CVD-Reactor

Abstract

The invention relates to a device for depositing layers onto one or more substrates (21), in which a process chamber (12) is arranged in a housing (2). The process chamber chamber has a ceiling (13) and a floor, the floor being formed by a susceptor arrangement which has storage areas for substrates (21) that are to be thermally treated in the device, for example, a semiconductor layer is to be deposited onto the substrates (21). A process gas is fed into the process chamber by means of a gas inlet device (6, 18), in particular through several vertically arranged gas inlet zones. The process gas flows through the process chamber (12) and exits the process chamber (12) through a gas outlet device (200).The vertically arranged gas inlet zones allow different reactive gases of the process gas to be fed separately into the process chamber (12). A portion of the process gas fed in through a lower gas inlet zone forms a natural diffusion barrier for another portion of the process gas fed into the process chamber (12) through a gas inlet zone above it. According to the invention, it is proposed that the free surface of the cover plates (15, 16) have different distances from the support area.

Description

field of technology

[0001] The invention relates to a CVD reactor and a method for depositing layers on one or more substrates in a CVD reactor. State of the art

[0002] CVD reactors are known in particular from DE 10 2022 132 776 A1, DE 10 2022 101 806 A1, DE 10 2022 101 809 A1, DE 10 2022 114 717 A1, DE 10 2021 114 868 A1, DE 10 2021 110 305 A1, DE 10 2022 103 245 A1, DE 10 2020 126 597 A1, DE 10 2020 123 546 A1, DE 10 2020 112 569 A1, DE 10 2019 131 794 A1, DE 10 2019 117 479 A1, DE 10 2018 130 140 A1, DE 10 2018 130 139 A1, DE 10 2016 110 884 A1, DE 10 2014 106 871 A1, DE 10 2013 101 777 A1 and DE 10 2011 002 146 A1. Summary of the invention

[0003] The invention is based on the objective of further developing the technical design of a CVD reactor.

[0004] This application provides a variety of solutions to this problem, described below:

[0005] A CVD reactor, as technically developed by the disclosure content of this patent application, possesses at least one or some of the following features:

[0006] A gas inlet device for feeding a process gas into a process chamber is located in a stainless steel housing that is gas-tight from the environment. Such a CVD reactor with a gas inlet device is described in DE 10 2018 130 139 A1. The process gas consists of several reactive gases and at least one inert gas. The reactive gases are stored in a gas mixing system which includes mass flow controllers and valves with which several gas flows can be generated into the gas inlet device. In one process according to the invention, III-V layers are deposited, in particular, on substrates that can consist of a III-V material or a IV material. Another process according to the invention relates to the deposition of II-VI layers on corresponding substrates. Suitable reactive gases include hydrides of elements from Group V and organometallic compounds of elements from Group III.The gas inlet element can have several vertically arranged gas distribution chambers. The gas inlet element can be located in the center of a CVD reactor housing and surrounded by the process chamber. The cylindrical gas inlet element can have gas outlet openings on its outer surface through which the reactive gases are fed into the process chamber separately, each together with an inert gas, such as hydrogen or nitrogen. The gas inlet element can be made of graphite, metal, or a ceramic material. Preferably, the gas inlet element is made of quartz.

[0007] The process chamber can have a process chamber ceiling made of a ceramic material or a coated graphite plate. The process chamber ceiling can be supported by the gas inlet device. Alternatively, it can be attached to an upper housing wall using special fasteners. The process chamber ceiling can be attached to a housing top wall. The housing top wall can be detached from the rest of the housing. The housing top wall essentially forms a housing lid. The gas inlet device and the process chamber ceiling, which may be formed by a ceiling plate, can be attached to the housing top wall.

[0008] The substrates to be coated are placed on a susceptor assembly. The susceptor assembly can consist of a graphite susceptor. The susceptor, like the process chamber ceiling, can be formed from one or more coated graphite plates. The susceptor assembly can also include cover plates that rest on the upper surface of the susceptor facing the process chamber. These cover plates can surround openings, each containing a substrate. Alternatively, the cover plates can surround openings containing a substrate holder, on which one or more substrates can be placed. There can be radially inner and radially outer cover plates arranged around a gas inlet located in the center of the process chamber.

[0009] The substrate holders, arranged in a circular line around the center of the process chamber, can also be made of graphite or coated graphite. A CVD reactor with a susceptor is described in DE 10 2009 044 276 A1. The top of the susceptor forms pockets. A substrate holder can be arranged in each pocket. Outlets for the release of a carrier gas can be provided in the bottom of the pockets. The carrier gas creates a gas cushion between the underside of the substrate holder and the bottom of the pocket, on which the substrate holder can float. The outlets can direct the gas flow fed into the space between the substrate holder and the susceptor, thus rotating the substrate holder. The susceptor assembly is supported by a central shaft that is rotatable about an axis of rotation.The shaft can be driven by a motor to rotate the susceptor during the deposition of layers on the surfaces of the substrates.

[0010] The circular susceptor assembly is surrounded by a gas outlet. The gas outlet is ring-shaped and has openings facing the process chamber, through which inert gas, unused reactive gas, and reaction products, fed into the process chamber via the gas inlet, can be removed. The gas outlet is connected to a waste gas line with a pump and a gas purification system. The pump stabilizes the pressure within the process chamber at values ​​between 1 mbar and 1000 mbar.

[0011] A heating device is provided below the susceptor assembly. The heating device can be a flat coil. A protective plate can extend between the heating device and the susceptor assembly, its purpose being to prevent the transport of reactive gases into the section of the housing where the heating device is located. The coil can be a hollow coil. A cooling fluid can flow through the hollow coil. Such a coil can generate an alternating electromagnetic field that induces eddy currents in the susceptor, thus heating the susceptor to a process temperature. The process chamber ceiling can also be heated. Preferably, however, the process chamber ceiling is heated by thermal radiation from the susceptor.

[0012] Other heating devices can also be used to heat the susceptor assembly to a process temperature, for example an infrared heater or a resistance heater.

[0013] The aforementioned graphite parts can be coated with silicon carbide or tantalum carbide.

[0014] The CVD reactor can include an optical device. This optical device can be a sensor for detecting light. The sensor can be an imaging sensor. Preferably, the sensor is a pyrometer capable of measuring light within a narrowly defined wavelength range. Multiple pyrometers can be provided to measure light of different wavelengths. The sensor can determine both the intensity and wavelength of the light. For example, such an optical device can be used to measure the temperature of a substrate resting on a substrate holder or to determine the layer thickness of a substrate. Preferably, the optical device can also be used to determine emissivity and reflectance values.Particularly for determining reflectance values, the optical device can additionally include a light source, for example a laser or an LED, with which a substrate surface is irradiated. The reflected light is then measured by the sensor, for example a pyrometer. Such an optical device and a related method are disclosed in DE 10 2022 101 809 A1. The pyrometers according to the invention can measure light in the UV range, in the visible range, and also in the IR range.

[0015] The optical device can also include a light source with which a substrate or a section of the susceptor assembly is irradiated with energy in order to heat the substrate or the susceptor assembly locally.

[0016] The optical device can interact with the susceptor or the substrate resting on it via an optical path. This optical path can cross the process chamber and extend through an opening in the process chamber ceiling as well as an opening in the housing.

[0017] One variant of a CVD reactor according to the invention can have a rectangular plan. The susceptor or susceptor assembly then has the shape of a rectangle. The gas inlet is located at one edge of the rectangle. The gas outlet is located at the opposite edge of the rectangle. Here, too, the gas inlet can have a plurality of gas distribution chambers arranged one above the other. Reference is also made to the features described above, which this CVD reactor can also possess. It differs from the variant described at the outset essentially in that the flow lines along which the process gas flows through the process chamber are parallel, whereas in the variant described at the outset, the flow lines are arranged in a star-shaped pattern.

