Reactor casing assembly

Abstract

To provide a reactor casing assembly.SOLUTION: The present invention relates to a reactor casing assembly for epitaxial deposition of a semiconductor film on a substrate. The casing assembly includes an inner casing and an outer casing made of opaque quartz and transparent quartz and connected by at least two flanges. The present invention also relates to a reaction chamber enclosed by the casing assembly and a reactor employing at least one of the reaction chambers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of epitaxial deposition of semiconductor films on substrates, and in particular to a casing assembly for a reaction chamber characterized by a double casing design. The present invention further relates to a reaction chamber and a reactor comprising such a casing assembly.

[0002] Additionally, although not exclusively, the present invention relates to the field of deposition of silicon carbide and gallium nitride films on semiconductor substrates in hot-wall, cross-flow, homoepitaxial, or heteroepitaxial reactors. [Background technology]

[0003] Semiconductor films made by epitaxial growth, also known as epilayers, are formed by deposition in a reaction chamber of a reactor. The deposited material may be the same as the substrate or may involve a different semiconductor with specific desired qualities. Epitaxial techniques allow for control of the crystalline structure formed over the substrate and for improving the surface characteristics of the epilayer, making it suitable for the fabrication of highly complex microprocessors and memory devices.

[0004] Typically, the reaction chamber is heated to a desired temperature prior to film deposition, and the temperature is then maintained substantially constant throughout the deposition process. To this effect, an isolation system is used to reduce the energy required to achieve and maintain the nominal temperature of the deposition process.

[0005] Epitaxial growth equipment for the silicon (Si), silicon germanium (SiGe), silicon carbide (SiC), or gallium nitride (GaN) industries may include hot-wall reaction chambers, where the walls are actively heated and temperatures can reach 1800°C in the area where the chemical vapor deposition process occurs.

[0006] These temperatures may be achieved, for example, via an induction heating system comprising an induction coil wound around the reaction chamber and connected to a power generation circuit. In this case, the chamber may comprise one or more heat-conducting elements, such as an assembly of one or more graphite pieces. Indeed, graphite is characterized by high sensitivity and will be effectively heated under an alternating electromagnetic field.

[0007] The above-mentioned chambers typically include an enclosure that may perform one or more of the following functions: (i) protect the chamber from contamination; (ii) provide an enclosure for vacuum generation; (iii) prevent overheating of the chamber's ambient environment; and (iv) prevent leakage of process gases within the reactor.

[0008] The enclosure must avoid interaction and interference with the electromagnetic fields generated by the induction heating system and should be able to satisfactorily withstand temperatures up to 1000°C without suffering structural damage and without releasing contaminants into the chamber.

[0009] To provide an enclosure with the above characteristics, quartz tubes, such as those described in U.S. Patent No. 5,627,499, are often used. The tubes may be hollow and may be cooled with an internal liquid flow. Cooling the tubes allows the quartz to better withstand the heat radiating from the reaction chamber.

[0010] Quartz enclosures are typically fabricated by welding two concentric quartz tubes together and joining them at their edges, which allows for the creation of a fluid-tight gap between the tubes for the flow and evacuation of cooling fluids, such as water, through a series of inlets and outlets protruding above the surface of the outer tube.

[0011] However, these solutions are not ideal, and welding concentric quartz tubes often results in irreparable damage to the tubes, thereby affecting production costs. Overall, the welding process is primarily an artisanal process with inherently unpredictable yields, which substantially increases the manufacturing cost of quartz enclosures and creates serious procurement issues. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] US Patent Application Publication No. 2023 / 0313410 Summary of the Invention [Means for solving the problem]

[0013] An object of the present invention is to overcome the drawbacks of the prior art. More specifically, it is an object of the present invention to provide a casing assembly for a reaction chamber comprising: (i) a quartz inner casing and a quartz outer casing extending along a longitudinal direction (x), where the inner casing is coaxially disposed relative to and at least partially housed within the outer casing; and (ii) a first flange and a second flange connecting the inner casing and creating a liquid-tight space therebetween. The first flange comprises at least one inlet for directing a cooling fluid into the liquid-tight space, and either the first flange or the second flange comprises at least one outlet for discharging the cooling fluid out of the liquid-tight space. Either the quartz inner casing or the quartz outer casing, or both, comprise one opaque quartz portion and one transparent quartz portion.

