Gas inlet member of a CVD reactor with two supply points

Abstract

The present invention relates to an apparatus and method for depositing at least one layer on at least one substrate (4), wherein a first gas flow containing at least one reactant gas is supplied through at least one first gas inlet (39) and at least one second gas flow is supplied through at least one second gas inlet (25, 28) to at least one gas distribution space (11) of a gas inlet member (10). The gas inlet member (10) has a gas outlet face (61) facing a process chamber (8) and having a number of gas outlet holes (16) communicating with the gas distribution space (11) through which the reactant gas enters the process chamber (8), and the substrate (4) is arranged in the process chamber (8) such that regions containing different concentrations of the reactant gas are formed in the gas distribution space (11) such that products of physical or chemical reactions of the reactant gases flowing into the process chamber (8) form a layer on the surface of the substrate (4). To avoid uneven layer thickness caused by bulging of the substrate, according to the present invention, reactive gases are supplied to the gas distribution chamber (11) through gas inlets (25, 28) at different concentrations and at different locations together with the carrier gas.

Description

Technical Field

[0001] The present invention relates to a method for depositing at least one layer on at least one substrate, wherein a first gas stream containing at least one reaction gas passes through at least one first gas inlet hole and at least one second gas stream passes through at least one second gas inlet hole and is supplied to at least one gas distribution space of a gas inlet member, the gas inlet member having a gas outlet surface facing a process chamber with a plurality of gas outlet holes in fluid communication with the gas distribution space, through which the reaction gas flows into the process chamber, and the substrate is disposed in the process chamber such that the product of the physical or chemical reaction of the reaction gas flowing into the process chamber forms a layer on the surface of the substrate. Both gas streams are provided and supplied to the same gas distribution space so as to form regions in the gas distribution space where reaction gases having different concentrations are present.

[0002] The present invention further relates to an apparatus for depositing at least one layer on at least one substrate, the apparatus comprising a gas inlet member having a gas outlet surface facing a process chamber with a plurality of gas outlet holes in fluid communication with the gas distribution space of the gas inlet member, a susceptor having a carrier surface facing the process chamber for receiving the substrate to be coated, and a gas mixing system, the gas mixing system having a mass flow controller, at least one gas source for the reaction gas, and a gas source for the carrier gas, and being capable of providing and supplying a first gas stream containing the reaction gas to a first supply pipe, the first supply pipe opening into the gas distribution space through at least one first gas inlet hole, and being capable of providing and supplying a second gas stream to a second supply pipe using the gas mixing system, the second supply pipe opening into the same gas distribution space through a second gas inlet hole.

Background Art

[0003] Patent Document 1 describes a method and apparatus for depositing a layer on a substrate, wherein a first gas flow containing a reaction gas is supplied to the central region of the gas distribution space of the gas inlet member. Dilution gases are supplied to the same gas distribution space at multiple surrounding locations.

[0004] Patent Document 2 describes a method and apparatus for supplying a first gas flow to the central region of the gas distribution space of a gas inlet member through a first gas inlet hole. A second gas flow can be supplied to the central region through a plurality of second gas inlet holes.

[0005] Apparatus and methods for supplying a reaction gas together with a carrier gas to a process chamber through a gas inlet member are further known from Patent Documents 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, and 17. In the prior art, there are CVD reactors having a gas inlet member in the form of a showerhead. Within the gas inlet member, there is one or more gas distribution spaces that may extend over the entire surface of the gas outlet surface, or only over a segment or subsection of the gas outlet surface. A supply pipe opens into the gas distribution space, through which a process gas, which may be a mixed gas consisting of a reaction gas and a carrier gas or an inert gas, can be supplied to the gas distribution space. The process gas is substantially evenly distributed within the gas distribution space so that it can flow into the process chamber through the gas outlet hole on the gas outlet surface in evenly divided small gas flows. The process gas is uniformly distributed within the gas distribution space. In the prior art, the arrangement of gas distribution spaces is known, and it is known that multiple gas distribution spaces are arranged concentrically or in a band parallel to each other around the geometric center of a gas inlet member. Different process gases can be supplied to different gas distribution spaces, and in particular, process gases that differ only in the mixing ratio of reaction gas to carrier gas can also be supplied. Such an arrangement of gas distribution spaces makes it possible to set a concentration gradient of reaction gas in the carrier gas within the process chamber. At the boundaries of the gas distribution spaces, a large difference in the concentration of reaction gas in the process gas can occur within the process chamber.

[0006] For example, in an apparatus for depositing a GaN layer, a GaAlN layer, or a III-V layer system, a process gas is supplied through a gas outlet hole into the process chamber where the substrate is placed. The substrate is placed on a heated susceptor. Multiple layers can be deposited one above the other in sequential process steps. These process steps can be performed at different temperatures. In some processes, only one substrate may be placed on the susceptor, and it may be positioned concentrically with the gas outlet surface. The heat flow imparted by the heated susceptor causes the substrate to flex. In this case, the central region of the substrate may flex in the opposite direction to the gas outlet surface or flex toward the gas outlet surface. In either case, the distance from the substrate surface to the gas outlet surface in the central region changes. This distance differs between the central and peripheral regions. As a result, the layer in the central region is deposited at a different growth rate than the layer in the peripheral region. Depending on the direction of flexure, the deposited layer may be thicker or thinner in the central region than in the peripheral region. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent Application Publication No. 2007 / 0218200 [Patent Document 2] U.S. Patent Application Publication No. 2016 / 0194756 [Patent Document 3] U.S. Patent No. 6,756,235 [Patent Document 4] U.S. Patent Application Publication No. 2018 / 350562 [Patent Document 5] U.S. Patent Application Publication No. 2017 / 194172 [Patent Document 6] U.S. Patent Application Publication No. 2018 / 135177 [Patent Document 7] International Publication No. 2017 / 200696 [Patent Document 8] U.S. Patent Application Publication No. 2016 / 340781 [Patent Document 9] U.S. Patent Application Publication No. 2016 / 020074 [Patent Document 10] U.S. Patent Application Publication No. 2013 / 299009 [Patent Document 11] U.S. Patent Application Publication No. 2011 / 033638 [Patent Document 12] U.S. Patent Application Publication No. 2007 / 251642 [Patent Document 13] International Publication No. 2006 / 020424 [Patent Document 14] International Publication No. 01 / 04931 [Patent Document 15] U.S. Patent No. 6,161,500 [Patent Document 16] European Patent No. 0821084 [Patent Document 17] European Patent No. 0550058 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide means that can address radial non-uniformity of layer thickness caused by deflection. A further object of the present invention is to identify means that can set a small concentration gradient of reaction gas in the process gas within a process chamber. [Means for solving the problem]

[0009] The objective is achieved by the invention as specified in the claims, and the dependent claims not only represent an advantageous development of the subject matter described in the independent claims, but also serve as an independent solution to the objective.