[0018] An alternative CVD reactor according to the invention can be a so-called "showerhead reactor" in which the gas inlet element is formed by the process chamber ceiling. This ceiling has a plurality of uniformly distributed gas outlet openings through which one or more process gases flow into the process chamber. The substrates can be arranged uniformly distributed over the entire surface of the susceptor. Such a susceptor is described, for example, in DE 10 2014 100 024 A1.

[0019] A CVD reactor according to the invention can be part of a cluster system with a plurality of CVD reactors or other units. To enable automated loading and unloading of the process chamber of a CVD reactor, a housing wall has a loading and unloading opening. A transfer chamber of a transfer module can be adjacent to this housing opening. A robot is arranged in this transfer chamber and has a gripper that can be moved through the housing opening into the process chamber to pick up or place a substrate. Preferably, the substrates are supported by substrate holders that have an annular projection which can be gripped by two arms of the gripper. Each substrate holder can then be handled by the gripper. The gripper can be attached to two arms that are articulated together. Such a substrate holder is described, for example, in DE 10 2020 122 198 A1.

[0020] An apparatus according to the invention can include a control unit with which a plurality of process steps are carried out sequentially according to a recipe. In at least some of these process steps, a layer can be deposited on one of the substrates. The recipe controls the mass flow controllers and the valves to feed a suitable gas mixture into the process chamber. The control unit can also regulate the process chamber temperature. The measured value for the process chamber temperature can be determined by the optical device. The control unit is also capable of controlling the robot. Brief description of the drawings

[0021] Exemplary embodiments of reactors according to the invention are described below based on the Fig. 1 to 8 explained. They show: Fig. 1 a cross-section through a planetary reactor in which several substrate holders 20, each carrying a substrate 21, are arranged in a circle around a center of a susceptor 14, Fig. 2 the view of the susceptor 14, Fig. 3 enlarges section III in Fig. 1, Fig. 4 enlarges section III in Fig. 1, Fig. 6 a cross-section through a horizontal reactor in which the susceptor 14 has a rectangular shape, Fig. 7 a view of the susceptor 14 of a horizontal reactor according to Fig. 6, Fig. 8 an embodiment of a device in which a CVD reactor 1 is connected to a transfer module 45, Fig. 9 a representation according to Fig. 1 of a “showerhead reactor”. Description of the embodiments

[0022] The in the Fig. The embodiment shown in Figures 1 to 5 is a so-called planetary reactor in which a gas inlet element 6, made of quartz, for example, is arranged in the center of a process chamber 12. The process chamber 12 is bounded at the top by a process chamber ceiling 13 made of coated graphite or a ceramic material. The process chamber 12 is bounded at the bottom by a susceptor arrangement extending parallel to the process chamber ceiling 12. The susceptor arrangement can consist of a single-piece or multi-piece susceptor 14 – the susceptor 14 can, for example, have a single plate or several plates, such as ring-shaped nested plates – and one or more cover plates 15, 16 arranged on the top of the susceptor 14. A typical arrangement of the cover plates is shown in Figure 1. Fig. 2. There are radially inner cover plates 15 and radially outer cover plates 16, with several cover plates 15, 16 arranged in an azimuthal direction around the center of the susceptor 14.

[0023] The cover plates 15, 16 surround circular openings in which a substrate holder 20 is located, which in the exemplary embodiment carries a substrate 21.

[0024] The Fig. Figure 3 shows an enlarged view of a substrate holder 20 arranged in a pocket 34, which is suspended by a gas stream that creates a gas cushion. The gas stream, flowing through a supply line 32, is directed by the orientation of the opening 33 in such a way as to cause the substrate holder 20 to rotate. During this rotation, an underside of the substrate holder 20 moves away vertically from a base 34' of the pocket 34.

[0025] Below the susceptor arrangement 14, 15, 16 is a heating device 17, which consists of a flat, hollow coil that generates alternating electromagnetic fields. These fields induce eddy currents in the susceptor 14, which in turn heat the susceptor 14. A coolant can flow through the hollow coil.

[0026] A plate 31, which acts as a diffusion barrier, can be arranged between the heating device 17 and the underside of the susceptor 14.

[0027] The heating device 14 is arranged around a shaft 28 which can be driven by rotation and which carries the susceptor arrangement 14, 15, 16, so that when layers are deposited on the substrates 21 not only the substrate holders 20 and the substrates 21 resting on them, but also the susceptor 14 or the susceptor arrangement rotates.

[0028] The gas inlet organ 6, which is described in more detail in the Fig. The gas inlet device 6, as shown in Figure 4, is fixedly connected to the housing. It is supplied by a gas mixing system 10 via a plurality of supply lines 7. Each supply line 7 opens into one of several vertically stacked gas distribution chambers 8. Each gas distribution chamber 8 extends over a vertical section of a gas outlet surface running along the outer surface of a cylinder. The gas outlet surface has a plurality of uniformly distributed gas outlet openings 9 through which the process gas supplied to the gas distribution chambers 8 can exit into the process chamber 12.

[0029] A bottom chamber or another chamber of the gas inlet device 6 can be a cooling chamber 29 through which a coolant can flow. The corresponding supply and discharge lines are not shown in the drawings.

[0030] The gas mixing system 10 has mass flow controllers and valves (not shown) with which a process gas can be mixed from gas sources (also not shown). The process gas contains several reactive gases, which are fed separately, each together with an inert gas, into the process chamber 12 via separate gas distribution chambers 8. The inert gas can be hydrogen, nitrogen, argon, or another noble gas. The reactive gases can be gases of elements from Group 13 and Group 15. The reactive gases can also contain a dopant.

[0031] The susceptor 14, or the susceptor arrangement 14, 15, 16, is surrounded by an annular gas outlet element 18, which has openings 19 through which waste gas can be removed from the process chamber 12. For this purpose, a gas outlet (not shown) may be provided, to which a vacuum pump is connected, with which a total pressure within the process chamber 12 can be set in a range between 1 mbar and 1000 mbar. The process chamber 12 may have a side wall 27, which closes the process chamber 12 radially. The side wall 27 may connect a radially outer edge of the process chamber ceiling 13 with a radially outer edge of the gas outlet element 18. The side wall 27 may be made of graphite or coated graphite.

[0032] The susceptor 14 or the susceptor arrangement 14, 15, 16 can be rotated relative to the gas inlet element 6. For this purpose, it is advantageous if a section of the susceptor 14 arranged below the gas inlet element 6 has a vertical distance to the underside of the gas inlet element 6.

[0033] Reference numeral 22 designates an optical device, for example a light source, a laser, or a sensor, for example a pyrometer. The optical device 22, which is located in the Fig. As shown in more detail in Figure 5, a measuring device 36, for example the aforementioned pyrometer, is present. The optical device 22 interacts with the surface of the substrate 21 or the susceptor arrangement 14, 15, 16 via an optical path 25 through an opening 23 in the housing wall 3. The optical path 25 also passes through an opening 26 in the process chamber ceiling 13.

[0034] A transparent sealing element 24, for example a quartz plate, is provided for the gas-tight closure of the opening 23. This can be attached to a housing wall 3 by means of a holder 37. Seals 38, 39, for example O-rings, can be provided between the sealing element 24 and the housing wall 3 or the holder 37 for sealing purposes.

[0035] The Fig. Figure 8 shows the combination of a CVD reactor 1 with a transfer module 45, which has a transfer chamber 46. A robot 47, which can be controlled by the control unit 11, is located in the transfer chamber 46. The robot 47 has one or more robot arms 48 that are articulated to one another. A gripper 49 with two gripping arms 50 is provided, which can reach through a loading / unloading opening in a housing wall 4 of the housing 2 to handle substrates 21 or substrate holders. The robot 47 can be used to load or unload the susceptor with substrates 21 or substrate holders 20.

