DE102023100077A1 - Device and method for treating substrates - Google Patents

Abstract

The invention relates to a device and 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 evenly over the storage locations (7) to a gas outlet element (9) arranged downstream of the storage locations (7) in relation 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. In order to compensate for the locally limited 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 limited compensating gas flow (S3) of a compensating gas flows.

Description

Field of technology

The invention relates to a method for treating a plurality of substrates that are arranged on storage locations of a susceptor arranged in a housing cavity of a reactor housing. A process gas flow of a process gas is fed into the housing cavity from gas outlet openings of a gas inlet element. This is done in such a way that the process gas flows essentially evenly over the storage locations to a gas outlet element arranged downstream of the storage locations in relation to the process gas flow. The process gas is guided out of the housing cavity by the gas outlet element. At least one control gas inlet opening opens into the housing cavity, with which a locally limited control gas flow of a control gas is fed into the housing cavity.

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

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. Storage locations are arranged on the susceptor in a uniform circumferential distribution around the axis of rotation, on each of which at least one substrate is arranged. A process gas is fed into the housing cavity through a gas inlet element arranged in the center of the housing cavity in such a way that it flows over the storage locations of the susceptor to an edge of the susceptor. The process gas is led out of the housing cavity by means of a gas outlet element surrounding the susceptor. The process gas flowing over the side of the susceptor having the storage locations forms a lateral flow profile. A compensating gas is locally fed into the housing cavity or pumped out of the housing cavity through a compensating gas inlet or outlet opening.

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

The EN 10 2019 104 433 A1 describes a device and a method for depositing layers on substrates of the generic type. A susceptor arranged below a process chamber is tempered from below with a tempering device. The tempering device is an RF coil that has a cavity through which a coolant flows. A control gas flow can be fed in between the tempering device and the side of the susceptor facing away from the process chamber. There, the control gas flow forms a tempering gas flow with which a heat flow from the susceptor to the cooled RF coil can be adjusted in order to locally influence the temperature at a storage location of a substrate.

The EN 10 2018 124 957 A1 describes a device and a method for depositing layers on substrates, wherein the storage locations are formed by substrate holders that are supported on a gas cushion, wherein the gas cushion is 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 upstream of the substrate holder, wherein the sum of the compensating gas flow and the control gas flow is kept constant.

The US6,531,069 B1 describes a CVD reactor with a gas inlet element in the form of a showerhead that extends over the entire lateral surface of a process chamber. The susceptor arranged below the showerhead is surrounded by a gas inlet element that has gas outlet openings only over a partial circumference. The gas outlet openings are assigned to a rotating gas outlet ring.

The US8,152,925 B2 describes a CVD reactor with a gas inlet element designed as a showerhead and a storage area for a substrate arranged underneath. The substrate is surrounded by a gas outlet ring which has a large number of gas outlet openings. The gas outlet ring also has a large number of gas outlet openings from which a compensating gas can be fed into the housing cavity of the CVD reactor.

The EN 10 2020 107 517 A1 describes a device for thermally treating substrates in a susceptor that is driven in rotation about a rotation axis, wherein gas supply lines are arranged in the susceptor that exit from the underside of the susceptor facing the heating device. Each of the substrates is locally assigned an outlet opening arranged on the underside.

In a process as described above, the process gas flow can vary greatly depending on the type of process carried out in the process chamber. For example, in When depositing III-V semiconductor layers and in particular when depositing layers containing indium and/or phosphorus or layers containing gallium and/or arsenic, it may be necessary to use very low process gas flows so that the process gas flows at a relatively low flow rate over the side of the susceptor facing the process chamber. If, in such a process, a tempering gas flow also flows along the opposite side of the susceptor and this tempering gas flow flows into the process gas flow, the flow profile, i.e. 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 the layer thickness of the deposited layer.

However, the flow profile of the process gas flow through the process chamber is also influenced by other circumstances, for example by a non-exactly central arrangement of a gas inlet element or by a slight tilting of the susceptor which is driven to rotate about a rotation axis or by a non-homogeneous suction effect of a gas outlet element which is connected to a vacuum pump in order to set a negative pressure within the housing cavity of the CVD reactor.