[0010] It is essentially presented that a first gas inlet hole is opened in the gas distribution space, and a first gas flow containing at least one reaction gas can be supplied to the gas distribution space through this hole, and that a second gas inlet hole is opened in the same gas distribution space, and a second gas flow can be supplied to the gas distribution space through this hole.

[0011] According to a first aspect of the present invention, both gas flows may contain different or the same reaction gas at different concentrations. According to a second aspect of the present invention, one or more first gas inlet holes are located in the central region, and more second gas inlet holes are located in the peripheral region. In this case, the first and second gas inlet holes are arranged and the first and second gas flows are adjusted such that the gas flow exiting the gas inlet holes has a constant concentration of the reaction gas in the carrier gas in the circumferential direction relative to the center of the gas outlet surface. On the other hand, the concentration of the reaction gas in the carrier gas should be different in the radial direction relative to the center. Such embodiments and methods allow for the radial adjustment of the partial pressure of the group III components in the process chamber, for example, so that there is a higher or lower partial pressure in the central region than in the peripheral region, depending on the direction of substrate deflection, thereby allowing the growth rate in the central region to be greater or smaller than that in the peripheral region.

[0012] Therefore, it is proposed that at least two gas inlet holes are provided in the gas distribution space, through which gas or a gas mixture of different compositions is supplied to the gas space. This is done such that the gas is not uniformly mixed within the gas distribution space, but rather at least one region with a different concentration of the reaction gas is formed within the gas distribution space. As a result, in the regions containing reaction gases with different concentrations, a gas stream containing reaction gases with different concentrations flows into the process chamber through the gas outlet holes assigned to that region. Preferably, there is no partition wall, flow barrier, or reduced cross-section region, etc. between the two gas inlet holes, thereby forming a slow concentration gradient between the regions within the gas distribution space. However, a restriction plate extending within the gas distribution space can be provided, which can be, for example, a porous plate or a glass frit made of a porous and gas-permeable material. A small concentration gradient is formed within the process chamber.

[0013] In the above-described form of the present invention, it is proposed that another gas contains the second reaction gas. The second reaction gas can be the same as the first reaction gas, or can have different elements of the same main group. It may also be different from the first reaction gas in other respects. Furthermore, the other gas can be only a carrier gas or only an inert gas. However, a variant is preferred in which the same reaction gas but with different dilution degrees by the carrier gas is supplied to the gas distribution space through both gas inlet holes. Therefore, the present invention relates to an apparatus and a method in which the same reaction gas is supplied at two different locations in the same gas distribution space, but with different mixing ratios of the reaction gas to the carrier gas, thereby forming a concentration gradient within the gas distribution space. Furthermore, it is provided that the gas distribution space has a geometric center, and that one or more first gas inlet holes are arranged at or around the geometric center. One or more second gas inlet holes can be arranged at a location away from the geometric center. One or more gas distribution elements can be arranged within the gas distribution space.

[0014] The first gas flow can be supplied to the gas distribution space at the first supply location. The supply location can form a gas inlet hole. However, a gas distribution element forming a plurality of gas inlet holes can also be communicated with the supply location. One or more other gas distribution elements can be arranged around the first supply location, and the second gas flow can be supplied to the gas distribution space using them. The second gas flow is supplied to the gas distribution element at the second supply location. It flows into the gas distribution space through the gas inlet holes formed in the gas distribution element. These holes can extend in an annular arrangement around the geometric center. However, a plurality of other supply locations that are uniformly distributed around the geometric center and arranged at an equal distance from the geometric center can also be provided. In that case, another gas can also be directly supplied to the gas distribution space at that other supply location. However, that other gas can also be supplied to a gas distribution element that distributes the gas to the gas distribution space in a planar or linear manner. Furthermore, at the first supply location, a process gas can also be locally supplied. Also, here, it is also possible to supply the first process gas to a gas distribution element arranged in that region, which distributes the gas over a large area to the central region of the gas distribution space.

[0015] In particular, it is provided that the gas distribution element is arranged such that the radial concentration gradient of the reaction gas inside the gas distribution space can be adjusted and the concentration gradient in the azimuthal direction can be eliminated. The device or method according to the present invention is particularly suitable for depositing IV-IV layers, III-V layers, or II-VI layers on a large-area substrate. Preferably, a substrate having an area slightly smaller than the gas outlet surface is used. The gas outlet surface preferably extends at least over the entire surface of the substrate. The cross-section of the gas distribution space can extend over the entire gas outlet surface. According to a variant of the present invention, it is provided that two or more gas distribution spaces each extend over a partial surface of the gas outlet surface. Also, here, each of one or more gas distribution spaces has one first supply location and at least one other supply location, and gas mixtures having different compositions can be supplied at those locations.

[0016] Prior art describes a gas inlet member in which multiple gas distribution spaces run adjacent to each other in a strip-like manner. To produce the effects described above within a process chamber, process gases of different compositions are supplied to these multiple parallel gas distribution spaces at different supply points. For example, a central elongated gas distribution space can be provided so as to run through or approximately through the geometric center of the gas inlet member. A first supply point can be provided at the center of the central gas distribution space, and second supply points can be provided at each end of the gas distribution space. Both supply points can each form a gas inlet hole. However, gas distribution elements with gas inlet holes can also be provided at the supply points. In addition to these central gas distribution spaces, another elongated gas distribution space of a similar shape extends along the edge of the gas inlet member. Each of these gas distribution spaces has one central supply point and a second supply point at each end thereof. Reaction gases of different compositions or concentrations in the carrier gas can be supplied through both of these, preferably through the second supply points located at the edge of the gas inlet member.

