section through the gas inlet zone 51 located at the top, Fig. 15 shows a second embodiment of the invention in a representation according to Figure 11, wherein here the gas inlet body is not formed by a single gas distribution element 2, as in the first embodiment, but by a total of three gas distribution elements 2 which combine to form a ring shape, Fig. 16 shows in perspective a gas distribution element 2 of the second embodiment extending only over a circular sector and Fig. 17 shows a state-of-the-art CVD reactor. Description of the embodiments

[0022] The exemplary embodiments relate to a gas inlet device for a CVD reactor, as schematically depicted in Figure 17. The CVD reactor has a housing 30, which can be made of stainless steel. Inside the housing 30 is a process chamber 31. The process chamber 31 is bounded at the top by a process chamber ceiling 32. At the bottom, the process chamber 31 is bounded by a disc-shaped susceptor 33, which is supported by a central shaft that can rotate about an axis. During operation, the susceptor 33 is rotated about the axis. A heating device 34 is located below the susceptor 33 to heat it. Reference numeral 35 indicates substrates that rest on the susceptor 33 and are coated by feeding process gases into the process chamber 31. Decomposition products of the process gas 31379PCT drg / 28.11.2025 Gases can be removed from the process chamber 31 by means of a gas outlet device 36. A gas inlet device 1 with several vertically arranged gas inlet zones 51 to 56 is located in the center of the process chamber 31. Each of the gas inlet zones 51 to 56 is connected to an individual supply line 22. A bottom surface 20' is vertically spaced from a plate located in the center of the susceptor 33. The gas inlet device 1 is rigidly connected to the housing 30.

[0023] Figures 1 to 16 describe a gas inlet device according to the invention, as it can be used in such a CVD reactor.

[0024] Figure 1 shows a view of a gas inlet element 1 according to the invention. The gas inlet element 1 has an upper section forming a head 20, which can be located above a process chamber ceiling 32. The section arranged below a mounting bead has a total of six vertically arranged gas inlet zones 51 to 56. In the embodiment described in Figures 11 to 14, each of these gas inlet zones 51 to 56 is formed by an annular gas distribution element 2. In the second embodiment shown in Figures 15 to 16, each of these gas inlet zones 51 to 56 is formed by several gas distribution elements 2, which together can be arranged to form a circular shape.

[0025] The head 20 has channels arranged in a ring around a center on its upward-facing end face. Each of these channels forms a gas distribution line 21. A process gas, supplied by a gas mixing system, is fed into this gas distribution line 21 via pipes (not shown). Several supply lines 22 originate from each of these gas distribution lines 21, extending at different angles to a central axis. 31379PCT drg / 28.11.2025 The head 20 extends. The supply lines 22 open into gas inlet channels 10, 11, 12, 13, 14, which extend along a circular arc around the center. In the exemplary embodiment, three supply lines 22 originate from each gas distribution line 21. However, embodiments are also provided in which the number of supply lines 22 originating from the gas distribution line 21 is greater, for example, four, five, six, seven, eight, or nine. The supply lines 22 are arranged at a uniform angular distribution.

[0026] Below the head 20 are the gas distribution bodies made of quartz. In the first embodiment, each gas distribution body of one of the gas inlet zones 51 to 56 has exactly one gas distribution element 2, which has an annular shape. The gas distribution elements 2 arranged one above the other differ essentially only in the number of gas inlet channels 10 arranged in a rear wall 8.

[0027] The arranged gas inlet device 2, shown in Figure 11, has a free space 15 in the area of ​​its rear wall 8, into which a supply line 22 opens directly. Five through-bores extend between the three free spaces 15, each forming a gas inlet channel 10 to 15. A supply line 22 opens into each of these gas inlet channels 10 to 15 and is connected to one of the gas distribution lines 21 individually assigned to each of the gas inlet zones 51 to 56.