[0014] It is a further object of the present invention to provide a reaction chamber for epitaxial film deposition equipped with the above-described casing assembly, and a reactor incorporating the reaction chamber.

[0015] The above-mentioned main objects are achieved through the invention as recited in the appended claims, which form an integral part of this specification.

[0016] It should be noted that the use of reference signs in the claims does not limit their scope: their sole purpose is to make the claims easier to understand.

[0017] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description of Example Embodiments of the Disclosure. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. [Brief explanation of the drawings]

[0018] [Figure 1] Figure 1 provides a simplified schematic diagram of a first embodiment of a casing assembly according to the present invention. Panel a) provides a side view of the casing assembly along the longitudinal direction (x), while panel b) provides a front view in a plane perpendicular thereto (yz). [Figure 2] 1 provides a side view of a second embodiment of a casing assembly according to the present invention. [Figure 3] 1A and 1B schematically illustrate a portion of a reaction chamber according to another embodiment of the invention, where panel a) provides a lateral side view along the longitudinal direction (x), while panel b) provides a front view in a plane perpendicular thereto (yz). DETAILED DESCRIPTION OF THE INVENTION

[0019] It will be appreciated that elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be omitted or exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure.

[0020] While certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious modifications and equivalents thereof. It is therefore not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0021] According to a first aspect, the present invention relates to a casing assembly for a reaction chamber suitable for epitaxial deposition of semiconductor films on substrates, including but not limited to deposition of Si, SiGe, SiC, or GaN films on semiconductor substrates of the same or different material in a horizontal, hot-wall, single-wafer reaction chamber.

[0022] The casing assembly according to the invention comprises an inner casing and an outer casing made of quartz and extending along a longitudinal direction (x) in a horizontal plane, the inner casing being arranged coaxially with respect to the outer casing and being partially or completely housed within the latter.

[0023] The inner and outer casings are hollow and may have an essentially prismatic or cylindrical shape in the transverse plane (yz), defined here as any plane perpendicular to the longitudinal direction (x), and preferably have a circular, oval, elliptical, or rectangular cross section.

[0024] The lengths of the inner and outer casings in the longitudinal direction may be different, for example the inner casing may extend beyond the edge of the outer casing.

[0025] The outer casing and / or the inner casing include at least one transparent quartz portion and at least one opaque quartz portion, which allows for easier manufacturing and procurement of the outer casing and / or the inner casing having a variable cross-section and for better configuration of the outer casing and / or the inner casing to the shape of the first flange and / or the second flange.

[0026] The casing assembly provides an enclosure for the reaction chamber in which the reaction chamber (and portions thereof) can be located, accessed, and moved. The reaction and deposition unit is the core of the reactor where semiconductor substrates are typically placed on substrate holders to perform the actual epitaxial deposition process.

[0027] The sides of the inner and outer casings are open in cross section and may be closed or partially closed as described below, and are also referred to as upstream and downstream sides, respectively, depending on the direction of injection / exhaust of precursor gases in the reaction and deposition units.

[0028] The inner and outer casings are connected to a first flange on one side and a second flange on the other side. These flanges create a closed, liquid-tight space between the inner surface of the outer casing and the outer surface of the inner casing. This liquid-tight space is suitable for flowing a cooling fluid, such as demineralized water, to protect the quartz element from overheating. The cooling fluid may be under slight pressure, creating a pressure differential of approximately 0.3 to 1 bar relative to its surroundings. To counter this pressure, multiple pushers and / or spacers located on the outer surfaces of the flanges can prevent the flanges from displacing outward.

[0029] The first flange includes at least one inlet for directing cooling fluid into the liquid-tight space, and either the first flange or the second flange includes at least one outlet for discharging the cooling fluid out of the liquid-tight space.

[0030] The expression "liquid-tight interspace" is understood to mean a cavity through which the cooling fluid may flow without leakage to its surroundings. The cavity is surrounded by the inner and outer casings and the first and second flanges. The cavity may communicate through one or more of its inlets with a piping system and / or a container that provides the cooling fluid, optionally under pressure. The cavity may also communicate through one or more of its outlets with a piping system and / or a container and / or a drain that allows the cooling fluid to be discharged after use. The cooling fluid may also follow a closed loop that allows continuous circulation of the liquid into and out of the cavity.

[0031] The number of inlets and outlets each may be kept below 20 to simplify manufacturing of the part and / or due to space constraints.