[0017] The present invention can also be realized with respect to a gas inlet member in which a plurality of partial gas spaces are arranged in a concentric row. According to the present invention, a supply point or a gas distribution element fluidly communicating therewith is arranged such that the gas flow exiting the gas outlet hole on the gas outlet surface contains reaction gases of different concentrations radially with respect to the center of the gas outlet surface. The supply point or the gas distribution element assigned thereto may also be arranged such that the gas flow exiting the gas outlet hole contains reaction gases of a constant concentration in the azimuthal direction with respect to the center of the gas outlet surface.

[0018] However, it can also be provided that gas distribution elements are arranged in fluid communication with multiple supply points or supply pipes opening to those supply points, such that the gas flow exiting the gas outlet hole contains different concentrations of reaction gas across the entire surface of the gas outlet surface. This is advantageous when the reaction gas is supplied from a common gas source. The reaction gas reaches the CVD reactor from the gas mixing system via the supply pipe. The supply pipe can be branched. A first branch opens to a gas distribution space or gas distribution element at a first supply point. A second branch opens to a gas distribution space or gas distribution element at a second supply point. At the second branch, an additional carrier gas flow is supplied using a mass flow controller, thereby diluting the process gas supplied to the second branch compared to the process gas supplied to the first branch. However, it is also possible to dilute the process gas flow supplied to the first branch. However, preferably, the diluted gas is supplied in an annular region spaced apart from the center. This annular region may have a ring-shaped or horseshoe-shaped gas distribution element. Multiple annular regions can be arranged concentrically with respect to each other, and diluted reaction gas can be supplied to each of them, for example, using a gas distribution element or a supply pipe opening at that location.

[0019] An electronic control device can be provided to control the valves and mass flow controller. The control device is programmable and can also control the heating device or exhaust pump. In a further aspect of the present invention, the gas mixing system can be configured to provide process gas for two reactors. A mass flow controller can be provided to provide a mass flow of reaction gas. Another mass flow controller can be used to add carrier gas to the mass flow of reaction gas. This gas flow is supplied to only one gas distribution space at a first supply point, or is divided into two gas flows at multiple supply points, particularly two gas distribution spaces, belonging to different reactors. In a corresponding configuration, the gas mixing system also provides a smaller, separate carrier gas flow supplied to another branch of the process gas supply pipe. The process gas supply pipe opens to another supply point to supply diluted process gas to the gas distribution space. Preferably, the dilution is about 1-10% or 2-10%.

[0020] In one modification of the present invention, the gas distribution space can be separated into an upper and a lower portion. This separation is performed using the restricting plate described above. The restricting plate is gas permeable, but the passage of gas through the restricting plate requires a small pressure difference between the upper and lower portions. According to a modification of the present invention, all gas inlets or all gas distribution elements can be arranged so as to be located in the upper portion. In this modification, the same reaction gas, but with different concentrations in the carrier gas, is supplied to the upper portion through the gas inlets or gas distribution elements at different radial distances from the center of the gas inlets or the center of the gas distribution elements. Preferably, the reaction gas is a group III element. A group V element gas can be supplied to a separate gas distribution space. According to a further modification, the reaction gas is supplied, in particular, together with the carrier gas, through only one or more central gas inlets of the central gas distribution element. To dilute the reaction gas in the gas distribution space, only the carrier gas is supplied through the central gas inlets or other gas distribution elements arranged around the central gas distribution element. In this modified configuration, the central gas inlet or gas distribution element is located in the upper part. Another gas inlet or gas distribution element, supplied only with an inert carrier gas, is located in the lower part.

[0021] In yet another variant, a directed gas flow is provided to flow from a gas inlet hole into a gas distribution space. In this case, the gas flow is provided to have a directional component parallel to the direction in which the gas outlet surface extends. The gas distribution space may have one upper wall. The directional component of the gas flow may run parallel to the direction in which the upper wall extends. The gas flow may run entirely parallel to the direction in which the upper wall extends. In yet another variant, a gas flow exiting a gas inlet hole is provided to have a directional component in the direction of the upper wall. The gas flow may be inclined toward the upper wall. Thus, it may have a directional component away from the gas outlet surface and at the same time have a directional component in the direction in which the gas outlet surface extends. Preferably, the gas inlet holes are arranged regularly in a region around the geometric center of the gas outlet surface. [Brief explanation of the drawing]

[0022] Hereinafter, examples of embodiments of the present invention will be described with reference to the attached drawings. [Figure 1] Figure 1 shows a schematic longitudinal section through the CVD reactor 1, illustrating a first exemplary embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 3 is a diagram similar to Figure 1 of the second exemplary embodiment. [Figure 4] Figure 4 is a diagram similar to Figure 2 of the second exemplary embodiment. [Figure 5] Figure 5 is a diagram similar to Figure 1 of the third exemplary embodiment. [Figure 6] Figure 6 is a top view along arrow VI in Figure 5. [Figure 7] Figure 7 is a diagram similar to Figure 1 of the fourth exemplary embodiment. [Figure 8] Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7. [Figure 9] Figure 9 is a diagram similar to Figure 1 of the fifth exemplary embodiment. [Figure 10]Figure 10 is a cross-sectional view taken along line XX in Figure 9. [Figure 11] Figure 11 is a diagram similar to Figure 1 of the sixth exemplary embodiment. [Figure 12] Figure 12 is a cross-sectional view taken along line XII-XII in Figure 11. [Figure 13] Figure 13 is a schematic diagram of the seventh exemplary embodiment. [Figure 14] Figure 14 is a schematic diagram of the eighth exemplary embodiment. [Figure 15] Figure 15 is a diagram similar to Figure 1 of the ninth exemplary embodiment. [Figure 16] Figure 16 is a diagram similar to Figure 1 of the tenth exemplary embodiment. [Figure 17] Figure 17 is a diagram similar to Figure 1 of the 11th exemplary embodiment. [Modes for carrying out the invention]

[0023] The exemplary embodiments relate to arrangements having at least one CVD reactor 1, the CVD reactor 1 being supplied with process gas by a gas mixing system, and the CVD reactor 1 being provided with a gas exhaust system (not shown) which may have a pump and a gas cleaning device. The CVD reactor 1 has an externally airtight housing comprising a housing wall 3 surrounding a cavity. Inside the vacuumable cavity of the reactor housing 1 is a graphite susceptor 3, the susceptor 3 supporting one or more coated substrates 4 on its upward-facing surface. Below the susceptor 3, which is formed as a disc, is a heating device 5 which can be used to heat the susceptor 3 to a process temperature between 500°C and 1000°C.

