WO2021160785A1

WO2021160785A1 - Cvd reactor and method for handling a process chamber cover plate

Info

Publication number: WO2021160785A1
Application number: PCT/EP2021/053424
Authority: WO
Inventors: Olivier Feron
Original assignee: AIXTRON Ltd.
Priority date: 2020-02-14
Filing date: 2021-02-12
Publication date: 2021-08-19
Also published as: CN115190918A; KR20220141827A; TW202202651A; DE102020103947A1

Abstract

The invention relates to a CVD reactor comprising a housing (1), comprising a susceptor (5) bordering a process chamber (23) from below, and comprising a cover plate (6) bordering the process chamber (23) from above, wherein the cover plate (6) can be raised into a contact position on a securing section (21) of the housing (1) by means of a lifting element (11) that can be raised from a lowered position into a mounting position, wherein the cover plate (6) can be secured to the housing (1) at said securing section (21). In order to be able to automatically or semi-automatically secure the cover plate (6) to the housing (1), a lifting element (11) is provided, which either surrounds the susceptor (5) or supports same on its edge. The lifting element (11) can also be formed by a protective tube. Using the lifting element (11), the cover plate (6) can be brought into a position in which it can be removed via a loading opening (18).

Description

description

CVD reactor and method for handling a process chamber ceiling plate

Field of technology

The invention relates to a method for handling a process chamber of a CVD reactor upwardly limiting ceiling plate, in particular for fully or semi-automatic replacement of the ceiling plate.

The invention also relates to a further development of a CVD reactor in which the cover plate can be raised from a lowered position into an assembly position by means of a lifting element.

State of the art

A CVD reactor is previously known from DE 102012110125 A1. The ceiling plate there is a screen plate with gas passage openings arranged below a gas outlet plate of a showerhead, which is brought into the assembly position by a simultaneous vertical displacement of the susceptor and ceiling plate, the susceptor being displaced in the vertical direction by a lifting device and the screen plate on its surface wearing. Fastening means are provided which enable the ceiling plate to be fastened automatically. A similar device is described in DE 102019117479 A1. WO 2007/060143 A1 also discloses a ceiling plate fastened with retaining elements below a gas outlet plate. JP 5721132 B2 also belongs to the prior art.

SUMMARY OF THE INVENTION [0003] The invention is based on the object of further developing the generic device and the generic method in an advantageous manner. The object is achieved by the invention specified in the claims, the subclaims not only representing advantageous developments of the independent claims of the invention, but also independent solutions to the problem.