[0032] The first flange may be located without distinction on the upstream or downstream side of the reaction chamber (and the second flange conversely downstream or upstream) depending on the structural features of the reactor.

[0033] The use of a flange avoids the problem of welding the inner and outer quartz casings together, thereby ensuring a faster, more efficient, and cost-effective manufacturing process. The physical characteristics of the flange depend on the size of the casing assembly, the weight of its parts, and the differential pressure induced by the cooling liquid to which the assembly is subjected compared to its ambient environment.

[0034] According to another embodiment, the casing assembly of the present invention further comprises one or more pipes positioned within the liquid-tight space and extending in a straight line or a winding, serpentine line along the longitudinal direction, the number of pipes being advantageously kept below 20 and being chosen to be the same as the number of inlets.

[0035] In this embodiment, each pipe is connected to an inlet and is provided with at least one opening for injecting cooling fluid into the liquid-tight space. The pipes allow for better distribution of the cooling fluid within the liquid-tight space. This is particularly true when the inlet and outlet are located on the same flange, where the pipes force the cooling fluid to flow over a larger surface of the inner and outer casings by bringing the cooling fluid further longitudinally from the outlet. The number and spacing of the inlets and outlets in the cross-section also affect the distribution of the cooling fluid, as one skilled in the art may deduce.

[0036] Advantageously, the pipe may be provided with a plurality of openings arranged at different positions along its length in order to improve the spatial distribution of the cooling fluid and thus ensure particularly uniform and effective cooling of the casing assembly. The openings may be of the same size and shape or of different sizes and shapes.

[0037] In general, cooling of the casing assembly ensures better mechanical stability of the quartz elements and is particularly important for hot-wall reactors such as those described above for Si, SiGe, SiC, or GaN epitaxial deposition, and especially for SiC or GaN deposition. In the latter case, for example, the casing assembly may be exposed to temperatures of up to 1000°C due to the extremely high temperatures (1000-1800°C) of the adjacent reaction and deposition units, resulting in heat radiation into the casing assembly.

[0038] According to another embodiment, the casing assembly of the present invention further comprises (i) a first O-ring and a second O-ring connecting the first flange and the second flange to the inner casing, respectively, and (ii) a third O-ring and a fourth O-ring connecting the first flange and the second flange to the outer casing, respectively.

[0039] These four O-rings are essential to prevent leakage of the cooling fluid from the liquid-tight space. The first flange and the second flange will feature appropriate notches to fit the four O-rings.

[0040] When pipe(s) connected to the inlet(s) are used, the O-ring sealing the outer casing is subject to different constraints depending on whether it is placed (i) on a flange with an inlet, or (ii) on a flange without an inlet.

[0041] In the first example, the pipe, or any connecting conduit to it, passes through the flange below the O-ring, so that the O-ring is always positioned facing outwards relative to the pipe, or any conduit connecting the pipe to the inlet.

[0042] In the second example, the O-ring may be positioned behind the tip of the tube to save space. Therefore, the third and fourth O-rings can have different diameters as well as flanges corresponding to the two O-rings. In this case, the outer casing must have a variable cross-section in order for the two O-rings to properly seal against it.

[0043] The above configuration may advantageously be achieved by maintaining an essentially constant cross section of the outer casing throughout its length and locally varying that cross section to correspond to the flange having the inlet, thereby creating a variation or "step".

[0044] There are numerous ways in which this local modification of cross section may be achieved. To utilize standard, commercially available cylindrical or parallelepiped quartz duct casing, it is possible to manufacture / procure the modified and standard structures separately and then join them together in a permanent manner.

[0045] To avoid damaging these quartz parts when they are assembled, the inventors have found that diffusion welding techniques work particularly well in the practice of the present invention.

[0046] The inventors also observed that the quartz used for the standard duct casing may be different from the quartz used for the added custom pieces. Specifically, the former may be transparent and the latter may be opaque to facilitate component sourcing. The difference in optical properties between the two components does not affect the overall performance and functionality of the outer casing. However, it should be noted that if the inner and / or outer casings were made entirely of opaque quartz, they would be more likely to overheat due to the increased heat absorption properties of the material.

[0047] The inventors have found that an essentially cylindrically shaped casing assembly works well in the practice of the invention, the symmetry of which allows for easy assembly of the parts.

[0048] By essentially cylindrical shape is meant a shape which may locally deviate from the ideal cylindrical shape for up to 15% of its length.

