Apparatus and method for treating substrates

Abstract

The invention relates to a device and a method for treating a plurality of substrates (32), wherein the substrates (32) are arranged in storage locations (7) of a susceptor (5) arranged in a housing cavity of a reactor housing (1), wherein a process gas flow (S1) of a process gas is fed into the housing cavity from one or more gas outlet openings (6') of a gas inlet member (6), in such a way that the process gas flows evenly over the storage locations (7) to a gas outlet member (9) arranged downstream of the storage locations (7) in relation to the process gas flow, by means of which the process gas is fed out of the housing cavity, wherein a locally limited control gas flow (S2) of a control gas is fed into the housing cavity through at least one control gas inlet opening (10) opening into the housing cavity. In order to compensate for the locally bounded influence of the control gas flow (S2) on the flow profile, a compensating inlet or outlet opening (23) is provided downstream of the control gas inlet opening (10) and downstream of the storage location (7), through which a locally bounded compensation gas flow (S3) of a compensation gas flows.

Description

Description Device and method for treating substrates field of technology

[0001] The invention relates to a method for treating a plurality of substrates arranged on storage positions of a susceptor located in a housing cavity of a reactor housing. A process gas flow is fed into the housing cavity from gas outlet openings of a gas inlet device. This occurs such that the process gas flows essentially uniformly across the storage positions to a gas outlet device located downstream of the storage positions with respect to the process gas flow. The process gas is discharged from the housing cavity via the gas outlet device. At least one control gas inlet opening opens into the housing cavity, through which a locally confined control gas flow is fed into the housing cavity.

[0002] The invention further relates to a device with a susceptor arranged in a housing cavity of a reactor housing for carrying out the method.

[0003] The invention further relates to a method for treating a plurality of substrates arranged on a susceptor, wherein the susceptor is arranged in a housing cavity of a reactor housing and is driven to rotate about an axis of rotation. Bearing positions are arranged on the susceptor in a uniform circumferential distribution around the axis of rotation, each bearing at least one substrate. A process gas is fed into the housing cavity by means of a gas inlet device located in the center of the housing cavity such that it flows over the bearing positions of the susceptor towards an edge of the susceptor. By means of a susceptor- The process gas is discharged from the housing cavity via the gas outlet surrounding the susceptor. The process gas flowing over the side of the susceptor containing the bearings forms a lateral flow profile. A compensating gas is locally introduced into or pumped out of the housing cavity through a compensating gas inlet or outlet opening.

[0004] The invention further relates to a device with a susceptor arranged in a housing cavity of a reactor housing for carrying out this method. State of the art

[0005] DE 10 2019104433 A1 describes a device and a method for depositing layers onto substrates of the generic type. A susceptor arranged below a process chamber is temperature-controlled from below by a temperature control device. The temperature control device is an RF coil with a cavity through which a coolant flows. A control gas flow can be introduced between the temperature control device and the side of the susceptor facing away from the process chamber. There, the control gas flow forms a temperature control gas flow, which allows the heat flow from the susceptor to the cooled RF coil to be adjusted in order to locally influence the temperature at a storage location of a substrate.

[0006] DE 10 2018 124 957 A1 describes a device and a method for depositing layers onto substrates, wherein the bearing positions of substrate holders are formed and supported on a gas cushion, the gas cushion being generated by a control gas. The height of the gas cushion can be influenced by changing the control gas flow. A compensating gas is fed in downstream of the substrate holder, whereby the sum of the compensating gas flow and the control gas flow is kept constant.

[0007] US Patent 6,531,069 Bl describes a CVD reactor with a showerhead-shaped gas inlet extending across the entire lateral surface of a process chamber. The susceptor, located below the showerhead, is surrounded by a gas inlet that has gas outlet openings only on a partial circumference. These gas outlet openings are associated with a rotating gas outlet ring.

[0008] US Patent 8,152,925 B2 describes a CVD reactor with a showerhead-type gas inlet and a substrate storage area located below it. The substrate is surrounded by a gas outlet ring with numerous gas outlet openings. The gas outlet ring also has numerous gas discharge openings from which a compensating gas can be fed into the housing cavity of the CVD reactor.

[0009] DE 10 2020 107517 A1 describes a device for the thermal treatment of substrates in a susceptor driven about a rotary axis, wherein gas supply lines are arranged in the susceptor, exiting the susceptor on the underside facing the heating element. Each substrate is locally assigned an outlet opening on its underside.

[0010] In the process described above, the process gas flow can vary considerably depending on the type of process carried out in the process chamber. For example, when depositing III-V semiconductor layers, and especially when depositing layers containing indium and / or phosphorus or layers containing gallium and / or arsenic, it can vary significantly. It may be necessary to use very low process gas flows, so that the process gas flows at a relatively low velocity over the side of the susceptor facing the process chamber. If, in such a process, a temperature control gas flow also flows along the opposite side of the susceptor and this temperature control gas flow merges into the process gas flow, the flow profile—that is, the local flow directions of the process gas or its pressure at the edge of the susceptor—can be influenced in such a way that this influence on a process parameter affects the quality or thickness of the deposited layer.

[0011] However, the flow profile of the process gas flow through the process chamber is also influenced by other circumstances, for example by a non-precisely central arrangement of a gas inlet device, or by a slight tilting of the susceptor driven by a rotary axis, or by a non-homogeneous suction effect of a gas outlet device connected to a vacuum pump to establish a negative pressure within the housing cavity of the CVD reactor. Summary of the invention

[0012] The invention is based on the objective of providing means by which the flow profile can be influenced, at least in the region of the edge of the susceptor.

[0013] The problem is solved by the invention specified in the claims, wherein the dependent claims not only represent advantageous further developments of the invention specified in the dependent claims, but are also independent solutions to the problem.

[0014] The primary proposal is to arrange a compensating gas inlet or outlet downstream of the susceptor. This inlet allows a localized flow of compensating gas to be either introduced into or extracted from the housing cavity. This compensating gas flow can introduce or extract an additional gas flow into the housing cavity, influencing the flow profile of the process gas flow through the susceptor, at least at its edge. The compensating gas flow can thus locally influence the total local pressure within the housing cavity, which is partly responsible for the formation of the flow profile. Furthermore, the compensating gas flow can introduce an additional impulse into the gas flow, resulting in localized dynamic modification of the flow profile.This compensating gas flow can compensate for a locally limited effect of a control gas flow, which, for example, is confined to a single point of action, in such a way that the sum of the locally limited control gas flow and the compensating gas flow associated with it is kept at a constant value. The compensating gas flow can also be used to reduce inhomogeneities in the flow profile caused by other factors by introducing a locally limited compensating gas flow.