First and foremost, it is proposed that a body surrounding the susceptor is used as the hub element or that a body supporting the susceptor at its edge is used as the hub element. The body can be in one piece or in several pieces. The body surrounding the susceptor can be a closed body or a body interrupted in the circumferential direction. The lifting element can be a pipe, for example. The body can be formed from a plurality of partial bodies lying next to one another in the circumferential direction, so the body can, for example, have a plan corresponding to a circular ring. For example, the body can have an annular outline. The body can, however, also be formed by a plurality of rods, columns or the like which extend in the vertical direction and which are arranged at different azimuthal positions around the susceptor or a heating device. In a preferred embodiment of the invention, the lifting element can be formed by a support element carrying the susceptor, as is previously known, for example, from DE 102007027704 A1. The support element can have an upper edge and the shape of a tube. A susceptor is supported on the upper edge in a process position. The edge of the susceptor rests on the upper edge. In order to use this support element for lifting the ceiling plate, the susceptor is first brought out of the housing of the CVD reactor through a loading opening. For this purpose, a gate that closes the loading opening is opened. It can be provided that for this purpose an annular gas outlet member surrounding the susceptor must also be lowered so that it does not lie in the movement path of the susceptor which is moved in its plane of extension. The lifting element can be on a vertical be attached displaceable carrier device. The carrier device can be displaceable in the vertical direction. The carrier device can also carry the heating device with which the susceptor is heated from below in the process position. In a variant of the invention, the gas outlet organ can perform the function of the lifting element. In a preferred variant, the mounting of the ceiling plate takes place automatically and, in particular, fully automatically. In particular, provision is made for the ceiling panel to be exchanged semi-automatically or fully automatically. In a variant of the invention, the cover plate can be attached to a cover of the housing which closes an upwardly facing housing opening. A gas inlet member in the form of a showerhead can be attached to this cover. The cover plate can be a protective plate which extends parallel to a gas outlet surface of the gas inlet element. The gas outlet surface can have a multiplicity of gas outlet openings opening in the direction of the cover plate. A gap can be located between the gas outlet surface and an upper side of the cover plate having gas passage openings, in which the gas emerging from the gas outlet surface can be distributed. The edge of the ceiling plate te can form a sealing bead that rests in the assembled position of the ceiling plate sealingly on the fastening portion, for example on a fastening ring or the like. The ceiling plate can be fastened by means of fasteners, for example screws, bayonets or the like, on the section. The fastening means or a plurality of fastening means can also be arranged outside an outer ring zone of the ceiling plate. Fastening means can be seen on the entire surface of the cover plate in order to connect it to the cover or the gas inlet element. They can also be arranged near the center of the ceiling tile. These fastening means are preferably designed in such a way that they allow a slight lateral displacement of the plate relative to the gas inlet element without blocking. This means that different thermal expansions can be compensated for. In a first variant of the invention, when exchanging the Ceiling plate a ceiling plate used in previous separation processes, on which deposits have formed, exchanged for a cleaned ceiling plate. For this purpose, the lifting element can be brought into a raised position in which it supports the ceiling plate attached to the fastening section. Fastening means, with which the ceiling plate is attached to the fastening section, are solved in this position in which the lifting element rests against the ceiling plate. By lowering the lifting element, the ceiling plate is brought into a position in which it can be gripped by means of a gripper reaching through the loading opening into the interior of the housing in order to be able to be removed from the loading opening from the interior. The cleaned ceiling panel is attached to the section in the reverse order. In a second variant of the invention, a cover which closes an opening in a housing and carries the cover plate is raised.

In the raised position, temporary fasteners are used to hold the ceiling panel to the fastening section. Screws or other fasteners with which the ceiling plate is fastened to the section fixing, can be solved manually or automatically. The cover is then lowered to a position in which the cover plate is supported by the lifting element. In this position, the temporary fastening means are released. By lowering the lifting element, the cover plate is released from the fastening section and brought into a position in which it can be gripped by the gripper. The cleaned ceiling panel is placed on the lifting element. The latter is brought into a raised position in which the ceiling plate rests on the fastening section, where it is fastened with the temporary fasteners. The lid can be raised further to a position in which the screws or other fasteners can be installed on it. The temporary fasteners are removed. The lid can be brought into its closed position. C-shaped brackets can be used as temporary fastening means, with which the ceiling panel is temporarily attached to the fastening section, in particular to the cover. will hold. The transport of the ceiling plate from the interior or into the interior can be done with a robot arm that can reach through the loading opening. In the case of fully automatic assembly, the ceiling panel is connected to the fastening section with automatically actuated fasteners. In the case of semi-automatic assembly, temporary fastening means, for example C-shaped brackets, are used with which the ceiling panel is temporarily fastened to the fastening section. This is preferably done with a cover in the first open position, the cover plate being brought by the lifting element over the upper edge of the housing opening so that the edge of the cover plate is accessible to which the temporary fastening means can be attached. Subsequently, during the semi-automatic assembly, the cover is raised further until the downward-facing broad side surface of the cover plate is accessible in order to attach the fastening means there, which can be threaded elements, for example. These intermediate steps are not required with fully automated assembly. The ceiling plate can be installed with the cover closed. After the fastening means have been fastened, the lifting element can be lowered. If a support element carrying the susceptor in the process position is used as the lifting element, the susceptor must be removed from the process chamber before the cover plate is replaced. This takes place after a lowering of the gas outlet element located in the process position in the movement path of the susceptor to be removed. After the cover plate has been replaced, a susceptor equipped with substrates to be coated can be brought into the process chamber through the loading opening via the lowered gas outlet element. This is done with a robot arm that places the susceptor on the support element. The gas outlet element is then raised until an upper edge of the gas outlet element abuts the edge of the cover plate or a section of the housing surrounding the cover plate. The ceiling plate, which can consist of quartz, steel, in particular stainless steel, or a ceramic material, has passage openings for a product to pass through. process gas that is fed into the gap between the ceiling plate and the gas inlet element. The lifting element surrounding the susceptor can be made of steel, in particular special stainless steel, quartz or a ceramic material. It can be formed by a tubular body, in the cavity of which a heating device for heating the susceptor is arranged. The heating device can be moved vertically together with the lifting element. In the process position, the lifting element can also perform the function of a liner, with which a space arranged below the susceptor is shielded from the process gases. The lifting element can thus form the function of an umbrella tube.