Summary of the invention

The invention is based on the object of specifying means by which the flow profile can be influenced at least in the region of the edge of the susceptor.

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

First and foremost, it is proposed to arrange a compensating gas inlet or outlet opening downstream of the susceptor in order to either feed a locally limited compensating gas flow into the housing cavity or to pump it out of the housing cavity through this opening. With this compensating gas flow, an additional gas flow can be fed into the housing cavity or pumped out of it, which influences the flow profile of the process gas flow over the susceptor at least at its edge. With the compensating gas flow, the local total pressure within the housing cavity, which is partly responsible for the formation of the flow profile, can be influenced locally. With the compensating gas flow, however, an additional impulse can also be introduced into the gas flow, which causes a locally limited dynamic influence on the flow profile. With this balancing gas flow, a locally limited effect of a control gas flow, which is limited to one point of action, for example, can be compensated in such a way that, for example, the sum of the locally limited control gas flow and the balancing gas flow locally assigned to it is kept at a constant value. However, the balancing gas flow can also be used to reduce inhomogeneity in the flow profile that is due to other causes by feeding in a locally limited balancing gas flow.

The control gas flow can be a mixture of several gases, in particular of two gases. The gases can have a different viscosity of thermal conductivity. For example, the two gases can be hydrogen and nitrogen. Each of the several gases can be fed into the gas supply line in a controlled manner using a mass flow controller assigned to it, so that a compensating gas with a defined viscosity of thermal conductivity can act in an effective location. This is particularly advantageous if the control gas flow can also be composed of gases with different viscosities of thermal conductivity, for example a mixture of hydrogen and nitrogen. The compensating gas flow can also be given a specific direction, whereby this direction can be a direction towards the gas outlet element, a direction towards the process chamber or process chamber ceiling or a direction in the circumferential direction of the susceptor. It is also possible to provide the compensating gas inlet or outlet opening in a fixed location on the housing. It can also be provided that the compensating gas inlet or outlet opening is assigned to the susceptor. In a rotating susceptor, the compensating gas inlet or outlet opening rotates with it. It remains stationary and assigned to one of the substrates. It can be provided that each of the substrates is assigned a compensating gas inlet or outlet opening. This compensating gas inlet or outlet opening can be assigned to the top of the susceptor that faces upwards. However, the opening can also be arranged radially on the narrow edge of the susceptor that faces outwards. It is also possible to arrange the opening on the underside. The compensating gas inlet or outlet opening is preferably adjacent to the edge of the susceptor. Here, too, it can be provided that the opening gives the compensating gas flow a direction.

In a first variant of the invention, a method is proposed in which a plurality of substrates are stored in storage locations of a storage device arranged in a housing cavity of a reactor housing. Susceptor. A substrate can lie on one of the storage locations. However, several substrates can also lie on one of the storage locations. The storage locations can be formed by substrate holders that are supported by a gas cushion that is used to rotate the substrate holders. 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 that borders on a gas outlet element through which the process gas or reaction products that form during treatment of the substrates are led out of the housing cavity. This can be done by means of a vacuum pump that is connected to the gas outlet element via a suction line. The gas outlet openings are arranged in such a way that the process gas flow is as uniform as possible over the substrates arranged in the flow direction of the process gas between the gas inlet element and the gas outlet element. In a rotationally symmetrical arrangement around a central gas inlet element, a rotationally symmetrical flow profile should be formed as far as possible. It can be provided that a control gas is fed into the housing cavity. This takes place through a control gas inlet opening that opens into the housing cavity. A single control gas inlet opening can be provided. However, several control gas inlet openings can also be provided. 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 a heat flow from a temperature control device to the susceptor or from the susceptor to the temperature control device. This can be done in particular if the control gas is a tempering gas that flows between the tempering device and the susceptor. This is preferably done locally. The control gas can be a mixture of a gas with high thermal conductivity and a gas with low thermal conductivity, so that the heat flow between the tempering device and the susceptor can be influenced by the composition of the control gas. The tempering device can be an RF heater with which eddy currents are generated within the susceptor in order to heat the susceptor. The RF heater can be formed by a tube running spirally below the susceptor, through which a cooling liquid flows, so that the tempering device can also perform a cooling function, whereby the heat flow from the susceptor to the tube can be influenced by the tempering gas. The mass flow of the tempering gas can also be changed. The tempering gas enters the housing cavity through the control gas inlet opening, particularly in the area of the edge of the susceptor, where it can mix with the process gas flow. The local influence on the flow profile by feeding the control gas into the process gas flow is compensated according to the invention by the compensating gas flow.

