Substrate processing apparatus and method

Abstract

An improved substrate processing apparatus having a fluid inlet assembly is provided. [Solution] A substrate processing apparatus and related methods are provided, comprising: a sealed pressure vessel such as an atomic layer deposition (ALD) apparatus; a fluid inlet assembly 120 attached to a wall 130 of the sealed pressure vessel, the fluid inlet assembly having a fluid inlet pipe passing through the wall; and an elastic element in the fluid inlet assembly around the inlet pipe connecting the fluid inlet pipe to the wall, one of the inner and outer surfaces of the elastic element being subjected to the pressure prevailing in the pressure vessel and the other being subjected to ambient pressure, the elastic element preventing fluid carried inside from coming into contact with the elastic element.

Description

FIELD OF THEINVENTION

[0001] The present invention relates generally to substrate processing reactors and methods of their operation. More particularly, but not exclusively, the present invention relates to atomic layer deposition (ALD) reactors. FIELD OF THEINVENTION

[0002] This section presents useful background information that describes the current state of the art without including any of the technology described herein.

[0003] Various substrate processing equipment, such as deposition reactors, typically have components at different pressure regions ranging from ambient pressure to vacuum pressure. Vacuum components are typically sized at ambient pressure, and temperature and pressure differences would cause deformations in undesirable locations. In particular, chemical inlet pipes are typically led from or through ambient pressure regions to a chamber at reduced pressure, in most cases through a set of regions with different temperatures. This would cause significant stresses on the chemical inlet pipes, which could be a critical failure point. An example of a chemical inlet into a chamber is shown in U.S. Pat. No. 8,741,062 (B1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 8,741,062(B1) Abstract

[0005] It is an object of some embodiments of the present invention to provide an improved device with a fluid inlet assembly, or at least to provide an alternative to existing technology.

[0006] According to a first exemplary aspect of the present invention, A sealed pressure vessel; a fluid inlet assembly attached to a wall of the sealed pressure vessel, the fluid inlet assembly having a fluid inlet pipe passing through the wall; There is provided a substrate processing apparatus comprising: The fluid inlet assembly further includes an elastic element in the fluid inlet assembly around the inlet pipe that couples the fluid inlet pipe to the wall, one of the inner and outer surfaces of the elastic element being subjected to the pressure prevailing in the pressure vessel and the other being subjected to the ambient pressure, and the fluid inlet pipe prevents the fluid conveyed inside from contacting the elastic element.

[0007] The disclosed apparatus, in some example embodiments, provides pressure regulated inlet clamping, in some example embodiments, the resilient element is configured to press against the pressure vessel due to a pressure differential between ambient pressure and the pressure prevailing within the interior of the pressure vessel.

[0008] By the pressure vessel is sealed, it is meant that in some example embodiments, the reaction vessel is a closed or closable chamber.

[0009] In some example embodiments, the elastic element is configured to deform under displacement between stationary components of the device or assembly. In some example embodiments, the elastic element is airtight or nearly airtight. When the elastic element is only nearly airtight, it is preferred that there is only a small leakage of gas through the elastic element in order to maintain the separate pressure areas.

[0010] In some example embodiments, the sealed pressure vessel forms an outer chamber that surrounds an inner chamber that is a sealed reaction chamber.

[0011] In some example embodiments, the fluid inlet assembly is attached to a reaction chamber wall. In some example embodiments, the fluid inlet assembly is attached to an outer chamber that surrounds the reaction chamber. Depending on the implementation, the above identified sealed pressure vessel may be referred to as an outer chamber or a reaction chamber (either a reaction chamber with or without an outer chamber surrounding it).

[0012] In some example embodiments, the inlet pipe is arranged to be disassembled by removing at least a portion of the inlet pipe inwardly through the interior (or reaction chamber) of the apparatus.

[0013] In some example embodiments, the inlet pipe is arranged to be disassembled by removing at least a portion of the inlet pipe outwardly in a direction facing away from the apparatus (or reaction chamber).

