Gas inlet for a CVD reactor

Abstract

The invention relates to a device for feeding a process gas into a process chamber (4) of a CVD reactor, the device comprising: a gas distribution body (12) having a central region (15) in which an opening (14) of a gas supply line (13) is arranged, which opening extends only over a partial circumference of the outer side thereof; and comprising flow barriers (17, 19, 21) having an inner side (17', 19', 21') and an outer side (17'', 19'', 21'') and comprising a plurality of gas passage channels (22, 23, 24) which are identical to one another and evenly distributed over the circumference of the flow barrier (17, 19, 21). In order to reduce the required manufacturing tolerances, the gas passage channels (22, 23, 24) are longer than the distance, measured in the radial direction, between the inner side (17', 19', 21') and the outer side (17'', 19'', 21''). The passage channels (22, 23, 24) each have an inlet channel (25) which branches into at least two branch channels (26, 26') in the interior of the flow barrier (17, 19, 21), wherein the branch channels (26, 26') each continue at least into one outlet channel (27) which opens out in the outer side of the flow barrier (17, 19, 21).

Description

Description Gas inlet for a CVD reactor field of technology

[0001] The invention relates to a device for feeding a process gas into a process chamber of a CVD reactor, with at least one gas distribution body arranged around an axis, which has a central region with an outer side surrounding the axis, in which an orifice of a gas supply line extending only over a partial circumference of the outer side is arranged, with a flow barrier having an inner side facing a gas distribution chamber and an outer side facing away from this, with a plurality of gas passage channels connecting the inner side to the outer side, having an identical design and arranged evenly distributed over the circumference of the flow barrier for the even distribution of the process gas emerging from the orifice and distributed in the gas distribution chamber into the process chamber. State of the art

[0002] A generic device is described in WO 2020 / 109361 A2. Several substantially uniformly designed gas distribution bodies are arranged vertically one above the other. In a central region of each gas distribution body, gas supply lines arranged circumferentially around an axis extend, each of the gas supply lines supplying one of the gas distribution bodies with a process gas, which is fed into a process chamber of a CVD reactor in which the device is arranged. The gas supply line opens into a gas distribution chamber surrounding the central region. The outlet of the gas supply line is arranged eccentrically - relative to the axis - in an outer wall of the central region, which adjoins the gas distribution chamber. The device has an outer wall with a plurality of gas passages evenly distributed across its cylindrical outer wall, through which the process gas can enter the process chamber. To homogenize the process gas flow, at least one flow barrier with gas passages is provided between the outer wall and the central region.

[0003] Such a device is used as a gas inlet device in a CVD reactor to feed various process gases into the process chamber of the CVD reactor at different vertical heights. These process gases flow radially through the process chamber and are discharged from the CVD reactor through a gas outlet device. Several substrates are arranged in a circular arrangement around the center of the gas inlet device, which is located in the center of the process chamber. The formation of a homogeneous process gas flow that flows evenly into the process chamber over the entire circumference of the gas inlet device requires a uniform distribution of the process gas exiting the mouth of the gas supply line in the one or more gas distribution chambers in the gas inlet device. For this purpose, it is advantageous if the gas passage channels of a flow barrier or the outer wall have a very small cross-sectional area so that a sufficiently high pressure drop occurs across the gas passage channels.However, it is technically challenging to produce reproducible gas passages with the smallest cross-sectional areas. The smaller the cross-sectional areas, the greater the relative deviations. Furthermore, there is the problem that the cross-sections of the gas passages can change due to parasitic deposits of reaction products of the process gases.

[0004] DE 100 64944 A1 describes a CVD reactor with a gas inlet element having a gas outlet wall with gas outlet holes running obliquely to the radial direction.

[0005] KR 101487410 Bl describes a gas inlet device for generating a linear process gas flow from a flat gas outlet surface of a CVD reactor, in which a single supply line branches multiple times. The multiple branches end in outlet channels of the gas outlet surface. Summary of the invention

[0006] The invention is based on the object of implementing measures to improve the homogeneity of a process gas flow from a gas inlet element having a cylindrical gas outlet surface, into which a process gas is fed eccentrically and delivered through a plurality of gas outlet openings. Furthermore, the manufacturing tolerances required for this purpose are to be reduced.

[0007] The problem is solved by the invention specified in the claims, wherein the subclaims represent not only advantageous developments of the invention specified in the main claim, but also independent solutions to the problem.