[0028] The gas distribution element of the gas inlet zone 52, located below the uppermost gas distribution element 2, has only the gas inlet channels 10 to 13. The gas inlet channel 14 opens into a free space 15 of the gas distribution element 2 of the gas inlet zone 52. 31379PCT drg / 28.11.2025

[0029] The gas inlet zone 53, located below the gas distribution element 2 of the gas inlet zone 52, has a lower height than the gas inlet zone 52. The gas inlet channel 13 opens into the gas distribution element 2 of the gas inlet zone 53.

[0030] Below the gas distribution element of the gas inlet zone 53 is a gas distribution element 2 of the gas inlet zone 54. The gas inlet channel 12 opens into this gas distribution element 2.

[0031] The gas inlet channel 11 opens into the gas distribution element 2 of the gas inlet zone 55, which in turn has a reduced height. The gas inlet channel 10 finally opens into the gas distribution element 2 of the lowest gas inlet zone 56.

[0032] The gas inlet channels 10 to 14 each open into a niche formed by a reduced-thickness section of the rear wall 8 of the gas distribution element 2. The rear wall 8 has a material thickness significantly greater than that of a gas outlet wall 7 opposite the rear wall 8, which has a multitude of gas outlet openings 4, only indicated in the drawings, arranged uniformly across its surface. A gas-permeable partition 16, which may also have openings, extends between the rear wall 8 and the gas outlet wall 7. The partition 16 divides a gas distribution chamber 5 of the gas distribution element 2 into two concentrically arranged chambers 5' and 5".

[0033] The broad side surface of the rear wall 8 forms end faces 10', 11', 12', 13', 14', 15' extending in a common plane, each of which surrounds a gas channel 10 to 14. In the exemplary embodiment, the end faces are connected to each other. However, other embodiments are also provided. 31379PCT drg / 28.11.2025 in which the gas channels 10 to 14 are formed as tubes originating from the base of a gas distribution chamber 5. The end faces 10' to 15' are then the end faces of these tubes. The end faces 10' to 15' can lie in the same plane as the broad side face of the gas outlet wall 7 and the partition wall 16. In the assembled state of the gas inlet device, these broad side faces each rest against the underside of a base 9 of the gas distribution element 2 arranged directly above it, so that the underside of the base 9 seals the chambers 5', 5" at the top.

[0034] The rear wall 8 defines a cylindrical cavity 19 radially outwards. The cavity is of sufficient size and volume to accommodate a cooling device 40. The outer diameter of the gas outlet wall 7 can be between 150 and 250 mm. The diameter of the cavity 19 is at least one-third the diameter of the gas outlet wall 7.

[0035] The cooling device 40, housed in the cavity 19, has an outer wall 41 with an outer diameter slightly smaller than the inner diameter of the cavity 19. Heat transfer elements (not shown in the drawings) can be arranged between the outer surface of the outer wall 41 and the inner wall of the cavity 19 to transfer heat from the gas distribution element 2 to the cooling device 40. These heat transfer elements can be, for example, metal springs, such as leaf springs, which bear against both the inner wall of the cavity 19 and the outer wall 41.

[0036] The outer wall 41 surrounds an annular outer chamber 44 of the cooling device 40. The cooling device 40 has an inner wall 42 that runs coaxially to the outer wall 51. Between the inner wall 42 and the outer- 31379PCT drg / 28.11.2025 A partition wall 43 extends along wall 41, the lower narrow side of which is spaced away from a base of the cooling device 40, so that a cooling liquid can flow from one chamber 44 into the other chamber 45.

[0037] In the head 20 a supply line 46 is provided for a liquid coolant which flows into the chamber 44, can flow under the partition 43 and into the chamber 45, which in turn is connected to a drain 47 that extends through the head 20.

[0038] The lowest gas distribution element 2 forms a base element 3 with a base plate 13 that closes the cavity 19 at the bottom. The base plate 13 can have a central opening 17; this can be aligned with an axial opening of the head 20. The two openings can be used as purge channels. However, the openings can also accommodate a retaining element, as is generally known in the prior art. The cooling device 14 can be made of metal, in particular stainless steel.

[0039] In the exemplary embodiment, a cylindrical free space remains within the inner wall 42, which can be purged by a purge gas.

