Gas inlet component for CVD reactor

Abstract

The present invention relates to a sealing element for a CVD reactor. The side of the sealing element (2) facing the interior of a housing (1) sealed by a closure plate supports a ring web (25), the ring web surrounds a cavity in which a gas inlet member (3) is disposed. The front of the ring web (25) lies coplanar with the gas outlet surface (29) of the gas inlet member. The plate (32) is placed in a second cavity of a disc-shaped body (26) disposed within a first cavity (19), the first cavity being disposed on the side of the sealing element (2) facing the interior of the housing (1).

Description

Technology Field

[0001] The present invention relates to a gas inlet member, wherein the sealing element comprises a cavity in which a gas distributing volume is disposed therein, and said gas distributing volume is fluidly connected to a plurality of gas discharge openings disposed on a gas discharge surface facing the interior of a housing.

[0002] The present invention relates to a CVD reactor formed to have a gas inlet member of the above type in addition. Background Technology

[0003] U.S. Patent Application US 2004 / 0082251 A1 describes a CVD reactor having a pot-shaped housing, wherein a susceptor supporting a substrate is disposed inside the housing, and the substrate is processed within a process chamber. The cover of the process chamber is formed by a gas outlet plate comprising a plurality of gas outlet openings, and process gas can flow into the process chamber from the gas outlet openings. The gas outlet plate is formed by a gas inlet member which is an integrated component of the cover of the housing. The cover has an outer edge forming a support surface, and the cover is placed on the end face of the housing wall of the housing by the support surface. The gas inlet member has a gas distribution chamber surrounded by heated walls and is placed within the cavity of the cover.

[0004] German patent application DE 101 36 858 A1 describes a gas inlet member of a reactor for manufacturing OLEDs. The gas inlet member is equipped with a heater, and the gas inlet member can be heated to a temperature raised by the heater. Steam can be supplied into the gas distribution volume of the gas inlet member, and the steam can be discharged into a process chamber through gas discharge openings. The gas inlet member is located within a central cavity of a cover plate, which forms a cover for sealing the reactor.

[0005] European patent application EP 1 252 363 B1 also describes a similar device. In this application as well, a gas inlet member in the form of a shower head is inserted into the cavity of a cover plate.

[0006] Devices of a similar type according to the present invention for depositing layers on substrates, particularly MOCVD reactors, have a gas discharge surface in the form of a substantially circular disc having a plurality of gas discharge openings arranged in the form of a shower head, and process gas can be introduced into the process chamber from said gas discharge openings. The gap between the gas discharge surface and the upper surface of the susceptor supporting the substrates is 9 mm to 20 mm. Technically, such a gap, that is, the height of the process chamber, must be maintained constant over the entire surface area of ​​the susceptor. The height must be maintained constant, particularly even when the internal pressure within the process chamber fluctuates. Thus, a situation in which the gas discharge surface bends when the pressure inside the housing decreases must be prevented.

[0007] Other similar types, or devices according to the present invention, have a loading opening within the housing wall, and substrates can be loaded onto the susceptor through the loading opening. In the case of the prior art, the gas inlet member must rise or the susceptor must descend so that a gripper engaged through the loading opening can engage with the substrates supported by the susceptor. The problem to be solved

[0008] The objective of the present invention is to provide measures that allow for simpler loading into a process chamber or stabilize the condition of the gas discharge surface during pressure fluctuations. means of solving the problem

[0009] The above problem is solved by the invention set forth in the claims. Dependent claims represent not only preferred improvements of the independent claims but also independent solutions to the problem.