The invention also relates to a further development of the ceiling plate. The cover plate has near its edge an annular bead directed towards the gas inlet element or the gas outlet plate. This annular bead defines a gap between the gas outlet plate and the ceiling plate. The annular bead is preferably in sealing contact with a flat underside of the gas inlet element or the gas outlet plate formed by the gas inlet element. The gas outlet plate can have a beveled edge surface in the area of the bead. The bead extends in the area of this beveled edge surface. The bead prevents the process gas fed into the gap from escaping to the side.

Another aspect of the invention relates to a development of the cover of the housing. The gas inlet element is an integral part of the housing cover. For this purpose, the housing cover forms an annular web which is integrally molded onto the cover plate of the cover as a single material. The ring web has a radially outwardly facing wall which, when the cover is installed, rests against an inner surface of a wall of the housing. The ring web also has a radially inwardly directed surface on which an outer edge cut of the gas inlet element. The gas inlet element is preferably surrounded by the annular web and is enclosed by the annular web.

Brief description of the drawings

Embodiments of the invention are explained below with reference to attached drawings. Show it:

Fig. 1 in the manner of a cross-section a CVD reactor in a process position in which a process chamber 23 is delimited at the bottom by a susceptor 5 and at the top by a cover plate 6, the process chamber 23 being surrounded by a gas outlet element 3 , Fig. La enlarges the section Ia,

Fig. 2 shows a representation according to Figure 1, but with lowered gas outlet member 3,

3 shows an illustration according to FIG. 2, in which the susceptor 5 is removed through a loading opening 18,

4 shows a representation according to FIG. 3, in which the cover 2 is brought into a first open position, in which it is located approximately 20 to 30 mm above an edge 24 'of the opening 24 of the housing 1, with temporary fastening means 19 being attached who, for the temporary fixation of the ceiling plate 6 on the cover 2,

FIG. 5 shows an illustration according to FIG. 4, the cover 2 being brought into a second open position, 6 shows an illustration according to FIG. 5, with threaded elements 20, with which the cover plate 6 are fastened to the cover 2, being loosened and the cover plate 6 is only held on the cover 2 by means of the temporary fastening means 19, FIG. 7 shows an illustration according to FIG 6, the top plate 6, which is only held on the cover 2 by means of the temporary fastening means 19, is brought into the first open position, with an upper edge of a lifting element 11 supporting the top plate 6,

8 shows an illustration according to FIG. 7, the temporary fastening means 19 having been removed so that the ceiling plate 6 is only supported by the lifting element 11,

9 shows an illustration according to FIG. 8 after the lifting element 11 has been lowered into a position in which the cover plate 6 has detached itself from the cover 2 and can be removed through the loading opening 18 by means of a gripping arm,

10 shows a representation according to FIG. 9, in which the interior 22 contains neither a susceptor nor a cover plate 6 before a cleaned cover plate is brought into the interior 22, which is attached to the cover 2 in essentially the reverse order,

Fig. 11 shows a representation according to Figure la of a second embodiment, for example, in which the gas outlet member 3 performs the function of a lifting element. Description of the embodiments

FIG. 1 shows schematically in the form of a cross section through a CVD reactor its essential components. The CVD reactor has a gas-tight housing 1 which has an opening 24 pointing upwards.