[0040] The embodiment shown in Figures 15 and 16 differs from the previously described embodiment essentially in that each gas inlet zone 51 to 56 is not formed by a single gas distribution element made of a single material. In this embodiment, the gas distribution element is multi-part. It has several individual gas distribution elements 2 that can be assembled to form an annular gas distribution element. In the assembled state, the radially extending side walls 6, 6' of adjacent gas distribution elements 2 are in contact with each other. 31379PCT drg / 28.11.2025

[0041] Each of the gas distribution elements 2 has a gas distribution chamber 5, or several individual chambers 5', 5", separated from the adjacent gas distribution element 2 by the side walls 6, 6', which are separated from each other by a gas-permeable partition 16. One of the several gas channels 10, 11, 12, 13, 14 opens into each gas distribution chamber 5, 5'. Here, too, gas channels 10 to 14 are aligned with gas channels of further gas distribution elements 2 arranged above a gas distribution element 2.

[0042] These gas distribution elements 2 can also be manufactured using SLE. However, the manufacturing process is more cost-effective because the workpieces to be produced are smaller.

[0043] The foregoing statements serve to explain the inventions covered by the application as a whole, which each independently further develop the prior art at least through the following combinations of features, whereby two, several or all of these combinations of features may also be combined, namely:

[0044] A device characterized in that several gas inlet channels 10, 11, 12, 13, 14 open into each of the annular gas distribution volumes located below the uppermost gas inlet zone 51, and each gas distribution volume forms at least one gas distribution chamber 5, 5', 5" which has a rear wall 8 facing away from the gas outlet wall 7, which surrounds a cavity 19, the diameter of which is sufficiently large to accommodate a cooling device 40 in the cavity, or is larger than one third of the diameter of the gas outlet wall 7.

[0045] A device characterized in that at least three gas channels 10, 11, 12, 13, 14 open into each of the gas distribution volumes, wherein 31379PCT drg / 28.11.2025 The gas channels 10, 11, 12, 13, 14 are arranged in a uniform angular distribution around a center.

[0046] A device characterized in that each gas inlet zone 51 to 56 is formed by several circumferentially separated gas distribution elements 2, wherein each gas distribution element 2 has a gas distribution chamber 5, 5', 5" and the gas distribution volume is formed by the gas distribution chambers 5', 5" of all gas distribution chambers 5 assigned to a gas inlet zone 51 to 56, wherein each gas distribution element 2 has a rear wall 8 facing away from the gas outlet wall 7, wherein the rear walls 8 of the gas distribution elements 2 surround the cavity 19.

[0047] A device characterized in that each of the gas distribution elements arranged above a lowest gas inlet zone 56 has 2 gas inlet channels 10, 11, 12, 13 through which the reactive gas can be fed into the gas distribution chamber 5 of the gas distribution element 2 arranged directly below it.

[0048] A device characterized in that the gas distribution elements 2 are made of quartz and are manufactured by selective laser etching.

[0049] A device characterized by a bottom element 3 arranged below the gas distribution elements 2 of the lowest gas inlet zone 56 or a bottom element 3 formed by the lowest gas inlet zone 56, which forms a bottom plate 18 that limits the cavity 19 downwards.

[0050] A device characterized in that the gas distribution element 2 of a gas inlet zone 51 to 56 extends over a full circle 31379PCT drg / 28.11.2025 or that several gas distribution elements 2 of each gas inlet zone 51 to 56 each extend over a circular sector, in particular it is provided that the gas distribution elements 22 extend over circular sectors with an identical arc angle.

[0051] A device characterized in that the gas distribution elements 2 have side walls 6, 6' extending on radial lines with reference to a center point of the cavity 19 and adjacent gas distribution elements 2, each assigned to the same gas inlet zone 51 to 56, are touching each other with their side walls 6, 6'.