[0014] In some example embodiments, the inlet pipe is arranged to be in a fixed position relative to the reaction chamber wall, in such embodiments, the inlet pipe may be configured to deform or bend at other points or joints.

[0015] In some example embodiments, the inlet pipe is positioned such that it is in a rotatable position relative to the reaction chamber wall, and in such embodiments, the inlet pipe may be configured to deform or bend at other points or joints.

[0016] In some example embodiments, the resilient element may be configured to exert mechanical pressure against the inlet pipe.

[0017] In some example embodiments, the direction of the mechanical pressure is inward, towards the reaction chamber.

[0018] In some example embodiments, the inlet pipe is formed from two pipes arranged to slide inside each other.

[0019] In some example embodiments, the reaction chamber includes a collar that locks the inlet pipe in place.

[0020] In some example embodiments, the inlet pipe is equipped with a heat distribution element for distributing heat along the inlet pipe. In some example embodiments, the heat distribution element extends over the entire longitudinal distance of the inlet pipe. In some example embodiments, the heat distribution element extends over only a portion of the entire longitudinal distance of the inlet pipe. In some example embodiments, the heat distribution element is formed from a single piece. In some example embodiments, the heat distribution element is formed from multiple pieces. In some example embodiments, the heat distribution element is or comprises an active heater element. In some example embodiments, the heat distribution element is placed at ambient pressure conditions. In some example embodiments, the heat distribution element is placed on the vacuum side (of the pressure vessel).

[0021] In some example embodiments, the heat distribution element extends beyond the feed-through location in the wall of the closed pressure vessel.

[0022] In some example embodiments, the contact point where the inlet pipe meets the reaction chamber is a non-permanent fixed point.

[0023] In some example embodiments, the contact points are sealed and / or reinforced.

[0024] According to a second exemplary aspect of the present invention, A method is provided which includes providing a sealed pressure vessel with a fluid inlet assembly attached to a wall of the sealed pressure vessel, the fluid inlet assembly having a fluid inlet pipe passing through the wall, and a resilient element in the fluid inlet assembly around the inlet pipe coupling the fluid inlet pipe to the wall, one of an inner and outer surface of the resilient element being subjected to the pressure prevailing in the pressure vessel and the other being subjected to ambient pressure, the fluid inlet pipe preventing fluid conveyed therein from contacting the resilient element, the method comprising: The method further includes creating mechanical pressure on the inlet pipe through contraction of the elastic element, the direction of the mechanical pressure being toward the interior of the pressure vessel.

[0025] In some example embodiments, the mechanical pressure is generated by a pressure difference between the pressure prevailing within the pressure vessel and the ambient pressure.

[0026] Various non-binding exemplary aspects and embodiments of the present invention have been presented above. The above embodiments are merely used to illustrate selected aspects or steps that may be utilized in implementing the present invention. Certain embodiments will be presented with reference to only some exemplary aspects of the present invention. Of course, corresponding embodiments apply to other exemplary aspects as well. Any suitable combination of the embodiments may be formed.

[0027] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0028] [Figure 1] 1 illustrates components of a substrate processing apparatus according to some example embodiments of the present invention. [Diagram 2] 2 shows an enlarged cross-sectional view of the fluid inlet assembly of FIG. 1; [Diagram 3] 2 illustrates a cross-sectional view of a fluid inlet assembly according to another example embodiment of the present invention. [Figure 4] 1 shows some of the components disclosed in the previous embodiment. [Diagram 5] 5a and 5b illustrate the operation of a mechanical limiter according to some example embodiments of the present invention. [Figure 6] 13 shows a cross-sectional view of a fluid inlet assembly according to yet another example embodiment of the present invention. [Figure 7] 13 shows a cross-sectional view of a fluid inlet assembly according to yet another example embodiment of the present invention. [Figure 8] 13 shows a cross-sectional view of a fluid inlet assembly according to yet another example embodiment of the present invention. [Figure 9] 13A-13C show further cross-sectional views of the contact point between the inlet pipe and the reaction chamber wall according to some example embodiments. Detailed explanation