[0015] The control gas flow can be a mixture of several gases, particularly two gases. These gases can have different viscosities and thermal conductivities. For example, the two gases could be hydrogen and nitrogen. Each of the multiple gases can be fed into the gas supply line in a controlled manner using its associated mass flow controller, ensuring that a compensating gas with a defined viscosity and thermal conductivity can act at a specific point. This is particularly advantageous when the control gas flow also consists of gases with different viscosities and thermal conductivities, for example, from a mixture of hydrogen and nitrogen. The compensating gas flow can be composed of hydrogen and nitrogen. Furthermore, a specific direction can be given to the compensating gas flow, which can be directed towards the gas outlet, towards the process chamber or process chamber ceiling, or circumferentially around the susceptor. It is also possible to have the compensating gas inlet or outlet fixed in place on the housing. Alternatively, the compensating gas inlet or outlet can be assigned to the susceptor. If the susceptor rotates, the compensating gas inlet or outlet rotates with it. It remains fixed in place and assigned to one of the substrates. It is possible to have a compensating gas inlet or outlet assigned to each substrate. This compensating gas inlet or outlet can be located on the upward-facing top surface of the susceptor.The opening can also be arranged radially on the outwardly facing narrow edge of the susceptor. It is also possible to arrange the opening on the underside. Preferably, the compensating gas inlet or outlet opening is adjacent to the edge of the susceptor. Here, too, the opening can be designed to direct the compensating gas flow.

[0016] In a first embodiment of the invention, a method is proposed in which a plurality of substrates are located on storage positions of a susceptor arranged in a housing cavity of a reactor housing. One substrate can be located on a single storage position, or several substrates can be located on a single storage position. The storage positions can be formed by substrate holders supported by a gas cushion, which drives the substrate holders rotationally. The susceptor has an upstream region in which a gas inlet element is arranged. The gas inlet element has one or more gas outlet openings through which a process gas flow is fed into a process chamber extending above the susceptor. The susceptor has a downstream region adjacent to a gas outlet element through which the process gas or gases present during the susceptor discharge are discharged. The reaction products forming the substrates are removed from the housing cavity. This can be achieved using a vacuum pump connected to the gas outlet via a suction line. The gas outlet openings are arranged to ensure the most uniform process gas flow possible over the substrates, which are positioned between the gas inlet and outlet openings in the direction of process gas flow. With a rotationally symmetrical arrangement around a central gas inlet, a rotationally symmetrical flow profile should be achieved. A control gas can be introduced into the housing cavity. This is done through a control gas inlet opening that opens into the housing cavity. A single control gas inlet opening may be provided, or multiple control gas inlets may be used.According to a preferred embodiment of the invention, one or more control gas inlet openings are arranged along the edge of the susceptor. The control gas can be used to influence the heat flow from a temperature control device to the susceptor or from the susceptor to the temperature control device. This can be achieved, in particular, by using a temperature control gas that flows between the temperature control device and the susceptor. This is preferably done in a locally confined area. The control gas can be a mixture of a gas with high thermal conductivity and a gas with low thermal conductivity, so that the composition of the control gas can influence the heat flow between the temperature control device and the susceptor. The temperature control device can be an RF heater that generates eddy currents within the susceptor to heat it.The RF heater can be configured as a spiral tube running below the susceptor, through which a cooling fluid flows, allowing the temperature control device to also perform a cooling function. The heat flow from the susceptor to the tube can be influenced by the temperature control gas. The mass flow of the temperature control gas can also be varied. The temperature control gas enters through the control gas inlet, particularly in the area... the edge of the susceptor into the housing cavity and can mix there with the process gas flow. According to the invention, the local influence on the flow profile caused by the injection of the control gas into the process gas flow is compensated by the compensating gas flow.

[0017] It can be advantageous if the susceptor is driven by a rotary drive around its axis of rotation. The susceptor can have a multitude of bearing positions arranged in a uniform circumferential distribution along a circular arc around its center. At least one control gas inlet can be fixed in position such that a control gas flow is fed into the casing cavity at a fixed point relative to the reactor casing. The control gas can first pass through a gap between the temperature control device and the susceptor, acting as a temperature control gas. In order to thermally influence only specific bearing positions at any given time, the temperature control gas can flow through the control gas inlet into the casing cavity in sync with the rotation of the susceptor.According to the invention, it is proposed that a compensating gas outlet opening, located at a fixed point on the reactor casing, is arranged at the control gas inlet opening, through which the compensating gas flow is introduced. It may be provided that further compensating gas outlet openings, also each located at a fixed point relative to the reactor casing, are provided, through which a compensating gas flow can each be introduced into the casing cavity. It may be provided that the multiple compensating gas outlet openings are arranged in the same circumferential distribution around the center of the susceptor as the bearing positions. By lowering one of the compensating gas flows, an increase in a control gas flow can thus be compensated. In a variant, however, it may also be provided that the compensating gas flow is discharged from the casing cavity through a compensating gas outlet opening.For this purpose, the compensating gas outlet opening can be connected to a vacuum line through which gas from the housing is drawn. The fluid can be pumped out of the cavity. This can also be synchronized with the rotation of the susceptor.

[0018] According to a preferred embodiment of the invention, it is proposed that the compensating gas inlet or outlet opening opens into the gas outlet device, so that either a locally confined flow of compensating gas can be fed into the gas outlet device or a locally confined flow of compensating gas can be pumped out of the gas outlet device. The point of action where the process gas mixes with the control gas can also be located in the gas outlet device. The control gas inlet opening can also open directly into the gas outlet device. However, it is also provided that the control gas inlet opening opens into the housing cavity upstream of the gas outlet device. It can further be provided that the process gas contains a reactive gas with elements of Group III and a reactive gas with elements of Group V. The process gas can also contain reactive gases with elements of Groups II or VI, or reactive gases of an element of Group IV.The two gases, which can be formed from a metal-organic compound and a hydride, are fed in together with an inert gas, for example hydrogen, through the gas inlet, which is preferably located in the center of the process chamber. The process gas then flows through the process chamber, which is bounded below by the susceptor and above by a process chamber ceiling, where it thermally decomposes. The decomposition products form a III-V semiconductor layer on the substrate. In other embodiments, the decomposition products form a II-VI semiconductor layer or a IV semiconductor layer. Preferably, this is a single-crystal semiconductor layer. Preferably, several semiconductor layers with preferably different compositions and thicknesses are deposited one on top of the other. These can be GaAs, InP, GaP, InAs layers, or mixtures of these crystals.In some of these material systems, and especially in one material system that contains As and P. In such cases, the optimal flow velocities of the process gas through the process chamber are so low that the flow profile is affected by even the slightest control flows or other design inhomogeneities within the process chamber. These inhomogeneities can be reduced by selectively introducing the compensating gas.