In the process position shown in FIG. 1, the opening 24 is closed by a cover 2. The cover 2 carries a gas inlet element 4 in the form of a showerhead. The gas inlet element 4 has a gas distribution volume which is delimited at the bottom by a gas outlet plate 21 which, with its underside, forms a gas outlet surface. The gas outlet plate 21 has a multiplicity of gas outlet openings 17 with which gas can exit from the gas distribution chamber 17 into a gap 15. The gap 15 extends between the gas outlet plate 21 and a cover plate 6 which is arranged below the gas inlet element 4. One edge of the essentially circular disk-shaped cover plate 6 has a bead 14 which is supported on an edge section of the gas outlet plate 21, the height of the bead 14 defining the height of the gap 15. To define the gap, however, further spacer elements can also be provided, which are not shown in the drawings and are arranged within the area surrounding the bead 14. With such distance elements, thermal deformations can be compensated. The height of the gap 15 can also be limited by other spacer elements. The cover plate 6 has a plurality of gas passage openings 16 through which the gas that has entered the gap 15 can flow into a process chamber 23 arranged below the cover plate 6. While the cover plate 6 delimits the process chamber 23 towards the top, a susceptor 5 delimits the process chamber 23 towards the bottom.

The edge of the cover plate 6 can in the area in which the circumferential bead 14 is arranged, have a smaller material thickness than in the central area, the material thickness preferably being on the upper side. is reduced, so that an outwardly rising gap to the gas inlet member can result. The material thickness can also be reduced on the upper side, so that there is an outwardly rising gap to the gas inlet element.

The edge of the susceptor 5 rests on a support element which, in the exemplary embodiment, can have the shape of a tube. It can in particular be formed by a protective tube 11. The protective tube 11 surrounds an arrangement with a heating device 7, which is located below the susceptor 5 and which has a carrier plate 12 for supplying power to the Heizein direction 7 will. The tube 11, on which the edge of the susceptor is supported, has the function of a support tube in a variant of the invention. The tube 11 forms the carrier of the susceptor 5.

The process chamber is surrounded by an annular gas outlet element 3. With a further lifting device, the gas outlet element 3 can be lowered from a process position shown in FIG. 1, in which it is arranged in front of a loading opening 18, into a position in which the loading opening 18 is free. In this position shown in FIG can be removed in order to be exchanged for another susceptor 5. An element denoted by the reference number 9 forms a gas outlet pipe with which the gas which is collected in the gas outlet element 3 can be transported to the outside. The egg designated in the drawings with the reference number 9 However, ment can also clarify the further lifting device with which the gas outlet element 3 can be lowered and raised.

In a fully automated replacement of the ceiling plate 6 moves a the edge region of the ceiling plate 6 reaching under lifting element 11, which is formed in the embodiment of the protective tube, up to support the ceiling plate 6 so that they on the cover 2 or the gas inlet organ 4 holding fasteners can be automatically released, as is proposed, for example, in the prior art mentioned at the beginning. Subsequently, the ceiling plate 6 is brought into a removal position by lowering the Hubelemen tes 11, in which it can be removed from the inner space 22 by means of a gripping arm engaging through the Bela deloch 18 in the interior 22. A replaced cover plate 6 is fastened to the cover 2 or to the gas inlet element 4 in the reverse order. The ceiling plate 6 is placed on the lifting element 11. The lifting element 11 is raised until the cover plate 6 or the bead 14 rests on the gas inlet element 4 or on the cover 2. Then the fastening means are brought into a fastening position. Additional centering means can be provided with which the ceiling plate 6 can be brought into a centered position. The centering means can, however, also be formed by the fastening means.

In order to replace the ceiling plate 6 semi-automatically, the cover 2 is raised into the first open position shown in Figure 4, in which the cover is arranged in particular with the lifting element 11 about 10 to 30 mm above an opening edge 24 '. In this first open position, C-shaped brackets 19 are attached to the cover plate 6 which is fastened to a fastening section 21 of the cover 2 with screws 20 (see FIG. 6). The cover 2 is then inserted into the second opening shown in FIG. Position brought. Alternatively, the cover 2 can also be brought directly into the open position shown in FIG. 5 in order to fasten the temporary fastening means formed by the C-shaped brackets 19 there.