[0052] A device characterized in that the gas distribution elements 2 of the uppermost gas inlet zone 51 are arranged on a bottom surface 20' of a gas inlet head 20, wherein supply lines 22 run in the gas inlet head 20, which open into the gas inlet channels 10, 11, 12, 13, 14 of the gas distribution elements 2 of the uppermost gas inlet zone 51 and / or that gas distribution lines 21 running in a ring shape around a center are arranged in the gas inlet head 20, from which supply lines 22 each originate and / or that at least some of the supply lines 22 run obliquely to an axis of the gas inlet head 20.

[0053] A device characterized in that a cooling device 40 with a cooling chamber 44, 45 is arranged within the cavity 19, through which a liquid coolant can flow.

[0054] A device characterized in that the gas distribution chamber 5 forms two chambers 5', 5" separated from each other by a gas-permeable partition 15 extending circumferentially around the center. 31379PCT drg / 28.11.2025

[0055] A CVD reactor characterized in that a device according to one of the preceding claims is arranged in the center of the process chamber 31.

[0056] A method characterized in that a plurality of gas distribution elements 2 are manufactured by selective laser etching, wherein identically designed gas distribution elements 2 of each gas inlet zone 51 to 55 are arranged on a circular ring such that the gas distribution elements 2 surround a cavity 19.

[0057] All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of this application hereby incorporates in full the disclosure content of the associated / attached priority documents (copy of the earlier application), also for the purpose of including features of these documents in the claims of the present application. The dependent claims, even without the features of a referenced claim, characterize independent inventive developments of the prior art, in particular for the purpose of filing divisional applications based on these claims. The invention specified in each claim may additionally comprise one or more of the features described above, in particular those identified by reference numerals and / or listed in the reference numeral list.The invention also relates to design forms in which individual features mentioned in the preceding description are not realized, in particular insofar as they are recognizably unnecessary for the respective purpose or can be replaced by other technically equivalent means. 31379PCT drg / 28.11.2025 List of reference symbols 1 Gas inlet element 20 Gas inlet head 2 Gas distribution element 20' Underside 3 Base element 21 Gas distribution line 4 Gas outlet opening 22 Supply line 5 Gas distribution chamber 5' Chamber 30 Case 5" Chamber 31 Process Chamber 6 Side Wall 32 Process Chamber Ceiling 6' Side Wall 33 Susceptor 7 Gas outlet wall 34 Heating device 8 Rear wall 35 Substrate 9 Bottom 36 Gas outlet 10 Gas inlet channel 10' Front surface 40 Cooling device 11 Gas inlet channel 41 Outer wall 11' Front surface 42 Inner wall 12 Gas inlet channel 43 Partition 12' Front surface 44 Outer chamber 13 Gas inlet channel 45 Inner chamber 13' Front surface 46 Supply line 14 Gas inlet channel 47 Diverter 14' Front surface 15 Free space 51 Gas inlet zone 16 Partition wall 52 Gas inlet zone 17 Opening 53 Gas inlet zone 18 Base plate 54 Gas inlet zone 18' Edge section 55 Gas inlet zone 19 Cavity 56 Gas inlet zone 31379PCT drg / 28.11.2025

Claims

Claims 1. Device for injecting multiple reactive gases into a process chamber (31) of a CVD reactor with several vertically stacked gas inlet zones (51 to 56), wherein each gas inlet zone (51 to 56) has a gas distribution volume into which one of the reactive gases can be fed via a gas supply line, which can exit from the gas distribution volume into the process chamber (31) through gas outlet openings (4) arranged in a gas outlet wall (7), wherein the gas supply line at least to the gas inlet zones (52 to 56) arranged below an uppermost gas inlet zone (51) is formed by mutually aligned gas inlet channels (10, 11, 12, 13, 14) which are surrounded by end faces (10', 11', 12', 13', 14') which abut the underside of a base (9) of a vertically above gas inlet zone (51 to 55), characterized in that several gas inlet channels (10, 11, 12, 13, 14) open into each of the annular gas distribution volumes located below the uppermost gas inlet zone (51) and each gas distribution volume forms at least one gas distribution chamber (5, 5', 5") which has a rear wall (8) facing away from the gas outlet wall (7) and which surrounds a cavity (19) whose diameter is sufficiently large to accommodate a cooling device (40) in the cavity or is larger than one third of the diameter of the gas outlet wall (7).