It can be advantageous if the susceptor is driven to rotate about its axis of rotation. The susceptor can have a large number of bearing locations arranged in a uniform circumferential distribution on a circular arc around its center. At least one control gas inlet opening can be arranged in a stationary manner such that a control gas flow is fed into the housing cavity at a fixed location relative to the reactor housing. The control gas can first pass through a gap between the temperature control device and the susceptor, acting as a tempering gas. In order to thermally influence only certain bearing locations, the tempering gas can flow through the control gas inlet opening into the housing cavity in a manner synchronized with the rotational movement of the susceptor. According to the invention, it is proposed that the control gas inlet opening be locally arranged with a compensation gas outlet opening arranged at a fixed location on the reactor housing, through which the compensation gas flow is fed. It can be provided that further balancing gas outlet openings are provided, each arranged at a fixed location - in relation to the reactor housing - through which a balancing gas flow can be fed into the housing cavity. It can be provided that the multiple balancing gas outlet openings are arranged in the same circumferential distribution around the center of the susceptor in which the storage locations are arranged. By lowering one of the balancing gas flows, an increase in a control gas flow can thus be compensated. In a variant, however, it can also be provided that the balancing gas flow is led out of the housing cavity through a balancing gas outlet opening. For this purpose, the balancing gas outlet opening can be connected to a vacuum line through which gas can be pumped out of the housing cavity. This can also be done synchronized with the rotation of the susceptor.

According to a preferred development of the invention, it is proposed that the compensating gas inlet or outlet opening opens into the gas outlet element, so that either a locally limited compensating gas flow can be fed into the gas outlet element or a locally limited compensating gas flow can be pumped out of the gas outlet element. The active point at which the process gas mixes with the control gas can also be located in the gas outlet element. The control gas inlet opening can also flow directly into the gas outlet element. However, it is also provided that the control gas inlet opening flows into the housing cavity upstream of the gas outlet element. It can also be provided that the process gas contains a reactive gas with elements of main group III and a reactive gas with elements of main group V. However, the process gas can also contain reactive gases with elements of main group II or VI or reactive gases of an element of main group IV. The two gases, which can be formed from an organometallic compound and a hydride, are fed in together with an inert gas, for example hydrogen, through the gas inlet element, which is preferably arranged in the center of the process chamber. The process gas then flows through the process chamber, which is delimited at the bottom by the susceptor and at the top 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. This is preferably a single-crystal semiconductor layer. Preferably, several semiconductor layers with preferably different compositions and layer thicknesses are deposited on top of one another. These can be GaAs, InP, GaP, InAs layers or mixtures of these crystals. In some of these material systems, and in particular in a material system that contains As and P, the optimal flow speeds of the process gas through the process chamber are so low that the flow profile is influenced by even the smallest control flows or other structural inhomogeneities in the process chamber. Such inhomogeneities can be reduced by targeted feeding of the compensation gas.

