Method for chemically depositing a semiconductor layer, separating system, and spray nozzle assembly

Abstract

The invention relates to a method for chemically depositing a semiconductor layer (10) from a vapor phase onto a substrate (12), having the steps of placing the substrate (12) in a process chamber (14), heating (44) the substrate (12), discharging (40) a precursor liquid (16) in the form of an aerosol (20) in the process chamber (14) and moving (42) the aerosol (20) in the direction of the substrate (12), and evaporating the discharged precursor liquid (16) in an evaporation zone (22) directly adjoining the substrate (12). The invention also relates to a separating system (70) for carrying out the method and to a spray nozzle assembly (50).

Description

[0001] NXW002DE0 20.12.2024

[0002] 1

[0003] Method for the chemical deposition of a semiconductor layer,

[0004] Separation system and spray nozzle arrangement

[0005] The invention relates to a method for chemically depositing a semiconductor layer from a vapor phase onto a substrate, a spray nozzle arrangement for use in this method, and a deposition system for carrying out the method.

[0006] Semiconductor layers are often produced by chemically depositing them from a vapor phase onto a substrate. In English, such processes are commonly referred to as chemical vapor deposition, or CVD for short. Both relatively thin and comparatively thick layers can be deposited using chemical vapor deposition. In particular, semiconductor layers can be deposited with such thickness that, after separation from the substrate, they form self-supporting semiconductor wafers. If the deposition is epitaxial on a monocrystalline seed substrate, monocrystalline semiconductor wafers can be produced cost-effectively in this way, for example, for the manufacture of solar cells.The quality of the deposited semiconductor layers has a significant influence on the performance of the semiconductor devices manufactured from these semiconductor layers, especially the solar cells manufactured from these semiconductor layers.

[0007] From US 8,465,587 B2, it is known to pass precursor gases through distributor plates or diffuser plates provided with a plurality of holes for the purpose of depositing a semiconductor layer. In this way, a laminar flow is formed which is directed onto the substrate to be coated and NXW002DE0 20.12.2024

[0008] 2

[0009] The precursor gases flow towards the heated substrate. Until now, it was assumed that such laminar flow was essential for the deposition of high-quality semiconductor layers. However, as the gases approach the heated substrate, they become increasingly hotter, leading to premature chemical reactions of the precursor and / or carrier gases. This, in turn, results in the nucleation of semiconductor material before the precursor and carrier gases reach the surface of the substrate to be coated or any components of the semiconductor layer already deposited on it. Such premature nucleation can negatively impact the quality of the deposited semiconductor layer. In particular, the homogeneity of the deposited semiconductor layer can be adversely affected.

[0010] Against this background, the present invention aims to provide a method by which semiconductor layers can be deposited with improved quality.

[0011] This problem is solved by a method having the features of claim 1.

[0012] Furthermore, the invention is based on the objective of providing a spray nozzle arrangement which enables the efficient implementation of the method according to the invention.

[0013] This problem is solved by a spray nozzle arrangement having the features of claim 14.

[0014] Furthermore, the invention is based on the objective of providing a separation system for carrying out the process according to the invention. NXW002DE0 20.12.2024

[0015] 3

[0016] This problem is solved by a separation system with the features of claim 17.

[0017] Advantageous further training courses are each the subject of dependent sub-claims.

[0018] The inventive method for chemically depositing a semiconductor layer from a vapor phase onto a substrate involves arranging the substrate in a process chamber. The substrate is heated. This can be achieved using a holding device in which the substrate is accommodated and which incorporates an electrical resistance heater. In principle, the holding device can be heated in any suitable manner known per se.

[0019] The method according to the invention further provides that a precursor liquid is dispensed in the process chamber in the form of an aerosol and that the aerosol is moved towards the substrate. Dispensing in the form of an aerosol, as used here, means that the precursor liquid is dispensed in the process chamber in such a way that it exists there as an aerosol. The aerosol thus contains, in addition to the precursor liquid, at least one gaseous component. Moving the aerosol towards the substrate, in other words, means that the aerosol is moved towards the substrate. Furthermore, in the method according to the invention, the dispensed precursor liquid is evaporated in an evaporation zone immediately adjacent to the substrate.

[0020] The described process makes it possible to keep precursor materials at comparatively low temperatures for extended periods. By using the precursor substances as a precursor liquid in the NXW002DE0 20.12.2024

[0021] 4

[0022] When the precursor liquid is dispensed from the process chamber, its enthalpy of vaporization can be used to cool the precursor substances. This ensures that the temperature of the precursor substances only rises sharply deep within the evaporation zone, and thus very shortly before reaching the substrate. Premature nucleation can therefore be avoided or at least significantly reduced. This makes it possible to produce semiconductor layers of improved quality.

[0023] Preferably, a semiconductor substrate is used as the substrate, particularly preferably a silicon substrate.