2. Device according to claim 1, characterized in that at least three gas channels (10, 11, 12, 13, 14) open into each of the gas distribution volumes, wherein the gas channels (10, 11, 12, 13, 14) are arranged in a uniform angular distribution around a center. 31379PCT drg / 28.11.2025 3. Device according to one of the preceding claims, characterized in that each gas inlet zone (51 to 56) is formed by several gas distribution elements (2) separated from each other in the circumferential direction, wherein each gas distribution element (2) has a gas distribution chamber (5, 5', 5"), and the gas distribution volume is formed by the gas distribution chambers (5', 5") of all gas distribution chambers (5) associated with a gas inlet zone (51 to 56), wherein each gas distribution element (2) has a rear wall (8) facing away from the gas outlet wall (7), wherein the rear walls (8) of the gas distribution elements (2) surround the cavity (19).

4. Device according to one of the preceding claims, characterized in that each of the gas distribution elements (2) arranged above a lowest gas inlet zone (56) has gas inlet channels (10, 11, 12, 13) through which the reactive gas can be fed into the gas distribution chamber (5) of the gas distribution element (2) arranged directly below it.

5. Device according to one of the preceding claims, characterized in that the gas distribution elements (2) consist of quartz and are manufactured by selective laser etching.

6. Device according to one of the preceding claims, characterized by a bottom element (3) arranged below the gas distribution elements (2) of the lowest gas inlet zone (56) or a bottom element (3) formed by the lowest gas inlet zone (56) which forms a bottom plate (18) that limits the cavity (19) downwards. 31379PCT drg / 28.11.2025 7. Device according to one of the preceding claims, characterized in that the gas distribution element (2) of a gas inlet zone (51 to 56) extends over a full circle or that several gas distribution elements (2) of each gas inlet zone (51 to 56) each extend over a circular sector, wherein it is particularly provided that the gas distribution elements (22) extend over circular sectors with an identical arc angle.

8. Device according to claim 7, characterized in that the gas distribution elements (2) have side walls (6, 6') extending on radial lines with reference to a center point of the cavity (19) and adjacent gas distribution elements (2) assigned to the same gas inlet zone (51 to 56) are adjacent to each other with their side walls (6, 6').

9. Device according to one of the preceding claims, characterized in that the gas distribution elements (2) of the uppermost gas inlet zone (51) are arranged on a bottom side (20') of a gas inlet head (20), wherein supply lines (22) run in the gas inlet head (20) which open into the gas inlet channels (10, 11, 12, 13, 14) of the gas distribution elements (2) of the uppermost gas inlet zone (51).

10. Device according to claim 9, characterized in that gas distribution lines (21) extending in a ring shape around a center are arranged in the gas inlet head (20), from which supply lines (22) each originate.

11. Device according to claim 10, characterized in that at least some of the supply lines (22) run obliquely to an axis of the gas inlet head (20). 31379PCT drg / 28.11.2025 12. Device according to one of the preceding claims, characterized in that a cooling device (40) with a cooling chamber (44, 45) is arranged within the cavity (19), through which a liquid coolant can flow.

13. Device according to one of the preceding claims, characterized in that the gas distribution chamber (5) forms two chambers (5', 5") separated from each other by a gas-permeable partition wall (15) extending circumferentially around the center.

14. CVD reactor with a housing (30), a process chamber (31) arranged in the housing, which is bounded downwards by a susceptor (33) which can be heated by a heating device (34), characterized in that a device according to one of the preceding claims is arranged in the center of the process chamber (31).

15. Method for manufacturing a device according to one of claims 3 to 13, characterized in that a plurality of gas distribution elements (2) are manufactured by selective laser etching, wherein identically designed gas distribution elements (2) of each gas inlet zone (51 to 55) are arranged on a circular ring such that the gas distribution elements (2) surround a cavity (19).

16. Device, CVD reactor or method characterized by one or more of the characterizing features of any of the preceding claims. 31379PCT drg / 28.11.2025

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