In a second variant of the invention, the compensating gas is therefore only used to locally influence the flow profile if, in this variant, no control gas flow is fed into the housing cavity. Here too, the compensating gas flow is preferably fed in synchronized with the rotation of the susceptor. The compensating gas can be introduced into the housing cavity as well as led out of the housing cavity in order to generate a local overpressure or a local negative pressure. Here too, it can be advantageous if the compensating gas inlet or outlet opening is located in the gas outlet element in such a way that the pressure within the gas outlet element changes locally due to the change in the mass flow of the compensating gas. The compensating gas inlet or outlet opening can furthermore be arranged in the gas outlet element in such a way that the compensating gas flowing through it has no dynamic effect outside the gas outlet element, but merely leads to a local pressure change in the region of an effective point which lies radially outside the susceptor.

It can further be provided that the compensating gas inlet or outlet opening is arranged in the flow direction upstream of the gas outlet element but downstream of the susceptor in the flow direction.

It can also be provided that the gas outlet element is an annular body which has a large number of openings arranged in a ring around the center on its upper side. The openings can have a constant distance. The openings can be connected to a channel which extends over the entire circumference of the gas outlet element and which is connected at at least one, but preferably several, points to a gas line through which gas can be pumped out of the gas outlet element. It can also be provided that the gas outlet element has only a single annular opening through which the process gas and optionally the control gas can enter the gas outlet element. The compensating gas inlet or outlet openings can be arranged in the region of the bottom of the channel or in the region of a wall of the channel. Only a single compensating gas inlet or outlet opening can be provided. However, several, for example two, compensating gas inlet or outlet openings opposite one another can also be provided. 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 their circumferential distribution corresponds to that of the storage locations on the susceptor.

Short description of the drawings

• 1 schematisch einen Vertikalschnitt durch einen Bereich einer Prozesskammer eines CVD-Reaktors, in dem ein äußerer Rand 5' eines Suszeptors 5 an eine Steuergas-Einlassöffnung 10 und eine Öffnung 9' eines Gasauslassorgans 9 angrenzt, zur Verdeutlichung des sich in einer Prozesskammer oberhalb des Suszeptors 5 ausbildenden Strömungsprofils eines Prozessgasflusses S1;
• 2 schematisch in der Horizontalebene das Strömungsprofil gemäß 1;
• 3 einen Querschnitt durch ein Reaktorgehäuse 1 eines ersten Ausführungsbeispiels;
• 4 einen Schnitt gemäß der Linie IV-IV in 3;
• 5 eine Darstellung gemäß 4 eines zweiten Ausführungsbeispiels;
• 6 eine Darstellung gemäß 4 eines dritten. Ausführungsbeispiels;
• 7 eine Darstellung gemäß 4 eines vierten Ausführungsbeispiels;
• 8 eine Darstellung gemäß 4 eines fünften Ausführungsbeispiels;
• 9 eine Darstellung gemäß 4 eines sechsten Ausführungsbeispiels;
• 10 eine Darstellung gemäß 4 eines siebten Ausführungsbeispiels
• 11 eine Darstellung gemäß 4 eines achten Ausführungsbeispiels,
• 12 eine Darstellung gemäß 11 eines neunten Ausführungsbeispiels,
• 13 eine Darstellung gemäß 11 eines zehnten Ausführungsbeispiels,
• 14 eine Darstellung gemäß 10 eines elften Ausführungsbeispiels,
• 15 eine Darstellung gemäß 3 eines zwölften Ausführungsbeispiels,
• 16 eine Darstellung gemäß 3 eines dreizehnten Ausführungsbeispiels, und
• 17 eine Darstellung gemäß 4 eines vierzehnten Ausführungsbeispiels.

Embodiments of the invention are explained below with reference to the accompanying drawings. They show:

• 1 schematically a vertical section through a region of a process chamber of a CVD reactor, in which an outer edge 5' of a susceptor 5 adjoins a control gas inlet opening 10 and an opening 9' of a gas outlet element 9, to illustrate the flow profile of a process gas flow S1 forming in a process chamber above the susceptor 5;
• 2 schematically in the horizontal plane the flow profile according to 1 ;
• 3 a cross section through a reactor housing 1 of a first embodiment;
• 4 a section along line IV-IV in 3 ;
• 5 a representation according to 4 a second embodiment;
• 6 a representation according to 4 a third embodiment;
• 7 a representation according to 4 a fourth embodiment;
• 8th a representation according to 4 a fifth embodiment;
• 9 a representation according to 4 a sixth embodiment;
• 10 a representation according to 4 a seventh embodiment
• 11 a representation according to 4 an eighth embodiment,
• 12 a representation according to 11 a ninth embodiment,
• 13 a representation according to 11 a tenth embodiment,
• 14 a representation according to 10 an eleventh embodiment,
• 15 a representation according to 3 a twelfth embodiment,
• 16 a representation according to 3 a thirteenth embodiment, and
• 17 a representation according to 4 of a fourteenth embodiment.

Description of the embodiments

With the 1 and 2 The problem underlying the invention is to be explained with reference to the 3 and 4 explained:

The 3 shows a CVD reactor, as it is basically made from EN 102019104433 A1 is already known. Reference is therefore also made to the statements therein on the design and functioning of the CVD reactor. The CVD reactor has a reactor housing 1 which has side walls 3, a base 4 and a cover 2, each made in particular of metal, for example aluminum or stainless steel. This seals off a housing cavity in a gas-tight manner from the outside. In the housing cavity there is a gas inlet element 6 with which process gases can be fed into the housing cavity. The gas inlet element 6 has one or more gas outlet openings 6' which preferably extend in the circumferential direction around the gas inlet element 6 arranged in the center of the housing cavity in such a way that the gas inlet element 6 feeds a rotationally symmetrical, homogeneous process gas flow S1 into the process chamber surrounding the gas inlet element 6. A gas mixing system 20 can be used to provide process gases which are fed into the gas inlet element 6. The gas mixing system 20 can be controlled by a control device 18.

The process chamber extends below a process chamber ceiling 11 and above a susceptor 5. The susceptor 5 is carried by a carrier 12, with which the susceptor 5 can be driven in rotation about its axis of rotation A so that it rotates in a horizontal plane. The susceptor 5 carries a plurality of substrate holders 7, each of which forms a storage location. In the exemplary embodiment, the substrate holders 7 can rest on gas cushions (not shown) that are generated by a purge gas flow, with which the substrate holder 7 can also be driven in rotation about an axis of rotation B. The surface temperature of the substrate 7 can be measured with a pyrometer 21.

Below the susceptor 5 there is a heating device 13 which, in the embodiments, is formed by a spiral coil which 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.

Radially outside the susceptor 5 there is a gas outlet element 9 extending along the edge 5' of the susceptor 5, which extends on a circular arc line, with an opening 9' pointing in the direction of the edge 5' of the susceptor 5. The gas outlet element 9 is connected to a plurality of gas lines (not shown in the drawings) with a pump (also not shown) in order to suck gas out of a channel of the gas outlet element 9.

In the 3 , 8th and 9 In the embodiments shown, there is a sealing plate 8 below the underside of the susceptor 5, which 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 element 9. The sealing plate 8 is located between the heating device 13 and an underside of the susceptor 5, so that a horizontal gap 17 is formed between the sealing plate 8 and the susceptor 5. A tempering gas can be fed into this gap 17 through a gas line 14. A tempering gas flow is formed, which flows through the gap 17 in the radial direction and opens through an opening 10 into an area radially outside the edge 5' of the processor 5.

By means of two mass flow controllers 28, 29 and A mixture of H ₂ and N ₂ can be fed into the gas line 4 via a changeover valve or mixing valve 27. It exits from the feed opening 14' into the gap 17 and forms a control gas flow S2 flowing through the gap 17.

The 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 at the end of the 4 In order to thermally influence a specific storage location 7, a tempering gas is fed in pulsed fashion through the gas line 14, synchronized with the rotational movement of the susceptor 5, which flows along the flow path in order to locally influence the heat flow to one of the storage locations 7 or from one of the storage locations 7.

With another pyrometer 22, a temperature below the susceptor 5 can be measured.