[0024] In a preferred embodiment, the semiconductor layer is epitaxially deposited onto the substrate. Advantageously, a monocrystalline semiconductor substrate is used, enabling the deposition of monocrystalline semiconductor layers. This has proven particularly effective in the production of monocrystalline semiconductor wafers.

[0025] Advantageously, a chlorosilane or a mixture of chlorosilanes is used as the precursor liquid. Preferably, a mixture of silicon tetrachloride and trichlorosilane is used. The substances mentioned have proven particularly effective in the deposition of silicon layers.

[0026] In a preferred embodiment, the substrate is heated to a temperature of more than 1000 °C. This allows, among other things, the deposition of high-quality silicon layers.

[0027] Further training stipulates that the aerosol outside the evaporation zone travels a certain distance in the direction of NXW002DE0 20.12.2024

[0028] 5

[0029] The substrate is moved along this path. This path therefore only extends to the edge of the evaporation zone. It does not extend through the evaporation zone to the substrate. The length of this path is at least 2.5 times the thickness of the evaporation zone, preferably at least three times, and particularly preferably at least four times. The thickness of the evaporation zone, in this context, refers to the spatial extent of the evaporation zone in the direction of the aerosol moving towards the substrate. By selecting the length of this path as described, the components carrying the precursor liquid can be positioned at a relatively large distance from the substrate, which is hot due to heating. Therefore, these components require less cooling than, for example, the distributor plates known from US 8,465,587 B2, which are typically positioned approximately 10 mm away from the substrate to be coated.The reduced cooling requirement is accompanied by a reduced energy requirement for heating the substrate, since less heat loss due to cooling needs to be compensated for and replenished. The method according to the invention thus exhibits improved energy efficiency and can be carried out more cost-effectively.

[0030] In practice, it has proven effective if the length of the aforementioned path is at least 20 mm. Preferably, it is at least 50 mm, and particularly preferably at least...

[0031] 150 mm.

[0032] In a preferred process variant, the precursor liquid is atomized using a carrier gas. The carrier gas can simultaneously participate in the chemical deposition reaction and thus be a precursor gas itself. Hydrogen gas is particularly preferred as the carrier gas. It has proven effective (NXW002DE0 20.12.2024).

[0033] 6

[0034] It has been shown that aerosols with a sufficiently homogeneous droplet distribution can be produced in this way. The use of hydrogen gas as a carrier gas has proven particularly effective in the deposition of silicon layers. In this application, the hydrogen gas is advantageously used simultaneously as a precursor gas.

[0035] In a particularly advantageous embodiment, the precursor liquid is atomized in the process chamber by means of at least one multi-component atomizing nozzle and thus dispensed in the process chamber in the form of an aerosol. The carrier gas and the precursor liquid are introduced separately into the at least one multi-component atomizing nozzle for the purpose of atomizing the precursor liquid. The use of multi-component atomizing nozzles makes it possible to dispense the precursor liquid so homogeneously, even at large distances between the multi-component atomizing nozzle and the substrate, that homogeneous layers can be deposited. As already explained above, increasing the distance between the component dispensing the precursor liquid—in this embodiment, the multi-component atomizing nozzle—and the substrate also reduces the energy required for process operation.Another advantage of the multi-component atomizing nozzle is that it can be cooled by the precursor liquid introduced into it. This eliminates the need for a separate cooling circuit. Furthermore, the multi-component atomizing nozzle can essentially replace evaporation devices, such as bubbler systems or falling film evaporators, which are used in previously known processes for evaporating the precursor liquid. The use of multi-component atomizing nozzles can therefore contribute to reducing process complexity. The we- NXW002DE0 20.12.2024.

[0036] 7

[0037] At least one multi-component atomizing nozzle can be designed for internal or external mixing. It is particularly preferred that the at least one multi-component atomizing nozzle is designed as a two-component atomizing nozzle.

[0038] At least one multi-component atomizing nozzle can be externally coated to improve its temperature resistance and / or its corrosion resistance in aggressive process environments and / or to prevent the introduction of unwanted metallic contaminants into the deposited layers. Suitable coating materials include, for example, silicon, silicon nitride, graphite, quartz glass, or silicon carbide. Other materials suitable for the specific application, particularly ceramic materials, can also be used.

[0039] A further development step involves aligning at least one multi-component atomizing nozzle towards the substrate. This is achieved by moving the aerosol formed by the atomization process towards the substrate. In this way, moving the aerosol towards the substrate can be implemented simply and cost-effectively.