[0010] A first aspect of the present invention proposes that a gas inlet member be an integrated component of a sealing element. The sealing element is, so to speak, a cover capable of sealing an opening in the housing of a CVD reactor. A cavity is located on the side of the sealing element facing the interior of the housing according to the present invention. The cavity may be surrounded by a web extending from the edge of the sealing element. However, the cavity may be a groove whose inner wall is formed by a ring web. However, the cavity may be a central region of the sealing element where the material thickness of the sealing element is smaller than within the web region or at the edge. The wall of such a cavity forms the wall of a gas distribution volume according to the present invention. The wall has an inner surface, and the inner surface of said wall forms the inner surface of the gas distribution volume. Additionally, the cavity may include a central groove in which the material thickness of the wall of the sealing element is further reduced within it. Such a groove may form a gas distribution volume. In this case, the volume of the groove corresponds to the volume of the chamber of the gas inlet member forming the gas distribution volume. The groove may be sealed by a plate. The plate preferably forms a separation plate that separates the chamber forming the gas distribution volume from the cooling chamber. The plate has a broad side in a plane facing the groove. The other broad side is also preferably likewise flat. The edge of such a broad side may be adjacent to the bottom of the cavity. In this case, specifically, it refers to the bottom area of ​​the cavity surrounding the central groove. There, within the groove, a sealing ring may be placed that surrounds the groove and extends between the separation plate and the bottom of the cavity. Accordingly, the vertical height of the chamber forming the gas distribution volume is defined by the vertical depth of the groove extending within the horizontal plane.The groove preferably extends across the entire gas discharge surface formed by the gas discharge plate, which runs perpendicularly to the separation plate. A cooling chamber extends within the gap between the gas discharge plate and the separation plate, and a coolant may flow through the cooling chamber. A component group comprising substantially two parts may be disposed within the cavity. The component group consists of a first body forming the gas discharge plate and a second body forming the separation plate. The edge of the separation plate may be placed on the stage of the outer edge section of the body forming the gas discharge plate. The outer wall of the ring-shaped or circular disc-shaped body may be adjacent to the inner wall of the web surrounding the cavity. The end face of the web facing the interior of the housing is preferably coplanar with the gas discharge surface. The component group is inserted into the cavity, that is, preferably within the groove surrounded by the ring web. The component group does not form all the components of the gas inlet member. The component group substantially forms only a limiting device for the gas distribution volume of the gas inlet member. The separation plate used for this purpose forms the inner surface of the gas distribution volume. Another inner surface of the gas distribution volume forms the surface of the groove, that is, forms the sealing element or the body of said sealing element.

[0011] According to a second aspect of the present invention, a stabilizing ring is provided that surrounds a gas inlet member and is disposed on the side of a cover facing the interior of the housing. The stabilizing ring is formed by a web that extends near the edge along the inner side of the housing wall, which is preferably cylindrical, of the housing of the CVD reactor. The web may be in direct contact with a support surface on which a sealing element is placed on the end face of the housing wall. Accordingly, the web may not only define a cavity in which elements of the gas inlet member are disposed, but also form a reinforcing element capable of preventing the gas outlet surface from bending during pressure fluctuations within the housing. It is found to be preferable for the web to proceed uninterruptedly along the inner side of the housing wall as a ring web. To this end, it is found to be preferable for the sealing element to have a first material thickness that may be 25 mm to 35 mm within the region of the support surface. The first material thickness is preferably 31 mm. Within the region of the web, the sealing element may have a second material thickness that is at least 1.5 times the first material thickness. The second material thickness may be 40 mm to 60 mm. The second material thickness is preferably 51 mm. The area connected to the web on the inside may have a third material thickness corresponding to at least half of the first material thickness and at most the first material thickness. Such an area forms the bottom of a cavity defined by the web and preferably has a material thickness of 25 mm. A groove spaced from the web may be located inside such a cavity. The cavity may also be understood as a first groove having a bottom, within which a second groove spaced from the web extends. There, a sealing element may be positioned within a range of 1 / 3 to 2 / 3 of the first material thickness and may have a material thickness preferably 15 mm. Such an area is preferably used as a gas distribution volume. The outside diameter of the sealing element may be greater than 1,000 mm.The width of the support surface can be placed within the range of 50 mm to 100 mm, preferably approximately 87 mm. The width of the web can be 25 mm. The web surrounds a cup-shaped cavity in which a circular disc-shaped body is placed. The body has an outer wall facing and adjacent to the inner wall of the web. The outer wall may be adjacent to the inner wall. The height of the body placed within the cavity corresponds to the height of the web within the inner region, so that consequently, the end surface of the web is coplanar with the gas discharge surface formed by the body. The surface of the disc-shaped body facing the bottom of the cavity is supported by a sealing ring, which runs within a groove at the bottom of the cavity extending along the web. Numerical experiments were conducted with different cover plates covering the housing of the CVD reactor. In the model calculations performed in this case, it was confirmed that bending of the cover plate during vacuuming inside the housing can be prevented by the ring web. A cover plate without a ring web bends up to 0.81 mm from the center, whereas if the cover plate includes the ring web described above, the maximum bend is only 0.37 mm. Accordingly, the ring web stabilizes the state of the gas discharge surface, which extends in a plane and includes a plurality of gas discharge openings regularly arranged, particularly on grid points.