Figure 6 shows how the above screws 20, with which the cover plate 6 are permanently attached to the cover 2, are solved in the second open position. The cover 2 is lowered into the first open position with the cover plate 6, which is only held by the clamps 19. The protective tube 11, which in this exemplary embodiment has the function of a lifting element, was brought into a raised assembly position in which the upper edge of the lifting element 11 supports the cover plate 6. The clamps 19 are removed so that the operating position shown in FIG. 8 is reached, in which the cover plate 6 is only supported by the lifting element 11. The cover 2 can be held temittel in this position by not shown further Hal.

By lowering the lifting element 11, the operating position shown in Figure 9 is reached, in which the ceiling plate 6 lies in a plane in which the loading opening 18 is, so that the ceiling plate 6 by a shift in its plane of extension by means of a not Darges split gripping arms can be removed through the loading opening 18 from the interior 22.

A cleaned ceiling panel 6 is attached to the cover 2 in essentially the reverse order. For this purpose, a cover plate 6 is brought into the interior 22 of the housing 1, which has an operating position according to FIG. The cover plate 6 is placed on the Hubele element 11 according to FIG. The lifting element 11 is shown in FIG. raised fenposition, in which the cover plate 6 on the gas inlet element 4 or rather on the cover 2 rests. The temporary fastening means 19 shown in FIG. 7 are attached, which hold the cover plate 6 on the cover 2. Any centering that may be required can be carried out. The cover 2 is raised into the second position shown in FIG. 6, in which the screws 20 or other fastening means are attached with which the cover plate 6 is permanently fastened to the cover 2. As an alternative to this, the centering of the ceiling plate 6 can also take place with the permanent fastening means 20.

The clips 19 can be removed. However, it is also possible to lower the cover 2 beforehand into the position shown in FIG. 4 in order to remove the clips 19 in this position. The cover 2 is then lowered into the closed position shown in FIG. The lifting element 11 is brought into a lowered order. In this a new susceptor 5 can be brought through the loading opening 18 into the interior 22, where it is placed on the lifting element 11.

FIG. 11 shows, in a representation according to FIG. La, a variant of the invention in which the edge of the cover plate 6 can be supported by an upper section of an annular gas outlet element 3. In this variant, the gas outlet element 3 can not only be lowered from the lowered position shown in FIG. The gas outlet element 3 can also be brought from the process position shown in FIG. 1 into a raised position, not shown, in which it protrudes over the edge 24 'in order to bring the cover plate 6 into a raised position. Figures 1 and la show an annular web 25 formed from the underside of the lid, which is integrally formed of the same material of the lid plate made of metal. This annular web 25 has a radially outwardly white transmitting surface which rests against a surface of the wall of the housing 1. When the cover is closed, the annular web 25 protrudes into the opening 24.

The annular web 25 surrounds the gas inlet element 4. The annular web 25 forms a circular receiving chamber in which the gas inlet element 4, which is attached to the underside of the cover 2, rests. An outer edge section 26 of the gas inlet element 4, which is preferably formed as one material from the gas outlet plate 21, has a radially outwardly facing wall which rests against the radially inwardly facing wall of the annular web 25. The height of the annular web 25 preferably corresponds to the height of the gas inlet element 4, so that the surface of the gas inlet element 4 facing the process chamber 23 runs flush with the surface of the annular web 25 pointing in the axial direction.

FIG. 1 a shows that the surface of the cover plate 6 facing the gas inlet element 4 runs obliquely in the edge region, so that the material thickness of the cover plate 6 is reduced in a wedge shape at the edge. The above-described bead 14, which is in contact with the gas inlet organ 4 or the gas outlet plate 21, extends into this area. In the embodiment example, the circular bead 14 rests on the outer edge portion 26. The bead 14 prevents process gas which enters the gap 15 through the gas outlet openings 17 from exiting the gap 15 laterally.

[0023] The above explanations serve to explain the inventions covered by the application as a whole which, at least by means of the following combinations of features, represent the state of the art in each case also independently. dig further, whereby two, more or all of these combinations of features can also be combined, namely:

A CVD reactor, which is characterized in that the lifting element 11 is formed by one or more bodies surrounding the susceptor 5 or supporting it at its edge.