[0040] Advantageously, the carrier gas, by means of which the precursor liquid is atomized, is pressurized to a pressure greater than 1 bar. Preferably, this pressure is greater than 1 bar and less than 30 bar. Particularly preferably, the aforementioned pressure is chosen to be greater than 1 bar and less than 6 bar. It has been shown that with these pressure values ​​advantageously large distances between the at least one multi-component atomizing nozzle and the substrate, as well as sufficient cooling of the at least one multi-component atomizing nozzle. NXW002DE0 20.12.2024

[0041] 8

[0042] This can be achieved if the deposited layers are of good quality.

[0043] In one process variant, the flow rates of the carrier gas and / or the precursor liquid are controlled by differential pressure measurements. For this purpose, distribution systems with measuring orifices can be provided. This eliminates the need for complex mass flow meters and allows for cost-effective measurement and / or control of the flow rates.

[0044] Advantageously, the evaporation zone is formed with a thickness of less than 15 mm. Preferably, the evaporation zone is formed such that its thickness is less than 10 mm and particularly preferably less than 5 mm. With such thin evaporation zones, rapid heating and evaporation of the precursor liquid can be achieved shortly before it reaches the substrate or a partial layer already deposited on it. As explained above, premature nucleation can be further avoided in this way, and consequently, the quality of the deposited layer can be further improved.

[0045] A further development involves generating a turbulent flow of vaporized precursor liquid in a reaction zone located within the evaporation zone and directly adjacent to the substrate. This can be achieved, for example, using the multi-component atomizing nozzle described above, by pressurizing the carrier gas to a sufficiently high pressure. The aforementioned carrier gas pressure values ​​have proven effective in generating the described turbulent flow. Furthermore, the evaporation of the precursor liquid in the evaporation zone increases its volume, which also contributes to the formation of the described turbulent flow. NXW002DE0 20.12.2024

[0046] 9

[0047] Turbulent flow contributes to this process. Higher concentrations of highly reactive radicals, particularly highly reactive dichlorosilyl radicals, can be achieved at the substrate surface using turbulent flow compared to laminar flow. The increased presence of these highly reactive radicals enables a more uniform deposition process and thus the deposition of layers with improved homogeneity. Furthermore, higher deposition rates can be achieved while maintaining the same quality of the deposited layer. In principle, turbulent flow can be generated by selecting sufficiently high pressure and flow rates for the carrier gas and the precursor liquid.

[0048] Advantageously, the precursor liquid is maintained in a liquid state until it reaches the evaporation zone. The temperature of the precursor liquid is kept within a range of 0 °C to 400 °C, preferably within a range of 0 °C to 100 °C. This allows for a particularly steep temperature rise of the precursor substances very shortly before they reach the substrate. As explained above, this further reduces premature nucleation.

[0049] Preferably, evaporated precursor liquid that was not deposited on the substrate is condensed and reused. For this purpose, it is dispensed again in the process chamber as precursor liquid. This can be done, for example, in the manner described above using the at least one multi-component atomizing nozzle. Provided that components of the precursor liquid were of sufficient purity before its initial dispensing in the process chamber, the condensed precursor liquid does not need to be purified by distillation before being dispensed again in the process chamber.

[0050] 10

[0051] Their components are separated. The condensed precursor liquid can instead be re-applied without such an intermediate distillation step using at least one multi-component atomizing nozzle. This applies, among other things, when using a mixture of chlorosilanes as the precursor liquid, in particular when using a mixture of silicon tetrachloride and trichlorosilane.

[0052] The method according to the invention opens up new possibilities for the extraction of process gases. For example, the process gases can be extracted at a low flow velocity in the vicinity of the holding device. For this purpose, extraction openings with a comparatively large cross-section of more than 25 cm² can be used. 2 be provided for.

[0053] The spray nozzle arrangement according to the invention comprises several multi-component atomizing nozzles arranged at intervals next to each other. Their outlet openings are oriented towards a uniform side. This means that they all point in the same direction. A carrier gas can be supplied to each of the several multi-component atomizing nozzles. Furthermore, a liquid to be atomized can be supplied to each of the several multi-component atomizing nozzles separately from the carrier gas. This spray nozzle arrangement makes it possible to atomize precursor liquid to be applied in a process chamber efficiently and homogeneously. It is therefore advantageously usable in carrying out the process according to the invention. In particular, it makes it possible to deposit semiconductor layers on several adjacent substrates simultaneously and cost-effectively using the process according to the invention.

[0054] The multiple multi-component atomizing nozzles can be designed as internally mixing or externally mixing nozzles. NXW002DE0 20.12.2024

[0055] 11

[0056] Advantageously, the multi-component atomizing nozzles are coated externally, at least in sections, to improve their resistance to high temperatures and / or aggressive reactants and / or aggressive reaction products. The materials already mentioned above as examples can be used as coating materials. Particularly preferred are the multi-component atomizing nozzles made of stainless steel and provided with a silicon carbide coating. This has proven especially effective in the deposition of silicon semiconductor layers and when using a mixture of chlorosilanes and hydrogen gas as a carrier gas.