[0036] The Fig. Figure 9 shows a further embodiment in which the gas inlet element 6 is designed as a "showerhead". The gas inlet element 6 extends over the entire upper surface of the susceptor 14 facing the process chamber 12 and has gas outlet openings 9 evenly distributed over the entire underside facing the process chamber 12, from which different gases from two or more gas distribution chambers 8 can flow into the process chamber 12.

[0037] The susceptor 14 has uniformly distributed storage places for one substrate 21 each on its surface facing the process chamber 12.

[0038] Below the susceptor 14 is a heating element 17, which heats the susceptor 14. The heating element 17 can have several radially nested heating zones. The gas inlet element 6 and the susceptor 14 have a circular plan. The susceptor 14 is surrounded by a gas outlet element 18.

[0039] Regarding the other properties of this CVD reactor, reference is made to the above statements.

[0040] The invention relates to the following individual components: 1. CVD reactor with a process chamber with cover plates of varying material thicknesses to influence the process chamber height.

[0041] The invention relates to a device for depositing layers onto one or more substrates, in which a process chamber is arranged in a housing. The process chamber chamber has a ceiling and a floor, and the floor is formed by a susceptor arrangement that has storage areas for substrates to be thermally treated in the device, for example, a semiconductor layer to be deposited onto the substrates. A process gas is fed into the process chamber by means of a gas inlet device, in particular through several vertically arranged gas inlet zones. The process gas flows through the process chamber and exits the process chamber through a gas outlet device. The vertically arranged gas inlet zones allow different reactive gases of the process gas to be fed into the process chamber separately.Part of the process gas, which is fed in through a lowest gas inlet zone, forms a natural diffusion barrier for another part of the process gas, which is fed into the process chamber through a gas inlet zone above it.

[0042] The susceptor assembly is heated to a process temperature by means of a heating device. The process gas flowing into the process chamber through the gas inlet is heated. Depending on the type of reactive gas, for example, whether it is a hydride of an element from group V or a metal-organic compound of an element from group III, the reactive gas has a different thermal stability. The more thermally stable reactive gas is therefore fed in through the lowest gas inlet zone, while a more thermally unstable gas, such as the metal-organic compound, is fed in at a higher vertical level. This prevents decomposition products of the less stable gas from depositing on the surface of the susceptor or a cover plate covering the susceptor in a pre-treatment zone upstream of a growth zone containing the one or more substrates.

[0043] On the other hand, the metal-organic compound must be available in sufficient quantity in the growth zone so that, for example, a III-V layer can be deposited on the substrate. It is therefore a particular challenge to design the geometry of the process chamber in such a way that the flow is as laminar as possible and the reactants are available in sufficient quantity in the growth zone on the surface of the substrate.

[0044] The partial pressure of the reactive gases and their decomposition products within the process chamber decreases in the direction of flow due to the condensation of these products on the surface. To nevertheless deposit a homogeneous layer on the substrates, the substrate holders, on which the substrates rest, are rotated around a vertical axis. A prerequisite for depositing a layer with a uniform thickness across its entire surface is a linear depletion curve of the reactant concentration in the direction of flow above the substrate, i.e., in the growth zone. In particular, the concentration of an element from group III must decrease linearly across the entire growth zone. Edge effects were also observed on layers deposited on the substrates, which are attributable to a flow profile within the process chamber.

[0045] The flow profile within the flow channel formed by the process chamber depends on its geometry and, in particular, on the flow velocities and mass flows of the gases fed into the process chamber through the various gas inlet zones. Since the gases heat up as they pass through the process chamber, and especially at the bottom near the susceptor assembly, more so than at the slightly cooler top of the process chamber, turbulence can occur if the flow velocity or the process chamber height is too low. This turbulence should be avoided.

[0046] Different materials, especially feedstocks introduced into the process chamber as reactive gases, require different process chamber temperatures. Consequently, different material pairings of feedstocks may also necessitate different optimal flow channel geometries.

[0047] Furthermore, there is evidence that the course of the concentration decrease of the reactants in the growth zone can be influenced not only by height differences of the process chamber in the direction of flow, but also by height differences of the process chamber perpendicular to the direction of flow.

[0048] The invention is based on the objective of providing means by which the process chamber can be adapted to changing hydromechanical conditions.

[0049] The problem is solved by the invention specified in the claims, and in particular in claims 1 and 2. The dependent claims not only represent advantageous further developments of the invention specified in the collateral claims, but also independent solutions to the problem.

[0050] First and foremost, it is proposed that the height of the process chamber be adjusted by the type of cover plates resting on the susceptor. Cover plates with different effective material thicknesses can be used, or they can have a top surface facing the process chamber that has varying vertical distances from a bottom surface that supports the susceptor. For example, the top surface of the cover plate facing the process chamber can be flat, while the bottom surface can be profiled or only bear against the susceptor at a few points. Hereinafter, "material thickness" refers to the effective material thickness that allows the process chamber height to be locally adjusted by appropriately selecting a cover plate.Additionally, the process chamber height can also be influenced by a suitable structuring of the process chamber ceiling. Material thickness is thus understood in particular as the distance of the support area, with which the cover plate rests on the susceptor, to the free surface of the cover plate, and more generally as the vertical level of the free surface of the cover plate relative to another cover plate.

[0051] The process chamber can be rectangular. A gas inlet can be arranged at one edge of the process chamber, from which the process gas exits and flows along parallel streamlines to a gas outlet located at the opposite edge of the process chamber. Alternatively, the process chamber can be circular, surrounding a gas inlet located in the center of the process chamber, from which the process gas flows along star-shaped streamlines to a gas outlet surrounding the process chamber. In both cases, cover plates with varying distances of their free upper surfaces from the susceptor, for example, with different material thicknesses, can be arranged one behind the other in the direction of flow. For example, a different process chamber height can be set using cover plates arranged in front of the substrates in the direction of flow than with cover plates arranged behind the substrates in the direction of flow.

[0052] In a preferred embodiment, a multitude of substrates are arranged side by side in a circular arrangement surrounding the gas inlet element. Here, it can be provided that adjacent cover plates also define different process chamber heights.

[0053] It is also possible for a cover plate to have a structured free surface rather than a flat one; for example, the free surface of the cover plate may be curved. The curvature may extend circumferentially, so that the surface of the cover plate has the shape of a shallow channel in the flow direction. The process chamber height may be reduced in the region of an edge of the substrate. The process chamber height may have a minimum in the midpoint between two circumferentially adjacent substrates. The process chamber height may have a maximum along a flow line passing through the center of the substrate.It is also provided that the process chamber height has a minimum along a flow line passing through the center of the substrate and rises to a maximum in the azimuthal direction in an area located between two adjacent substrates. In particular, it is provided that the height structure of the upper surface of the cover plates, relative to a line connecting the center of the gas inlet element with the center of the substrate, is flap-symmetrical and, for example, has a rounded shape.

[0054] However, it is also possible for the material thickness of the cover plates to change continuously in the direction of flow, for example, by continuously decreasing or increasing in a gas inlet zone between the gas inlet device and a growth zone where the substrate is located. Similarly, the material thickness of the cover plates located downstream of the substrate can also change continuously in the direction of flow. Here, too, as with the material thickness profile in the azimuthal direction, the surface of the cover plate can be curved or form an inclined plane.

[0055] It is considered advantageous that the process chamber height can be locally adjusted to the hydromechanical conditions required for optimal process control simply by exchanging cover plates with different material thicknesses or height structures.