[0049] Those skilled in the art will understand that, on a case-by-case basis, the casing assembly will require additional elements to function properly according to its purpose. For example, at least a third flange and a fourth flange may be used to connect the casing assembly, and more specifically the inner casing, with other elements / areas upstream and downstream of the reaction chamber. Advantageously, these flanges may be made of stainless steel.

[0050] The casing assembly may also include, for example, (a) an inlet on the first (or second) flange, and, if present, (b) an additional O-ring to seal the pipe against the inlet.

[0051] Under a second aspect, the present invention relates to a reaction chamber for epitaxial deposition of a semiconductor film on a substrate, comprising a casing assembly according to any one of the above-mentioned embodiments.

[0052] The reaction chamber also comprises a reaction and deposition unit where the actual film deposition takes place, and also comprises one or more structural / separation elements extending along its length and made of susceptor material, i.e., a highly sensitive material such as graphite that can be effectively heated under an electromagnetic field.

[0053] The reaction and deposition unit may be provided with a receiving area configured to receive a substrate holder and may further be equipped with means for rotating the substrate holder, measuring the angular velocity of the substrate holder, and controlling the angular velocity of the substrate holder. The reaction and deposition unit may optionally be specifically designed for a horizontal hot-wall reactor for Si or SiGe, and preferably SiC or GaN deposition. It may comprise elements made of SiC and / or components coated with SiC or TaC.

[0054] The reaction chamber further comprises an insulating system configured to encase the reaction and deposition unit and minimize heat dissipation from the reaction and deposition unit. The insulating system may be made of a porous carbonaceous material, such as a carbon composite made from short-cut carbon fibers, optionally interconnected or pressed together in a matrix. The insulating system may be composed of one or more insulating shells.

[0055] The thermal insulation system may further comprise thermal insulation caps for enclosing the upstream and downstream sides of the reaction and deposition units, which may be provided with inlets and outlets to allow the introduction and evacuation of precursors and other working gases.

[0056] The casing assembly defines the perimeter of the reaction chamber and encloses both the reaction and deposition unit and the thermal insulation system.

[0057] The casing assembly also has 10 chambers. -7 Pressures as low as mbar may be applied, so a connection to a vacuum generation system may also be included.

[0058] The casing assembly, the reaction and deposition unit, and the insulation system may all be essentially cylindrical in shape.

[0059] Under a third aspect, the present invention relates to a reactor for epitaxial deposition of a semiconductor film on a substrate.

[0060] The reactor comprises (i) at least one reaction chamber as described above, and (ii) an induction heating system configured to heat susceptor elements of the reaction and deposition units of the at least one reaction chamber.

[0061] The reactor according to the invention may advantageously be chosen for the homoepitaxial or heteroepitaxial deposition of Si or SiGe, and preferably SiC or GaN, and may be chosen to be of the horizontal, single-wafer, hot-wall type.

[0062] It will be understood that a reactor according to the present invention will include numerous other elements typically required for its operation.

[0063] For example, the reactor will include a gas panel for controlling the delivery of process and operating gases through an appropriate assembly of gas pipes and gas liners, including precursor and cooling gases for the reaction chamber, as well as gases for substrate holder rotation and / or gases for flushing the chamber to remove residue after use.

[0064] The reactor is generally equipped with a system for exhaust gas discharge and for controlling the rotation speed of the substrate holder. The reactor also typically includes a system and water lines for vacuum generation, as well as a demineralized water tank for cooling the casing assembly.

[0065] The examples presented below are not intended to be actual representations of any particular materials, structures, or devices, but merely idealized representations used to describe embodiments of the present disclosure. Specifically, they are not intended to otherwise limit the scope of aspects and implementations in any way. Indeed, for the sake of brevity, conventional manufacturing, association, preparation, and other functional aspects of systems may not be described in detail. Furthermore, connecting lines shown in the various figures are intended to represent example functional relationships and / or physical couplings between the various elements. Many alternative or additional functional relationships or physical connections may exist in an actual system and / or may not be present in some embodiments.

[0066] While certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, and obvious modifications and equivalents thereof. It is therefore not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0067] Figure 1 shows a simplified schematic diagram of an embodiment of a casing assembly (10) according to the present invention, providing a) a lateral view along the longitudinal direction (x) and b) a front view in a plane (yz) perpendicular to (x).