[0008] First and foremost, a device for feeding a process gas into a process chamber of a CVD reactor is proposed, which device has at least one gas distribution body. The device has an axis, which can be an axis of symmetry. The gas distribution body has a central region surrounded by a gas distribution chamber. A gas supply line extends across the body, said gas supply line having an opening in a wall adjacent to the gas distribution chamber, through which opening the process gas can enter the gas distribution chamber. The central region can have an outer side which runs on a cylindrical surface and in which the opening is arranged. The opening can extend only over part of the circumference or over the entire circumference of the cylindrical surface, for example a maximum of only a quarter, a fifth or a sixth of the circumference. Several such openings can also be arranged one behind the other in the circumferential direction. One or more flow barriers can be arranged around the central region, each of which borders an inner annular gas distribution chamber with an inner side and each of which borders an outer annular gas distribution chamber with an outer side.The at least one flow barrier can be an outer wall, the inner side of which borders a gas distribution chamber and the outer side of which borders the process chamber. The outer side can be a cylindrical surface of the gas distribution body. A further flow barrier can be arranged between the central region and the outer wall. The outer wall and the flow barriers each have a plurality of gas passage channels distributed evenly over their circumference and optionally also over their vertical height. The gas distribution chambers can be circular volumes that are closed at the top and bottom and that are delimited in the radially outward direction by the one or more flow barriers, for example the outer wall. In a preferred embodiment, a process gas is fed into an innermost gas distribution chamber through the opening arranged eccentrically to the axis.The process gas can be distributed in the gas distribution chamber arranged annularly around the axis and pass through the gas passage channels through the flow barrier. The flow barrier can be surrounded by an outer gas distribution chamber. It can also be surrounded by another flow barrier or can be directly surrounded by the outer wall. There are additional gas passage channels. Gas distribution can take place in one or more gas distribution chambers. The total pressure within a gas distribution chamber is essentially the same. There is therefore a small pressure difference within a gas distribution chamber. The pressure difference is smaller than the pressure difference between two adjacent gas distribution chambers, in particular between the pressure in the radially outermost gas distribution chamber and in the process chamber. In order to make the pressure difference between the adjacent gas distribution chambers or between the radially outermost gas distribution chamber and the process chamber as large as possible, or to ensure the most homogeneous gas distribution into the process chamber, it is initially proposed that the gas passage channels be longer than the distance measured in the radial direction between the inside and outside of the flow barrier.The passageways are thus no longer the shortest length, but are longer than the radial width of the flow barrier. This increases the hydraulic resistance of the gas passageways without requiring a reduction in their cross-section. Furthermore, it can be provided that an inlet channel of the gas passageway is adjoined by a section that extends in the circumferential direction of the flow barrier. An adjoining outlet channel can open into the outer side of the flow barrier. The circumferentially extending section extends the length of the gas passageway, which also determines the hydraulic resistance.According to a preferred variant, it is proposed that the gas passage channels of at least one inner flow barrier or the outer wall each have an inlet channel, which branches into at least two branch channels inside the flow barrier or the outer wall, each of which continues at least indirectly into an outlet channel that opens into the outer side of the flow barrier or the outer wall. In particular, it is provided that the passage channels have sections that... extend in different directions. It can be provided that the passage channels have sections that change direction several times. It is considered advantageous if a large number of identically designed gas passage channels of this type connect two adjacent gas distribution chambers or a radially outermost gas distribution chamber with the process chamber. Due to the measure according to the invention, the free cross-sectional areas of the gas passage channels can be increased compared to gas inlet elements known from the prior art. The number of gas inlet channels is smaller than in the prior art, so that their cross-sectional area can be made larger. A relatively high pressure can therefore drop in the gas passage channel. Because the inlet channel branches into at least two branch channels, at least twice as many openings are provided on the outside of the pressure barrier or the outer wall as on the inside.At least one flow barrier can be arranged between the central region and the outer wall. According to a further development of the invention, at least two flow barriers can be arranged between the central region and the outer wall. The flow barriers can be arranged in a ring around the central region. The at least one flow barrier can extend along a circular arc around the axis. The device preferably has a plurality of gas distribution bodies arranged vertically one above the other, the flow barriers or outer walls of which can be of identical design. However, the flow barriers or outer walls can also be designed differently from one another, for example have gas passage channels of a different shape or number. The gas supply lines are located in the central region and are arranged offset in the circumferential direction around the axis.In each of the multiple gas distribution bodies, one of the gas supply lines opens at a different circumferential position. The outlets of the gas supply lines of gas distribution bodies arranged one above the other are angularly offset. The gas distribution bodies have... Windows arranged at an angle and open at the top and bottom, through which a process gas can flow, said process gas flowing into a gas distribution chamber in a gas distribution body located underneath. According to a preferred embodiment, the inlet channels or outlet channels have an extension direction that runs in the radial direction - relative to the axis. The branch channels can extend in the circumferential direction or in the vertical direction. They can arise essentially at right angles to the inlet channel or merge into the outlet channel at right angles. Optionally, it is provided that the inlet channels or gas passage channels arising from a gas distribution chamber are arranged offset in the circumferential direction or in the vertical direction as outlet channels or gas passage channels opening into the same gas distribution chamber.Furthermore, it can be provided that, in order to extend the inlet channel or to extend the outlet channel, the inlet channel or the outlet channel has a first section which has a different direction than a second section. For example, one section can extend in a horizontal plane. A second section can extend in the vertical direction. A first section of the inlet channel extending in the radial direction can be followed by a second section extending in the vertical direction. A first section of an outlet channel extending in the vertical direction can be followed by a second section extending in the horizontal direction. The sections extending in the horizontal direction can extend in the radial direction. A device can be formed from a plurality of gas distribution bodies arranged one above the other.The gas distribution bodies can be circular disk-shaped objects with circular recesses. The circular recesses form the gas distribution volumes. The ribs flanking the circular recesses form at least one flow barrier and the outer wall. The top and bottom of the gas distribution body are essentially flat, so that when stacked on top of each other, the flat underside of the gas distribution bodies rests flat on the flat upper side. According to a preferred development of a device designed in this way, the inlet channel, the branch channels and / or the outlet channel can be open at the top. This is advantageous from a manufacturing technology perspective. The open side of the inlet channel, the branch channels or the outlet channel is then closed by the underside of the gas distribution body immediately above it. According to a development of the invention, it can be provided that the branch channel and / or the outlet channel is formed by sections of a volume which extends from a bottom plane of the gas distribution chamber to the top side of the gas distribution body. This volume can be open at the top side. However, it is also possible for the volume or the channels to be open at the bottom and closed by the top side of a gas distribution body arranged underneath.The volume can be U-shaped in the plan view of the top side of the gas distribution body. The branch channels or the outlet channels into which the branch channels can open can be formed by the volume. The U-shape of the volume can be created by a partial body that divides the volume into two channels that open either into the process chamber or into a gas distribution chamber. The partial body can have wedge-shaped side walls tapering to a rounded tip. The rounded tip can lie in front of an opening of the inlet channel. However, the tip can also lie in front of an opening of an outlet channel if the section of the gas passage channel arranged upstream of the volume already has a branch. Preferably, the inlet channel can branch into three or more outlet channels.In a further development, it can be provided that an inlet channel extending in the radial direction branches into two branch channels extending in the circumferential direction or in the vertical direction. The two branch channels can then branch again, with a branch channel extending in the horizontal direction preferably branching into itself in the vertical direction. further branch channels extending vertically branch into further branch channels, or a branch channel extending in a vertical direction preferably branches into further branch channels extending horizontally. The total of four further branch channels open outwards either to form an outlet channel in the outside of the flow barrier or the outer wall. The gas distribution bodies can be made of metal, graphite, a ceramic material or quartz. Preferably, the at least one gas distribution body consists of a one-piece quartz part, with the cavities or channels being produced using the SLE process. It proves to be advantageous if at least some of the channels, for example the inlet channels, the branch channels or the outlet channels, have a rectangular or square cross-section.However, it is also provided that at least some of the channels, for example the inlet channels, the branch channels, or the outlet channels, have a different, in particular circular, cross-section. Furthermore, it can be provided that only one flow barrier or only the outer side has gas passage channels designed according to the invention. Other flow barriers or the outer wall can then also have gas passage channels that do not branch. However, it is also provided that all gas passage channels of all flow barriers and of the outer wall have the branches according to the invention. According to the invention, the gas passage channels formed by a flow barrier or by the outer wall can be designed identically to one another.It can be provided that the total number of gas passages of the flow barriers arranged one behind the other in the flow direction or of the outer wall is at least doubled. For example, an innermost flow barrier can have a first number of gas passages, each of which branches, and a second flow barrier surrounding it or an outer wall surrounding it can have at least or approximately twice the number of gas passages. preferably branch again. The cross-sectional areas of the inlet channels and / or the outlet channels can be at least 1 mm 2 The cross-sectional areas of the branch channels can be larger. Short description of the drawings