[0024] A process chamber 8 extends above the susceptor 3, into which process gas is supplied. The process chamber 8 is realized by a gas outlet surface 6' that forms a ceiling, and this gas outlet surface 6' is realized by a shielding plate 9. However, a diffusion plate can be placed there instead of the shielding plate. However, the gas outlet surface 6' can also be directly formed by the floor plate of the gas inlet member 10.

[0025] In an exemplary embodiment, a gas inlet member 10 extending directly above the shielding plate 9 is formed by a hollow body having at least one gas distribution space 11. In an exemplary embodiment, the gas inlet member 10 has another gas distribution space 13 extending below the gas distribution space 11. Adjacent to the floor plate of the gas inlet member 10 is a refrigerant chamber 14 through which a cooling medium flows. Each chamber forming the gas distribution spaces 11, 13 is in fluid communication with a gas outlet surface 6' by pipes 17, 20, so that the process gas supplied to the gas distribution spaces 11, 13 can exit the gas outlet surface 6' in a uniformly distributed flow. The process gas flows into the process chamber 8 and flows radially through the process chamber 8 toward the gas outlet element 6. The gas outlet element 6 encircles the process chamber 8 in an annular manner and is connected to a gas discharge system by a gas outlet 7. Both gas distribution spaces 11, 13, shown only schematically, may be supplied with different reaction gases, each along with a carrier gas. As the reaction gases pass through tubes 17 and 20 and reach the process chamber 8 where they decompose and react with each other, a layer of reaction products of the reaction gases is deposited on the surface of the substrate.

[0026] A reaction gas containing Group III elements can be supplied to the gas distribution space 11 together with an inert gas, such as hydrogen. The inert gas constitutes the carrier gas. A reaction gas containing Group V elements can be supplied to the gas distribution space 13 together with an inert gas, such as hydrogen. A chemical reaction can occur between both reaction gases in the gas phase above the substrate 4 or on the surface of the substrate 4, thereby depositing layers consisting of Group III and Group V elements on the surface of the substrate 4. The growth rate is determined by the partial pressure of the Group III reaction gas, which can form organometallic compounds, on the substrate surface, or by the mass flow of the Group III reaction gas from the gas outlet surface.

[0027] The present invention will be described in more detail below with reference to the gas distribution space 11.

[0028] The gas distribution space 11 extends over the entire circular gas outlet surface 6' in the exemplary embodiments of the first to fourth and ninth to eleventh shown in Figures 1 to 8 and 15 to 17. The gas outlet holes 16 or corresponding pipes 1 7 The gas is uniformly distributed across the entire gas outlet surface 6'. Supply pipes 35, 36, and 38 open into the gas distribution space 11 at at least two different supply points 12, 23, and 26, thereby supplying each process gas to the gas distribution space 11 at different locations. In this case, the process gas enters the gas distribution space 11 through gas inlet holes 25, 28, and 39. In the exemplary embodiments shown in Figures 1 to 8, the gas distribution space has a constant height across its entire surface and does not have partitions or other elements that obstruct the flow of gas within the gas distribution space 11. In the exemplary embodiments shown in Figures 15 to 17, partitions or diffusion or flow barriers 40 are provided to allow molecules to slowly penetrate from one region to another in the gas distribution space 11. For each of the different supply points 12, 23, and 26, one region is assigned that is in fluid communication with the other regions.

[0029] Mixtures of reaction gases accompanied by carrier gases are supplied to three different supply points 12, 23, and 26, and the mixing ratio of each reaction gas to the carrier gas or inert gas differs at each supply point 12, 23, and 26.

[0030] The mixing ratio is set by the gas mixing system. The gas mixing ratio includes a gas source 30 for the reaction gas and a gas source 31 for the carrier gas or inert gas. The reaction gas may be an organometallic compound of a group II, III, or V element. It may also be a hydride of a group IV, V, or VI element. Preferably, it is a mixture of such gases. The inert gas may be hydrogen, nitrogen, or a noble gas. A mass flow of the reaction gas is provided by a mass flow controller 32 and diluted with the carrier gas using a mass flow controller 33. The mass flow of the process gas thus provided is divided into a supply pipe 35 that opens to a central gas inlet 12 in the gas distribution space 11 and a supply pipe 36 that opens to a peripheral gas inlet 23 in the gas distribution space 11. By supplying a carrier gas flow to the supply pipe 36 using a mass flow controller 34, the process gas supplied to the peripheral gas inlet 23 is diluted with respect to the process gas supplied to the central gas inlet 12.

[0031] In the exemplary embodiments shown in Figures 1 and 2, a gas distribution element 24 extends inside the gas distribution space 11, which may be formed as a pipe having an annular outer shape and bent in an annular manner. The walls of the gas distribution element 24 have gas inlet holes 25 that supply process gas supplied to the surrounding gas inlet locations 23 to the annular region around the geometric center of the gas distribution space 11.

[0032] At the gas inlet location 12 shown in Figure 1, a single supply pipe opens into the gas distribution space 11. Here, the gas inlet location 12 is formed from a gas inlet hole 39. However, it is also possible for multiple supply pipes to open into the gas distribution space 11 at its center. A first gas flow, which is a mixture of carrier gas and reaction gas, can flow into the gas distribution space 11 through one or more gas inlet holes 39. Furthermore, it is also possible to arrange an annular hole or a ring concentric with the gas inlet hole at the central gas inlet location.