The 1 and 2 show schematically the process gas flow S1 and the control gas flow S2, which mix at an active point 31, whereby the active point 31 is arranged radially outside the edge 5' of the susceptor 5 and upstream of the opening 9'. If a control gas is fed into the area of the active point 31 through the locally arranged control gas inlet opening 10, the pressure or the flow profile changes locally there, which in the 2 This is indicated schematically by the fact that the streamlines no longer run in an exact radial direction. The change in the flow profile means that the growth rate of the layer deposited on the substrate 7 is different at the edge than upstream of the edge. A crystal composition can also be different at the edge than upstream.

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

In the 3 In the embodiment shown, the control gas inlet or outlet opening 23' opens into a bottom of an annular channel of the gas outlet channel 9. The control gas flowing out of the control gas inlet or outlet opening 23' does not have to exit through the opening 9' in the direction of the effective point 31. The effect of the control gas flow S3 on the flow profile also occurs when the control gas flow S3 is only accompanied by a local and in particular pulsed pressure change at the effective point 31. Such a gas pulse can be generated with a mass flow controller 19 and, if necessary, an additional valve.

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

The 6 The third embodiment shown differs from the other two embodiments essentially in that each of the storage locations 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'.

The 7 The fourth embodiment shown differs from the previously described embodiments essentially in that each of the storage locations 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 the embodiment, there is only one control gas inlet opening 10. Nevertheless, it can also be provided here that there is an assigned control gas inlet opening 10 for each of the storage locations 7.

The 8th The fifth embodiment shown differs from that shown in the 3 illustrated embodiment 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 have such a width that the gas flow emerging from the opening 23' exerts an effect on the effective point 31.

The 9 The sixth embodiment shown differs from the ones shown in the 3 and 8th illustrated embodiments essentially in that here no compensating gas flow S3 flows into the reactor housing, but rather that here a compensating gas flow S3 is led out of the reactor housing. It is particularly provided here that a suction flow is generated with 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 element 9 in order to To generate a negative pressure locally at the point of action 31. A similar effect can be achieved with an arrangement according to 7 can be achieved if a smaller compensating gas flow S3 flows through one of the compensating gas inlet or outlet openings 23' than through all the others. The width of the opening 9' of the gas outlet element 9 can be adjusted here in such a way that the negative pressure generated via the suction line produces an effect at the effective point 31.

In the 10 In the seventh embodiment shown, the control gas inlet opening 10 is missing. No control gas flow is generated here, which would disturb the flow profile. Nevertheless, a compensating gas inlet or outlet opening 23' is provided here, with which a pressure difference can be generated locally at a circumferential location, in which either a compensating gas flow S3 is fed into the housing cavity through the compensating gas inlet or outlet opening 23', as is the case with the 10 shows, or a compensating gas flow S3 is pumped 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 element 9. This can be done either in the side wall or in the bottom. The process gas flow S1 mixes here within the gas outlet element 9 with the compensating gas flow S3. The gases in the 4 to 7 shown arrangements of the gas supply lines 23 or compensating gas inlet or outlet openings 23' can be realized. Here too, the opening 9' can have an opening width that allows the compensating gas emerging from the gas supply line 23 to act on the effective point 31.

The 11 The eighth embodiment shown differs from that shown in the 10 illustrated embodiment essentially in that the compensating gas inlet or outlet opening 23' does not open into the gas outlet element 9, but in the area of the active point 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 fact that the compensating gas flow S3 can be an adjustable mixture of different gases. With a mass flow controller 19, for example, a hydrogen flow can be fed into the gas feed line 23. With the mass flow controller 19', a nitrogen flow can be fed into the gas feed line 23. Both gases mix in the gas feed line 23, so that a compensating gas with a predetermined composition can emerge from the opening 23'.

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

In the 12 In the embodiment shown, the susceptor 5 has a gas supply line 23 which opens close to 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 as a compensating gas flow S3 downstream of the storage location 7. An end section of the gas supply line 23 gives the compensating gas flow S3 a direction obliquely upwards.

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

In 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' on the edge 5' of the substrate 5. A suction opening that rotates with the susceptor can be provided.