[0009] Embodiments of the invention are explained below with reference to the accompanying drawings. They show: Fig. 1 schematically shows a vertical section through a reactor housing 1 of a CVD reactor, Fig. 2 schematically shows five gas distribution bodies 12 of a feed device 11 of a gas inlet element 9 in a perspective view, Fig. 3 is a plan view of a gas distribution body 12, Fig. 4 is a perspective view of a section of an embodiment of a gas distribution body 12, Fig. 5 shows the section shown in Figure 4 in plan view, Fig. 6 shows an enlarged view of section VI in Figure 5 in a perspective view as a first embodiment, Fig. 7 shows the section along line VII-VII in Figure 5 as a second embodiment, Fig. 8 shows the section along the line VIII-VIII in Figure 5, Fig. 8a the section according to Figure 8 but of a third embodiment, Fig. 8b the section according to Figure 8 but of a fourth embodiment, Fig. 9 the section along the line IX-IX in Figure 5, Fig. 10 the view according to arrow X in Figure 9, Fig. 11 shows a perspective view of a section of a gas distribution body 12 of a fifth embodiment, Fig. 12 shows the plan view of the section shown in Figure 11, Fig. 13 the section along the line XIII-XIII in Figure 12, Fig. 14 the section along the line XIV-XIV in Figure 12, Fig. 15 the section along the line XV-XV in Figure 12, Fig. 16 is a plan view of a gas distribution body 12 of a sixth embodiment, Fig. 17 the section along the line XVII-XVII in Figure 16, Fig. 18 is a view in the direction of arrow XVIII in Figure 16, Fig. 19 is a plan view of a gas distribution body 12 of a seventh embodiment, Fig. 20 is a perspective view of a broken out Section of the gas distribution body 12 according to Figure 19, Fig. 21 enlarges section XXI in Figure 19, Fig. 22 the section along the line XXII-XXII in Figure 21, Fig. 23 the section along the line XXIII-XXIII in Figure 21, Fig. 24 enlarges section XXIV in Figure 19, Fig. 25 the section along the line XXV-XXV Figure 24, Fig. 26 the section along the line XXVI-XXVI in Figure 24, Fig. 27 the section along the line XXVII-XXVII in Figure 24, Fig. 28 is a plan view of a gas distribution body 12 of an eighth embodiment. Description of the embodiments