[0029] In the following description, the atomic layer deposition (ALD) technique is used as an example. However, the present invention is not limited to the ALD technique, and can be used in a wide variety of substrate processing apparatuses that apply different temperature and / or pressure ranges, for example, in a chemical vapor deposition (CVD) reactor. The substrate processing apparatus can be a vacuum deposition apparatus. Alternatively, the present invention can be applied to apparatuses that perform processes other than deposition, such as sintering or etching, for example, atomic layer etching (ALE).

[0030] The fundamentals of ALD growth mechanism are known to those skilled in the art. ALD is a special chemical deposition method based on the sequential introduction of at least two reactive precursor species to at least one substrate. However, it should be understood that one of these reactive precursors can be replaced by energy, for example, when using light-enhanced ALD or plasma-assisted ALD, for example PEALD, which results in a single precursor ALD process. For example, the deposition of pure elements such as metals requires only one precursor. Also, binary compounds such as oxides can be produced using one precursor chemical when the precursor chemical contains both elements of the binary material to be deposited. Thin films grown by ALD are dense, pinhole-free, and have a uniform thickness.

[0031] 1 illustrates components of a substrate processing apparatus 100 according to some example embodiments. A reaction space 112 is a volume defined within a reaction chamber. A desired substrate process, i.e., a desired chemical reaction, occurs on a surface of a substrate 101 in the reaction space 112. During processing, the substrate 101 in some example embodiments is supported by a substrate holder 110 within the reaction chamber.

[0032] The reaction chamber is a pressure vessel defined by reaction chamber wall(s) 130. In some example embodiments, as shown in Figure 1, the apparatus 100 comprises an additional pressure vessel, an outer chamber. The outer chamber surrounds the reaction chamber, thereby closing the intermediate space 114 between the reaction chamber wall 130 and the outer chamber (outer) wall 140.

[0033] During processing, the reaction space 112 in the reaction chamber is under vacuum. If the apparatus 100 is a deposition reactor, e.g., an ALD or CVD reactor, the pressure in the reaction chamber / reaction space 112 may be, for example, 1 μbar to 0.1 bar, or more preferably, 0.1 to 1 mbar. In some example embodiments, the intermediate space 114 has a higher pressure than the pressure in the reaction chamber, e.g., approximately 10 mbar. The intermediate space 114 may include a heater. This pressure arrangement prevents reactive chemicals from contacting, for example, the heater.

[0034] Ambient conditions (temperature, pressure) generally prevail outside the outer chamber wall 140. The space outside the outer chamber wall 140 where ambient temperature and pressure prevail is indicated by reference numeral 116.

[0035] The fluid inlet assembly 120 is attached to the outer chamber wall 140 for supplying desired chemicals to the reaction space 112 (although in other embodiments, such as embodiments lacking an outer chamber, a corresponding fluid inlet assembly can be attached to the reaction chamber wall 130 instead).

[0036] FIG. 2 shows an enlarged cross-sectional view of the fluid inlet assembly 120. The fluid inlet assembly 120 is attached to a fluid inlet pipe 201 at one end and to the outer surface of the chamber wall 140 at the other end. In an embodiment, the fluid inlet assembly comprises a first end piece 209 at a first end of the assembly and a second end piece 206 at an opposite end of the assembly. The end pieces 206, 209 may be flanges or the like. The fluid inlet pipe 201 passes through the chamber wall 140 within the assembly 120. The fluid inlet assembly 120 further comprises an elastic element 205 around the inlet pipe that couples the fluid inlet pipe 201 to the wall 140. The elastic element 205 may be airtight or nearly airtight. In an embodiment, the elastic element 205 is placed between the end pieces 206, 209. The end piece or flange 206 may be attached to the chamber wall 140 by a fastening element such as a bolt 207. The end piece 209 may be attached to the fluid inlet pipe 201, for example by a VCR (Vacuum Coupling Radiation) connection. The vacuum gap around the fluid inlet pipe 201 extends through the outer chamber wall 140 into the space within the assembly 120 bounded by the inner surface of the elastic element 205. The inner surface of the elastic element 205 is therefore subjected to the pressure prevailing in the intermediate space 114, and the outer surface of the elastic element 205 is subjected to the ambient pressure. In the depicted solution, the inner surface is also subjected to some degree to the pressure of the reaction space 112.