[0019] In a second embodiment of the invention, the compensating gas is therefore used only for local influencing of the flow profile if, in this embodiment, no control gas flow is introduced into the housing cavity. Here, too, the introduction of the compensating gas flow is preferably synchronized with the rotation of the susceptor. The compensating gas can be introduced into or discharged from the housing cavity to create a local overpressure or underpressure. Here, too, it can be advantageous if the compensating gas inlet or outlet is located in the gas outlet such that the pressure within the gas outlet changes locally due to the alteration of the compensating gas mass flow.Furthermore, the compensating gas inlet or outlet opening can be arranged in the gas outlet organ in such a way that the compensating gas flowing through it has no dynamic effect outside the gas outlet organ, but merely leads to a local pressure change in the area of ​​an action point that lies radially outside the susceptor.

[0020] It may also be provided that the compensating gas inlet or outlet opening is arranged upstream of the gas outlet device in the direction of flow but downstream of the susceptor in the direction of flow.

[0021] It can further be provided that the gas outlet device is an annular body having a plurality of openings arranged in a ring around the center on its upper surface. The openings can form a The openings must be spaced at a constant distance. They can be connected to a channel extending around the entire circumference of the gas outlet device, which is connected at least at one, but preferably several, points to a gas line through which gas can be pumped out of the gas outlet device. Alternatively, the gas outlet device may have only a single annular opening through which the process gas and, if applicable, the control gas can enter the gas outlet device. The compensating gas inlet or outlet openings can be located in the area of ​​the channel base or in the area of ​​a channel wall. A single compensating gas inlet or outlet opening may be provided, or several may be provided, for example, two opposing compensating gas inlet or outlet openings.However, it can also be provided that the number of compensating gas inlet or outlet openings corresponds to the number of storage locations and also that their circumference distribution corresponds to that of the storage locations on the susceptor.

[0022] It can be provided that the compensating gas inlet or outlet is arranged, or that several compensating gas inlet or outlet openings are arranged, in such a way that the changes in the flow profile downstream of a storage location or even on the storage location of a substrate, i.e., particularly above the substrate surface, are limited to specific areas of the substrate surface. For example, it can be provided that the one or more compensating gas inlet or outlet openings are arranged or operated in such a way that the flow profile is influenced only above a peripheral area of ​​the substrate or only above a central area. However, it is also possible to arrange one or more compensating gas inlet or outlet openings in such a way that the flow profile is influenced above the entire surface of the substrate.This can be caused by a slight local decrease in total pressure downstream of the storage site or by a slight local increase. of the total pressure downstream of the storage site by means of a gas flow or by a hydromechanical effect of a gas flow.

[0023] With respect to a first radial line extending through the center of the gas inlet device and an edge of the bearing area or the substrate supported by the bearing area, the compensating gas inlet or outlet opening can be arranged such that the hydromechanical effect of the compensating gas flow passing through it is limited to an edge region.

[0024] With respect to a second radial line extending through the center of the gas inlet device and a center of the storage area or of the substrate supported by the storage area, the compensating gas inlet or outlet opening can also be arranged in such a way that the hydromechanical effect of the compensating gas flow passing through it is limited to the central area.

[0025] The invention also encompasses further developments of the prior art in which several compensating gas inlet or outlet openings are arranged on an azimuthal angular segment corresponding to the azimuthal angular segment of a substrate. For example, the effect of one compensating gas inlet or outlet opening on the first radial line and a second compensating gas inlet or outlet opening on the second radial line downstream of the susceptor can be limited. The compensating gas inlet or outlet openings can be fixed relative to the gas outlet element or the housing, such that the bearing positions for the substrate move relative to the compensating gas inlet or outlet openings. The outlet gas flows are then synchronized with the rotation of the susceptor such that a specific pulse of a gas flow, which is either fed into the process chamber, is The gas pulse generated, or extracted from the process chamber, is only produced when a specific storage location passes through the compensating gas inlet or outlet. This allows for targeted manipulation of one or more storage locations with different gas pulses. It is also possible to operate two compensating gas inlet or outlet openings, located on an azimuthal angular segment corresponding to the azimuthal angular segment of a storage location, in different ways. For example, a gas flow can be fed into the process chamber through one compensating gas inlet or outlet opening, while a gas flow is extracted from the process chamber through the other. This creates a local overpressure in the area of ​​one compensating gas inlet or outlet opening and a local underpressure in the area of ​​the other.This allows the flow profile to be specifically influenced differently over the edge of the substrate than over the central area of ​​the substrate.

[0026] The control unit is preferably programmed such that the aforementioned gas pulses are generated synchronously with the rotational speed of the susceptor. During a single rotation of a susceptor, multiple gas pulses can be generated, allowing flow profiles over different bearing positions to be individually influenced sequentially. Short description of the drawings

[0027] Exemplary embodiments of the invention are explained below with reference to the accompanying drawings. These show: Fig. 1 schematically shows a vertical section through a region of a process chamber of a CVD reactor, in which an outer edge 5' of a susceptor 5 borders a control gas inlet opening 10 and an opening of a gas outlet device 9, for Illustration of the flow profile of a process gas flow Sl forming in a process chamber above the susceptor 5; Fig. 2 schematically shows the flow profile according to Figure 1 in the horizontal plane; Fig. 3 shows a cross-section through a reactor housing 1 of a first embodiment; Fig. 4 shows a section along line IV-IV in Figure 3; Fig. 5 shows a representation according to Figure 4 of a second embodiment; Fig. 6 shows a representation according to Figure 4 of a third embodiment; Fig. 7 shows a representation according to Figure 4 of a fourth embodiment; Fig. 8 shows a representation according to Figure 4 of a fifth embodiment; Fig. 9 shows a representation according to Figure 4 of a sixth embodiment; Fig. 10 shows a representation according to Figure 4 of a seventh embodiment. Fig. 11 shows a representation according to Figure 4 of an eighth embodiment, Fig. 12 shows a representation according to Figure 11 of a ninth embodiment, Fig. 13 shows a representation according to Figure 11 of a tenth embodiment, Fig. 14 shows a representation according to Figure 10 of an eleventh embodiment, Fig. 15 shows a representation according to Figure 3 of a twelfth embodiment example, Fig. 16 shows a representation according to Figure 3 of a thirteenth embodiment, Fig. 17 shows a representation according to Figure 4 of a fourteenth embodiment, Fig. 18 shows a representation according to Figure 4 of a fourteenth embodiment and Fig. 19 shows a representation according to Figure 4 of a fifteenth embodiment. Description of the embodiments