[0010] Figure 1 shows a schematic representation of a CVD reactor for depositing, for example, II-VI layers, IV-IV layers, or III-III layers. Substrates are arranged in a susceptor 2, which can be coated in the process chamber 4 of the CVD reactor. The susceptor 2 has a circular disk shape and is heated to a process temperature from below by means of a heating device 3. The heating device 3 can be a resistance heater, an RF heater, or an IR heater. A shaft 8 supporting the susceptor 2 can be rotated about its contour axis. In the center of the reactor housing 1 is a gas inlet element 9, which has a feed device 11 projecting into the process chamber 4. The process chamber 4 is bounded at the bottom by the susceptor 2 and at the top by a process chamber ceiling 5. The substrates are arranged in a ring-shaped arrangement around the gas outlet surface of the feed device 11 arranged in the center of the process chamber 4. A gas outlet element 7 extends around the susceptor 2 for discharging the process gases or reaction products.

[0011] The gas inlet member 9 has a head 10 into which extend a plurality of gas supply lines 13, which continue into gas distribution bodies 12, which form the feed device 11.

[0012] The gas distribution bodies 12 are disc-shaped quartz bodies that have a central region 15 through which the gas supply lines 13 extend. Figure 2 shows a perspective and schematic view of five such gas distribution bodies 12, which, arranged directly one above the other, form the feed device 11. Each gas distribution body 12 has an opening 14 in which one of the gas supply lines 13 opens to a gas distribution chamber 16. A process gas can enter the gas distribution chamber 16 through the opening 14. The opening 14 can be divided into two opening sections by a baffle 31.

[0013] In the radially outward direction, the first gas distribution chamber 16 is adjoined by a flow barrier 17 which has gas passage channels 22 (not shown in Figure 2) through which the process gas can flow from the inner side 17' of the flow barrier 17 to its outer side 17". The outer side 17" borders a gas distribution volume 18 which is surrounded by an outer wall 21. The outer wall 21 has gas passage channels 24 distributed evenly over its circumference, through which the process gas can flow into the process chamber 4.

[0014] In other embodiments, for example in the embodiment shown in Figures 11 and 12, the second gas distribution volume 18 borders on a second flow barrier 19, which has gas passage channels 23 connecting the inner side 19' with the outer side 19".

[0015] Figures 4 to 8 show an embodiment of a gas distribution body 12, which has a flow barrier 17 surrounding a radially inner gas distribution chamber 16, a radially outer gas distribution chamber 18 surrounding the flow barrier 17, and an outer wall 21. Both the flow barrier 17 and the outer wall 21 each have branched gas passage channels 22 and 24, respectively.