[0056] Exemplary embodiments of the invention are described below with reference to the Fig. 10 to 14 are described. They show: Fig. 10 the top view of the cover plates 15, 16, which rest on a susceptor 14, Fig. 11 the cut according to line XI-XI in Fig. 10 of a first embodiment, Fig. 12 a representation according to Fig. 11 of a second embodiment, Fig. 13 looking in the direction of arrow XII, Fig. 14 a representation according to Fig. 11 of a third embodiment.

[0057] In the exemplary embodiments, a gas inlet element 6 is located in the center of a process chamber 12, which has a process chamber ceiling 13 with a flat underside. The cover plates 15, 16 rest on a flat upper surface of the susceptor 16 with a support area formed by the underside of the cover plate 15, 16. Due to varying distances between the free surface of the cover plates 15, 16 facing the process chamber 12 and the upper surface of the susceptor 16 (i.e., the support area), the height of the process chamber H1, H2, H3 can be configured differently in various areas. Without cover plates, the distance between the upper surface of the susceptor 16 and the underside of the process chamber ceiling is the same everywhere.By selecting suitable cover plates 15, 16 with different material thicknesses 170, 171, 172, the process chamber height H1, H2, H3 can be changed by simply exchanging cover plates 15, 16 and adapted to specific requirements for optimizing the flow profile of the gas flow in the process chamber 12.

[0058] In the Fig. In the embodiment shown in Figure 11, the cover plates are depicted as being made of solid material. However, the cover plates 15 and 16 can also have a different cross-section. The cover plates 15, which are closest to the gas inlet element 6, have a material thickness 170, which is greater than the material thickness 171 of the cover plates 16 located downstream of the substrate 21 or the substrate holder 20 supporting the substrate 21. Viewed in the direction of flow, the process chamber has three distinct zones, each with a different process chamber height H1, H2, and H3. The height H1 measured above the inner cover plate 15 is less than the height H3 measured above the outer cover plate 16. Heights H1 and H3 are also greater than height H2 above the substrate.In this embodiment, the surfaces of the cover plates 15, 16 facing the process chamber ceiling 13 run on planes that are parallel to a flat top of the susceptor 14 or a flat bottom of the process chamber ceiling 13.

[0059] In the Fig. In the embodiment shown in Figure 12, the upper surfaces of the cover plates 15, 16 facing the process chamber 12 have a height structure that deviates from a flat surface. The cover plates 15, which are immediately adjacent to the gas inlet element 6, have a considerable material thickness 170 in their upstream region, resulting in a minimum process chamber height H1' in this area. The height of the process chamber 12 increases in the direction of flow. The surface of the cover plate 15 slopes downwards in the direction of flow. The surface is curved. The material thickness of the inner cover plate 15 reaches a minimum at its edge adjacent to the substrate 21. At this edge adjacent to the substrate 21, the process chamber 12 has a height H1", which corresponds approximately to the height H2 that the process chamber 12 has above the substrate 21. Between the two edges, the process chamber 12 has a height H1.

[0060] The radially outer cover plate 16 has a material thickness 171, which has a minimum at the edge of the cover plate 16 adjacent to the substrate 21 and then, like the inner cover plate 15, does not run linearly in the flow direction. While the material thickness of the inner cover plate 15 decreases in the flow direction, the material thickness of the radially outer cover plate 16 increases in the flow direction. Here, too, the process chamber 12 has a process chamber height H3' at the edge adjacent to the substrate 21, which corresponds to the process chamber height H2 above the substrate 21. The process chamber height H3 then decreases until it reaches a minimum H3" at the outermost edge of the susceptor arrangement 14, 15, 16.

[0061] The previously described embodiments show that the cover plates 15, 16 can have a characteristic profile extending in the direction of flow.

[0062] The Fig. Figure 13 shows that the cover plates 15, 16 can also be profiled transversely to the flow direction. Only the cross-sectional profile of the radially inner cover plate 15 is shown here. The radially outer cover plate 16 can, however, have a similar cross-sectional profile. It is essential that the material thickness 170 of the cover plate 15, 16 has a minimum at its center, where a flow line passes through the center of the substrate 21. From this center, the material thickness increases towards both sides. In the exemplary embodiment, the cross-sectional line of the upper surface follows a curved line. In a region of a flow line that passes approximately centrally through an intermediate zone between two substrates 21, in particular along an edge of the cover plates 15, 16 extending in the flow direction, the material thicknesses 171 of the cover plates 15, 16 have a maximum.

[0063] The Fig. Figure 14 shows an embodiment in which the cover plates 15, 16 are supported by feet 173, 174. The feet 173, 174 can have different heights, so that the height H1, H3 of the process chamber in the radially inner region and in the radially outer region is defined not only by the thickness of a solid body, each forming a cover plate 15, 16, but also by the height of one or more feet 173, 174, which are supported on the top of the susceptor 14 and on which the solid bodies are arranged.

[0064] According to the invention, the height of the process chamber 12 can be locally changed by modifying the configuration of the process chamber 12 with different cover plates 15, 16. This increases the application range of a CVD reactor because different material pairings in the reactive gases require differently shaped flow channels. 2. CVD reactor with a process chamber ceiling consisting of several vertically movable elements

[0065] The invention relates to a device for depositing layers onto one or more substrates, in which a process chamber is arranged in a housing. The process chamber chamber has a ceiling and a floor, the floor forming a susceptor arrangement on which storage areas for substrates are located. In the device, the substrates are thermally treated; for example, a semiconductor layer is deposited onto the substrates. A gas mixing system provides a process gas, consisting of one or more reactive gases, which is fed into the process chamber through gas outlet openings of a gas inlet device. The different reactive gases are fed into the process chamber through vertically stacked gas inlet zones.Part of the process gas, which is fed in through a lowest gas inlet zone, forms a diffusion barrier for another part of the process gas, which is fed into the process chamber through a gas inlet zone above it.

[0066] The susceptor assembly is heated to a process temperature by means of a heating device. The process gas flowing into the process chamber through the gas inlet is heated. Depending on the type of reactive gas, for example, whether it is a hydride of an element from group V or a metal-organic compound of an element from group III, the reactive gas has a different thermal stability. The more thermally stable reactive gas is therefore fed in through the lowest gas inlet zone, while a more thermally unstable gas, such as the metal-organic compound, is fed in at a higher vertical level. This prevents decomposition products of the less stable gas from depositing on the surface of the susceptor or a cover plate covering the susceptor in a pre-treatment zone upstream of a growth zone containing the one or more substrates.

[0067] On the other hand, the metal-organic compound must be available in sufficient quantity in the growth zone so that, for example, a III-V layer can be deposited on the substrate. It is therefore a particular challenge to design the geometry of the process chamber in such a way that the flow is as laminar as possible and the reactants are available in sufficient quantity in the growth zone on the surface of the substrate.

[0068] The partial pressure of the reactive gases and their decomposition products within the process chamber decreases in the direction of flow due to the condensation of these products on the surface. To nevertheless deposit a homogeneous layer on the substrates, the substrate holders, on which the substrates rest, are rotated around a vertical axis. A prerequisite for depositing a layer with a uniform thickness across its entire surface is a linear depletion curve of the reactant concentration in the direction of flow above the substrate, i.e., in the growth zone. In particular, the concentration of an element from group III must decrease linearly across the entire growth zone. Edge effects were also observed on layers deposited on the substrates, which are attributable to a flow profile within the process chamber.

[0069] The flow profile within the flow channel formed by the process chamber depends on its geometry and, in particular, on the flow velocities and mass flows of the gases fed into the process chamber through the various gas inlet zones. Since the gases heat up as they pass through the process chamber, and especially at the bottom near the susceptor assembly, more so than at the slightly cooler top of the process chamber, turbulence can occur if the flow velocity or the process chamber height is too low. This turbulence should be avoided.