[0033] A second gas stream, a mixture of carrier gas and reaction gas, flows into the gas distribution space 11 through the gas inlet hole 25. However, its mixing ratio is different from that of the first gas stream.

[0034] The gas outlet holes 16 can be located at the intersections of the grid, and the cells of the grid can be selected to be rectangular, square, hexagonal, or polygonal. However, the gas outlet holes 16 can also be placed on concentric lines around the center of the gas outlet surface.

[0035] The second exemplary embodiment shown in Figures 3 and 4 differs substantially from the first exemplary embodiment in that a radially inward gas distribution element 27, which is also ring-shaped, is positioned within a radially outward gas distribution element 24. Both gas distribution elements 24 and 27 are concentrically positioned with respect to the central gas inlet 12. A supply pipe 38 opens at the gas inlet 26, and process gas diluted with carrier gas using a mass flow controller 37 is supplied through the supply pipe 38. By adjusting the degree of dilution of the process gas using the mass flow controllers 34 and 37, a radial concentration gradient is formed within the gas distribution space 11. As a result, process gas containing a higher concentration of reaction gas than that passing through the surrounding gas outlet holes 16 is supplied to the process chamber 8 through the gas outlet hole 16 located at the center of the gas outlet surface 6'.

[0036] In exemplary embodiments not shown, more than two annular regions can be provided within the gas distribution space 11, and gas distribution elements extending within each region are provided.

[0037] The gas inlet holes 25 or 28 of the gas distribution element 24 or 27 can extend in a direction perpendicular to the plane on which the gas distribution elements 24 and 27 extend, respectively. The gas inlet holes 25 or 28 can each be lateral holes. However, the gas inlet holes 25, 2 8 The opening can also be toward the gas outlet surface 6'. Therefore, the gas inlet holes 25 or 28 can each be downward-facing holes. However, the gas inlet holes 25 and 28 can also be upward-facing, and thus may have a directional component that moves away from the gas outlet surface 6'.

[0038] In the exemplary embodiments shown in Figures 5 and 6, a central gas inlet is provided at a central supply point 12 located at the geometric center of a gas distribution space 11 having a circular base. Multiple other supply points 23 are provided, uniformly distributed circumferentially around the geometric center. Each of the supply points 12 and the surrounding supply points 23 can directly supply process gases containing different mixtures to the gas distribution space.

[0039] In the exemplary embodiments shown in Figures 7 and 8, the central gas distribution element 43 is positioned at the geometric center of the gas distribution space 11. This is a pipe bent into an annular shape with a gas inlet hole 39 located in the pipe wall, supplied by a supply pipe (not shown), and the gas distribution element is located at the supply point 12. 43 It opens to the periphery. A plurality of gas distribution elements 24 are arranged around the central gas distribution element 43, uniformly distributed circumferentially, and in exemplary embodiments, they are formed by annularly bent pipes, which also have holes 25 in their pipe walls. The plurality of periphery gas distribution elements 24 can be supplied with the same process gas, i.e., the same mixture of reaction gas with carrier gas. However, different gas distribution elements 24 can also be supplied with different mixtures of reaction gas with carrier gas.

[0040] Each supply point 23 is provided with a gas distribution element 24 formed from a ring-shaped pipe. The gas distribution element 24 has a gas inlet hole 39 and extends in the region surrounding the central gas distribution element 43.

[0041] In the exemplary embodiments shown in Figures 9 and 10, the gas inlet member 10 has a plurality of gas distribution spaces 11 arranged in a strip. The central gas distribution space 11 extends diametrically through the center of the circular gas inlet member 10. Another gas distribution space 11 is adjacent to each of the long sides of the elongated gas distribution space 11. The plurality of elongated gas distribution spaces 11 are adjacent to each other and extend across the entire gas outlet surface 6'.

[0042] Each gas distribution space 11 has a first supply point 12, 12' in its center, from which process gas can be supplied to each gas distribution space. Except for the outer gas distribution space 11, each gas distribution space 11 further has another supply point 23 located at the edge of the gas outlet surface 6' at both ends, from which process gas containing different mixtures can be supplied.

[0043] The central supply point 12 corresponds to the gas inlet hole 39 for supplying the first gas flow. Each of the supply points 23 corresponds to a gas inlet hole 25 for supplying a second gas flow. The central supply points 12, 12', and 12'' can be supplied from a single common supply pipe. Similarly, supply points 23 can be supplied from a single common supply pipe.

[0044] In the exemplary embodiment described above, the susceptor 3 supports a single large-area substrate 4. However, in further exemplary embodiments (not shown) that correspond to the embodiments described above in other respects, multiple substrates 4 can be arranged on the susceptor 3, as shown in Figure 11.

[0045] The exemplary embodiments shown in Figures 11 and 12 differ substantially from the exemplary embodiments described above in the shape of the horseshoe-shaped gas distribution element 24. Furthermore, in these embodiments, multiple gas distribution elements 24 can be arranged concentrically with respect to the geometric center of the gas distribution space 11.

[0046] In this exemplary embodiment, different process gases can be supplied to both supply points 12 and 23. For this purpose, separate mass flow controllers 32', 33' are provided to generate a mixture of reaction gas supplied from gas source 30' and carrier gas supplied from gas source 31. This process gas mixture is supplied to supply point 23 of the gas distribution element 24 by a supply pipe 35'. The gas distribution element 24 comprises a plurality of uniformly spaced gas inlet holes 25 facing both laterally and downward.

[0047] The figure also shows a control device 42, which can be used to control the mass flow controllers 32, 37, and 34, as well as the gas sources 30, 31, or the heating device 5. The control device 42 can be used to control the gas flow so that the concentrations of the reaction gas in the process chamber described at the beginning and below are achieved.

[0048] The exemplary embodiment shown in Figure 13 illustrates a modified gas mixing system in which a mixture of reaction gas and carrier gas is generated by mass flow controllers 32 and 33. This mixture is supplied through a supply pipe that branches multiple times. The supply pipe first branches into a supply pipe 35 that opens to a supply point 12 in the gas distribution space 11 of the first CVD reactor 1, and then into a supply pipe 35' that opens to the gas distribution space 11 of the second CVD reactor 1'.