[0037] As mentioned above, the pressure in the intermediate space 114 during operation of the substrate processing apparatus 100 differs from the ambient pressure. This pressure difference causes the elastic element 205 to contract (i.e., deform), causing the inlet pipe 201 to push itself towards the reaction chamber.

[0038] When volumes 112 and 114 are pressurized to ambient pressure, for example during a maintenance period, this causes the elastic element 205 to regain its original length, with the effect of causing the inlet pipe 201 to recoil outwards. This further reduces the stiffness of the elastic element 205, allowing its movement in any direction or angle to facilitate removal of one or more parts from the apparatus when required.

[0039] In some example embodiments, as shown in Figure 2, the fluid inlet pipe 201 is formed from two pipes: pipe 201 and a larger diameter pipe 202. The fluid inlet pipe 201 enters inside the larger diameter pipe 202, travels a (short) distance within the larger diameter pipe, and then stops. Pipes 201 and 202 consequently overlap some distance. The larger diameter pipe extends from the discontinuity to the reaction chamber wall 130. The fitting between pipes 201 and 202 is shown by the double arrow in Figure 2. Inlet Assembly 120 contracts or expands due to pressure fluctuations. The larger diameter pipe 202 has a radial extension 211 that locks the position of the pipe 202. The larger diameter pipe 202 can be pushed from the direction of the reaction chamber to a position where the radial extension contacts the reaction chamber wall 130 and prevents further horizontal movement of the pipe 202. A collar 212 can be lowered over the radial extension to prevent the pipe 202 from moving backwards, thereby locking the pipe 202 in its horizontal position. The pipe 202 can be pulled out through the reaction chamber during maintenance.

[0040] In some example embodiments, Inlet Assembly 120 is Inlet Assembly120, in particular the horizontal movement of the elastic element 205. The mechanical limiter 208 may be implemented as a separate bar element that does not necessarily have rotational symmetry. The limiter(s) may be mounted between the end pieces 206 and 209.

[0041] In some example embodiments, Inlet Assembly 120 comprises a tubular heat conductor 204 around the pipe 201. In some example embodiments, Inlet Assembly 120 comprises a further tubular heat conductor 203 around the pipe 202. The heat conductors 203 and 204 may receive heat from one or more heaters or may be active heaters themselves. In some example embodiments, there is a heat distribution element on top of the heater elements around the inlet pipes 201 and / or 202. In some example embodiments, the heat conductor(s) is to balance the temperature difference and create a favorable thermal gradient. Heating the inlet pipe increases the temperature of the incoming fluid before it reaches the substrate 101. In some example embodiments, the chemical source connected to the pipe 201 is a heated source. In those example embodiments, the entire path from the heated source to the substrate should be heated to avoid the development of cold spots.

[0042] The described fluid inlet assembly 120 provides pressure-regulated inlet clamping. The elastic element 205 may be implemented, for example, by a tube having a pleated shape, such as a bellows, or in some example embodiments, by a spring. As previously mentioned, the inlet assembly 120 is configured to press against a reaction chamber or another pressure vessel due to a pressure difference between the ambient pressure and the pressure prevailing inside the pressure vessel. However, it should be noted that in other example embodiments, the described deformations (contraction or expansion action) of the fluid inlet assembly 120 or the elastic element 205 can be actuated by other means, for example, by mechanical actuation. In those embodiments, for example, a motor(s) or a shape memory alloy can be used to perform the actuation.