[0012] Another aspect of the present invention relates to an elongate opening within a sealing element. A window is extended within such an opening. The direction of the window's extension is preferably radial with respect to the central axis of the sealing element in the form of a circular disc. Furthermore, the cover plate may include a plurality of openings into which pipes forming observation openings are inserted, said pipes protrude through a gas distribution volume, a cooling chamber, and a gas discharge plate.

[0013] A CVD reactor designed according to the present invention comprises a housing having a sealing element as described above and a loading opening immediately below said sealing element. The loading opening is positioned slightly below the end face of the web. The loading opening is positioned at the height of the process chamber, and the side facing away from the gas inlet member of said process chamber is limited by a susceptor supporting substrates. Below the susceptor, a heating device capable of heating said susceptor is located. Brief explanation of the drawing

[0014] Embodiments of the present invention are described below by the attached drawings. FIG. 1 shows a schematic cross-sectional view of a first embodiment of a CVD reactor, and FIG. 1a shows an enlarged view of Section Ia in FIG. 1, and FIG. 2 shows a perspective view of a sealing element forming the cover of the housing (1) of a CVD reactor, and FIG. 3 shows a second perspective view of the cover (2) from the rear, looking at the gas discharge surface (29), and Figure 4 shows a plan view of the gas discharge surface, and FIG. 5 shows a plan view of the outer side of the cover (2), and FIG. 6 shows a cross-sectional view along line VI-VI in FIG. 5, and FIG. 7 shows a cross-sectional view along line VII-VII in FIG. 5, and Figure 8 shows a cross-sectional view along line VIII-VIII in Figure 5. Specific details for implementing the invention

[0015] The drawings show embodiments of a CVD reactor comprising a housing (1) including an opening (24) that is sealed by a cover (2). The cover (2) supports a gas inlet member (4) capable of supplying process gas into a process chamber (23), the process chamber being restricted at the top by the gas inlet member and at the bottom by a susceptor (5). The gas inlet member (4) forms a gas discharge plate (21), the side of the gas discharge plate facing away from the cover (2) forms a gas discharge surface (29) into which gas discharge openings (17) engage, and the process gas supplied into the gas distribution volume (27) through the gas discharge openings can be discharged from the gas inlet member (4). The gas discharge surface is a central surface area of ​​the wide side of the sealing element (2) facing the housing (1) and is surrounded by an edge area (R). A shielding plate (6) is extended having gas penetration openings (16) that are open toward the process chamber (23) in front of the gas discharge surface (29) under the formation of a gap (15), and process gas supplied into the gap (15) through the gas discharge openings (17) can flow into the process chamber (23). The radially outer region of the shielding plate (6) includes a circumferential bead (14) that seals the gap (15) toward the edge.

[0016] The susceptor (5) is heated from below by a heating device (7). This can be achieved by thermal radiation, thermal conduction, or by inductive heat generation within the susceptor (5). The susceptor (5) is supported by a lifting element (10) of a support device. The heating device (7) may be supported by a shank (8). The process chamber (23) is surrounded by a gas exhaust member (3) that is height-displaceable by a lifting device (9). The susceptor (5) may be lowered by the lifting device (10). The gas exhaust member (3) may be lowered by the lifting device (9). In the lowered position, a gripper may engage through a loading opening (18) of the housing wall (13) of the housing (1). The above loading opening (18) extends until it is directly adjacent to the ring web (25), which is formed to match the material of the cover (2) forming a plate extending across the entire opening (24).

[0017] FIGS. 1 and FIGS. 1a show a ring web (25) formed from the lower side of the cover, said ring web formed to match the material of the cover plate made of metal. Such a ring web (25) has a surface radially outwardly facing adjacent to the surface of the wall of the housing (1). When the cover is closed, the ring web (25) protrudes into the opening (24).