[0057] In the spray nozzle arrangement according to the invention, a comparatively small number of multi-component atomizing nozzles is sufficient to deposit high-quality semiconductor layers using the inventive method. A cost-effectively manufactured spray nozzle arrangement therefore has a projection area density of the multiple multi-component atomizing nozzles of less than 2 per cm². 2The projection area density of the multiple multi-component atomizing nozzles is the area density of the multiple multi-component atomizing nozzles relative to a surface of the spray nozzle arrangement projected against a spray direction. If the multiple multi-component atomizing nozzles are arranged in a flat surface section and the spray direction is perpendicular to this flat surface section, the projection area density is the number of multi-component atomizing nozzles arranged in this flat surface section divided by the area of ​​this flat surface section. Preferably, the spray nozzle arrangement has a projection area density of the multiple multi-component atomizing nozzles of less than 1 per 50 cm². 2 and especially preferred by less than 1 per 100 cm 2 on. NXW002DE0 20.12.2024

[0058] 12

[0059] In one embodiment, the multiple multi-component atomizing nozzles are arranged in a single plane. This plane is referred to here as the nozzle plane. If the spray direction of the multi-component atomizing nozzles is perpendicular to the nozzle plane, the projection area density of the multiple multi-component atomizing nozzles in this embodiment is calculated by dividing the number of multiple multi-component atomizing nozzles arranged in the nozzle plane by the area of ​​a section of the nozzle plane in which the multiple multi-component atomizing nozzles are arranged. In practice, this nozzle plane can, for example, be formed by a flat metal sheet in which the multiple multi-component atomizing nozzles are arranged.

[0060] The separation system according to the invention comprises a process chamber. Furthermore, a heated holding device for receiving several substrates to be coated is provided. The holding device is designed such that several substrates to be coated can be arranged side by side in one substrate plane within the holding device. The separation system also includes the spray nozzle arrangement according to the invention in an embodiment in which the multiple multi-component atomizing nozzles are arranged in the nozzle plane as described above. Furthermore, the spray nozzle arrangement and the holding device are arranged such that the substrate plane and the nozzle plane are parallel or at least substantially parallel. In addition, the spray nozzle arrangement and the holding device are oriented such that the outlet openings of the multiple multi-component atomizing nozzles of the spray nozzle arrangement face the substrates to be coated.

[0061] The described separation system allows the inventive process to be carried out cost-effectively. Hal- NXW002DE0 20.12.2024

[0062] 13

[0063] The holding device can, in principle, be designed to be heated in any known manner. For example, an electric resistance heater can be provided. Alternatively or additionally, the holding device can be designed as a susceptor, which can be heated by the application of electromagnetic radiation.

[0064] An advantageous embodiment provides that the spray nozzle arrangement and the holding device are arranged such that the substrate plane and the nozzle plane are spaced at least 25 mm apart. Preferably, this distance is at least 60 mm and particularly preferably at least 180 mm. This makes it possible, when carrying out the process according to the invention, to move the aerosol outside the evaporation zone over a long distance towards the substrate. As explained above in connection with the process according to the invention, this reduces premature nucleation and consequently improves the quality of deposited semiconductor layers.

[0065] Advantageously, the spray nozzle arrangement and the holding device are positioned such that the substrate plane and the nozzle plane are vertical or at least substantially vertical. This arrangement has proven particularly effective in practice.

[0066] In a preferred embodiment, the holding device is movably arranged in the substrate plane. This means that the holding device can be moved, at least within the substrate plane. Furthermore, the holding device can be moved past the spray nozzle assembly. In this way, a convenient NXW002DE0 20.12.2024

[0067] 14

[0068] Continuous operation of the separation system can be achieved. Several holding devices can be provided for this purpose.

[0069] Advantageously, the multiple multi-component atomizing nozzles of the spray nozzle assembly are arranged in a wall of the process chamber. This allows for easier access to the multiple multi-component atomizing nozzles. Maintenance work on the multiple multi-component atomizing nozzles and / or their supply lines can thus be carried out more easily and quickly. This is not possible with previously known separation systems, as the precursor substances are passed through the distributor plates in gaseous form and at a significantly higher temperature, which necessitates intensive cooling of the distributor plates. However, the required intensive cooling of the distributor plates is not compatible with an arrangement of the distributor plate in the wall of the process chamber.

[0070] The invention will now be explained in more detail with reference to the figures. Where expedient, elements with the same effect are designated with the same reference numerals. The invention is not limited to the embodiments shown in the figures – not even with regard to functional features. The preceding description as well as the subsequent description of the figures contains numerous features, some of which are summarized in the dependent subclaims. However, those skilled in the art will also consider these features, as well as all other features disclosed above and in the subsequent description of the figures, individually and combine them into meaningful further combinations. In particular, all the aforementioned features can be considered individually and in any suitable combination with the method according to claim 1 and / or the spray nozzle arrangement according to claim 14. NXW002DE0 20.12.2024

[0071] 15

[0072] and / or the separation system according to claim 17. The following are shown:

[0073] Figure 1: A schematic representation of an embodiment of the method according to the invention.