[0049] Two mass flow controllers 34 and 37 are provided, each used to dilute the process gas with carrier gas supplied to supply pipes 36 or 38, respectively. Each supply pipe 36 or 38 opens to a supply point 23 in the gas distribution space 11. The CVD reactors 1 and 1' can be configured as shown in Figures 1 to 11.

[0050] The exemplary embodiment shown in Figure 14 illustrates a further variation of the gas mixing system in which only carrier gas is supplied to the gas distribution space 11 at the surrounding supply points 23.

[0051] Figure 15 shows an exemplary embodiment that is substantially different from the exemplary embodiment shown in Figure 1, in that the gas inlet hole 25 is oriented at an inclination with respect to the upper wall 44 of the gas distribution space 11. Furthermore, Figure 15 shows a measuring instrument 41, for example, an optical measuring instrument, which can be used to determine the deflection of the substrate 4. The measuring instrument can provide the measured value to the control device 42. Mino Depending on the degree, the control device 42 can be used to change the mixing ratio of the reaction gas and carrier gas in the gas flow to individual supply points 12 and 23. Thus, during the deposition process, the mixing ratio of the gas flow is changed by the control device 42, and this change may depend on the measured deflection of the substrate 4. However, the mixing ratio may also depend on the type of individual process step. The deflection may range from 0.5 to 1 mm.

[0052] Figure 16 shows a further variation in which multiple annular gas distribution elements 24 are arranged around a central annular gas distribution element 43. A first gas flow can be supplied to the upper portion of the gas distribution space 11 through the gas inlet holes 39 of the central annular gas distribution element 43, and multiple second gas flows can be supplied through the gas inlet holes 25 of the surrounding gas distribution elements 24. The upper portion is separated from the lower portion by a limiting plate 40. The lower portion is in fluid communication with the gas outlet surface 6' by a pipe 17. In the exemplary embodiment shown in Figure 16, all gas distribution elements 24, 43 are located in the upper portion. Each gas distribution element 24, 43 supplies a mixture of reactive gases together with an inert gas, but with different mixing ratios. The gas distribution elements 24, 43 may be located in a common plane.

[0053] In the exemplary embodiment shown in Figure 17, the gas distribution space 11 is divided into an upper and lower portion by a limiting plate 40. A gas distribution element 43 is located in the upper portion, thereby supplying the reaction gas along with the inert gas to the upper portion. In the lower portion, a plurality of ring-shaped gas distribution elements 24 are located in a common plane. Here, the gas distribution elements 24 are located in a different plane from the gas distribution elements 43. In this exemplary embodiment, the gas distribution elements 24 located in the lower portion supply only the carrier gas to the lower portion of the gas distribution space 11 as a means of diluting the process gas.

[0054] In exemplary embodiments, these gas distribution elements are shown as annular, closed or horseshoe-shaped pipes. However, these gas distribution elements may also have other shapes, such as walled cavities with holes capable of supplying process gases to the gas distribution space over a large area.

[0055] The above description is intended to explain the inventions encompassed by the entire application, which, in each case, independently further advance the prior art through at least a combination of the following features, where any combination of two, more, or all of these features is possible.

[0056] A method characterized in that a gas different from the process gas is supplied to the same gas distribution space at at least one second supply point 23, 26 such that regions with different concentrations of reaction gas are formed within the gas distribution space 11.

[0057] The apparatus is characterized in that openings for supply points 23 and 26 are arranged so as to form regions with different concentrations of reaction gas within the gas distribution space 11, and mass flow controllers 32, 33, 34, and 37 are connected to them.

[0058] A method characterized in that both gas streams contain different or the same reaction gas at different concentrations in the carrier gas.

[0059] A method characterized in that the first and second gas inlet holes 39, 25, and 28 are arranged such that the gas flow exiting the gas outlet hole 16 has a constant concentration of reaction gas in the carrier gas in the azimuthal direction with respect to the center of the gas outlet surface 6', and different concentrations of reaction gas in the carrier gas in the radial direction with respect to the center, and the first and second gas flows are adjusted.

[0060] A method characterized in that at least one of both gas streams contains a carrier gas, thereby diluting the reaction gas, or each of at least two gas streams contains the reaction gas in the carrier gas at different concentrations.

[0061] A method characterized by supplying only carrier gas to the gas distribution space 11 through second gas inlet holes 25 and 28.

[0062] A method characterized in that a reaction gas has elements of Group III, a second reaction gas having elements of Group V is supplied to a second gas distribution space 13, and the two reaction gases are supplied to a process chamber 8 through a gas outlet hole 16.

[0063] A method characterized in that gas flows of reaction gases with different concentrations in the carrier gas are supplied into the process chamber 8 in at least three, four, or five concentrically arranged regions around the center.

[0064] A method characterized in that the concentration of the reaction gas in at least one of a plurality of gas streams is changed during the deposition of at least one substrate 4.

[0065] A method characterized in that, during layer deposition, the deflection of the substrate 4 is monitored, and the concentration of the reaction gas in at least one of several gas flows is changed according to the degree of deflection of the substrate 4.

[0066] A method characterized in that the gas distribution space 11 is separated into an upper and lower portion by a limiting plate 40, and a first gas flow is supplied to the upper portion and a second gas flow is supplied to the lower portion, or both gas flows are supplied to the upper portion.

[0067] A method characterized in that a process gas flow consisting of a carrier gas and a reaction gas is equally separated into one or more gas flows, and an additional carrier gas for dilution is supplied to at least one of the gas flows.

[0068] A method characterized in that the additional carrier gas constitutes a maximum of 2% or 1% of the process gas flow.

[0069] Gas distribution elements 24, 27, 29 are used, each having gas inlet holes 39, 28 for supplying a first and / or second gas flow, and the gas flow from the gas inlet holes 39, 28 into the gas distribution space 1 1 A method characterized in that gas flows into a gas outlet, and the gas flow has a component in a direction parallel to the plane on which the gas outlet surface 6' extends and / or a component in a direction away from the gas outlet surface 6'.