[0018] The ring web (25) surrounds the gas inlet member (4). The ring web (25) forms a circular receiving chamber in which the gas inlet member (4), which is fixed and in contact with the lower side of the cover (2), is placed. Preferably, the outer edge section (26) of the gas inlet member (4), which is formed to match the material of the gas discharge plate (21), has a wall that is radially outwardly adjacent to a wall that is radially inwardly oriented of the ring web (25). The height of the ring web (25) preferably corresponds to the height of the gas inlet member (4), so that consequently, the surface of the gas inlet member (4) facing toward the process chamber (23) is coplanar with the surface of the ring web (25) facing axially.

[0019] The ring web (25) extends within the edge region (R), just like the radial outer region of the support surface (33) and the gas discharge plate (21).

[0020] FIG. 1a shows that the surface of the shielding plate (6) facing the gas inlet member (4) proceeds obliquely within the edge region, so that as a result, the material thickness of the shielding plate (6) decreases wedge-shaped at the edge side. Within this region, an adjacent bead (14) extends in contact with the gas inlet member (4) or the gas discharge plate (21) of the gas inlet member (4). In this embodiment, a bead (14) proceeding in a circular manner is adjacent to the outer edge section (26). By the bead (14), a situation in which process gas flowing into the gap (15) through the gas discharge openings (17) is discharged from the gap (15) from the side is prevented. Accordingly, the process gas flows only through the gas penetration openings (16) of the shielding plate (6) and is uniformly distributed and flows into the process chamber (23) placed underneath.

[0021] A second embodiment of a plate-shaped cover-shaped sealing element (2) shown in FIGS. 2 through 8, having an outer wall extending in a plane to distribute process gas supplied into a gas distribution volume (27) through a supply opening (37) to a plurality of gas passage tubes (28), forms a chamber used as a gas distribution volume (27) by means of an internal cavity (19) or a groove (30). The gas passage tubes (28) are arranged to be uniformly distributed over the entire surface where the groove (30) extends. An intermediate plate (31) runs within the groove (30), which divides the gas distribution volume (27) into an upper region into which process gas is supplied and a lower region from which the gas passage tubes (28) originate.

[0022] The above groove (30) is surrounded by a section of the bottom of the cavity (19), which is surrounded by a ring web (25). A groove with a sealing ring (35) placed inside it extends to surround the groove (30) having a circular layout. The edge of a separating plate (32) extending parallel to the bottom of the groove (30) rests on this section of the bottom of the cavity (19) and on the sealing ring (35).

[0023] The above cavity (19) accommodates a disc-shaped body (26) having an outer edge section (26'). The outer edge section (26') has an outer wall (26'') facing the inner wall (25'') of the web (25) under the formation of a small gap. The gap may have a gap width of 0. The end surface (25''') of the ring web (25) is coplanar with the gas discharge surface (29) formed by the gas discharge plate (21), the gas discharge plate being connected to the outer edge section (26') in a material match.

[0024] An intermediate space forming a cooling chamber (22) remains between the gas discharge plate (21) and the separation plate (32). A liquid coolant can be supplied into the cooling chamber (22) through the coolant supply line (36). The coolant can exit the cooling chamber (22) through the coolant discharge line (36'). The outer edge section (26') is adjacent to another sealing ring (34) placed within a groove that extends to surround the groove (30) and the sealing ring (35) in a ring shape.

[0025] The above gas penetration tubes (28) are engaged across the cooling chamber (22) into the gas discharge openings (17) of the gas discharge surface (29).

[0026] The cover plate of the sealing element (2), made of metal, forms the support surface (33), the web (25), the wall of the cavity (19), and the wall of the groove (30) so as to match the material. The inner surface of the groove (30) forms the inner surface of the gas distribution volume (27). Accordingly, the inner surface of the gas distribution volume (27) is mostly formed by the surface of the cover plate of the sealing element (2). Bores are located within the edge region of the cover plate, and fastening elements, such as screws, that can secure the cover (2) to the housing (1) are engaged through the bores.