[0074] Figure 2: A front view of an embodiment of a spray nozzle arrangement according to the invention in a schematic representation.

[0075] Figure 3: Schematic representation of a side view of the spray nozzle arrangement from Figure 2.

[0076] Figure 4: An embodiment of the separation system according to the invention in a schematic representation.

[0077] Figure 5: Front view of the holding device from Figure 4 in a schematic representation.

[0078] Figure 6: A further embodiment of the separation system according to the invention in a schematic representation.

[0079] Fig. 1 illustrates an embodiment of the method according to the invention by means of a schematic representation. In this embodiment, a silicon layer 10 is deposited from a vapor phase onto a silicon substrate 12. For this purpose, the silicon substrate 12 is arranged in a process chamber 14. This is done by means of a holding device 13 in which the silicon substrate 12 is arranged. The silicon substrate 12 is heated by means of an electric resistance heater 44, which is shown schematically in Fig. 1. In this way, the silicon substrate 12 is heated in the present NXW002DE0 20.12.2024

[0080] 16

[0081] Exemplary embodiment heated to a temperature of more than 1000 °C.

[0082] A precursor liquid 16 is dispensed in the process chamber 14 in the form of an aerosol 20. In the present embodiment, a mixture of silicon tetrachloride and trichlorosilane is used as the precursor liquid 16. The precursor liquid 16 is dispensed by means of at least one two-component atomizing nozzle 15. For the sake of clarity, only one two-component atomizing nozzle 15 is shown in the schematic diagram of Fig. 1. However, depending on the requirements of the respective application, several such two-component atomizing nozzles can easily be provided. The precursor liquid 16 is atomized 40 in the process chamber 14 by means of the two-component atomizing nozzle 15, and the aerosol 20 is dispensed in the process chamber 14 in this way. For this purpose, a carrier gas 18 and the precursor liquid 16 are introduced separately into the two-component atomizing nozzle 15.In the present embodiment, hydrogen gas is used as the carrier gas 18. This is pressurized to a pressure greater than 1 bar, preferably to a pressure greater than 1 bar and less than 10 bar, and particularly preferably to a pressure greater than or equal to 6 bar and less than 8 bar. In the present embodiment, the hydrogen gas simultaneously serves as a precursor gas and participates in the chemical deposition reaction.

[0083] As can be seen in Fig. 1, the two-component atomizing nozzle 15 is aligned towards the silicon substrate 12. This is done in such a way that the aerosol 20 formed by atomization 40 is moved towards the silicon substrate 12 42. This movement 42 of the aerosol 20 is schematically represented in Fig. 1 by the arrow 42. The aerosol 20 is ejected outside an evaporation zone 22 via a NXW002DE0 20.12.2024

[0084] 17

[0085] The path 24 moves towards the silicon substrate 12. The length L of this path 24 is more than three times the thickness D of the evaporation zone 22. Preferably, the length L of the path 24 is chosen to be even longer, such that it is at least four times the thickness D of the evaporation zone 22. The thickness D of the evaporation zone 22 is less than 15 mm, preferably less than 10 mm, and particularly preferably less than 5 mm.

[0086] As schematically depicted in Fig. 1, the precursor liquid 16 is maintained in a liquid state until it reaches the evaporation zone 22. This is reflected in the temperature profile of the evaporating substance shown in a lower part of Fig. 1. As this temperature profile shows, the temperature of the precursor liquid 16 is maintained in a range of 0 °C to 100 °C before reaching the evaporation zone 22. Only in the evaporation zone 22, which is immediately adjacent to the silicon substrate 12, does the temperature of the precursor liquid 16 rise significantly, and the precursor liquid 16 is evaporated. As explained above, this late, steep temperature increase significantly reduces and largely prevents premature nucleation. Consequently, silicon layers 10 with improved homogeneity can be deposited in the present embodiment.

[0087] To further improve the quality of the deposited silicon layer 10, in the embodiment shown in Fig. 1, a turbulent flow of evaporated precursor liquid is generated in a reaction zone 26 located within the evaporation zone 22 and directly adjacent to the silicon substrate 12. This allows for a comparatively high concentration of highly reactive dichlorosilyl radicals to be deposited on a surface of the silicon substrate 12.

[0088] 18

[0089] at the desired deposition location. This enables a particularly uniform deposition process, allowing silicon layers 10 to be deposited with further improved homogeneity. In addition to the further improved homogeneity of the deposited silicon layer 10, higher deposition rates can be achieved.