[0070] The apparatus is characterized in that mass flow controllers 32, 33, 34, and 37 are arranged such that either two different reaction gases with different concentrations in the carrier gas, or the same reaction gas, are supplied to the gas distribution space 11 through both supply pipes 35; 36, and 38.

[0071] An apparatus characterized in that a reaction gas source 30 is in fluid communication with a first supply pipe 35 and second supply pipes 36, 38, and a carrier gas source 31 is in fluid communication with at least one of the first or second supply pipes 35; 36, 38, or another reaction gas source is in fluid communication with the second supply pipes 36, 38.

[0072] The apparatus is characterized in that the second gas inlet holes 25 and 28, which are in fluid communication with the second supply pipes 36 and 38, are arranged on concentric lines or in concentric regions around the geometric center of the gas outlet surface 6'.

[0073] The apparatus is characterized in that one or more second supply pipes 36, 38 open into gas distribution elements 24, 27, 29 which are spaces located within the gas distribution space 11 and form second gas inlet holes 25, 28, and one or more gas distribution elements 24, 27, 29 extend in a region that runs concentrically around the geometric center of the gas outlet surface 6'.

[0074] The apparatus is characterized in that at least one first gas inlet hole 39 opens to the upper part of the gas distribution space 11, and second supply pipes 36 and 38 open to the lower part of the gas distribution space 11, with the lower part separated from the upper part by a limiting plate 40.

[0075] The apparatus is characterized in that a gas distribution space 11 is connected to a gas source 30 containing a reaction gas containing elements of Group III, and a second gas distribution space 13, which is in fluid communication with a gas outlet hole 16 located on the gas outlet surface 6', is connected to a gas source containing a second reaction gas containing elements of Group V.

[0076] The apparatus is characterized in that one first gas inlet hole 39 is assigned to a central gas inlet location 12, or multiple first gas inlet holes 39 are assigned to a central gas distribution element 29, and a second gas inlet hole 28 is formed in at least one gas distribution element 24, 27, 29, and the gas distribution elements 24, 27, 29 distribute the second gas flow supplied to the gas distribution elements 24, 27 at at least one gas inlet location 23, 26 to the gas distribution space in the form of a space arranged within the gas distribution space 11.

[0077] The apparatus is characterized in that the first or second gas inlet holes 25, 28, 39 generate a gas flow having a flow direction having a directional component perpendicular to the flow direction of the gas flow from the gas distribution space 11 to the gas outlet surface 6' and / or a directional component moving away from the gas outlet surface 6'.

[0078] The apparatus is characterized in that the gas distribution elements 24 and 27 extend along concentric lines around the geometric center of the gas outlet surface 6' and have a plurality of gas inlet holes 25 and 28 that open into an annular region around the geometric center.

[0079] The apparatus is characterized in that two, three, four, or five gas distribution elements 29 are arranged concentrically around a central gas inlet location 12 or around a central gas inlet element.

[0080] The apparatus is characterized by being provided with a measuring instrument 41 capable of measuring the deflection of the substrate 4, and a control device 42 that changes the concentration of the reaction gas in the first or second gas stream according to the deflection of the substrate 4.

[0081] The apparatus is characterized in that a first supply point 12 for supplying a first gas flow is located in the center of the gas distribution space 11, and two second supply points 23 for supplying a second gas flow are located at the edges of the gas distribution space 11.

[0082] All disclosed features are essential to the present invention (both in themselves and in combination with each other). The disclosures of this application encompass the disclosures of any related / additional priority documents (copies of earlier applications) in their entirety, and are intended to incorporate the features of those documents into the claims of this application. Dependent claims feature independent inventive further developments of the prior art, even without the features of the cited claims, particularly for the purpose of filing a divisional application based on these claims. The invention specified in each claim may have one or more additional functions, particularly those specified in the preceding description, especially those to which reference numerals are assigned, and / or specified in the descriptions of the reference numerals. The present invention also relates, in particular, to embodiments in which individual features described above are not implemented, insofar as they are obviously unnecessary for their respective intended use or can be replaced by other means having the same technical effect. [Explanation of Symbols]

[0083] 1 Reactor Housing 1' CVD Reactor 2 Housing Walls 3 Susceptors 4 circuit boards 5 Heating device 6. Gas outlet mechanism 6' Gas outlet surface 7 Gas outlet 8 process chambers 9 Shielding plate 10 Gas inlet member 11 Gas distribution space 12. Central gas inlet and supply points 13 Gas distribution space 14 Refrigerant Chamber 15 Gas outlet plate 16 Gas outlet hole 17 tube 18. Partition plate 19 Gas outlet hole 20 tubes 21 Partition Plate 23. Gas inlet and supply locations in the surrounding area 24 Gas distribution elements 25 Gas inlet port 26. Surrounding gas inlet locations 27 Gas distribution elements 28 Gas inlet hole 29 Gas distribution elements 30 Gas sources, reaction gases 30' Gas source, reaction gas 31. Gas sources, conveying gases / inert gases 32 Mass Flow Controllers 32' Mass Flow Controller 33 Mass Flow Controller 33' Mass Flow Controller 34 Mass Flow Controller 35 Supply pipe 35' supply pipe 36 Supply pipe 37 Mass Flow Controller 38 Supply pipe 39' Gas inlet port 40 Restriction Plate 41 Optical measuring instruments 42 Control device 43 Gas distribution elements 44 Upper wall

Claims

1. A method for depositing at least one layer on a substrate (4), A first gas flow containing at least one reaction gas is supplied to at least one gas distribution space (11) of the gas inlet member (10) through at least one first gas inlet hole (39), and at least one second gas flow is supplied through a plurality of second gas inlet holes (25, 28). The gas inlet member (10) has a circular gas outlet surface (6') facing the process chamber (8) and is equipped with a number of gas outlet holes (16) that are in fluid communication with the gas distribution space (11), and the reaction gas flows into the process chamber (8) through these gas outlet holes (16), and the products of the physical or chemical reaction of the reaction gas that has flowed into the process chamber (8) form a layer on the surface of the substrate (4), such that only one substrate (4) is placed on the susceptor (3) in the process chamber (8) concentrically with the gas outlet surface (6'). The at least one first gas inlet hole (39) is located in the central region of the gas inlet member (10), and the plurality of second gas inlet holes (25, 28) are located in the peripheral region of the gas inlet member (10) radially outward from the central region, and In the method, both of the aforementioned gas streams contain different or the same reaction gas at different concentrations in the carrier gas, A method characterized in that, during the deposition of the layer, the deflection of the substrate (4) is monitored, and the concentration of the reaction gas in at least one of the first or second gas flows is changed according to the degree of deflection of the substrate (4).