[0028] Figures 1 and 2 are intended to illustrate the problem underlying the invention, also with reference to Figures 3 and 4:

[0029] Figure 3 shows a CVD reactor, as is generally known from DE 102019104433 A1. Reference is therefore made to the details of the design and operation of the CVD reactor described therein. The CVD reactor has a reactor housing 1, which has side walls 3, a base 4, and a lid 2, each preferably made of metal, for example, aluminum or stainless steel. This creates a gas-tight seal within the housing cavity. A gas inlet 6 is located in the housing cavity, through which process gases can be fed into the housing cavity. The gas inlet 6 has one or more gas outlet openings 6', which preferably extend circumferentially around the gas inlet 6, which is located in the center of the housing cavity, such that a rotationally symmetrical, homogeneous process gas flow S1 is fed into the process chamber surrounding the gas inlet 6.A gas mixing system 20 can supply process gases which are fed into the gas inlet device 6. The gas mixing system 20 can be controlled by a control unit 18.

[0030] The process chamber extends below a process chamber ceiling 11 and above a susceptor 5. The susceptor 5 is supported by a carrier 12, which allows the susceptor 5 to be driven about its axis of rotation A, causing it to rotate in a horizontal plane. The susceptor 5 carries a plurality of substrate holders 7, each forming a storage position. In the exemplary embodiment, the substrate holders 7 can rest on gas cushions (not shown) generated by a purge gas flow, which also drives the substrate holder 7 about an axis of rotation B. This is possible. The surface temperature of the substrate 7 can be measured using a pyrometer 21.

[0031] Below the susceptor 5 is a heating device 13, which in the exemplary embodiments is formed by a spiral coil that generates an RF field with which eddy currents are generated in the susceptor 5 in order to bring the susceptor 5 to a process temperature.

[0032] Radially outside the susceptor 5 is a gas outlet element 9 extending along the edge 5' of the susceptor 5, which extends along a circular arc, with an opening 9' that points towards the edge 5' of the susceptor 5. The gas outlet element 9 is connected to several gas lines (not shown in the drawings) and a pump (also not shown) to draw gas from a channel of the gas outlet element 9.

[0033] In the embodiments shown in Figures 3, 8, and 9, a sealing plate 8 is located below the underside of the susceptor 5. This sealing plate does not rotate with the susceptor 5 but is fixed to the reactor housing 1, for example, resting on a step of the gas outlet device 9. The sealing plate 8 is located between the heating element 13 and an underside of the susceptor 5, creating a horizontal gap 17 between the sealing plate 8 and the susceptor 5. A temperature control gas can be introduced into this gap 17 via a gas line 14. This creates a flow of temperature control gas that flows radially through the gap 17 and exits through an opening 10 into an area radially outside the edge 5' of the processor 5.

[0034] By means of two mass flow controllers 28, 29 controlled by the control unit 18 and a switching valve or mixing valve 27 A mixture of H2 and N2 can be injected into gas line 4. It exits the injection opening 14' into the gap 17 and forms a control gas flow S2 through the gap 17.

[0035] Figure 4 shows an embodiment in which only one gas line 14 is provided, which opens into the gap 17 at exactly one circumferential position, so that only one outlet opening 10 is formed, which is located at the end of the flow path of the temperature control gas shown as a dashed line in Figure 4. In order to thermally influence a specific storage location 7, a temperature control gas is injected through the gas line 14 in pulsed increments, synchronized with the rotation of the susceptor 5. This gas flows along the flow path to locally influence the heat flow to or from one of the storage locations 7.

[0036] A further pyrometer 22 can be used to measure a temperature below the susceptor 5.

[0037] Figures 1 and 2 schematically show the process gas flow S1 and the control gas flow S2, which mix at an action point 31. The action point 31 is located radially outside the edge 5' of the susceptor 5 and upstream of the opening 9'. If a control gas is introduced through the locally located control gas inlet opening 10 in the region of the action point 31, the pressure and / or the flow profile change locally. This is schematically indicated in Figure 2 by the fact that the streamlines no longer run in a precise radial direction. The change in the flow profile results in the growth rate of the layer deposited on the substrate 7 being different at the edge than upstream of the edge. The crystal composition may also differ at the edge compared to upstream.

[0038] In order to reduce the influence of the control gas flow S2 on the flow profile, in the embodiments shown in Figures 3 to 8, a control gas flow S3 is fed into the housing cavity at the same radial position as the control gas inlet opening 10 through a control gas inlet or outlet opening 23'.

[0039] In the embodiment shown in Figure 3, the control gas inlet or outlet opening 23' opens into the base of an annular channel of the gas outlet channel 9. The control gas flowing from the control gas inlet or outlet opening 23' does not need to exit through the opening 9' towards the point of action 31. The effect of the control gas flow S3 on the flow profile occurs even if the control gas flow S3 is accompanied only by a local and, in particular, pulsed pressure change at the point of action 31. Such a gas pulse can be generated with a mass flow controller 19 and, optionally, an additional valve.

[0040] The second embodiment shown in Figure 5 differs from the first embodiment essentially in that two diagonally opposite gas lines 14 are provided, each of which can be independently supplied with a control gas and to which a gas supply line 23 for a compensating gas is locally assigned.

[0041] The third embodiment shown in Figure 6 differs from the other two embodiments essentially in that each of the bearing positions 7 is locally assigned a gas line 14 and thus a control gas inlet opening 10. Furthermore, each control gas inlet opening 10 is also assigned a compensating gas inlet or outlet opening 23'.

[0042] The fourth embodiment shown in Figure 7 differs from the previously described embodiments essentially in that each of the storage positions 7 is locally assigned a compensating gas inlet or outlet opening 23', but the number of control gas inlet openings 10 differs from the number of compensating gas inlet or outlet openings 23'. In this embodiment, there is only one control gas inlet opening 10. However, it is also possible here to provide that each of the storage positions 7 has an assigned control gas inlet opening 10.