[0090] In the embodiment shown in Fig. 1, evaporated precursor liquid 16 that was not deposited on the silicon substrate 12 is extracted by means of an extraction device 28, condensed, and reused 46. This is schematically represented in Fig. 1 by a return arrow 46. Separation of the silicon tetrachloride from the trichlorosilane by fractional distillation is omitted. Instead, the condensed precursor liquid is reintroduced into the binary atomizing nozzle 15 without prior separation into its components and is again discharged into the process chamber 14.

[0091] Fig. 2 shows a schematic front view of an embodiment of a spray nozzle arrangement 50 according to the invention. This arrangement comprises several two-component atomizing nozzles 55 arranged at intervals next to each other. The outlet openings 56 of these two-component atomizing nozzles 55 are all oriented towards a uniform side, namely projecting out of the plane of Fig. 2. Fig. 3 shows a schematic side view of the spray nozzle arrangement 50 from Fig. 2. The described orientation of the outlet openings 56 towards a uniform side is also evident here. Thus, in the representation of Fig. 3, all outlet openings 56 are oriented to the right.

[0092] In the embodiment shown in Figures 2 and 3, the two-component atomizing nozzles 55 are arranged in a housing 52. (NXW002DE0 20.12.2024)

[0093] 19

[0094] Sections of the two-component atomizing nozzles 55 located inside the housing 52 are therefore shown as dashed lines in Fig. 3. A carrier gas can be supplied to each of the two-component atomizing nozzles 55. Furthermore, a liquid to be atomized can be supplied to them separately from the carrier gas. The two-component atomizing nozzles 55 can be designed for internal or external mixing. In the present embodiment, the two-component atomizing nozzles 55 are made of stainless steel and are provided on the outside, at least in the area of ​​the outlet openings 56, with a silicon carbide coating. Alternatively or additionally, coatings made of other materials, in particular ceramic materials, can be provided.

[0095] The spray cones 58 of the two-component atomizing nozzles 55 are shown in Fig. 3, as is a spray direction 59 of the two-component atomizing nozzles 55. In the illustration of Fig. 3, both the spray cones 58 and the spray direction 59 point to the right. As can be seen in Fig. 3, the two-component atomizing nozzles 55 are arranged in a nozzle plane 60. The two-component atomizing nozzles 55 are distributed in a flat surface section of the nozzle plane 60, to which the spray direction 59 is perpendicular. This flat surface section occupies an area equal in size to a side surface 53 of the housing 52 in which the two-component atomizing nozzles 55 are distributed. In the present embodiment, a surface of the spray nozzle arrangement 50 projected opposite to the spray direction 59 thus occupies the same area as the side surface 53.The size of the side surface 53 can therefore be considered the size of the aforementioned projection area. In the present embodiment, the projection area density of the two-component atomizing nozzles 55 is less than 1 per 100 cm². 2 NXW002DE0 20.12.2024

[0096] 20

[0097] A schematic representation of an embodiment of the separation system according to the invention is shown in Fig. 4. The separation system 70 shown therein comprises a process chamber 14 and a holding device 72. The holding device 72 is designed to accommodate several substrates 73 to be coated. As can be seen in the schematic front view of the holding device 72 shown in Fig. 4, several of the substrates 73 to be coated can be arranged side by side in a substrate plane 74 within the holding device 72. The separation system 70 also comprises a spray nozzle arrangement. In the present embodiment, the spray nozzle arrangement 50 is shown in Figs. 2 and 3.

[0098] As shown in Fig. 4, the spray nozzle assembly 50 and the holding device 72 are arranged such that the substrate plane 74 and the nozzle plane 60 are parallel. The spray nozzle assembly 50 and the holding device 72 are aligned such that the outlet openings 56 of the two-component atomizing nozzles 55 of the spray nozzle assembly 50 face the substrates 73 to be coated. The holding device 72 can be heated by means of an electrical resistance heater 71, shown schematically. As explained above, an alternative or supplementary heating technology can also be used.

[0099] In the embodiment shown in Figures 4 and 5, the spray nozzle arrangement 50 and the holding device 72 are arranged such that the substrate plane 74 and the nozzle plane 60 are separated by at least 25 mm, preferably at least 60 mm, and particularly preferably at least 180 mm. Furthermore, the holding device 72 is movably arranged in the substrate plane 74. The holding device 72 can thus be moved within the substrate plane NXW002DE0 20.12.2024

[0100] 21

[0101] 74 can be moved. The described mobility of the holding device 72 is schematically represented in Fig. 4 by a movement arrow 76.