[0027] The dimensions shown in FIG. 6 have the following values:

[0028] A is approximately 30 mm, B is approximately 50 mm, C is approximately 25 mm, D is approximately 15 mm, E is approximately 25 mm, G is approximately 15 mm, H is approximately 5 mm, E is approximately 25 mm, F is approximately 90 mm, K is approximately 1,100 mm, H is approximately 1,000 mm, I is approximately 900 mm, and J is approximately 700 mm. For dimensions I, J, H, and K, they refer to diameters.

[0029] A gas inlet member (4) is placed within the cavity (19) of a metal cover plate, and a chamber forming the gas distribution volume is formed by the groove (30) such that the surface of the groove simultaneously becomes the inner surface of the gas distribution volume, thereby forming a sealing element for sealing a housing, particularly a narrow housing. The thickness is approximately 50 mm. Thus, the loading opening (18) can have a minimum gap from the end surface (13') of the housing wall (13) on which the supporting surface (33) of the cover (2) is supported.

[0030] The above gas inlet member (4) is preferably placed within a cavity (19) surrounded by a ring web (25). The ring web (25) provides a reinforcing element that reduces the degree of bending of the central region of the cover (2) during pressure fluctuations inside the housing (1). Model calculations have confirmed that the ring web (25) provides a significant reduction in bending compared to a cover otherwise designed identically without including such a ring web (25).

[0031] The aforementioned embodiments are used to illustrate the inventions described in their entirety by this application, which each independently improve upon the prior art by at least the following combinations of features, wherein two, multiple, or all such combinations of features may be combined with one another:

[0032] A gas inlet member (4) characterized in that the wall of the gas distribution volume (27) is formed by the wall of the cavity (19).

[0033] A gas inlet member (4) characterized by including a web (25) that is directly adjacent to the support surface (33) and protrudes from the inner side of the cover (2).

[0034] A gas inlet member (4) characterized in that the wall of the cavity (1) and / or the wall of the groove (30) extending within the cavity (19) forms the inner surface of the gas distribution volume (27), and the gas distribution volume extends across the entire gas discharge surface (29).

[0035] A gas inlet member (4), characterized in that the cavity (19) includes a groove (30) forming a gas distribution volume (27), and the gas distribution volume is limited by a separation plate (23) that is hermetically adjacent to the bottom of the cavity (19) surrounding the groove (30).

[0036] The web (25) is a ring web that proceeds uninterruptedly along the inner side (13'') of the housing wall (13), and / or the ring web proceeds in a circular manner, and / or the sealing element (2) has a first material thickness (A) within the area of ​​the support surface (33), a second material thickness (B) within the area of ​​the web (25) that is at least 1.5 times the first material thickness (A), and a third material thickness (C) within the inner area of ​​the sealing element (2) that is directly adjacent to the web (25) and surrounded by the web (25), which is within the range of 0.5 to 1 times the first material thickness (A), and / or the width (E) of the web (25) is within the range of 50% to 150% of the width (F) of the support surface (3), and / or the width (E) of the web (25) is within the area of ​​the web (25) the material thickness (B) of the sealing element (2) and the A gas inlet member (4) characterized by being greater than the difference in material thickness (A) of the sealing element (2) within the area of ​​the support surface (33).

[0037] A gas inlet member characterized in that a disc-shaped body (26) forming a gas discharge plate (21) is disposed in a form-filling way within a bowl-shaped or cup-shaped cavity (19) surrounded by a web (25), and / or the disc-shaped body (26) includes an outer wall (26'') facing adjacent to an inner wall (25'') of the web (25), and / or the disc-shaped body (26) includes an outer edge section (26'), and the height of the outer edge section corresponds to the height of the web (25), so that consequently, the end surface (25''') of the web facing away from the sealing element (2) is coplanar with the gas discharge surface (29) formed by the gas discharge plate (21) of the body (26).

[0038] An outer edge section (26') of a body (26) disposed within a cavity (19) surrounded by a web (25) surrounds a cavity in which a separation plate (23) is disposed, said separation plate restricts a cooling chamber (22) toward a sealing element (2), and the boundary of the cooling chamber facing away from the sealing element (2) is a gas discharge plate (21), and / or the edge region of said separation plate (23) is adjacent to the bottom of the cavity surrounded by the body (26) and is supported on the end (44) of said outer edge section (26'), and / or said separation plate (23) has a wide side that is coplanar with the supporting surface of said outer edge section (26') adjacent to the bottom of the cavity surrounded by the web (25), characterized in that the gas inlet member (4).