[0068] Specifically, panel a) shows a casing assembly (10) made of quartz and comprising an inner casing (100) and an outer casing (150) connected via a first flange (200) and a second flange (250). The outer casing comprises a transparent quartz portion (151) and an opaque quartz portion (152).

[0069] In this example, the sides of the outer casing abut against the first and second flanges, while the inner casing is longer and extends beyond them. Both the inner and outer casings are hollow and essentially cylindrical in shape. The first flange is provided with two inlets (300) for the injection of a cooling fluid, such as demineralized water, into the liquid-tight space.

[0070] Each inlet is connected to a pipe (310) having an open end, i.e., an opening (315) at its tip. The openings are located in close proximity to the second flange. The cooling fluid therefore expands correspondingly to the second flange and flows back towards the first flange, where two outlets (350) are located (only one of which is visible in this view).

[0071] The inlet and the pipe may be connected via a short longitudinal conduit manufactured into the flange, and the pipe may be partially placed within this conduit.

[0072] Panel b) shows the same casing assembly (10) of panel a) in cross section (yz), seen from the front. This view showcases the circular cross-sections of both the inner casing (100) and the outer casing (150), as well as the first flange (200). The inlet (300) and outlet (350) are located on the first flange. Conduits (301, 351) respectively connect the inlet with a pipe (not shown) and the outlet to a liquid-tight space so that the cooling liquid may be drained after use. The conduits are short longitudinal channels and are also manufactured within the flanges. They connect the inlet with the pipe, the latter optionally partially inserted within the conduit for its entire length or a section thereof.

[0073] Generally, when the inlets and outlets are located on one and the same flange, it is convenient to have them alternate radially. In both panels a) and b), the thicknesses of the inner and outer casings, the pipes, and the inlets and outlets are not shown.

[0074] 2 provides a simplified transverse view of an embodiment of the casing assembly (10) of the present invention along a longitudinal direction (x) perpendicular to the transverse plane (yz). A first flange (200) and a second flange (250) connect the inner casing (100) and the outer casing (150), which are two quartz tubes of different lengths.

[0075] The flange and pipe define a liquid-tight space between them. Two inlets (300) and two outlets (350, only one shown) are located on the first flange. Generally, one skilled in the art will configure the number of connections to the size of the assembly and the temperatures reached during operation.

[0076] The inlet is configured to inject a cooling fluid into the fluid-tight space, where the fluid may expand and reach an outlet on the other side of the outer casing for discharge.

[0077] To better achieve this goal, in this embodiment, each inlet is connected to a pipe (310) having openings (315) spaced apart along its length (x).

[0078] At least two stainless steel flanges (600, 650) are located on the sides of the inner casing (100). The stainless steel flanges may have a ring-like shape. They are used to separate chambers or to connect the casing assembly with other elements located upstream and downstream of the reaction chamber, such as enclosed areas or drums used to perform specific operations.

[0079] A plurality of pushers (700) are used to counter the pressure exerted on the first flange and the second flange by the cooling fluid in the space.

[0080] At least four O-rings (410, 420, 430, 440) are used. The first O-ring (410) and the second O-ring (420) connect the first flange and the second flange with the inner casing, respectively. They are positioned in suitable grooves or notches made in the flanges.

[0081] A third O-ring (430) and a fourth O-ring (440) connect the first flange and the second flange with the outer casing, respectively, and are both positioned in suitable grooves or notches made in the flanges.

[0082] Note that both the first and second flanges feature variable cross sections in the transverse plane, represented here by "steps" on both flanges, and also host seats for the third and fourth O-rings, respectively.

[0083] The lateral shape of the flanges is emphasized for clarity by the use of a crisscross pattern, and also makes it possible to see how the "steps" bring portions of the first flange and second flange below the outer casing on either side.

[0084] The outer casing comprises a transparent quartz part (151) of standard cylindrical shape and an opaque quartz part (152) that partially encases the first flange by creating a slight step that locally increases the cross section of the outer casing. The opaque quartz part is highlighted with a diagonal line pattern. It can be custom-made to wrap precisely around the abutting part of the first flange and can be easily welded onto a standard transparent tube. To avoid breakage of the parts, it may be advantageous to use a diffusion welding technique.

[0085] 3 schematically illustrates a reaction chamber (500) according to an embodiment of the present invention. Panel a) provides a lateral view along the longitudinal direction (x), while panel b) provides a view in a simplified cross-section (yz), using the same frame of reference as in FIG.