[0016] Figure 6 shows a first embodiment of a branching gas passage channel 22. Y-shaped depressions are introduced into the upper side 28 of the annular flow barrier 17. A section of the depression adjacent to the inner side 17' forms a radially extending inlet channel 25, which branches into two circumferentially extending branch channels 26. The inlet channels 25 of circumferentially adjacent gas passage channels 22 are arranged uniformly distributed in the circumferential direction. The branch channels 26 are continued in radially direction extending outlet channels 27, which open into the outer side 17" of the flow barrier 17. Adjacent outlet channels 27 are evenly spaced from one another. The angle between two adjacent outlet channels 27 is thus half the size of the angle between two adjacent inlet channels 25. The channels 25, 26, 27 are open towards the upper side 28 of the gas distribution body 12 and, in the assembled state of the feed device 11, are closed by the underside 29 of a gas distribution body 12 arranged above it.

[0017] Figures 8, 9, and 10 show a second exemplary embodiment of a branching gas passage channel 24. An inlet channel 25 with a rectangular cross-section is located approximately halfway up the inner side 21' of the outer wall 21. The outer wall 21 forms a plurality of volumes 30 separated from one another by partition walls 34, which extend from a bottom surface of the gas distribution volume 18 to the top side 28. The volumes 30 are closed at the bottom but open at the top. The inlet channel 25 opens approximately centrally into the volume 30. The volume 30 is divided into two sections by a partial body 33. These two sections each form a branch channel 26. The inlet channel 25 opens in front of a rounded end face of the wedge-shaped partial body 33. The partial body 33 forms side walls that taper towards the rounded end face and flank the branch channels.

[0018] The branch channels open into outlet channels 27, which have a circular cross-section. In the embodiment shown in Figure 10, three outlet channels 27, arranged vertically one above the other, emerge from each of the branch channels 26.

[0019] In the third embodiment shown in Figure 8a, the branch channel 26 opens into only one outlet channel 27.

[0020] In the fourth embodiment shown in Figure 8b, the branch channel 26 opens into two outlet channels 27.

[0021] In the fifth embodiment shown in Figures 11 to 15, a first section 25 of an inlet channel opens into a second section 25' of the inlet channel. While the first section 25 extends in the radial direction, the second section 25' extends vertically upwards. There, the second section 25' splits into two branch channels 26 extending in the circumferential direction. The two branch channels 26 each merge into a radially extending outlet channel 27. A second flow barrier 19 surrounding the flow barrier 17 has radially extending gas passage channels 23 with a square cross-section. The outer wall 21 surrounding the second flow barrier 19 has gas passage channels 24 that have a circular cross-section. While the first section 25 extends approximately halfway up the inner wall 17', the outlet channel 27 opens into the uppermost region of the outer wall 17".The outlet channel 27 and the branch channels 26 are open towards the upper side 28 in order to be closed in the assembled state by the lower side 29 of the gas distribution body 12 located thereabove.

[0022] In the sixth embodiment illustrated in Figures 16 to 18, the inlet channel 25 initially branches into two first branch channels 26, which extend in a horizontal plane in the circumferential direction. The first branch channels 26 then each branch into second branch channels 26', which extend in the vertical direction and are open at the top to be closed by the underside of the overlying gas distribution body 12. The second branch channels 26' each open into an outlet channel 27. The inlet channel 25 and the outlet channels 27 extend in the radial direction and are offset both vertically and circumferentially.

[0023] The inlet channel 25 branches at 90° in one circumferential direction and at 90° in the opposite circumferential direction. The length of the branch channels 26 can be greater than the diameter of the branch channel 26. However, the length can also be less than the diameter of the branch channel. The two branch channels 26 each branch at 90° upwards and at 90° downwards into the second branch channels 26'. The length of the second branch channels 26' can also be smaller or larger than their diameter here. The second branch channels 26' each bend at 90° into an outlet channel 27. Two outlet channels 27 are located vertically one above the other.

[0024] The embodiment illustrated in Figure 19 has two flow barriers 17, 19, each having branching gas passage channels 22, 23, 24. The gas passage channels 22 of the flow barrier 17 are illustrated in detail in Figures 21 to 23. These are T-shaped branching gas passage channels 22, in which an inlet channel 25 branches into two branch channels 26, which in turn each merge into an outlet channel 27. Here, all channels 25, 26, 27 extend approximately halfway up the flow barrier 17 and lie in the same horizontal plane.