[0070] Furthermore, the molecular weight of the gases also influences the mass transport perpendicular to the flow direction and thus the growth rate of a layer on the substrate.

[0071] Different materials, especially feedstocks introduced into the process chamber as reactive gases, require different process chamber temperatures. Consequently, different material pairings of feedstocks may also necessitate different optimal flow channel geometries.

[0072] Furthermore, there is evidence that the course of the concentration decrease of the reactants in the growth zone can be influenced not only by height differences of the process chamber in the direction of flow, but also by height differences of the process chamber perpendicular to the direction of flow.

[0073] The invention is based on the objective of providing means by which the process chamber can be adapted to changing hydromechanical conditions.

[0074] The problem is solved by the invention specified in the claims, and in particular in claims 2 to 5. The dependent claims not only represent advantageous embodiments of the invention specified in the dependent claims, but also independent solutions to the problem.

[0075] First and foremost, it is proposed that the process chamber ceiling comprises process chamber ceiling elements that are displaceable, at least in the vertical direction. The susceptor assembly can include a susceptor that can be rotated about a vertical axis. The plane of rotation in which the susceptor rotates is fixed relative to the housing. A non-rotatable susceptor has a plane of extension, which may be a horizontal plane. The process chamber ceiling elements can be displaced relative to this plane, or relative to the housing, such that the process chamber height can be changed locally. The process chamber ceiling elements can be arranged in a ring around a gas inlet located in the center of the process chamber. The process chamber ceiling elements can be arranged side by side in the circumferential direction and be individually adjustable in the vertical direction.This can be achieved via an actuator, such as a stepper motor. However, vertical adjustment can also be performed manually, for example, using adjusting screws. It is also possible for the one or more vertically adjustable process chamber ceiling elements to be arranged one behind the other in the direction of flow, allowing the height of the flow channel to be varied in the direction of flow. Here, too, it is possible for the vertical adjustment to be made outside the housing. In this case, it is even possible for the process chamber ceiling elements to be adjusted during a deposition process in which layers with different compositions are deposited onto the substrate.

[0076] The invention thus also relates to a method for depositing layers in which, in an intermediate time between the depositing of two layers or even during the depositing of one layer, at least one process chamber ceiling element is vertically displaced.

[0077] Exemplary embodiments of the invention are described below with reference to the Fig. Explained in sections 15 to 18. They show: Fig. 15 a cross-section through a process chamber 12, Fig. 16 a top view of a process chamber arrangement according to arrow XVI in Fig. 15 of a first embodiment, Fig. 17 a representation according to Fig. 16 of a second embodiment, Fig. 18 a representation according to Fig. 16 of a third embodiment.

[0078] In the Fig. In the embodiments shown in Figures 15 to 18, the process chamber ceiling 3 consists of several process chamber ceiling elements 181, 183, 185. Each of these process chamber ceiling elements can be adjusted vertically to change the height H1, H2, H3 of the process chamber 12. This can be done with an actuator 180, 182, 184. The actuators can be located outside the housing of the CVD reactor. Alternatively, they can be located inside the housing. The actuators can have stepper motors, so that the vertical height of the process chamber H1, H2, H3 can be changed by adjusting the process chamber ceiling elements 181, 183, 185 even during a deposition process, for example, when a layer with a different composition is to be deposited on a substrate.The actuator 180, 182, 184 can also be an adjusting screw, by turning which the vertical position of the process chamber ceiling element 181, 183, 185 can be changed relative to the susceptor arrangement 14, 15, 16.

[0079] The Fig. Figure 16 shows an embodiment in which the process chamber ceiling elements 181, 183, 185 have a ring shape. Several ring-shaped process chamber ceiling elements are arranged around an inlet element 6 located in the center of the process chamber 12, which has a plurality of vertically arranged gas distribution chambers 8, into each of which a different reactive gas can be fed, so that the process gas flows into the process chamber 12 as vertically layered individual gas flows.

[0080] The Fig. Figure 17 shows an embodiment in which the process chamber ceiling elements 181, 183, 185 are additionally separated in the azimuthal direction, i.e., circumferentially around the gas inlet element 6. The elements shown in the Fig. The 38 annular process chamber ceiling elements shown here are divided according to the number of storage locations for substrates 21 extending in a circular arrangement around the center of the process chamber 12, so that each of the several storage locations is individually assigned several process chamber ceiling elements 181, 183, 185. With this arrangement, the flow profile can be individually optimized for each of the substrates 21 by changing the process chamber height H1, H2, H3.

[0081] In the Fig. Figure 15, referenced with numeral 186, shows the concentration profile of a decomposition product of one of the reactive starting materials, which is significant for the growth rate of the layer. In a pre-flow zone between gas inlet 6 and substrate holder 20, the availability of a decomposition product that has a layer-forming effect increases sharply until it reaches a maximum value. The concentration curve should then decrease as linearly as possible above the substrate 21 in order to produce a layer of homogeneous thickness, especially with regard to the substrate rotating during the deposition process.

[0082] With the device described above, the profile of the flow channel through which the process gas flows, and thus also the concentration profile 186 of one of the reactive gases or a component of this reactive gas above a growth zone extending over the substrates 21, can be optimized such that the concentration decreases linearly in the direction of flow. In a particularly preferred embodiment, it is even possible to optimize the concentration profile for each storage location, for example, for each substrate holder 20 on which one or more substrates 21 rest. In the method according to the invention, the profile of the flow channel can be changed during a deposition process.

[0083] The Fig. Figure 18 shows an embodiment in which each of the storage places for the one or more substrates 21 is locally assigned only one process chamber ceiling element 181. 3. CVD reactor with process chamber elements that can be individually removed from the reactor housing

[0084] The invention relates to a device and a method for depositing layers onto one or more substrates, comprising a process chamber ceiling and a process chamber floor arranged in a housing for receiving the substrates. A robotic gripper arm can reach into the interior of the housing through a closable loading / unloading opening in a wall of the reactor housing to load or unload the susceptor with substrates. The gripper arm can directly handle the substrates. However, it is also possible to grip support rings or plates on which one or more substrates rest. The invention is based on the objective of providing measures by which parts of the process chamber can also be exchanged during loading / unloading.

[0085] The problem is solved by the invention specified in the claims, in particular claims 6 to 8.

[0086] The invention primarily involves a mechanical coupling of a process chamber ceiling element with a susceptor element arranged below the process chamber ceiling element. In this aspect, the process chamber can consist of process chamber ceiling elements arranged side-by-side in the circumferential direction. It is not necessary for multiple process chamber ceiling elements to be arranged one behind the other in the flow direction. The essential point is that the process chamber ceiling element and the susceptor element are connected to each other, for example via connecting elements, in such a way that an assembly consisting of a process chamber ceiling element with an associated susceptor element can be removed from the housing of the CVD reactor. The assembly can be removed from the housing and reinserted for loading and unloading the process chamber with substrates.Preferably, the process chamber ceiling element and the associated susceptor element extend over an identical azimuthal angle. Each of these units, consisting of the process chamber ceiling element and the susceptor element, can additionally have a gas outlet element extending over the respective azimuthal angle. In this embodiment, the gas outlet element can consist of a plurality of gas outlet elements arranged one behind the other in an azimuthal direction, which are separable from one another.

[0087] Exemplary embodiments of the invention are described below with reference to the Fig. Explained in sections 19 to 22. They show: Fig. 19 a cross-section through a process chamber 12, Fig. 20 a top view of a process chamber arrangement, Fig. 21 a representation according to Fig. 19 of a second embodiment, and Fig. 22 a representation according to Fig. 19 of a third embodiment.