[0086] The reaction chamber comprises a casing assembly enclosing a reaction and deposition unit (510) equipped with a receiving area (515) for a substrate holder. In panel b), the reaction and deposition unit is highlighted in grey for clarity. It comprises graphite and SiC elements. The former is half-moon shaped and is suitable for being heated via induction means for the deposition of SiC.

[0087] The reaction and deposition unit illustrated here is surrounded by an insulating system. The latter comprises at least two insulating shells (551, 552). Panel a) shows two additional insulating caps (575), which are not included in panel b) for clarity.

[0088] The reaction and deposition unit and the thermal insulation system are enclosed by a casing assembly according to an embodiment of the present invention.

[0089] The casing assembly comprises an inner casing (100), an outer casing (150), a first flange (200) and a second flange (250), a plurality of inlets (300), and a plurality of outlets (350). The outer casing comprises a clear quartz portion (151) and an opaque quartz portion (152) joined together by a diffusion welding technique.

[0090] Each inlet is connected to a pipe (310) that is provided with a plurality of openings (315) and abuts the inside of the second flange.

[0091] The induction heating system comprises a coil (1100) wound around the casing and connected to a generator. The coil is not part of the reaction chamber and is therefore shown schematically with dashed lines. The coil is configured to heat the reaction and deposition unit to temperatures up to 1800°C.

[0092] It should be understood that the configurations and / or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be construed in a limiting sense, as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various illustrated operations may be performed in the order illustrated, in other orders, or omitted in some cases.

[0093] In this application, the words "comprises," "has," "includes," and variations thereof, both when used in the specification and when used in the claims, do not exclude the presence of other additional elements, components, or steps.

[0094] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, and other features, functions, operations and / or properties disclosed herein, as well as all equivalents thereof.

Claims

1. A casing assembly (10) for a reaction chamber for epitaxial deposition of semiconductor films on substrates, comprising: an inner casing (100) and an outer casing (150) made of quartz and extending along a longitudinal direction (x), the inner casing (100) and the outer casing (150) being coaxially disposed relative to the outer casing and at least partially housed within the outer casing; a first flange (200) and a second flange (250) that connect the inner casing and the outer casing and define a liquid-tight space; A casing assembly, wherein the first flange or the second flange has at least one inlet (300) for directing a cooling fluid into the liquid-tight space, and the first flange or the second flange has at least one outlet (350) for discharging the cooling fluid out of the liquid-tight space, and the outer casing and / or the inner casing has at least one transparent quartz portion (151) and at least one opaque quartz portion (152).

2. 2. The casing assembly of claim 1, further comprising one or more pipes (310) positioned within the liquid-tight space and extending along the longitudinal direction, each of the one or more pipes connected to an inlet and having at least one opening (315).

3. The casing assembly of claim 2 , wherein each of the one or more pipes has a plurality of openings disposed at different positions along the length.

4. a first O-ring (410) and a second O-ring (420) connecting the first flange and the second flange with the inner casing, respectively; The casing assembly of claim 1, further comprising a third O-ring (430) and a fourth O-ring (440) connecting the first flange and the second flange with the outer casing, respectively.

5. The casing assembly according to claim 4 , wherein the at least one opaque quartz portion is disposed corresponding to the third O-ring or the fourth O-ring.

6. The casing assembly of claim 1 , wherein the transparent quartz portion and the opaque quartz portion are joined together by diffusion welding.

7. The casing assembly of claim 1 , wherein the inner casing and the outer casing have a cylindrical shape.

8. A reaction chamber (500) for the epitaxial deposition of a semiconductor film on a substrate, comprising: a reaction and deposition unit (510) extending along the longitudinal direction (x) and comprising one or more structural elements made of a susceptor material and provided with a receiving area (515) configured to receive a substrate holder; an insulation system comprising one or more insulating shells (551, 552) encasing the reaction and deposition unit; A reaction chamber (500) comprising: a casing assembly (10) according to any one of claims 1 to 7, enclosing the reaction and deposition unit and the thermal insulation system.

9. A reactor (1000) for epitaxial deposition of a semiconductor film on a substrate, comprising: At least one reaction chamber (500) according to claim 8, The reactor (1000) further comprises at least one induction heating system (1100) configured to heat structural elements of the reaction and deposition unit (510) of said reaction chamber.

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