[0043] The fifth embodiment shown in Figure 8 differs from the embodiment shown in Figure 3 essentially in that the compensating gas inlet or outlet opening 23' opens into a side wall of the channel of the gas inlet element. The opening 9' of the gas outlet element 9 can be of such a width that the gas flow exiting the opening 23' exerts an effect at the point of action 31.

[0044] The sixth embodiment shown in Figure 9 differs from the embodiments shown in Figures 3 and 8 essentially in that no compensating gas flow S3 flows into the reactor housing, but rather a compensating gas flow S3 is discharged from the reactor housing. Specifically, a suction flow is generated by a suction line 23 and a pump 24 controlled by a valve 25, with which the compensating gas flow S3 is pumped out of the channel of the gas outlet device 9 in order to create a local negative pressure at the point of action 31. A similar effect can be achieved with an arrangement according to Figure 7 if a lower compensating gas flow S3 flows through one of the compensating gas inlet or outlet openings 23' than through all the others. The diameter of the opening 9' of the gas outlet device 9 can Here, it is adjusted in such a way that the negative pressure generated via the suction line produces an effect at the point of action 31.

[0045] In the seventh embodiment shown in Figure 10, the control gas inlet opening 10 is missing. Here, no control gas flow is generated to disturb the flow profile. Nevertheless, a compensating gas inlet or outlet opening 23' is provided, which can generate a pressure differential located locally at a circumferential point. This differential is achieved by either feeding a compensating gas flow S3 into the housing cavity through the compensating gas inlet or outlet opening 23', as shown in Figure 10, or by pumping a compensating gas flow S3 out of the housing cavity, as is the case in an embodiment not shown. Here, too, it is advantageous if the compensating gas inlet or outlet opening 23' opens into the channel of the gas outlet device 9. This can be located either in the side wall or in the base. The process gas flow S1 mixes here within the gas outlet device 9 with the compensating gas flow S3.The arrangements of the gas supply lines 23 and the compensating gas inlet or outlet openings 23' shown in Figures 4 to 7 can be implemented. Here, too, the opening 9' can have an opening width that allows the compensating gas exiting the gas supply line 23 to act at the point of action 31.

[0046] The eighth embodiment shown in Figure 11 differs from the embodiment shown in Figure 10 essentially in that the compensating gas inlet or outlet opening 23' does not open into the gas outlet element 9, but rather in the region of the point of action 31 downstream of the edge 5' of the susceptor. The compensating gas flow S3 can have an adjustable viscosity, adjustable thermal conductivity, or another adjustable property. This is made possible by the compensating gas flow S3 being an adjustable mixture of different gases. This can be the case. For example, a mass flow controller 19 can be used to feed a hydrogen flow into the gas supply line 23. A mass flow controller 19' can be used to feed a nitrogen flow into the gas supply line 23. The two gases mix in the gas supply line 23, so that a compensating gas with a predetermined composition can escape from the opening 23'.

[0047] In one embodiment, it can be provided that the composition of the compensating gas corresponds to the composition of the control gas flow S2.

[0048] In the embodiment shown in Figure 12, the susceptor 5 has a gas supply line 23 that opens near the edge 5' of the susceptor. A mixture of hydrogen and nitrogen can be fed into this gas supply line 23, which enters the reactor cavity downstream of the storage area 7 as a compensating gas flow S3. An end section of the gas supply line 23 gives the compensating gas flow S3 an oblique upward direction.

[0049] In the embodiment shown in Figure 13, an end section of the gas supply line 23 gives the compensating gas flow S3 a downward direction.

[0050] In exemplary embodiments not shown, the gas lines 23 can also lead to a pump, so that a suction flow can emerge from the reactor cavity through the openings 23' at the edge 5' of the substrate 5. A suction opening that rotates with the susceptor can be provided.

[0051] In the embodiment shown in Figure 14, which essentially corresponds to the embodiment shown in Figure 10, the compensating gas inlet or outlet opening 23' is not connected to the gas The gas outlet 9 is not assigned to the gas outlet. The compensating gas inlet or outlet opening 23' is instead located in the area of ​​the process chamber ceiling 11. The compensating gas inlet or outlet opening 23' is located downstream of the storage location 7. In particular, it can be located downstream of the edge 5'. A gas flow exiting the compensating gas inlet or outlet opening 23' can be directed towards the gas outlet 9 and flow past the edge 5' of the susceptor.

[0052] Here too, it is possible to use opening 23' as a suckling opening.

[0053] The embodiment shown in Figure 15 corresponds essentially to the embodiment shown in Figure 3. Similar to the embodiment shown in Figures 12 and 13, the compensating gas inlet or outlet opening 23' is fixed to the susceptor 5. Here, the compensating gas inlet or outlet opening 23' is located in the region of the narrow circumferential wall of the susceptor 5. However, as shown in Figures 12 and 13, it can also generate a directed flow that has not only a radial component but also an axial component.

[0054] The embodiment shown in Figure 16 corresponds essentially to the embodiment shown in Figure 3. However, it differs in that, as in the embodiment shown in Figure 14, the compensating gas inlet or outlet opening 23' is arranged in the process chamber ceiling 11. Here, too, a directed compensating gas flow S3 can flow out of the compensating gas inlet or outlet opening 23', preferably with the flow direction of the compensating gas flow S3 directed towards the gas outlet element 9.

[0055] Figure 17 shows the arrangement of the compensating gas inlet or outlet 23' of the embodiments shown in Figures 12, 13, and 15. Each of the storage locations 7 can be assigned a compensating gas inlet or outlet 23' downstream. The compensating gas inlet or outlet 23' can be supplied by a common gas supply line, so that, for example, a mass flow provided by mass flow controllers 19, 19' is divided into a corresponding number of branch flows.

[0056] In each of the embodiments of this application, each of the storage locations 7 can also be assigned a compensating gas inlet or outlet opening 23' through which an individualized gas flow can flow. For this purpose, each of the compensating gas inlet or outlet opening 23' can have an individual supply line which has at least one mass flow controller 19, 19'. Preferably, however, the individual gas supply lines each have a pair of mass flow controllers 19, 19' so that an individualized gas mixture can be fed in.

[0057] The latter also applies to the embodiments shown in Figures 11, 14 and 16, in which the compensating gas inlet or outlet opening 23' is assigned to the housing. Here, too, compensating gas inlet or outlet opening 23' can be arranged in the housing in the same angular distribution as the bearing positions 7 on the susceptor 5.