[0088] The Fig. Articles 19 to 22 describe an invention which is an optimization of the loading and unloading of the process chamber with substrates 21.

[0089] The process chamber ceiling 13 consists of several process chamber ceiling elements 191 arranged circumferentially around the gas inlet device 6, wherein a process chamber ceiling element 191 is assigned to each storage location for one or more substrates 21 and in particular to each substrate 21 or substrate holder 20.

[0090] The susceptor 14 has susceptor elements 190, with one susceptor element 190 assigned to each storage location or substrate 21. As in the previously described embodiments, the number of process chamber ceiling elements 191 can correspond to the number of storage locations for each substrate 21 or to the number of substrate holders 20 on which one or more substrates 21 are located. The number of susceptor elements 190 can correspond to the number of process chamber ceiling elements 191.

[0091] The process chamber ceiling elements 191 lie congruently on each susceptor element 190. The respective process chamber ceiling element 191 is connected to the susceptor element 190 below it by connecting elements 192, 193, so that each process chamber ceiling element 191 with a susceptor element 190 can be removed as a unit from the housing 2 of the CVD reactor 1, for example through a loading / unloading opening 44, and can also be reinserted into the housing 2 through this loading / unloading opening 44.

[0092] The connecting elements 192, 193 can be connecting rods that extend in a vertical direction between susceptor element 190 and process chamber ceiling elements 191.

[0093] In the Fig. 21 and Fig. In the embodiment shown in Figure 22, the gas outlet element 18 is additionally divided into several gas outlet elements 194. Each of the previously described ensembles, consisting of a process chamber ceiling element 191 and a susceptor element 190, is locally assigned a gas outlet element 194, so that the unit removable from the housing 2 also has a gas outlet element 194. The individual elements 191, 190, 194, which extend over a circular segment, together form a circular object. Several arc-shaped gas outlet elements 194 are provided, which are separate from one another and, in a combined state, form a gas outlet element 18 extending along a circular arc.

[0094] The device described above can shorten a cleaning step in which the process chamber is cleaned by introducing a cleaning gas, by combining the susceptor element 190, the process chamber ceiling element 191 and, optionally, the gas outlet element. 4. Process chamber of a CVD reactor with several vertically stacked gas outlet devices.

[0095] The invention relates to a device for depositing layers onto one or more substrates. A process chamber is located within a housing. The process chamber has a ceiling that defines its upper boundary and a susceptor assembly that defines its lower boundary and provides storage positions for substrates that are thermally treated within the device. A process gas, supplied by a gas mixing system and containing one or more reactive gases and at least one carrier gas, is fed into the process chamber via a gas inlet. Reaction products exit the process chamber through a gas outlet located at the vertical level of the susceptor assembly.

[0096] In such a CVD reactor, the reactive gases are fed separately into the process chamber through vertically stacked gas inlet zones. A key requirement for process control in the deposition of semiconductor layers onto substrates is achieving consistent homogeneity of both layer composition and layer thickness across the entire substrate surface. The hydromechanical flow profile within the process chamber has a significant influence on this homogeneity.

[0097] The invention is therefore based on the objective of specifying measures by which the flow profile can be influenced.

[0098] The problem is solved by the invention specified in the claims, and in particular in claims 9 to 12. The dependent claims not only represent advantageous embodiments of the invention specified in the dependent claims, but also independent solutions to the problem.

[0099] The first and main proposal is that a second gas outlet device be provided. This second gas outlet device should be located at a different vertical height.

[0100] Each of the two gas outlet devices creates a negative pressure at a different vertical height. This negative pressure is capable of influencing the flow profile within the process chamber. The CVD reactor can be a so-called horizontal reactor, in which the process chamber has a rectangular footprint, with the gas inlet and gas outlet devices positioned opposite each other. Preferably, the CVD reactor is a so-called planetary reactor, in which the process chamber surrounds a central gas inlet device, such that the two gas outlet devices form a ring around the process chamber. It is particularly preferred if the second gas inlet device is located at the vertical height of the process chamber ceiling. The second gas outlet device, like the first gas outlet device, can have a gas collection channel that extends over the entire circumference of the gas outlet device.While the gas outlet openings of the first gas outlet, which connect the gas collection channel to the process chamber, are located above the gas collection channel, the gas outlet openings of the second gas outlet can be located below the gas collection channel. It is particularly advantageous if each of the two gas outlets is connected to an individual exhaust port for discharging the exhaust gases. A throttle valve and a pressure sensor can be installed in each of these ports. The throttle valve allows the gas flow through the ports to be controlled. The pressure sensor allows a vacuum to be set, which can then be used to influence the flow profile in the process chamber. The two ports can be connected to the same pump. However, it is also possible to have two or more pumps, with each port connected to a different pump.

[0101] It can also be provided that the second gas outlet device is vertically displaceable relative to the first gas outlet device 18. Actuators, such as stepper motors, can be provided for this purpose.

[0102] The invention further relates to a method by which the flow profile within the process chamber is influenced by varying the gas flow through the drains.

[0103] According to a further aspect of the invention, the susceptor assembly can optionally be lowered with a heating device that heats the susceptor assembly to a process temperature. At a lower vertical level, the housing wall of the reactor housing can have a loading / unloading opening that is closed by a door. With the door open, the gripper arm of a robot can engage in the reactor housing to load the susceptor assembly with substrates or substrate holders.

[0104] The invention further relates to a method for loading and unloading a process chamber in which the susceptor assembly is lowered. The susceptor assembly is lowered below the vertical level of the lower gas outlet device.

[0105] Exemplary embodiments of the invention are described below with reference to the Fig. Explained in sections 23 to 27. They show: Fig. 23 in a representation according to Fig. 1 or Fig. 6 a first embodiment of the invention, in which a second gas outlet element 200 is arranged above a first gas outlet element 18, Fig. 24 a representation according to Fig. 23 of a second embodiment, Fig. 25 schematically a representation of a gas drainage system, Fig. 26 a variant of the in the Fig. 25 gas drainage system shown, Fig. 27 a representation according to Fig. 25 of a variant in which the second gas outlet device 200 can be moved vertically with an actuator 209.

[0106] According to the invention, in the case of a Fig. 1, Fig. 6 or Fig. In the embodiment shown in Figure 9, in addition to a lower gas inlet element 18, a second gas inlet element 200 is provided, which is arranged at a different vertical level compared to the lower gas inlet element 18 and, in particular, is arranged above the lower gas inlet element 18. In the embodiments shown, the second gas outlet element 200 is arranged at the level of the process chamber ceiling 13.

[0107] According to an alternative, the second gas outlet device 200 can also be adjusted in a vertical direction.

[0108] The second gas outlet device 200 can have essentially the same shape as the first gas outlet device 18. In both the first gas outlet device 18 and the second gas outlet device 200, the gas outlet openings 19, 202, which connect the volume of the process chamber 12 with a gas collecting channel 201 each, can lie in a plane in which the floor of the process chamber or the ceiling of the process chamber 12 extends.

[0109] The second gas outlet device 200, like the first gas outlet device 18, can surround the process chamber 12 in a circular fashion.

[0110] The gas collection channels 201 of the two gas outlet devices 18, 22 can each be connected to separate lines 203, 204, through which the exhaust gases from the first gas outlet device 18 and from the second gas outlet device 22 can be extracted, respectively. For this purpose, the two lines 203, 204 are equipped with a pump 207 ( Fig. 25) or each with a separate pump 207, 208 ( Fig. 26) connected. In each of the two lines 203, 204, a pressure sensor 210 (not shown) and a throttle valve 205, 206 can be arranged. The throttle valves are connected to the control unit 11. The control unit 11 can have a control device with which the throttle valves 205, 206 are actuated such that a negative pressure in the respective gas collection channel 201 is maintained at a setpoint value.