[0043] Depending on the implementation, the fluid inlet assembly 120 creates a mechanically tight connection of the inlet pipe to a counterpart, which may be, for example, the reaction chamber wall 130, the collar 212 and / or the larger diameter pipe 202. In some example embodiments, the elastic element 205 allows the inlet pipe 201, 202 to move relative to the reaction chamber wall 130. In some example embodiments, this movement occurs due to pressure, temperature, or stress induced by other structures of the device, e.g., a lid. The movement may actually be in any direction and angle. In some example embodiments, one or more additional parts, such as a pushing valve, are suspended from the inlet pipe and positioned so as not to restrict the movement of the elastic element 205. The elastic element 205 does not come into contact with the chemical(s) being guided in the inlet pipe 201. Therefore, potential material leakage through the element 205 does not affect the chemical reaction in the reaction space 112.

[0044] Figure 3 shows a cross-sectional view of a fluid inlet assembly 120 according to another example embodiment. The embodiment shown corresponds to the embodiment shown in Figures 1 and 2, except that the thermal conductor 204, which in the previous embodiment was placed in the pressure region 114, is now placed in the ambient pressure region 116. At the same time, the point of attachment where the end piece 209 connects the fluid inlet pipe 201 has been moved towards the reaction chamber. The thermal conductor 204 may alternatively be an active heater.

[0045] Figure 4 shows the juncture of fluid inlet pipes 201 and 202. Pipe 201 is allowed to slide within the larger diameter pipe 202. Figure 4 also shows a radial extension included in pipe 202. Figure 4 further shows collar 212. The collar has a tight enough opening to allow pipe 202 to fit but prevent extension 211 from fitting, thereby providing a locking effect for pipe 202.

[0046] Figures 5a and 5b are cross-sectional views illustrating the operation of the mechanical limiter(s) 208. Figure 5a shows the situation where the outer surface of the elastic element 205 is subjected to the same pressure as its inner surface, while Figure 5b shows the situation where the pressure is lower on the inner surface side.

[0047] The example of a mechanical limiter 208 shown in Figures 5a and 5b is formed from two connected bars 208' and 208''. Bar 208' is attached to end piece 206 and piece 208'' to end piece 209. Bar 208' has two end stops and bar 208'' has a protrusion that is allowed to move between the end stops, thus setting an end point for the longitudinal movement of elastic element 205.

[0048] In the situation of Fig. 5a, the elastic element 205 is at its normal length, with the protrusion near the end stop closer to the end piece 209. In the situation of Fig. 5b, the elastic element 205 tends to contract in its length direction, with the protrusion setting a limit to the maximum contraction together with the other end stop (closer to the end piece 206). It will be appreciated that the limiter is drawn here to restrict the movement horizontally, but depending on the implementation it may be possible to limit the range of movement in any direction.

[0049] Figure 6 shows a cross-sectional view of a fluid inlet assembly 120 according to yet another example embodiment. The embodiment shown generally corresponds to the embodiment shown in Figures 1 and 2. However, in this embodiment, the fluid inlet pipe 201 extends all the way to the reaction chamber wall 130, and it is this pipe 201 that comprises the radial extension 211. The larger diameter pipe 202 is omitted.

[0050] FIG. 7 shows a cross-sectional view of the fluid inlet assembly 120 according to yet another example embodiment. The embodiment shown generally corresponds to the embodiment shown in FIG. 6. However, in this embodiment, the radial extension 211 is placed on the inlet assembly side of the reaction chamber wall 130, whereas in the embodiment shown in FIG. 6, the radial extension 211 is placed on the reaction chamber side of the reaction chamber wall 130. Contraction of the elastic element 205 pushes the fluid inlet pipe 201 towards and / or against the reaction chamber wall 130. The radial extension 211 acts as a limiter for the longitudinal movement of the pipe 201. The heater(s) or heat conductor(s) 203 and 204 can be implemented as separate elements side-by-side or overlapping each other. Alternatively, the elements 203 and 204 can be implemented as a single element. Furthermore, instead of being located in the vacuum side, the heater 204 can be located in the ambient pressure region (e.g., by placing it in a groove that runs along the surface of the inlet pipe 201 from the ambient side, or completely annularly surrounds it, as shown in Figure 3). During maintenance, the inlet pipe 201 can be pulled out from the outside (of the wall 140) together with the assembly 120.