A method which is characterized in that the lifting element 11 is formed by one or more bodies surrounding the susceptor 5 or supporting it at its edge.

A CVD reactor or a method, which is characterized in that the lifting element 11 is a support element carrying the susceptor 5 or a gas outlet element 3 surrounding the susceptor 5.

A CVD reactor or a method, which is characterized in that the lifting element 11 has an annular plan and / or that the lifting element 11 has the shape of a tube. A CVD reactor or a method, which is characterized in that the fastening portion 21 is formed by a cover 2 closing an upper opening 24 of the housing 1 and the lifting element 11 can be raised into a position in which at least one upper portion of the Hubelemen tes 11 over the edge 24 'of the opening 24 protrudes to the outside. A CVD reactor or a method, which is characterized in that the cover plate 6 with temporary and / or permanent fastening means 19, 20 can be fastened to the fastening section 21 or is fastened and / or that the cover plate 6 is a gas inlet member 4th or has circumferential annular bead 14 facing the gas outlet plate 21, which rests in sealing contact with the gas inlet element 4 or the gas outlet plate 21 and / or that the cover 2 has an annular web 25 which protrudes into the opening 24 and surrounds the gas inlet element 4.

A CVD reactor or a method, which is characterized in that the fastening section 21 is a gas inlet element 4 or surrounds a gas inlet element 4, the gas inlet element 4 having a plurality of gas outlet openings 17 which extend into a gap 15 between the Ceiling plate 6 and a gas outlet surface of the gas inlet element 4 open, with the ceiling plate 6 having gas passage openings 16.

A CVD reactor or a method, which is characterized in that the gas outlet element 3 can be displaced from a process position lying in the movement path of the susceptor 5 or the cover plate 6 into a lowered position.

A CVD reactor or a method, which is characterized in that the fastening portion 21 is assigned to an opening 24 of the housing 1 ver closing cover 2, and for mounting the cover plate 6 of the cover 2 before or when lifting the cover plate 6 is brought into a first open position, and after lifting the ceiling plate 6 supported by the lifting element 11 is fastened to the cover 2 with first fastening means 19, and then after lifting the cover 2 in a second position, during which the ceiling plate 6 separates from the lifting element 11, is attached to the cover 2 with second fastening means 20 and / or that, to remove the cover plate 6, the cover 2 is first brought into a first open position, in which the first fastening means 19 are attached to the cover 2, and after lifting of the cover 2 in a second open position second fastening means 20 are released and then the cover 2 is brought back to the first open position in which the cover plate 6 rests on the lifting element 11, in which position the first fastening means tel 19 are removed.

All the features disclosed are essential to the invention (individually, but also in combination with one another). In the disclosure of the application, the disclosure content of the associated / attached priority documents (copy of the previous application) is hereby fully included, also for the purpose of including features of these documents in the 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 on the basis of these claims. The invention specified in each claim can additionally have one or more of the features provided in the above description, in particular provided with reference numbers and / or specified in the list of reference numbers. The invention also relates to design forms in which some of the features mentioned in the preceding description are not implemented, in particular insofar as they are recognizable for the respective purpose or can be replaced by other technically equivalent means.

List of reference symbols

1 housing 21 gas outlet plate, fastening

2 cover section

3 gas outlet member 22 interior

4 gas inlet element 23 process chamber

5 susceptor 24 opening

6 ceiling plate 24 'edge of the opening

7 heating device 25 ring web

8 shaft 26 outer edge section

9 Lifting device, outlet pipe

10 lifting device

11 Lifting element, protective tube

12 support plate

13 carriers

14 bead

15 gap

16 gas passage opening

17 Gas outlet opening, gas distribution chamber

18 Loading opening

19 Retaining clip, fastening means

20 screw, fasteners, threaded element

Claims

Expectations

1. CVD reactor with a housing (1), with a susceptor (5) delimiting a process chamber (23) at the bottom and with a cover plate (6) delimiting the process chamber (23) at the top, the cover plate (6 ) by means of a lifting element (11) that can be raised from a lowered position into an assembly position into a contact position on one

Fastening section (21) can be raised, on which fastening section (21) the cover plate (6) can be fastened to the housing (1), characterized in that the lifting element (11) of one or more surrounding the susceptor (5) or on its Edge supporting bodies is formed.

