High-speed cooling reactor for epitaxial deposition of semiconductor film

Abstract

To provide a high-speed cooling reactor for epitaxial deposition of semiconductor film.SOLUTION: The present invention relates to a reactor (1) that is suitable for epitaxial deposition of a semiconductor film on a substrate, and is adapted to shorten the cooling time of the reactor after operation. The reactor is characterized by a reaction chamber (10) and a thermal insulation system. The latter is equipped with a plurality of thermal insulation constituent elements (110, 120, 130, 140, 150) and at least one actuator (200) adapted to move at least one of the thermal insulation constituent elements in order to minimize or maximize the thermal insulation of the reaction chamber if necessary. The present invention further relates to use of the reactor and a method for operating the reactor.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 reactor adapted to reduce cool-down time after deposition, and a method for operating the same.

[0002] Additionally, but not exclusively, the present invention relates to the field of depositing silicon, silicon carbide, and gallium arsenide films on semiconductor substrates in hot-wall, cross-flow homoepitaxial or cross-flow 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 contain a different semiconductor with certain desired qualities. Epitaxial technology is suitable for the manufacture of highly complex microprocessors and memory devices because it allows control over the crystal structure formed on the substrate and improved surface features of the epilayer.

[0004] Typically, the reaction chamber is heated to a desired temperature prior to film deposition, and the temperature is maintained substantially constant throughout the deposition process. To this effect, insulation systems are used to reduce the energy required to achieve and maintain the nominal temperature of the deposition process. For example, one or more casings of insulating material may surround the reaction chamber, thereby limiting heat dispersion in the adjacent environment.

[0005] The ability to maintain a constant and controlled temperature also impacts the quality of the film growth, however the more efficient the insulation the more downtime is required to cool the reactor after deposition in order to open the chamber to remove and handle the processed substrates.

[0006] This problem is especially felt in hot-wall reactors, which may be advantageously used in the epitaxial deposition of silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) on semiconductor substrates (of the same or different material). In the non-limiting examples above, the chambers operate at very high temperatures, typically between 800 and 1800°C, depending on the chemistry. In these hot-wall reactors, the walls of the reaction chamber are actively heated and kept at high temperatures during operation. One or more walls may be made of a highly susceptible material, such as graphite, and heated via inductive means. In any case, the high temperatures reached by the chamber and its surrounding walls affect the cool-down time and overall efficiency of the reactor operation.

[0007] Cooling of the reactor, and in particular the reaction chamber, is typically accomplished through passive and active means, either alone or in combination: (i) irradiation; (ii) conduction through the reactor's insulating and sensitive elements; and (iii) flow of hydrogen into the chamber.

[0008] Notwithstanding the above, reactor cool-down times remain long: for example, it can take up to 20 minutes to cool a SiC hot-wall reactor from 1650°C to 900°C (the approximate maximum temperature at which the reaction chamber can be opened to remove the substrate after deposition).

[0009] WO2023 / 037278 discloses a reactor for epitaxial deposition of semiconductor materials on a substrate comprising a box-shaped reaction chamber and an insulating plate that slides on the reaction chamber to provide variable thermal insulation. However, this design involves sliding surfaces and moving pieces in close proximity to the reaction chamber and just above the upper wall of the reaction chamber, which may further contribute to the presence of debris in the chamber. This may affect the quality of the epitaxial deposition and / or require further cleaning. Furthermore, the prior art design is not "as is" applicable to cylindrical reactors such as those disclosed in EP1570107, which have the advantage of being able to heat the reaction chamber uniformly and efficiently.

[0010] It is therefore desirable to provide a new method for reducing the cooling down time of cylindrical reactors, particularly, but not limited to, hot wall reactors for depositing Si, SiC and GaN films on semiconductor substrates of the same or different materials. Furthermore, it is desirable that the new method maintains proper insulation of the reaction chamber during heating and epitaxial deposition processes while limiting the possibility of contamination by debris in the deposition area. Furthermore, it is desirable to provide a new reactor suitable for carrying out the aforementioned method. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to overcome the drawbacks of the prior art. In particular, it is an object of the present invention to provide a method for reducing the cooling down time of reactors for depositing Si, SiC and GaN films on semiconductor substrates of the same or different materials, in particular but not exclusively hot-wall reactors. A further object of the present invention is to provide a method for maintaining a proper thermal insulation of the reaction chamber during heating and epitaxial deposition, while limiting the possibility of contamination by debris in the deposition area. In a different aspect, it is an object of the present invention to provide a new reactor suitable for carrying out the method described above, as well as the use of said reactor for the deposition of Si, SiC and GaN films on semiconductor substrates.