[0102] Fig. 6 illustrates a further embodiment of the separation system according to the invention by means of a schematic diagram. The separation system 170 shown here differs from the separation system 70 of Fig. 4 only in that the multiple two-component atomizing nozzles 55 of a spray nozzle arrangement 150 are not arranged in a housing, but rather in a side wall 115 of a process chamber 114. In this way, the multiple two-component atomizing nozzles 55 are more easily accessible than in the separation system 70 of Fig. 4. Maintenance or setup work can therefore be carried out more easily and quickly. Analogous to the embodiment of Fig. 4, the spray nozzle arrangement 150 and the holding device 72 are arranged such that the substrate plane 74 and a nozzle plane 160 of the spray nozzle arrangement 150 are parallel. The holding device 72 is again movably arranged in the substrate plane 74. NXW002DE0 20.12.2024

[0103] 22

[0104] Reference symbol list

[0105] 10 silicon layer

[0106] 12 Silicon substrate

[0107] 13 Holding device

[0108] 14th Trial Chamber

[0109] 15 Two-component atomizing nozzle

[0110] 16 Precursor liquid

[0111] 18 Carrier gas

[0112] 20 Aerosol

[0113] 22 Evaporation zone

[0114] 24 Pathway of the aerosol outside the evaporation zone

[0115] 26 reaction zone

[0116] 28 Extraction device

[0117] 40 Atomizing precursor liquid

[0118] 42 Moving the aerosol

[0119] 44 Heating Holding Device

[0120] 46 Condensation of evaporated precursor liquid, replenishment

[0121] 50 spray nozzle arrangement

[0122] 52 cases

[0123] 53 side surface

[0124] 55 Two-component atomizing nozzle

[0125] 56 Exit opening

[0126] 58 spray cones

[0127] 59 Spray direction

[0128] 60 nozzle level

[0129] 70 Separation system

[0130] 71 Electric resistance heating

[0131] 72 Holding device

[0132] 73 Substrat

[0133] 74 Substrate level

[0134] 76 Mobility of holding device

[0135] 114 Process Chamber NXW002DE0 20.12.2024

[0136] 23

[0137] 115 side wall

[0138] 150 Spray nozzle arrangement 160 Nozzle level

[0139] 170 Separation system

[0140] D Thickness of evaporation zone L Length of path

Claims

NXW002DE0 20.12.2024 24 Patent claims 1. Method for chemically depositing a semiconductor layer ( 10 ) from a vapor phase onto a substrate ( 12 ) which comprises the following process steps: - Arranging the substrate ( 12 ) in a process chamber ( 14 ); - Heating ( 44 ) the substrate ( 12 ); - Dispensing ( 40 ) a precursor liquid ( 16 ) in the form of an aerosol ( 20 ) into the process chamber ( 14 ) and moving ( 42 ) the aerosol ( 20 ) towards the substrate ( 12 ); - Evaporation of the applied precursor liquid ( 16 ) in an evaporation zone ( 22) immediately adjacent to the substrate ( 12 ).

2. Method according to claim 1, characterized by the fact that s - a chlorosilane or a mixture of chlorosilanes, preferably a mixture of silicon tetrachloride and trichlorosilane, is used as the precursor liquid (16); - the substrate (12) is heated to a temperature of more than 1000 °C (44); - the semiconductor layer ( 10 ) is epitaxially deposited on the substrate ( 12 ).

3. A method according to any of the preceding claims, characterized by: that the aerosol ( 20 ) outside the evaporation zone ( 22 ) is moved over a path ( 24 ) in the direction of the substrate ( 12 ) ( 42 ) and a length ( L ) of this path ( 24 ) is at least 2.5 times a thickness ( D) of the evaporation zone ( 22 ), preferably at least three times and particularly preferably at least four times. NXW002DE0 20.12.2024 25 4. Method according to claim 3, characterized by that the length (L) of the said path (24) is at least 20 mm, preferably at least 50 mm and particularly preferably at least 150 mm.

5. A method according to any of the preceding claims, characterized by: that the precursor liquid ( 16 ) is atomized by means of a carrier gas ( 18 ), preferably by means of hydrogen gas ( 18 ), wherein the hydrogen gas ( 18 ) is particularly preferably used simultaneously as a reaction gas participating in the chemical deposition reaction.

6. Method according to claim 5, characterized by that the precursor liquid ( 16 ) is atomized ( 40 ) in the process chamber ( 14 ) by means of at least one multi-component atomizing nozzle ( 15 ) and is thus applied in the process chamber ( 14 ) in the form of an aerosol ( 20 ), wherein the carrier gas ( 18 ) and the precursor liquid ( 16 ) are introduced separately into the at least one multi-component atomizing nozzle ( 15 ) for the purpose of atomizing ( 40 ) the precursor liquid ( 16 ).

7. Method according to claim 6, characterized by that the at least one multi-component atomizing nozzle ( 15 ) is directed towards the substrate ( 12 ) such that the aerosol ( 20 ) formed by atomizing ( 40 ) is moved towards the substrate ( 12 ) ( 42 ).