2. Method for handling a process chamber (23) of a CVD

Reactor delimiting, above a susceptor (5) arranged ceiling plate (6) with the following steps:

1. Depositing the cover plate (6) on one in the housing (1) angeordne th lifting element (11);

2. Lifting the lifting element (11) carrying the ceiling plate (6) into an assembly position;

3. Attaching the ceiling plate (6) to a fastening section (21) of the housing (1);

4. Lowering the lifting element (11) into a lowered position; and or

5. Raising the lifting element (11) from a lowered position into an assembly position;

6. Detaching the cover plate (6) from a fastening section (21) of the housing (1);

7. Lowering of the lifting element (11) carrying the ceiling plate (6) into the lowered position;

8. Removing the cover plate (6) from the lifting element (11), characterized in that the lifting element (11) is formed by one or more Ren the susceptor (5) surrounding or supporting bodies at its edge.

CVD reactor or method according to one of the preceding claims, characterized in that the lifting element (11) is a support element carrying the susceptor (5) or a gas outlet element (3) surrounding the susceptor (5).

CVD reactor or method according to one of the preceding claims, characterized in that the lifting element (11) has a circular shape and / or that the lifting element (11) has the shape of a tube.

CVD reactor or method according to one of the preceding claims, characterized in that the fastening section (21) is formed by a cover (2) closing an upper opening (24) of the housing (1) and the lifting element (11) extends into a Position can be raised in which at least an upper section of the lifting element (11) protrudes outward over the edge (24 ') of the opening (24).

CVD reactor or method in particular according to one of the preceding claims, characterized in that the cover plate (6) can be or will be fastened to the fastening section (21) with temporary and / or permanent fastening means (19, 20) and / or that the Cover plate (6) has a circumferential annular bead (14) pointing towards the gas inlet element (4) or towards the gas outlet plate (21), which is in sealing contact with the gas inlet element (4) or the gas outlet step plate (21) rests and / or that the cover (2) has an annular web (25) which protrudes into the opening (24) and surrounds the gas inlet device (4).

CVD reactor or method according to one of the preceding claims, characterized in that the fastening section (21) is a gas inlet element (4) or surrounds a gas inlet element (4), the gas inlet element (4) having a plurality of gas outlet openings (17) which open into a gap (15) between the cover plate (6) and a gas outlet surface of the gas inlet element (4), the cover plate (6) having gas passage openings (16).

CVD reactor with a housing (1), with a susceptor (5) delimiting a process chamber (23) at the bottom, with a cover plate (6) delimiting the process chamber (23) at the top and with a susceptor (5) surrounding the susceptor Gas outlet element (4), wherein the housing (1) has a loading opening (18) through which the susceptor (5) or the ceiling plate (6) with a movement that extends in the direction of its / their surfaces into the interior (22) of the housing (1) can be brought, characterized in that the gas outlet element (3) can be displaced from a process position lying in the movement path of the susceptor (5) or the cover plate (6) into a lowered position.

Method according to one of Claims 2 to 7, characterized in that the fastening section (21) is assigned to a cover (2) which closes an opening (24) in the housing (1), and the cover (2) for mounting the cover plate (6) ) is brought into a first open position before or when lifting the ceiling panel (6), and after lifting the ceiling panel (6) carried by the lifting element (11) with first fasteners fastening means (19) is fastened to the cover (2), and then after lifting the cover (2) into a second open position, during which the cover plate (6) separates from the lifting element (11), with second fastening means (20) on the Cover (2) is attached. 10. The method according to any one of the preceding claims, characterized in that in order to remove the cover plate (6) first the cover (2) is brought into a first open position in which the first fastening means (19) are attached to the cover (2), and after the cover (2) has been raised into a second open position, second fastening means (20) are released and then the cover (2) is brought back into the first open position in which the cover plate (6) rests on the lifting element (11) lies, in which position the first fastening means (19) are removed.

11. CVD reactor or method, characterized by one or more of the characterizing features of one of the preceding claims.