[0025] Figures 19 to 27 show the gas passage channels 23 of the flow barrier 19, which essentially correspond to those shown in Figures 16 and 17. An inlet channel 25 initially splits into two branch channels 26. These then split again into two further branch channels 26'. Each of the second branch channels 26' opens into an outlet channel 27 in the outer side 19'.

[0026] Figure 28 shows a further embodiment in which the flow barrier 17 initially has an inlet channel 25 which is divided into two branch channels 26, wherein the inlet channel 25 and the branch channels 26 each have a square cross-section and in particular have the same cross-section. The inlet channel 25 is again open at the top and continues into a vertically downward-running second section 25'. The latter splits into the branch channels 26. Each of the two branch channels 26 continues into an outlet channel 27, each of which opens into a volume 30. Several similarly shaped volumes 30 are arranged circumferentially along the outside of the flow barrier 17. In each of the volumes 30 there is a partial body 33, which divides the volume 30 into two channels 35. A rounded end face of the partial body 33 is located in front of the opening of the outlet channel 27. The channels 35 and the volume 30 extend over the entire height of the flow barrier 17.

[0027] The gas distribution chamber 18 surrounding the flow barrier 17 borders an outer wall 21, which forms gas passage channels 24, which are unbranched here. However, the gas passage channels 24 of the outer wall 21 can also branch, as in the other embodiments.

[0028] In all embodiments, the gas distribution chambers 16, 18, 20 can be open all around, forming an annular volume. In all embodiments, the flow barriers 17, 19 can be closed all around, separating the radially inner and radially outer gas distribution chambers from each other, and gas exchange between the radially inner and radially outer gas distribution chambers can only take place through the gas passage channels.

[0029] In all embodiments, the gas distribution chambers 16, 18, 20 can also have radial barriers which divide the gas distribution chambers 16, 18, 20, for example, into two half-chambers.

[0030] In some embodiments, the gas passage channels 22, 23, 24 may have a radially extending inlet channel 25, from which a section 26 bends approximately transversely to the radial direction and extends in the circumferential direction of the flow barrier 17, 19, 21. An outlet channel 27 may bend approximately transversely from this section 26 and again extend in the radial direction.

[0031] The above statements serve to explain the inventions covered by the application as a whole, which each independently develop the state of the art by at least the following combinations of features, whereby two, several or all of these combinations of features can also be combined, namely:

[0032] A device characterized in that the gas passage channels 22, 23, 24 are longer than the distance measured in the radial direction from the inner side 17', 19', 21' and the outer side 17", 19", 21".

[0033] A device characterized in that the gas passage channels 22, 23, 24 each have an inlet channel 25 which continues in the interior of the flow barrier 17, 19, 21 into at least one section 26, 26' which extends in the circumferential direction, and has an outlet channel 27 which opens into the outside of the flow barrier 17, 19, 21.

[0034] A device characterized in that the gas passage channels 22, 23, 24 each have an inlet channel 25 which branches into at least two branch channels 26, 26' inside the flow barrier 17, 19, 21, wherein the branch channels 26, 26' each continue into at least one outlet channel 27 which opens into the outside of the flow barrier 17, 19, 21.

[0035] A device according to one of the preceding claims, characterized by a plurality of flow barriers 17, 19, 21, each having passage channels 22, 23, 24, wherein a radially outermost of the flow barriers 17, 19, 21 forms an outer wall 21, the outer side 21" of which forms a cylindrical surface of the gas distribution body 12, wherein the inner side 17' of a radially innermost flow barrier 17 of the flow barriers 17, 19, 21 adjoins a radially innermost gas distribution chamber 16, which surrounds the outer side of the central region 15, and wherein the outer side 17" of the radially innermost flow barrier 17 adjoins a further gas distribution chamber 18, wherein at least the passage channels 22, 23, 24 of one of the flow barriers 17, 19, 21 or at least two of the Flow barriers 17, 19, 21 or all flow barriers 17, 19, 21 each have an inlet channel 25 which divides into at least two branch channels 26 in the interior of the flow barrier 17, 19, 21.26' branches.,

[0036] A device characterized in that the inlet channels 25 extend radially to the axis of symmetry A, and / or that the branch channels 26 branch off from the inlet channel 25 in the circumferential direction or parallel to the direction of the axis of symmetry A.

[0037] A device characterized in that the inlet channels 25 and outlet channels 27 assigned to a gas distribution chamber 18, 20 are arranged offset from one another in the circumferential direction and / or in the direction of the symmetry axis A.

[0038] A device characterized in that the inlet channel 25 has a first section extending in the radial direction and a second section 25' extending in the direction parallel to the axis of symmetry A to which two branch channels 26 running in the circumferential direction are connected.