[0051] FIG. 8 shows a cross-sectional view of the fluid inlet assembly 120 according to yet another example embodiment. The embodiment shown generally corresponds to the embodiment shown in FIG. 7. However, in FIG. 8, the sealing or reinforcement of the contact point where the inlet pipe meets the reaction chamber or wall 130 is shown in more detail. According to FIG. 8, the fluid inlet assembly can include a seal 801, such as an O-ring, between the pipe 201 and the reaction chamber wall 130 to reduce chemical leakage into the intermediate space 114. The contact point can be implemented in various ways. Instead of or in addition to the stepped connection shown in FIG. 7 and the sealed implementation shown in FIG. 8, a cone-shaped connection, a ball-like or hemispherical connection, any surface connection with a suitable inverse shape in the chamber wall 130 can be implemented. For example, the contact point can be reinforced by a stepped joint, a round bar joint, a ball joint, or by a separate cylinder.

[0052] 9 shows one implementation where the contact point (or junction) 901 between the inlet pipe 201 and the reaction chamber wall 130 is rotatably positioned. The inlet pipe 201 has a curved or balled end and the reaction chamber or chamber wall 130 has a concave opposing surface. The inlet pipe 201 is allowed rotational movement at the formed joint or junction when needed. In some example embodiments, the feedthrough opening through the wall 130 at the junction may have a diameter larger than the inner diameter of the inlet pipe 201. In some example embodiments, the joint is implemented on the inside of the reaction chamber wall 130.

[0053] In yet alternative embodiments, the elastic element 205 is not a separate element, but an element that is manufactured to be an integral part of the chamber 140. Furthermore, the disclosed embodiments are not intended to limit the position of the elastic element 205, but rather its mechanical function to permit movement of one or more components to which it is connected. In some example embodiments, a pressure arrangement in which the pressure in the intermediate space 114 is higher than the pressure in the reaction chamber prevents reactive chemicals from contacting the elastic element 205.

[0054] In some alternative embodiments, the intermediate space 114 has a higher pressure than the pressure in the surrounding region 116. In such conditions, mechanical pressure on the inlet assembly 120 can be created from the inside to the outside of the closed pressure vessel or reaction chamber.

[0055] In some example embodiments, the mechanical pressure on element 120 may be augmented, offset, or created entirely by a mechanical actuator or by spring loading.

[0056] Additionally, in some alternative embodiments, the substrate processing apparatus includes more than two walls, with the inlet assembly operating beyond each wall.

[0057] Descriptions of any particular previous embodiment may be directly applied to the other disclosed embodiments, this being true both as to the structure and operation of the disclosed devices.

[0058] Without limiting the scope and interpretation of the claims, some technical advantages of one or more example embodiments disclosed herein are set forth below. One technical advantage is providing a reduction in unnecessary stresses in the chemical inlet pipes and associated structures. Another technical advantage is adjustable inlet pipe clamping by pressure or other means. Another technical advantage is avoidance of cold spots and improved heat distribution in the chamber feedthroughs. Another technical advantage is improved serviceability.

[0059] It should be noted that some of the functions or method steps discussed above may be performed in different orders and / or concurrently with one another. Furthermore, one or more of the above functions or method steps may be optional or may be combined.

[0060] As non-limiting examples of specific implementations and embodiments of the present invention, a complete and informative description of the best mode for carrying out the present invention currently contemplated by the inventors has been provided. However, the present invention is not limited to the details of the embodiments presented above, and it will be apparent to those skilled in the art that the present invention can be carried out in other embodiments using equivalent means without departing from the characteristics of the present invention.