In the 14 illustrated embodiment, which essentially corresponds to the 10 illustrated embodiment, the compensating gas inlet or outlet opening 23' is not assigned to the gas outlet element 9. The compensating gas inlet or outlet opening 23' is rather arranged in the area of the process chamber ceiling 11. The compensating gas inlet or outlet opening 23' is arranged here downstream of the storage location 7. It can in particular be arranged downstream of the edge 5'. A gas flow emerging from the compensating gas inlet or outlet opening 23' can be directed towards the gas outlet element 9 and flow past the edge 5' of the susceptor.

Here too, it is possible to use the opening 23' as a suction opening.

The 15 The embodiment shown essentially corresponds to the one in the 3 Similar to the example shown in the 12 and 13 In the embodiment shown, the compensating gas inlet or outlet opening 23' is assigned to the susceptor 5 in a fixed position. Here, the compensating gas inlet or outlet opening 23' is located in the area of the narrow peripheral wall of the susceptor 5. However, it can also, as in the 12 and 13 shown, produce a directed flow that has not only a radial component but also an axial component.

The 16 The embodiment shown essentially corresponds to the one in the 3 However, it differs in that, as in the example shown in the 14 illustrated embodiment, 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', wherein it is preferred that the flow direction of the compensating gas flow S3 is directed towards the gas outlet element 9.

The 17 shows the arrangement of compensating gas inlet or outlet openings 23' of the embodiments of the 12 , 13 and 15 . Each of the storage locations 7 can be assigned a compensating gas inlet or outlet opening 23' downstream. The compensating gas inlet or outlet openings 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.

In each of the embodiments of this application, however, 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 openings 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.

The latter also applies to the 11 , 14 and 16 illustrated embodiments, in which the compensating gas inlet or outlet openings 23' are assigned to the housing. Here too, compensating gas inlet or outlet openings 23' can be arranged in the housing in the same angular distribution in which the bearing positions 7 are arranged on the susceptor 5.

In the embodiments shown in the drawings, the control gas inlet opening 10 is located upstream of an opening 9' of the gas outlet element 9. In embodiments not shown, the control gas inlet opening 10 can also open directly into the gas outlet element 9, for example into a wall delimiting the annular channel of the gas outlet element 9. The effective point 31 is then located within the gas outlet element 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 area of the edge 5' of the susceptor 5. This local pressure inhomogeneity can be reduced with the compensating gas flow S3, for example by feeding compensating gases S3 into the gas inlet element 6 at different circumferential positions and by feeding a smaller compensating gas flow S3 into the gas outlet element 9 where the control gas flow S2 flows into the gas outlet element 9. Alternatively, a compensating gas flow S3 can also be pumped out of the gas outlet element 9 at the point of action. It is advantageous here if the compensating gas flow S3 is fed directly into the gas outlet element 9 or pumped out directly from the gas outlet element 9.

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

The above statements serve to explain the inventions covered by the application as a whole, which also independently develop the state of the art at least through the following combinations of features, whereby two, several or all of these combinations of features can also be combined, namely:

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 the housing cavity or pumped out of the housing cavity through a compensating gas inlet or outlet opening 23'.

A method which is 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.

A method characterized in that the control gas flow S2 is directed into a region is fed between the susceptor 5 and a tempering 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 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 with a heating device 13 at which a III-V semiconductor layer is deposited on the substrates 32 in each case.

A method 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.

A device which is characterized in that downstream of the control gas inlet opening 10 and downstream of the storage location 7 in the gas outlet element 9 there 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.

A device which is 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 effective point 31 a locally limited influence on 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.

A device 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 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.

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.

A device which is characterized in that the storage locations 7 are arranged in a circular ring around the center of the susceptor 5, which has 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, which is individually controlled by the control device 18, flows.

A device which is characterized in that the susceptor 5 can be driven in rotation 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 kept at a predetermined value at each of the storage locations 7.

A method which is 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.

A method 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.

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 feeding or pumping out 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.

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 member.