[0039] A device which is characterized in that several gas distribution bodies 12 are located directly above one another and form gas supply lines 13 arranged eccentrically to the axis of symmetry A.

[0040] A device characterized in that the inlet channel 25, the branch channels 26 and the outlet channel 27 have a rectangular cross-section.

[0041] A device characterized in that at least one of the inlet channel 25, the branch channels 26 and the outlet channel 27 is open to one side 28 of the gas distribution body 12 and is closed by an opposite side 29 of an adjacent gas distribution body 12.

[0042] A device which is characterized in that the branch channels 26 are formed by a volume 30 which is U-shaped in plan view onto the top side of the gas distribution body 12, wherein side walls of the U-legs converge at an acute angle into a curve.

[0043] A device characterized in that the gas passage channel 22, 23, 24 branches into three or more outlet channels 27.

[0044] A device which is characterized in that an outer side 17" of the flow barrier 17 has a plurality of volumes 30 separated by partition walls 34, wherein the volume 30 is divided by a partial body 33 into two channels 35 which open into a gas distribution volume 18, and wherein the partial body 33 is arranged in front of an outlet channel 27 opening into the volume 30.

[0045] All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of the application hereby fully incorporates the disclosure content of the associated / attached priority documents (copy of the prior application), also for the purpose of incorporating features of these documents into claims of the present application. The subclaims characterize, even without the features of a referenced claim, independent inventive developments of the prior art with their features, in particular for filing divisional applications based on these claims. The invention specified in each claim may additionally comprise 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 unnecessary for the respective intended use or can be replaced by other technically equivalent means. List of reference symbols 1 reactor casing 22 gas passage channel 2 Susceptor 23 Gas passage channel 3 Heating device 24 Gas passage channel 4 Process chamber 25 Inlet channel 5 Process chamber ceiling 25' section of the inlet channel 7 Gas outlet device 26 Branch channel, section 8 shaft 26' branch channel, section 9 Gas inlet element 27 Outlet channel 10 Head 28 Top 11 Feed device 29 Bottom 12 gas distribution bodies 30 volume 13 Gas supply line 31 Baffle wall 14 Mouth 32 Partition 15 Central area 33 Partial body 16 first gas distribution chamber 34 partition wall 17 first flow barrier 35 channel 17' inside 17" exterior 18 second gas distribution chamber 19 second flow barrier, 19' inside 19" exterior 20 third gas distribution chamber 21 third flow barrier, outer wall A symmetry axis 21' inside 21" outside

Claims

Claims 1. Device (1) for feeding a process gas into a process chamber (4) of a CVD reactor, with at least one gas distribution body (12) arranged around an axis (A), which has a central region (15) with an outer side surrounding the axis (A), in which an orifice (14) of a gas supply line (13) is arranged, which orifice extends only or at least over a partial circumference of the outer side, with a flow barrier (17, 19, 21) having an inner side (17', 19', 21') facing a gas distribution chamber (16, 18, 20) and an outer side (17", 19", 21") facing away from this, with a plurality of identically designed and uniformly distributed over the circumference of the flow barrier (17, 19, 21) distributed gas passage channels (22, 23, 24) for uniformly distributing the gas emerging from the mouth (14) and located in the gas distribution chamber (16, 18,20) distributing process gas into the process chamber (4), characterized in that the gas passage channels (22, 23, 24) are longer than the distance measured in the radial direction between the inside (17', 19', 21') and the outside (17", 19", 21"), wherein the gas passage channels (22, 23, 24) each have an inlet channel (25) which continues inside the flow barrier (17, 19, 21) into at least one section (26, 26') which extends in the circumferential direction or in a direction parallel to the axis (A), and has an outlet channel (27) which opens into the outside of the flow barrier (17, 19, 21).

2. Device (1) for feeding a process gas into a process chamber (4) of a CVD reactor, with at least one gas distribution body (12) arranged around an axis (A), which has a central region (15) with an outer side surrounding the axis (A), in which a gas distribution body which is only or an orifice (14) of a gas supply line (13) extending at least over a partial circumference of the outer side is arranged, with a flow barrier (17, 19, 21) having an inner side (17', 19', 21') pointing towards a gas distribution chamber (16, 18, 20) and an outer side (17", 19", 21") pointing away from this, with a plurality of gas passage channels (22, 23, 24) connecting the inner side (17', 19', 21') with the outer side (17", 19", 21"), of identical design to one another and evenly distributed over the circumference of the flow barrier (17, 19, 21) for the even distribution of the process gas emerging from the orifice (14) and distributed in the gas distribution chamber (16, 18, 20) into the process chamber (4), characterized in that the gas passage channels (22, 23, 24) are longer than the distance measured in the radial direction from the inside (17', 19', 21') and outside (17", 19", 21"), wherein the gas passage channels (22, 23,24) each have an inlet channel (25) which branches into at least two branch channels (26, 26') inside the flow barrier (17, 19, 21), wherein the branch channels (26, 26') each continue into at least one outlet channel (27) which opens into the outside of the flow barrier (17, 19, 21).