[0111] By appropriately setting this negative pressure, the flow profile within the process chamber 12 can be influenced.

[0112] The Fig. 25 shows a variant of the one in the Fig. 24 illustrated embodiment, in which an arrangement consisting of the susceptor 14, cover plates 15, 16 resting on the susceptor 14, a substrate holder 20 and a substrate 21 resting on the substrate holder 20 is separated from a process position (see Fig. 23) can be lowered into a loading / unloading position. In this loading / unloading position, a loading / unloading opening 44 can be opened so that a substrate 21 or a substrate holder 20 can be removed from the susceptor 14 using the gripper 49.

[0113] The Fig. Figure 27 shows an embodiment with a gas outlet element 200 having a ring shape. In this embodiment, the gas outlet openings 202 are arranged on a vertically extending side wall, specifically on the radially inwardly directed side wall.

[0114] The vertical position of the gas outlet element 200 can be changed by means of an actuator 209, which may be a servo motor or an adjusting screw. The gas outlet element 200 can thus be arranged at various vertical positions between the process chamber ceiling 13 and the susceptor 14 in order to influence the flow profile.

[0115] 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:

[0116] A device characterized in that the free surface of the cover plates 15, 16 have different distances to the support area.

[0117] A device characterized in that a cover plate 15 adjacent to the gas inlet element 6 has a different material thickness 170, 171 than a cover plate 16 adjacent to the gas outlet element 18, and / or that the gas inlet element 6 is arranged in the center of a process chamber 12 and several cover plates 15, 16 are arranged one behind the other in the radial direction, which have at least partially different material thicknesses 170, 171, and / or that the gas inlet element 6 is arranged in the center of a process chamber 12 and several cover plates 15, 16 are arranged next to each other in the azimuthal direction, which have at least partially different material thicknesses 170, 171, and / or that the cover plates 15, 16 have a locally varying material thickness 170, 171, 172, wherein it is particularly provided that an underside facing a susceptor 14 of the cover plates 15,16 runs horizontally and the upper surface of the cover plates 15, 16 facing the process chamber 12 has a height structure, and / or that a height structure of the upper surface of the cover plates 15, 16 with respect to a line connecting the center of the gas inlet organ 6 with the center of a substrate 21 is symmetrical and, for example, has a curve.

[0118] A device characterized in that the process chamber ceiling has 12 process chamber ceiling elements 181, 183, 185 which are movable at least in the vertical direction.

[0119] A device characterized in that several vertically displaceable process chamber ceiling elements 181, 183, 185 are arranged in a ring around the gas inlet element 6 located in the center of the process chamber 12, and / or that several vertically displaceable process chamber ceiling elements 181, 183, 185 are arranged next to each other in the circumferential direction around a center of the process chamber 12, and / or that at least some of the process chamber ceiling elements are assigned actuators 180, 182, 184 with which the respective process chamber ceiling element 181, 183, 185 can be displaced vertically.

[0120] A process characterized in that during the deposition of a layer or in an intermediate time between the deposition of two layers, one or more process chamber ceiling elements 181, 183, 185 are vertically displaced.

[0121] A device characterized in that a susceptor element 190 is mechanically connected to a process chamber ceiling element 191 and can be removed from the housing 2 and reinserted into the housing 2 as a unit.

[0122] A device characterized in that the susceptor element 190 and the associated process chamber ceiling element 191 are parts of a process chamber outer wall 27 and a gas outlet device 18, and / or that the susceptor element 90 and the associated process chamber ceiling element 191 extend over an identical azimuthal angle and are arranged vertically one above the other.

[0123] A method characterized in that a unit consisting of a susceptor element 190 and a process chamber ceiling element 191 connected thereto is handled by means of a gripper.

[0124] A device characterized in that a second gas outlet device 200 is arranged at a different vertical height.

[0125] A device characterized in that the second gas outlet element 200 is arranged at the vertical height of the process chamber ceiling 13, and / or that the second gas outlet element 200 surrounds the process chamber 12 arranged circularly around the gas inlet element 6, and / or that the second gas outlet element 200 has a gas collecting channel 201 into which gas outlet openings 202 open, the gas collecting channel 201 being arranged above the gas outlet openings 202, and / or that a side wall 27 of the process chamber 12 connects the first gas outlet element 18 with the second gas outlet element 200, and / or that the susceptor arrangement 14, 15, 16 can be lowered from a process position to a loading / unloading position at a height at which a loading / unloading opening 201 is located in a housing wall 4, and / or that the Gas outlet devices 18, 200 with separate lines 203, 204, in each of which a throttle valve 205, 206 is arranged,are connected to a pump 207 or to separate pumps 207, 208 and / or that the second gas outlet device 200 is vertically displaceable, in particular by means of an actuator 209.

[0126] A method characterized in that the susceptor arrangement 14, 15, 16 together with the heating device 17 is lowered from a process position to a loading / unloading position in which the susceptor arrangement 14, 15, 16 is located below that of the lower gas outlet device 18.

[0127] A method characterized in that the gas outlet devices 18, 200 are connected to a pump 207 or to separate pumps 207, 208 via separate lines 203, 204, in each of which a throttle valve 205, 206 is arranged, wherein a flow profile within the process chamber 12 is influenced by varying the gas flows through the lines 203, 204.

[0128] 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. List of reference symbols 1 CVD reactor 2 cases 3 upper case wall 4 side case wall 5 lower case wall 6 Gas inlet device 7 Supply line 8 Gas distribution chamber 9 Gas outlet opening 10 Gas mixing system 11 Control unit, regulating unit 12th Tribunal 13 Process chamber ceiling 14 Susceptor 15 Cover plate 16 Cover plate 17 Heating system 18 Gas outlet device 19 Opening 20 substrate holders 20' Underside 20" top 21 Substrat 21' Underside 21" top 22 optical device, sensor 23 Opening 24 transparent closure elements, windows 24' surface 25 optical path 26 Opening 27 side wall 28 shaft 29 Cooling element 30 Heating equipment 31 plate 32 Supply line 33 Mouth 34 bags 34' floor 35 gas cushions 36 Measuring device, pyrometer 37 bracket 38 Seal 39 Seal 40 Purge gas supply line 40' Mouth 41 Gas outlet area 42 Separation plane 43 Cold storage room 44 Loading / unloading opening 45 Transfer module 46 Transfer Chamber 47 robots 48 Arm 49 grippers 50 Gripper arm 50' grab arm 170 material thickness 171 material thickness 172 material thickness 173 feet 180 actuator 181 Process chamber ceiling element 182 Actuator 183 Process chamber ceiling element 184 Actuator 185 Process chamber ceiling element 186 Concentration profile 190 Susceptor element 191 Process chamber ceiling element 192 Connecting element 193 Connecting element 194 Gas outlet element 200 Gas outlet device 201 Gas collection channel 202 Gas outlet 203 Derivation 204 Derivative 205 Throttle valve 206 Throttle valve 207 Pump 208 Pump 209 Actuator 210 Pressure sensor H Height (Process Chamber) QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 132 776 A1