8. Method according to any one of claims 5 to 7, characterized by, NXW002DE0 20.12.2024 26 that the carrier gas ( 18 ), by means of which the precursor liquid ( 16 ) is atomized ( 40 ), is subjected to a pressure greater than 1 bar, preferably to a pressure greater than 1 bar and less than 30 bar and particularly preferably to a pressure greater than 1 bar and less than 6 bar.

9. A method according to any of the preceding claims, characterized by: that the flow rates of the carrier gas ( 18 ) and / or the precursor liquid ( 16 ) are controlled by means of differential pressure measurements.

10. Method according to any of the preceding claims, characterized by, that the evaporation zone ( 22 ) is designed such that its thickness ( D) is less than 15 mm, preferably less than 10 mm and particularly preferably less than 5 mm.

11. Method according to any of the preceding claims, characterized by, that a turbulent flow of evaporated precursor liquid is generated in a reaction zone (26) located within the evaporation zone (22) and directly adjacent to the substrate (12).

12. Method according to any one of the preceding claims, characterized by, that a liquid state of matter of the precursor liquid (16) is maintained before reaching the evaporation zone (22), wherein its temperature is kept in a range of 0 °C to 400 °C, preferably in a range of 0 °C to 100 °C. NXW002DE0 20.12.2024 27 13. Method according to any one of the preceding claims, characterized by, that evaporated precursor liquid which was not deposited on the substrate ( 12 ) is condensed and reused ( 46 ) by being reapplied to the process chamber ( 14 ).

14. Spray nozzle arrangement ( 50; 150 ) for use in the method according to any one of claims 1 to 13, comprising - several spaced-apart multi-component atomizing nozzles ( 55 ) whose outlet openings ( 56 ) are oriented towards a uniform side; - wherein each of the several multi-component atomizing nozzles ( 55 ) can be supplied with a carrier gas and, separately from the carrier gas, with a liquid to be atomized.

15. Spray nozzle arrangement ( 50; 150 ) according to claim 14, characterized by, that, with reference to a surface of the spray nozzle arrangement (50; 150) projected against a spray direction (59), the projection area density of the multiple multi-component atomizing nozzles (55) is less than 2 per cm² 2 is preferably less than 1 per 50 cm 2 and especially preferred to have less than 1 per 100 cm² 2 .

16. Spray nozzle arrangement ( 50; 150 ) according to one of claims 14 to 15, characterized by that the multiple multi-fuel atomizing nozzles ( 55 ) are arranged in a nozzle plane ( 60; 160 ).

17. Separation system ( 70; 170 ) for carrying out the method according to one of claims 1 to 13, comprising NXW002DE0 20.12.2024 28 - a trial chamber ( 14; 114 ); - a heated holding device ( 72 ) for holding several substrates to be coated ( 12 ); characterized by the fact that s - in the holding device ( 72 ) several substrates ( 73 ) to be coated can be arranged next to each other in one substrate plane ( 74 ); - a spray nozzle arrangement ( 50; 150 ) according to claim 16 is provided; - the spray nozzle arrangement ( 50; 150 ) and the holding device ( 72 ) are arranged such that the substrate plane ( 74 ) and the nozzle plane ( 60; 160 ) are parallel or substantially parallel; - wherein the spray nozzle arrangement ( 50; 150 ) and the holding device ( 72 ) are aligned such that the outlet openings ( 56 ) of the multiple multi-component atomizing nozzles ( 55 ) of the spray nozzle arrangement ( 50 ) are directed towards the substrates ( 73 ) to be coated.

18. Separation system ( 70; 170 ) according to claim 17, characterized by, that the spray nozzle arrangement ( 50; 150 ) and the holding device ( 72 ) are arranged such that the substrate plane ( 74 ) and the nozzle plane ( 60; 160 ) are spaced apart by at least 25 mm, preferably at least 60 mm and particularly preferably at least 180 mm.

19. Separation system ( 70; 170 ) according to one of claims 17 to 18, characterized by that the spray nozzle arrangement ( 50; 150 ) and the holding pre- NXW002DE0 20.12.2024 29 direction ( 72 ) are arranged such that the substrate plane ( 74 ) and the nozzle plane ( 60; 160 ) are vertical or at least substantially vertical.

20. Separation system ( 70; 170 ) according to one of claims 17 to 19, characterized by that the holding device ( 72 ) is movably arranged in the substrate plane ( 74 ) and is movable past the spray nozzle arrangement ( 50; 150 ).

21. Separation system ( 170 ) according to one of claims 17 to 20, characterized by, that the multiple multi-component atomizing nozzles ( 55 ) of the spray nozzle arrangement ( 150 ) are arranged in a wall ( 115 ) of the process chamber ( 114 ).

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