[0058] In the embodiments shown in the drawings, the control gas inlet opening 10 is located upstream of an opening 9' of the gas outlet device 9. In embodiments not shown, however, the control gas inlet opening 10 can also open directly into the gas outlet device 9, for example into a wall bounding the annular channel of the gas outlet device 9. The point of action 31 is then located inside the gas outlet device 9. Without the additional compensating gas flow S3, the flow profile above the susceptor 5 would also be influenced by the control gas flow S2 in these embodiments, because an increased pressure develops locally in the region of the edge 5' of the susceptor 5. This local pressure inhomogeneity can be reduced with the compensating gas flow S3, for example, by introducing compensating gases S3 into the gas inlet 6 at different circumferential positions and by introducing a smaller compensating gas flow S3 into the gas outlet 9 where the control gas flow S2 enters the gas outlet 9. Alternatively, a compensating gas flow S3 can also be pumped out of the gas outlet 9 at the point of action. It is advantageous here if the compensating gas flow S3 is fed directly into the gas outlet device 9 or pumped directly out of the gas outlet device 9.

[0059] With the devices described above, it is not only possible to compensate for disturbances in the flow profile within the process chamber, and especially at its outer edge, caused by design deficiencies or local flows or pressure changes. It is also possible to selectively influence the flow profile by means of a compensating gas flow S3. This can be done, as described above, in a manner synchronized with the rotation of the susceptor 5. However, it is also possible to influence the flow profile by means of asynchronous or constant compensating gas flows S3.

[0060] Figures 18 and 19 additionally show two radial lines RI, R2, each extending radially from a center Z of the gas inlet organ 6 located in the center of the susceptor 5 across the susceptor 6, with the radial line RI forming an edge 7' of a bearing position 7 tangent and the radial line R2 passes through the center 7" of storage site 7.

[0061] In the embodiment shown in Figure 18, a compensating gas inlet or outlet opening is operated in such a way that a gas pulse is generated each time the radial line RI of the rotating susceptor 5 passes the compensating gas inlet or outlet opening 23', so that the flow profile is only influenced in the area of ​​an edge 7' of the bearing space or of the substrate stored there.

[0062] In one variant, the compensating gas inlet or outlet opening 23' is operated in such a way that a gas pulse is generated each time the radial line R2 of the rotating susceptor 5 passes the compensating gas inlet or outlet opening 23', so that the flow profile is only influenced in the area of ​​a center 7" of the storage location or of the substrate stored there.

[0063] In both cases, the pulse length is measured so short that the influence on the flow only extends over a partial azimuthal angle of the total angle over which the bearing surface extends. However, it is also possible to measure the pulse length so that the influence on the flow affects the entire azimuthal angle over which the bearing surface extends.

[0064] In the embodiment shown in Figure 19, two compensating gas inlet or outlet openings 23', 23" are provided, which are positioned so close together that their angular separation is smaller than the azimuthal angle over which the bearing position 7 or the substrate supported by the bearing position 7 extends. In this variant, various gas pulses can be synchronized with the rotation of the bearing position in close temporal succession. Susceptors 5 are generated. It is possible to generate a gas flow inflowing into or out of the process chamber through both compensating gas inlet or outlet openings 23', 23". However, it is also possible to generate a gas flow into the process chamber through one of the two compensating gas inlet or outlet openings 23', 23" and out of the process chamber through the other compensating gas inlet or outlet opening 23', 23".

[0065] This is preferably achieved such that the gas pulses influence only one flow profile over each bearing position 7 or a substrate arranged on the bearing position 7. The gas pulses can also influence only a partial angle over the bearing position 7 or substrate. This is achieved in particular by synchronizing the pressure change achieved with the gas pulses with the susceptor rotation.

[0066] 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:

[0067] A method characterized in that, downstream of the control gas inlet opening 10 and downstream of the storage location 7, a locally limited compensating gas flow S3 of a compensating gas is fed into or pumped out of the housing cavity through a compensating gas inlet or outlet opening 23'.

[0068] A method characterized in that the compensating gas flow S3 is controlled by a control device 18 such that a The locally limited influence on the flow profile downstream of storage location 7 caused by the control gas flow S2 at an action point 31 is compensated by the compensating gas flow S3, and / or the sum of the locally limited control gas flow S2 and the compensating gas flow S3 assigned to it is kept at a constant value by a control device 18.

[0069] A method characterized in that the control gas flow S2 is fed into an area between the susceptor 5 and a temperature control device 13, with which a heat flow to or from the susceptor 5 is influenced in a locally limited area and / or that the process gas contains a reactive gas with an element of group III and a reactive gas with an element of group V and / or that the reactive gas has an arsenic compound, a phosphorus compound and / or an indium compound or a gallium compound and that the susceptor is brought to a process temperature by a heating device 13 at which a III-V semiconductor layer is deposited on the substrates 32.

[0070] A method characterized in that the compensating gas flow S3 is fed directly into or pumped out of the gas outlet device 9.

[0071] A device characterized in that downstream of the control gas inlet opening 10 and downstream of the storage location 7 in the gas outlet device 9, a compensating gas inlet or outlet opening 23' opens, through which a compensating gas can be fed into the housing cavity or pumped out of the housing cavity.

[0072] A device characterized in that a control unit 18 for controlling valves 27, 25 and mass flow controllers 19, 28, 29 for influencing at least one control gas flow S2 and at least one compensating gas flow S3 is configured such that the compensating gas flow S3 at an action point 31 compensates for a locally limited influence of a flow profile of the process gas flow S1 via the storage locations 7 by the control gas flow S2 and / or that the sum of the locally limited control gas flow S2 and the compensating gas flow S3 assigned to it is kept at a constant value.

[0073] A device characterized in that the control gas flow S2 is guided through a gap 17 between the side of the susceptor 5 pointing away from the bearing places and a temperature control device 13 in order to influence a heat flow to or from the susceptor 5 in a locally limited area by the control gas flow S2 and that, with respect to the extension plane of the susceptor 5, the compensating gas inlet or outlet opening 23' is arranged where the control gas flow S2 mixes with the process gas flow S3.

[0074] A device characterized in that the compensating gas inlet opening 23' is arranged downstream of an edge 5' of the susceptor 5 adjacent to the gas outlet element 9 and / or that the compensating gas inlet or outlet opening 23' is arranged in the gas outlet element 9.