[0002] DE 10 2022 101 806 A1

[0002] DE 10 2022 101 809 A1 [0002, 0014] DE 10 2022 114 717 A1

[0002] DE 10 2021 114 868 A1

[0002] DE 10 2021 110 305 A1

[0002] DE 10 2022 103 245 A1

[0002] DE 10 2020 126 597 A1

[0002] DE 10 2020 123 546 A1

[0002] DE 10 2020 112 569 A1

[0002] DE 10 2019 131 794 A1

[0002] DE 10 2019 117 479 A1

[0002] DE 10 2018 130 140 A1

[0002] DE 10 2018 130 139 A1 [0002, 0006] DE 10 2016 110 884 A1

[0002] DE 10 2014 106 871 A1

[0002] DE 10 2013 101 777 A1

[0002] DE 10 2011 002 146 A1

[0002] DE 10 2009 044 276 A1

[0009] DE 10 2014 100 024 A1

[0018] DE 10 2020 122 198 A1

[0019]

Claims

[1] Device for depositing layers onto one or more substrates (21), wherein a process chamber (12) is arranged in a housing (2), which is bounded upwards by a process chamber ceiling (13) and downwards by a susceptor arrangement (14, 15, 16) supporting one or more substrates (21), wherein the susceptor arrangement (14, 15, 16) has a susceptor (14) which forms a bearing surface on which cover plates (15, 16) each support a support area, with a gas inlet device (6) which has gas outlet openings (9) directed towards the process chamber (12), through which a process gas consisting of one or more reactive gases provided by a gas mixing system (10) flows into the process chamber (12), and with a gas outlet device (18) with which decomposition products of the process gas and an inert gas fed into the process chamber (12) together with the process gas are removed from the process chamber (12), wherein the height of the process chamber (12) is defined by a distance between a free surface of cover plates (15, 16) of the process chamber arrangement (14, 15, 16) facing the process chamber (12) and a free surface of the process chamber ceiling (13) facing the process chamber (12) has locally different values, characterized by , that the free surface of the cover plates (15, 16) have different distances to the support area. [2] Device according to claim 1, characterized by , that a cover plate (15) adjacent to the gas inlet device (6) has a different material thickness (170, 171) than a cover plate (16) adjacent to the gas outlet device (18), and / or that the gas inlet device (6) is arranged in the center of a process chamber (12) and several cover plates (15, 16) are arranged one behind the other in the radial direction, which have at least in some areas a different material thickness (170, 171), and / or that the gas inlet device (6) is arranged in the center of a process chamber (12) and several cover plates (15, 16) are arranged side by side in an azimuthal direction, which have at least partially different material thicknesses (170, 171), and / or that the cover plates (15, 16) have a locally varying material thickness (170, 171, 172), wherein it is provided in particular that a bottom surface of the cover plates (15, 16) facing a susceptor (14) is flat and the top surface of the cover plates (15, 16) facing the process chamber (12) has a height structure, and / or that a height structure of the upper surface of the cover plates (15, 16) with respect to a line connecting the center of the gas inlet organ (6) with the center of a substrate (21) is flap-symmetric and, for example, has a rounded shape. [3] Device for depositing layers onto one or more substrates (21), wherein a process chamber (12) is arranged in a housing (2), which is bounded upwards by a process chamber ceiling (13) and downwards by a susceptor arrangement (14, 15, 16) supporting one or more substrates (21), with a gas inlet device (6) which has gas outlet openings (9) directed towards the process chamber (12), through which a process gas consisting of one or more reactive gases provided by a gas mixing system (10) flows into the process chamber (12), and with a gas outlet device (18) with which decomposition products of the process gas and an inert gas fed into the process chamber (12) together with the process gas are removed from the process chamber (12), wherein a height (H1, H2, H3) of the process chamber (12) defined by a distance of a free surface of the process chamber arrangement (14, 15, 16) facing the process chamber (12) to a free surface of the process chamber ceiling (13) facing the process chamber (12) has locally different values, characterized by , that the process chamber ceiling (12) has process chamber ceiling elements (181, 183, 185) which are movable at least in the vertical direction. [4] Device according to claim 3, characterized by , that several vertically movable process chamber ceiling elements (181, 183, 185) are arranged in a ring around the gas inlet element (6) located in the center of the process chamber (12), and / or that several vertically movable process chamber ceiling elements (181, 183, 185) are arranged side by side in the circumferential direction around a center of the process chamber (12), and / or that at least some of the process chamber ceiling elements are assigned actuators (180, 182, 184) with which the respective process chamber ceiling element (181, 183, 185) can be moved vertically. [5] Method for depositing layers on one or more substrates (21) in a device according to one of claims 3 or 4, characterized by , that during the deposition of a layer or in an intermediate time between the deposition of two layers, one or more process chamber ceiling elements (181, 183, 185) are vertically displaced. [6] Device for depositing layers onto one or more substrates (21), wherein a process chamber (12) is arranged in a housing (2), which is bounded at the top by a process chamber ceiling (13) which has several process chamber ceiling elements (191), and which is bounded downwards by a susceptor arrangement (14, 15, 16) supporting one or more substrates (21) and which has several susceptor elements (190), characterized by , that each susceptor element (190) is mechanically connected to a process chamber ceiling element (191) and can be removed from the housing (2) and reinserted into the housing (2) as a unit. [7] Device according to claim 6, characterized by , that the susceptor element (190) and the associated process chamber ceiling element (191) are parts of a process chamber outer wall (27) and a gas outlet organ (18), and / or that the susceptor element (90) and the associated process chamber ceiling element (191) extend over an identical azimuthal angle and are arranged vertically one above the other. [8] Method for loading and unloading a device according to one of claims 6 or 7, characterized by , that a unit consisting of a susceptor element (190) and a process chamber ceiling element (191) connected to it is handled by means of a gripper. [9] Device for depositing layers onto one or more substrates (21), wherein a process chamber (12) is arranged in a housing (2), which is bounded at the top by a process chamber ceiling (13) and at the bottom by a susceptor arrangement (14, 15, 16) supporting one or more substrates (21), with a heating device (17) for heating the susceptor arrangement (14, 15, 16), with a gas inlet device (6) for feeding a process gas provided by a gas mixing system (10) into the process chamber (12) and with a lower gas outlet device (18) arranged at the vertical height of the susceptor arrangement (14, 15, 16), characterized by , that a second gas outlet device (200) is arranged at a different vertical height. [10] Device according to claim 9, characterized by , that the second gas outlet device (200) is arranged at the vertical height of the process chamber ceiling (13), and / or that the second gas outlet element (200) surrounds the process chamber (12) arranged circularly around the gas inlet element (6), and / or that the second gas outlet element (200) has a gas collecting channel (201) into which gas outlet openings (202) open, wherein the gas collecting channel (201) is arranged above the gas outlet openings (202), and / or that a side wall (27) of the process chamber (12) connects the first gas outlet device (18) with the second gas outlet device (200), and / or that the susceptor arrangement (14, 15, 16) can be lowered from a process position to a loading / unloading position at a height at which a loading / unloading opening (201) is located in a housing wall (4), and / or that the gas outlet devices (18, 200) are connected to a pump (207) or to separate pumps (207, 208) via separate lines (203, 204) in which a throttle valve (205, 206) is arranged, and / or that the second gas outlet device (200) can be moved vertically, in particular by means of an actuator (209). [11] Method for depositing layers on one or more substrates (21) in a device according to claim 9 or 10, characterized by, that the susceptor arrangement (14, 15, 16) together with the heating device (17) is lowered from a process position to a loading / unloading position in which the susceptor arrangement (14, 15, 16) is located below that of the lower gas outlet device (18). [12] Method for depositing layers on one or more substrates (21) in a device according to claim 9 or 10, characterized by , that the gas outlet devices (18, 200) with separate lines (203, 204) in which a throttle valve (205, 206) is arranged are connected to a pump (207) or to separate pumps (207, 208), whereby a flow profile within the process chamber (12) is influenced by varying the gas flows through the lines (203, 204). [13] apparatus or method, characterized by one or more of the characterizing features of any of the preceding claims.

Images