2. The method according to claim 1, characterized in that at least one of the two gas streams contains a carrier gas that dilutes the reaction gas, or each of the at least two gas streams contains the reaction gas in the carrier gas at different concentrations.

3. The method according to 1 or 2, characterized in that the reaction gas contains elements of Group III, a second reaction gas containing elements of Group V is supplied to a second gas distribution space (13), and both reaction gases are supplied to the process chamber (8) through a gas outlet hole (16).

4. The method according to any one of 1 to 3, characterized in that gas flows of the reaction gas with different concentrations in the carrier gas are supplied to the process chamber (8) to at least three, four, or five concentrically arranged regions around the center.

5. The method according to any one of 1 to 4, characterized in that the concentration of the reaction gas in at least one of the plurality of gas flows is changed during the deposition of at least one of the layers (4).

6. The method according to any one of 1 to 5, characterized in that a gas distribution element (24, 27, 29) having gas inlet holes (39, 28) is used for supplying the first and / or second gas flow, the gas flow flows from the gas inlet holes (39, 28) into the gas distribution space (1), and the gas flow has a directional component parallel to the plane on which the gas outlet surface (6') extends and / or a directional component away from the gas outlet surface (6').

7. An apparatus for depositing at least one layer on a substrate (4), The system comprises a gas inlet member (10) having a circular gas outlet surface (6') facing the process chamber (8) and equipped with numerous gas outlet holes (16), a susceptor (3) having a support surface facing the process chamber (8) for receiving the substrate (4) to be coated, and a gas mixing system. A single substrate (4) is placed on the susceptor (3) concentrically with the gas outlet surface (6'), The gas mixing system comprises a mass flow controller (32, 33, 34, 37), at least one gas source (30) for the reaction gas, and a gas source (31) for the carrier gas. The gas mixing system is capable of providing and supplying a first gas flow containing the reaction gas to a first supply pipe (35), the first supply pipe (35) having at least one first gas inlet hole (39), and The gas mixing system is capable of providing a second gas flow and supplying it to a second supply pipe (36, 38), the second supply pipe (36, 38) having a plurality of second gas inlet holes (25, 28), The first and second gas inlet holes (39; 25, 28) open into at least one gas distribution space (11) of the gas inlet member (10), and the gas distribution space (11) and the gas outlet hole (16) are in fluid communication. The at least one first gas inlet hole (39) is located in the central region of the gas inlet member (10), and the plurality of second gas inlet holes (25, 28) are located in the peripheral region of the gas inlet member (10) radially outward from the central region, and In the apparatus, the mass flow controllers (32, 33, 34, 37) are arranged such that either two different reaction gases with different concentrations in the carrier gas, or the same reaction gas, flow through both of the supply pipes (35; 36, 38), The apparatus is characterized by being provided with a measuring instrument (41) capable of measuring the deflection of the substrate (4), and a control device (42) that changes the concentration of the reaction gas in the first or second gas stream according to the deflection of the substrate (4).

8. The apparatus according to claim 7, characterized in that the gas source (30) of the reaction gas is in fluid communication with the first supply pipe (35) and the second supply pipes (36, 38), and the gas source (31) of the carrier gas is in fluid communication with at least one of the first or second supply pipes (35; 36, 38), or another gas source of the reaction gas is in fluid communication with the second supply pipes (36, 38).

9. The apparatus according to claim 7 or 8, characterized in that the second gas inlet holes (25, 28) that are in fluid communication with the second supply pipes (36, 38) are arranged on a concentric line or in a concentric region around the geometric center of the gas outlet surface (6').

10. The apparatus according to any one of claims 7 to 9, The apparatus is characterized in that one or more second supply pipes (36, 38) open into gas distribution elements (24, 27, 29) which are spaces located within the gas distribution space (11) and form the second gas inlet holes (25, 28), and one or more of the gas distribution elements (24, 27, 29) extend in a region that runs concentrically around the geometric center of the gas outlet surface (6').

11. The apparatus according to any one of claims 7 to 10, The apparatus is characterized in that at least one first gas inlet hole (39) opens into the upper part of the gas distribution space (11), and the second supply pipes (36, 38) open into the lower part of the gas distribution space (11), and the lower part is separated from the upper part by a limiting plate (40).

12. The apparatus according to any one of 7 to 11, characterized in that the gas distribution space (11) is connected to a gas source (30) containing a reaction gas containing elements of Group III, and a second gas distribution space (13) that is in fluid communication with a gas outlet hole (16) located on the gas outlet surface (6') is connected to a gas source containing a second reaction gas containing elements of Group V.

13. The apparatus according to any one of 7 to 12, characterized in that one of the first gas inlet holes (39) is assigned to a central gas inlet location (12), or a plurality of first gas inlet holes (39) are assigned to a central gas distribution element (29), and a second gas inlet hole (28) is formed in at least one gas distribution element (24, 27, 29), and the gas distribution element (24, 27, 29) distributes the second gas flow supplied to the gas distribution element (24, 27) at at least one gas inlet location (23, 26) to the gas distribution space in the form of a space arranged in the gas distribution space (11).

14. The apparatus according to any one of 7 to 13, characterized in that the first or second gas inlet holes (25, 28, 39) generate a gas flow having a flow direction having a directional component perpendicular to the flow direction of the gas flow from the gas distribution space (11) to the gas outlet surface (6') and / or a directional component moving away from the gas outlet surface (6').

15. The apparatus according to claim 10 or 13, characterized in that the gas distribution elements (24, 27) extend along concentric lines around the geometric center of the gas outlet surface (6') and have a plurality of gas inlet holes (25, 28) that open into an annular region around the geometric center.

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