[0039] A gas inlet member (4) characterized in that a window (40) is disposed within an elongated opening (41) of a cover plate forming a sealing element (2), and / or one or more tubes (45) forming an observation opening (39) are engaged through the cover plate forming the sealing element (2), the gas distribution volume (27), the cooling chamber (22), and the gas discharge plate (21), and / or the outer surface of the sealing element (2) is flat.

[0040] A CVD reactor having a gas inlet member (4), wherein the gas outlet surface (29) is directed toward a process chamber (23) whose bottom is formed by a susceptor (5), said susceptor is heatable by a heating device (7) and is surrounded by a gas outlet member (3), and / or the housing wall (13) includes a loading opening (18), said loading opening (18) extending until it is directly adjacent to a web (25).

[0041] A CVD reactor characterized in that the outer wall (25') of the web (25) proceeding on the cylindrical outer surface is spaced up to 1 mm away from the inner side (13'') of the housing wall (13), and / or a shielding plate (6) having gas penetration openings (16) is disposed between the process chamber (23) and the gas discharge surface (29).

[0042] All disclosed features are important to the present invention (in themselves, but also in combination with one another). Accordingly, for the purpose of including the features of the priority documents together in the claims of this application, the disclosures of the relevant / attached priority documents (copies of the preliminary application) are included in their entirety. In particular, to make a divisional application based on the dependent claims, the dependent claims characterize independent and progressive improvements of the prior art by their own features without the features of the cited claims. The invention presented in each claim may further include one or more features provided, in particular, by reference numerals in the foregoing description and / or the list of reference numerals. In particular, the invention relates to design forms in which the individual features mentioned in the foregoing description are not implemented, provided that the features are clearly unnecessary for the individual use or can be replaced by other means that function technically identically. Explanation of the symbols

[0043] 1 Housing 25' outer wall 2 Sealing element, cover 25'' inner wall 2' edge 26 Disc-shaped body 3 Gas exhaust member 26' outer edge section 4 Gas inlet member 26'' outer wall 5 Susceptor 27 Gas distribution volume 6 Shielding plate 28 Gas penetration tube 7 Heating device 29 Gas exhaust surface 8 Shank 30 Groove 9 Lifting device 31 Intermediate plate 10 Lifting device 32 Separating plate 11 Lifting element 33 Support surface 12 Support plate 34 Sealing ring 13 Housing wall 35 Sealing ring 13' end face 36 Coolant supply line 13'' inner 36' Coolant exhaust line 14 Bead 37 Supply opening 15 Clearance 38 Elongated opening 16 Gas penetration opening 39 Observation opening 17 Gas exhaust opening 40 Window 18 Loading opening 41 Elongated opening 19 Cavity 42 Fixing plate 20 Fixing element 43 Fixing Element 21 Gas exhaust plate 44 Stage 22 Cooling chamber 45 Tube 23 Process chamber 46 Observation opening 24 Opening 25 Ring web R Edge area