A method or a device, characterized in that the compensating gas inlet or outlet opening 23' is assigned to 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' arranged 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 mutually different viscosities or thermal conductivities.

All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure content of the associated/attached priority documents (copy of the prior application) is hereby fully included in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application. The subclaims characterize, even without the features of a referenced claim, with their features independent inventive developments of the prior art, in particular in order to make divisional applications based on these claims. The invention specified in each claim can additionally have one or more of the features provided in the above description, in particular with reference numbers and/or specified in the list of reference numbers. The invention also relates to designs in which individual features mentioned in the above description are not implemented, in particular insofar as they are clearly dispensable for the respective intended use or can be replaced by other technically equivalent means.

List of reference symbols

1

Reactor housing

2

Lid

3

Side wall

4

Floor

5

Susceptor

5'

edge

6

Gas inlet organ

6'

Outlet opening

7

Substrate holder, storage space

8th

Sealing plate

9

Gas outlet device

9'

opening

10

Control gas inlet opening

11

Process chamber ceiling

12

carrier

13

Heating device

14

Gas pipeline

17

gap

18

Control device

19

Mass flow controller

19'

Mass flow controller

20

Gas supply

21

first pyrometer

22

second pyrometer

23

Gas supply line

23'

Compensating gas inlet or outlet opening

24

pump

25

Control valve

27

Changeover valve

28

Mass flow controller

29

Mass flow controller

30

Cooling channel

31

Site of action

32

Substrate

A

Susceptor rotation axis

B

Substrate holder rotation axis

S1

Process gas flow

S2

Control gas flow

S3

Compensation gas flow

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. 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

• DE 102019104433 A1 [0005, 0024]
• DE 102018124957 A1 [0006]
• US 6531069 B1 [0007]
• US 8152925 B2 [0008]
• DE 102020107517 A1 [0009]

Claims (16)

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 evenly over the storage locations (7) to a gas outlet element (9) arranged downstream of the storage locations (7) in relation to the process gas flow, with which the process gas is led 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 that 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. Procedure 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). 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 region 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). 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). Device with a susceptor (5) arranged in a housing cavity of a reactor housing (1), on which a plurality of storage spaces (7) are arranged 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 evenly over the storage spaces (7), and with a gas outlet element (9) which is arranged downstream of the storage spaces (7) in relation 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 into the housing cavity, with which a locally limited control gas flow (S2) of a control gas in the housing cavity can be fed, which can be led out of the housing cavity through the gas outlet member (9), characterized in that downstream of the control gas inlet opening (10) and downstream of the storage location (7) in the gas outlet member (9) a compensating gas inlet or outlet opening (23') opens, with which a compensating gas can be fed into the housing cavity or pumped out of the housing cavity. 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 on 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. 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 ensure 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). Device according to one of the Claims 5 until 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). Device according to one of the Claims 5 until 8th , 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. Device according to Claim 9 , characterized in that the susceptor (5) can be driven in rotation about an axis of rotation (A) and, controlled by the control device (18), control gases or compensating gases flow in a pulsed manner synchronized with the rotation of the susceptor (5) through the control gas inlet openings (10) or compensating gas inlet or outlet openings (23') in such a way that a process parameter is kept at a predetermined value at each of the storage locations (7). 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) bearing places (7) are arranged in a uniform circumferential distribution about the axis of rotation (A), 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 bearing places (7), which flows over the surface of the substrates (7) to the edge (5') of the susceptor (5) while 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 a compensating gas flow (S3) of a compensating gas is synchronized with the rotation of the susceptor (5) through a Compensating gas inlet or outlet opening (23') is fed locally 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 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). Procedure 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). 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 is arranged downstream of the storage locations (7) in relation 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, with at least one compensating gas inlet or outlet opening (23') opening 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). 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 element. Method or device according to one of the preceding claims, characterized characterized in that the compensating gas inlet or outlet opening (23') is assigned to 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') arranged 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 mutually different viscosities or thermal conductivities. Device or method, characterized by one or more of the characterizing features of one of the preceding claims.

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