3. Device according to one of the preceding claims, characterized by a plurality of flow barriers (17, 19, 21), each having passage channels (22, 23, 24), wherein a radially outermost of the flow barriers (17, 19, 21) forms an outer wall (21), the outer side (21") of which forms a cylindrical surface of the gas distribution body (12), wherein the inner side (17') of a radially innermost flow barrier (17) of the flow barriers (17, 19, 21) adjoins a radially innermost gas distribution chamber (16) surrounding the outer side of the central region (15), and wherein the outer side (17") of the radially innermost flow barrier (17) adjoins a further gas distribution chamber (18), wherein at least the passage channels (22, 23, 24) of one of the flow barriers (17, 19, 21) or at least at least two of the flow barriers (17, 19, 21) or all of the flow barriers (17, 19, 21) each have an inlet channel (25) which branches into at least two branch channels (26, 26') in the interior of the flow barrier (17, 19, 21).

4. Device according to one of claims 2 or 3, characterized in that the inlet channels (25) run radially to the axis (A), and / or that the branch channels (26) branch off from the inlet channel (25) in the circumferential direction or parallel to the direction of the axis (A).

5. Device according to one of the preceding claims, characterized in that the inlet channels (25) and outlet channels (27) assigned to a gas distribution chamber (18, 20) are arranged offset from one another in the circumferential direction and / or in the direction of the axis (A).

6. Device according to one of claims 3 to 5, characterized in that the inlet channel (25) has a first section extending in the radial direction and a second section (25') extending in the direction parallel to the axis (A), to which two branch channels (26) extending in the circumferential direction are connected.

7. Device according to one of the preceding claims, characterized in that several gas distribution bodies (12) are located directly above one another and form gas supply lines (13) arranged eccentrically to the axis (A).

8. Device according to one of the preceding claims, characterized in that the inlet channel (25), the branch channels (26) and the outlet channel (27) have a rectangular cross-section.

9. Device according to one of the preceding claims, characterized in that at least one of the inlet channel (25), the branch channels (26) and the outlet channel (27) is open to one side (28) of the gas distribution body (12) and is closed by an opposite side (29) of an adjacent gas distribution body (12).

10. Device (1) for feeding a process gas into a process chamber (4) of a CVD reactor, with at least one gas distribution body (12) arranged around an axis (A), which has a central region (15) with an outer side surrounding the axis (A), in which an orifice (14) of a gas supply line (13) is arranged, which extends only or at least over a partial circumference of the outer side, with a flow barrier (17, 19, 21) having an inner side (17', 19', 21') facing a gas distribution chamber (16, 18, 20) and an outer side (17", 19", 21") facing away from this, with a plurality of identically designed and uniformly distributed over the circumference of the flow barrier (17, 19, 21) distributed gas passage channels (22, 23, 24) for uniformly distributing the gas emerging from the mouth (14) and located in the gas distribution chamber (16, 18,20) distributing process gas into the process chamber (4), characterized in that the gas passage channels (22, 23, 24) are longer than the distance measured in the radial direction from the inside (17', 19', 21') and outside (17", 19", 21"), wherein at least one of the gas passage channels (22, 23, 24) is open to one side (28) of the gas distribution body (12) and is closed by an opposite side (29) of an adjacent gas distribution body (12), 11. Device according to one of claims 2 to 9, characterized in that the branch channels (26) are formed by a in plan view of the top of the gas distribution body (12) U-shaped volume (30) are formed, wherein side walls of the U-legs converge at an acute angle into a curve.

12. Device according to one of the preceding claims, characterized in that the gas passage channel (22, 23, 24) branches into three or more outlet channels (27).

13. Device according to one of the preceding claims, characterized in that an outer side (17") of the flow barrier (17) has a plurality of volumes (30) separated by partition walls (34), wherein the volume (30) is divided by a partial body (33) into two channels (35) which open into a gas distribution volume (18), and wherein the partial body (33) is arranged in front of an outlet channel (27) opening into the volume (30).

14. Device characterized by one or more of the characterizing features of one of the preceding claims.

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