[0075] A device characterized in that the bearing positions 7 are arranged in an annular shape around the center of the susceptor 5, which has an outer rim 5' extending along a circular line, and the annularly shaped gas outlet element 9 surrounds the susceptor 5, wherein several or each of the bearing positions 7 have a locally assigned control gas inlet opening nung 10 and a compensating gas inlet or outlet 23' located radially away from the control gas inlet opening 10, through which a control gas flow S2 or compensating gas flow S3, respectively, individually controlled by the control device 18, flows.

[0076] A device characterized in that the susceptor 5 is rotatably driven about a rotary axis A and, controlled by the control device 18 through the control gas inlet openings 10 or compensating gas inlet or outlet openings 23', synchronizes the control gases or compensating gases with the rotation of the susceptor 5 in such a pulsed manner that a process parameter is kept at a predetermined value at each of the storage locations 7.

[0077] A method characterized in that the compensating gas inlet or outlet opening 23' is arranged in such a way or the compensating gas flow S3 flowing through the compensating gas inlet or outlet opening 23' is directed in such a way that the flow profile above the susceptor 5 is influenced at least in the region of the edge 5' of the susceptor 5.

[0078] A method characterized in that the compensating gas is fed radially outside the susceptor 5 into the housing cavity or into the gas outlet device 9 or is pumped out of the housing cavity or the gas outlet device 9.

[0079] A device characterized in that the compensating gas inlet or outlet opening 23' is arranged and the control device 18 is programmed such that the injection or pumping of the compensating gas influences the flow profile over the susceptor 5 at least in the region of the edge 5' of the susceptor 5.

[0080] A device characterized in that the compensating gas inlet or outlet opening 23' is arranged radially outside the susceptor 5 or in the gas outlet organ.

[0081] A method or device characterized in that the compensating gas inlet or outlet opening 23' is associated with the susceptor 5 and is arranged radially outside a storage location 7 adjacent to the edge 5' of the susceptor 5 and / or that the compensating gas flow S3 originates from a compensating gas inlet or outlet opening 23' adjacent to the edge 5' - with respect to the process gas flow 51 - downstream of the storage location 7 and / or that the compensating gas flow S3 is an adjustable mixture of gases with two different viscosities or thermal conductivities.

[0082] A device or method characterized in that one or more outlet openings 23', 23" are arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the area of ​​an edge 7' or a center 7" of a substrate resting on a substrate holder 7, or that the flow profile is influenced over the entire area of ​​the surface of a substrate resting on a substrate holder 7.

[0083] A device or method characterized in that a first outlet opening 23' is arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the area of ​​an edge 7' of a substrate resting on a substrate holder 7 and that a second outlet opening 23" is arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the area of ​​a center 7" of a substrate resting on a substrate holder 7.

[0084] 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 include 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 Reactor housing 23 Gas supply line 2 Covers 23' Compensating gas inlet or outlet 3 Side wall opening 4 Bottom 23" Compensating gas inlet or outlet 5 Susceptor opening 5' Edge 24 Pump 6 Gas inlet device 25 Control valve 6' Outlet opening 27 Diverter valve 7 substrate holders, storage location 28 mass flow controllers 7' Rand 29 Mass Flow Controller 8 Sealing plate 30 Cooling channel 9 Gas outlet device 31 Point of action 9' opening 32 substrate 10 Control gas inlet opening 11 Process chamber ceiling 12 Support A Susceptor axis of rotation 13 Heating device B Substrate holder rotary axis 14 Gas pipeline 51 Process gas flow 17 gap 52 control gas flow 18 Control unit 53 Compensating gas flow 19 Mass flow controller RI radial line 19' Mass flow controller R2 radial line 20 Gas supply 21 first pyrometer 22 second pyrometer

Claims

Claims 1. A method for treating a plurality of substrates (32), wherein the substrates (32) are arranged on storage locations (7) of a susceptor (5) arranged in a housing cavity of a reactor housing (1), wherein a process gas flow (S1) of a process gas is fed into the housing cavity from one or more gas outlet openings (6') of a gas inlet element (6) in such a way that the process gas flows uniformly over the storage locations (7) to a gas outlet element (9) arranged downstream of the storage locations (7) with respect to the process gas flow, with which the process gas is guided out of the housing cavity, wherein a locally limited control gas flow (S2) of a control gas is fed into the housing cavity through at least one control gas inlet opening (10) opening into the housing cavity, characterized in thatthat downstream of the control gas inlet opening (10) and downstream of the storage location (7) through a compensating gas inlet or outlet opening (23') a locally limited compensating gas flow (S3) of a compensating gas is fed into the housing cavity or pumped out of the housing cavity.

2. Method according to claim 1, characterized in that the compensating gas flow (S3) is controlled by a control device (18) in such a way that a locally limited influence on the flow profile downstream of the storage location (7) caused by the control gas flow (S2) at an effective point (31) is compensated by the compensating gas flow (S3), and / or that the sum of the locally limited control gas flow (S2) and the compensating gas flow (S3) locally assigned to it is kept at a constant value by a control device (18).

3. Method according to one of the preceding claims, characterized in that the control gas flow (S2) is fed into a region between the susceptor (5) and a temperature control device (13) with which a heat flow to or from the susceptor (5) is influenced in a locally limited area and / or that the process gas contains a reactive gas with an element of the III. main group and a reactive gas with an element of the V. main group and / or that the reactive gas comprises an arsenic compound, a phosphorus compound and / or an indium compound or a gallium compound and that the susceptor is brought to a process temperature with a heating device (13) at which a III-V semiconductor layer is deposited on each of the substrates (32).

4. Method according to one of the preceding claims, characterized in that the compensating gas flow (S3) is fed directly into the gas outlet element (9) or pumped out of the gas outlet element (9).

5. Device with a susceptor (5) arranged in a housing cavity of a reactor housing (1), on which a plurality of storage locations (7) are arranged, each for at least one substrate (32) to be treated in the device, with a gas inlet element (6) which has one or more gas outlet openings (6') designed and arranged in such a way that a process gas flow (S1) of a process gas emerging through the one or more gas outlet openings (6') flows uniformly over the storage locations (7), and with a gas outlet element (9) which is arranged downstream of the storage locations (7) with respect to the process gas flow (S1), with which the process gas or gaseous reaction products formed during the treatment can be led out of the housing cavity, wherein at least one control gas inlet Opening (10) opens, with which a locally limited control gas flow (S2) of a control gas can be fed into the housing cavity, which can be led out of the housing cavity through the gas outlet element (9), characterized in that downstream of the control gas inlet opening (10) and downstream of the storage space (7) in the gas outlet element (9) opens a compensating gas inlet or outlet opening (23'), with which a compensating gas can be fed into the housing cavity or pumped out of the housing cavity.