[0061] Furthermore, some of the features of the embodiments of the invention disclosed above may be used to advantage without the corresponding use of other features. Thus, the foregoing description should be considered as merely illustrative of the principles of the invention, and not in limitation thereof. The scope of the invention is therefore limited only by the appended claims.

Claims

1. 1. A fluid inlet assembly for a substrate processing apparatus, comprising: a fluid inlet pipe configured to pass through a wall of the closed pressure vessel; an elastic element disposed around the fluid inlet pipe on the outside of the sealed pressure vessel to connect the fluid inlet pipe to the wall; a first end piece and a second end piece, the elastic element being coupled therebetween; 1. A fluid inlet assembly comprising: an inner surface of the elastic element is subjected to a pressure prevailing within the sealed pressure vessel and an outer surface of the elastic element is subjected to a pressure outside the sealed pressure vessel, the fluid inlet pipe having at least one heat distribution element around the fluid inlet pipe for preventing an internal fluid from contacting the elastic element and distributing heat along the fluid inlet pipe; the fluid inlet pipe is configured to pass through the wall of the sealed pressure vessel forming an outer chamber; The sealed pressure vessel defines an outer chamber surrounding an inner chamber which is a sealed reaction chamber; the fluid inlet pipe is configured to have a contact point with the reaction chamber; Fluid inlet assembly.

2. 1. A fluid inlet assembly for a substrate processing apparatus, comprising: a fluid inlet pipe configured to pass through a wall of the closed pressure vessel; an elastic element disposed around the fluid inlet pipe on the outside of the sealed pressure vessel to connect the fluid inlet pipe to the wall; a first end piece and a second end piece, the elastic element being coupled therebetween; at least one adjustable limiter coupled between the first end piece and the second end piece, the limiter having an adjustable length in a direction of a longitudinal axis of the fluid inlet pipe; an inner surface of the elastic element is subjected to a pressure prevailing within the sealed pressure vessel and an outer surface of the elastic element is subjected to a pressure outside the sealed pressure vessel, and the fluid inlet pipe prevents an internal fluid from contacting the elastic element.

3. 3. The fluid inlet assembly of claim 1 or 2, wherein the elastic element is configured to deform under a displacement between the first and second end pieces of the fluid inlet assembly.

4. The fluid inlet assembly of claim 1 or 2, wherein the elastic element is configured to exert a mechanical pressure on the fluid inlet pipe.

5. The fluid inlet assembly of claim 4 , wherein the direction of the mechanical pressure is inwardly directed towards the sealed pressure vessel.

6. The fluid inlet assembly of claim 2 , wherein the elastic element around the fluid inlet pipe is located between the fluid inlet pipe and the at least one adjustable limiter.

7. The fluid inlet assembly of claim 2 , wherein the at least one adjustable limiter is configured to limit movement of the elastic element, thereby limiting movement of the fluid inlet assembly.

8. The fluid inlet assembly of claim 2 , wherein the resilient element is configured to deform in at least the same direction as the at least one adjustable limiter.

9. The at least one heat distribution element comprises: - the entire length of the fluid inlet pipe located outside the sealed pressure vessel and the entire length of the feed-through point in the wall of the sealed pressure vessel; or - existing along the entire length of the fluid inlet pipe; The fluid inlet assembly of claim 1 .

10. The fluid inlet assembly of claim 1 , wherein the at least one heat distribution element is configured to balance a temperature difference and create a preferred temperature gradient for fluid in the fluid inlet pipe.

11. 11. A fluid inlet assembly according to any preceding claim, wherein the fluid inlet pipe is formed from two pipes arranged to slide inside each other.

12. The fluid inlet assembly of claim 1 , wherein the fluid inlet pipe is disassembled by removal of at least a portion of the fluid inlet pipe.

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