Claims

Claim 1 A CVD reactor having a housing (1), wherein the housing includes an upwardly facing opening, the opening is sealed by a sealing element (2), the sealing element (2) includes a cover plate having a first cavity in which a gas distribution volume (27) is disposed inside, the first inner surface of the gas distribution volume (27) is formed by the surface of a groove (30) in the first cavity formed by the cover plate in a material conformation, and the second inner surface of the gas distribution volume (27) is formed by a plate disposed in the first cavity, the sealing element (2) has a support surface (33) that rests on an end surface (13') of a housing wall (13) of the housing (1), the plate is disposed in a second cavity of a disc-shaped body (26), the disc-shaped body is disposed in a first cavity disposed on the side of the sealing element (2) facing the interior of the housing (1), and the edge region of the plate is the A CVD reactor characterized by being supported on the end (44) of the outer edge section (26') of the body (26) and gas-tightly contacting the bottom of the first cavity surrounding the groove (30), a gas discharge plate (21) connected to the outer edge section (26'), the gas discharge plate forming a gas discharge surface (29) facing the interior of the housing, an intermediate space between the plate and the gas discharge plate (21) forming a cooling chamber (22), and a plurality of gas discharge openings (17) disposed on the gas discharge surface (29) connected to the gas distribution volume (27) so that fluid can flow through gas penetration tubes (28) crossing the cooling chamber (22). Claim 2 A CVD reactor according to claim 1, characterized in that a web (25) is adjacent to the housing wall (13). Claim 3 A CVD reactor according to claim 1, wherein the plate forms a separation plate between the cooling chamber (22) and the gas distribution volume (27). Claim 4 A CVD reactor according to claim 1, wherein a web (25) protruding from the inner side of the sealing element (2) into the interior of the housing (1), the housing wall (13) is adjacent to the web (25), and the web (25) surrounds the first cavity. Claim 5 In claim 4, the web (25) is a ring web that proceeds uninterruptedly along the inner side (13'') of the housing wall (13), and the gas outlet plate (21) forming the gas outlet surface (29) is formed by the disc-shaped body (26), the disc-shaped body is formed in a form-filling manner within a bowl-shaped or cup-shaped first cavity surrounded by the web (25), the plate forms a separation plate between the cooling chamber (22) and the gas distribution volume (27), and the gas distribution volume (27) is connected to the gas outlet openings (17) disposed within the gas outlet plate (21) by gas penetration tubes (28) that cross the cooling chamber (22) so that fluid can flow through them, characterized by a CVD reactor. Claim 6 A CVD reactor according to claim 1, wherein the web (25) has an end surface (25''') facing the interior of the housing (1), the end surface is in the same plane as the gas discharge surface (29) formed by the disc-shaped body (26), and / or the outer wall (26'') of the disc-shaped body (26) is adjacent to the inner wall (25'') of the disc-shaped body (26), filling the first cavity surrounded by the web (25) and forming the gas discharge surface (29). Claim 7 A CVD reactor according to claim 1, characterized in that a groove extending around the groove (30) has a sealing ring (35) placed thereon. Claim 8 In claim 4, the web (25) proceeds in a circular manner, and the sealing element (2) has a first material thickness (A) within the area of ​​the support surface (33), a second material thickness (B) which is at least 1.5 times the first material thickness (A) within the area of ​​the web (25), and a third material thickness (C) which is in the range of 0.5 to 1 times the first material thickness (A) within the inner area of ​​the sealing element (2) that is directly adjacent to the web (25) and surrounded by the web (25), and the width (E) of the web (25) is in the range of 50% to 150% of the width (F) of the support surface (33), and / or the width (E) of the web (25) is greater than the difference between the material thickness (B) of the sealing element (2) within the area of ​​the web (25) and the material thickness (A) of the sealing element (2) within the area of ​​the support surface (33). CVD reactor. Claim 9 A CVD reactor according to claim 1, wherein the disc-shaped body (26) includes an outer edge section (26'), and the height of the outer edge section corresponds to the height of the web (25). Claim 10 A CVD reactor according to claim 1, wherein the plate has a wide side that is coplanar with the supporting surface of the outer edge section (26') adjacent to the bottom of the first cavity surrounded by the web (25). Claim 11 A CVD reactor according to claim 1, wherein a window (40) is disposed within an elongated opening (41) of a cover plate forming the sealing element (2), and one or more pipes (45) forming an observation opening (39) are engaged through the cover plate forming the sealing element (2), the gas distribution volume (27), the cooling chamber (22), and the gas discharge plate (21), and the outer surface of the sealing element (2) is flat. Claim 12 In claim 1, the gas discharge surface (29) faces toward a process chamber (23) whose bottom is formed by a susceptor (5), and the susceptor is heatable by a heating device (7) and surrounded by a gas discharge member (3), in a CVD reactor. Claim 13 A CVD reactor according to claim 12, wherein the housing wall (13) includes a loading opening (18), and the loading opening (18) extends until it is directly adjacent to a web (25). Claim 14 A CVD reactor according to claim 12, characterized in that the outer wall (25') of the web (25) proceeding on the cylindrical outer surface is located at a maximum distance of 1 mm from the inner side (13'') of the housing wall (13). Claim 15 A CVD reactor according to claim 12, characterized in that a shielding plate (6) having gas penetration openings (16) is disposed between the process chamber (23) and the gas discharge surface (29).

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