6. Device according to claim 5, characterized in that a control device (18) for controlling valves (27, 25) and mass flow controllers (19, 28, 29) for influencing at least the at least one control gas flow (S2) and the at least one compensating gas flow (S3) is set up in such a way that with the compensating gas flow (S3) at an active point (31) a locally limited influence of a flow profile of the process gas flow (S1) via the storage locations (7) by the control gas flow (S2) is compensated and / or that the sum of the locally limited control gas flow (S2) and the compensating gas flow (S3) locally assigned to it is kept at a constant value.

7. Device according to claim 5 or 6, characterized in that the control gas flow (S2) is guided through a gap (17) between the side of the susceptor (5) facing away from the storage locations and a temperature control device (13) in order to influence a heat flow to or from the susceptor (5) in a locally limited area by the control gas flow (S2) and that, based on the plane of extension of the susceptor (5), the compensating gas inlet or outlet opening (23') is arranged where the control gas flow (S2) mixes with the process gas flow (S3).

8. Device according to one of claims 5 to 7, characterized in that the compensating gas inlet opening (23') is arranged downstream of an edge (5') of the susceptor (5) adjacent to the gas outlet element (9) and / or that the compensating gas inlet or outlet opening (23') is arranged in the gas outlet element (9).

9. Device according to one of claims 5 to 8, characterized in that the storage locations (7) are arranged in a circular ring around the center of the susceptor (5) having an outer edge (5') running on a circular line, and the ring-shaped gas outlet element (9) surrounds the susceptor (5), wherein several or each of the storage locations (7) are locally assigned a control gas inlet opening (10) and a compensating gas inlet or outlet opening (23') spaced radially from the control gas inlet opening (10), through which a control gas flow (S2) or compensating gas flow (S3) individually controlled by the control device (18) flows.

10. Device according to claim 9, characterized in that the susceptor (5) is rotatably driven about an axis of rotation (A) and controlled by the control device (18) through the control gas inlet openings (10) or compensating gas inlet or outlet openings (23') synchronized with the rotation of the susceptor (5), control gases or compensating gases flow in a pulsed manner such that a process parameter is maintained at a predetermined value at each of the storage locations (7).

11. A method for treating a plurality of substrates (32), wherein a susceptor (5) arranged in a housing cavity of a reactor housing (1) is driven in rotation about an axis of rotation (A), on the susceptor (5) in a uniform circumferential distribution about the axis of rotation (A) storage locations (7) are arranged, on each of which at least one substrate (32) is arranged wherein a process gas is fed into the housing cavity through a gas inlet element (6) on the side of the susceptor (5) having the storage spaces (7), which process gas flows over the surface of the substrates (7) to the edge (5') of the susceptor (5) forming a flow profile and is led out of the housing cavity by means of a gas outlet element (9) surrounding the susceptor (5), wherein, synchronized with the rotation of the susceptor (5), a compensating gas flow (S3) of a compensating gas is fed locally into the housing cavity through a compensating gas inlet or outlet opening (23') or is pumped out of the housing cavity, characterized in that the compensating gas inlet or outlet opening (23') is arranged in such a way or the compensating gas flow flowing through the compensating gas inlet or outlet opening (23') (S3) is directed in such a waythat the flow profile above the susceptor (5) is influenced at least in the region of the edge (5') of the susceptor (5).

12. Method according to claim 11, characterized in that the compensating gas is fed radially outside the susceptor (5) into the housing cavity or into the gas outlet element (9) or is pumped out of the housing cavity or the gas outlet element (9).

13. Device with a susceptor (5) arranged in a housing cavity of a reactor housing (1), on which a plurality of storage locations (7) are arranged, each for at least one substrate (32) to be treated in the device, with a gas inlet element (6) which has one or more gas outlet openings (6') designed and arranged in such a way that a process gas flow (S1) of a process gas exiting through the one or more gas outlet openings (6') and controlled by a control device (18) flows over the storage locations (7) to form a flow profile, with a gas outlet element (9) which, on the process gas flow (S1) is arranged downstream of the storage locations (7), with which the process gas or gaseous reaction products formed during the treatment can be led out of the housing cavity, wherein at least one compensating gas inlet or outlet opening (23') opens into the housing cavity, with which a locally limited compensating gas flow (S3) of a compensating gas, controlled by the control device, can be fed into the housing cavity or pumped out of the housing cavity, characterized in that the compensating gas inlet or outlet opening (23') is arranged in such a way and the control device (18) is programmed in such a way that the feeding in or pumping out of the compensating gas influences the flow profile above the susceptor (5) at least in the region of the edge (5') of the susceptor (5).

14. Device according to claim 13, characterized in that the compensating gas inlet or outlet opening (23') is arranged radially outside the susceptor (5) or in the gas outlet member.

15. Device or method according to one of the preceding claims, characterized in that the compensating gas inlet or outlet opening (23') is assigned to the susceptor (5) and radially outside a storage location (7) the edge (5 Z ) of the susceptor (5) is arranged adjacent.

16. Device or method according to one of the preceding claims, characterized in that the compensating gas flow (S3) of a the edge (5 Z ) adjacent - with respect to the process gas flow (51) - downstream of the storage location (7) arranged compensating gas inlet or outlet opening (23 z ) originates.

17. Device or method according to one of the preceding claims, characterized in that the compensating gas flow (S3) is an adjustable mixture of gases with two different viscosities or thermal conductivities.

18. Device or method according to one of the preceding claims, characterized in that one or more outlet openings (23', 23") are arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the region of an edge (7') or a center (7") of a substrate resting on a substrate holder (7) or that the flow profile is influenced over the entire area of ​​the surface of a substrate resting on a substrate holder (7).

19. Device or method according to one of the preceding claims, characterized in that a first outlet opening (23') is arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the region of an edge (7') of a substrate resting on a substrate holder (7) and that a second outlet opening (23") is arranged and operated in such a way that the flow profile is influenced only or to a greater extent only in the region of a center (7") of a substrate resting on a substrate holder (7).

20. Apparatus or method characterized by one or more of the characterizing features of any one of the preceding claims.

Images