[0012] The main objectives set forth hereinabove are achieved by the present invention as described in the appended claims, which form an integral part of this specification. The use of reference signs in the claims does not limit the scope of the claims. The sole purpose of the reference signs is to make the claims easier to understand.

[0013] This Summary is provided to introduce a selection of concepts in a simplified form that are further described in the Detailed Description of Exemplary Embodiments of the Disclosure below. 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 description of the drawings]

[0014] [Figure 1] 1 provides a simplified schematic of a reactor according to a first embodiment of the invention comprising a linear actuator. [Diagram 2] 1 provides a simplified schematic of a reactor according to a second embodiment of the present invention comprising a linear actuator. [Diagram 3] 1 provides a simplified schematic of a reactor according to a third embodiment of the invention comprising a rotary actuator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] It will be understood that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, some elements in the figures may be omitted or exaggerated in size relative to other elements to help to improve understanding of the illustrated embodiments of the present disclosure.

[0016] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS Although 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, and therefore it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0017] Cylindrical geometry epitaxial reactors such as those described in EP1570107 and US2022411961 have proven commercially successful due to the uniformity and efficiency of heating of the reaction chamber, the simplicity of construction, and the quality of the deposited films.

[0018] These cylindrical reactors typically extend relatively uniformly along their longitudinal horizontal extent and present a substantially circular cross-section.

[0019] They comprise a reaction chamber formed by one or more structural elements. Some of these structural elements may exhibit high sensitivity, for example made of graphite, and may optionally exhibit a half-moon shape. They may be heated via inductive means, such as one or more induction coils wound around the reactor. Other structural elements of the reaction chamber may be made of different materials in order to provide preferential current flow to the sensitive elements and facilitate their inductive heating.

[0020] The above structural elements are combined to form a substantially circular cross section and are surrounded by upper and lower casings made of insulating material. To this effect, a porous carbon material can be used, for example a carbon composite made from short-cut carbon fibers, optionally interconnected in a matrix or pressed together.

[0021] The cylindrical reactor may be surrounded by an enclosure, which may be made of quartz or other materials that are relatively transparent to inductive heating and resistant to high temperatures, and which may be cooled with a fluid, such as water, to maintain its structural properties even when exposed to high temperatures.

[0022] Cylindrical reactors, such as those described in the non-limiting examples above, provided for illustrative purposes only, heat up very efficiently, but typically require up to 20 minutes or more to cool down, which impacts the overall efficiency and throughput rate of the reactor. In order to reduce the cooling down time and improve the throughput rate, the following invention has been devised. It is noted that, although the present invention may be advantageously implemented in the cylindrical reactor described above, its general teachings may be successfully applied in a variety of different scenarios without departing from the scope of the present invention.

[0023] In one aspect, the present invention provides a method for producing a method for treating a cancer cell comprising: (i) a reaction chamber formed by at least one separator element and having a bottom adapted to receive a substrate holder; and (ii) A reactor suitable for epitaxial deposition of semiconductor films on a substrate, comprising a thermal insulation system adapted to provide thermal insulation to the reaction chamber by substantially enclosing at least one partition element.

[0024] The reactor is characterized by a substantially cylindrical shape, extending along a longitudinal axis and being predominantly circular in cross section. In this specification and below, the expressions "predominantly circular" or "substantially circular" are understood to encompass other rounded, elliptical or oblong shapes. Indeed, these shapes may be used in the same way for the same purpose to achieve the same or similar results and are therefore equivalent in the context of the present invention.

[0025] The insulation system, characterized by a substantially circular cross-section adapted to the cylindrical shape of the reactor, comprises a plurality of insulation components and at least one actuator.

[0026] The insulating components should have a circular or arc-shaped cross section and be made of a rigid material suitable for withstanding the high temperatures reached by the reactor, for example, but not exclusively, they may be made of a rigid carbonaceous material, such as a material including short cut carbon fibers, optionally interconnected in a matrix or pressed together.

[0027] All surfaces of the insulation components may advantageously be coated to improve their compactness and reduce the formation of debris that may result from the separation of fibers or other particles from the bulk insulation material. The coating used may be a graphite-based coating.

[0028] The term "actuator" means a device or part of a machine capable of producing physical movement. In this context, "actuator" can be used to convert electrical, mechanical, pneumatic, or hydraulic input into linear or rotational motion, or any continuous combination of both.

[0029] An actuator according to the present invention is coupled to at least one of the insulating components and adapted to move it from an insulating position to a cooling position (and vice versa), the insulating position and the cooling position being adapted to relatively maximize and relatively minimize the insulation of the reaction chamber, respectively, by variably adjusting the overall insulating extent of the reaction chamber.

[0030] Due to space constraints within the reactor, the insulating components cannot always be moved to reach the absolute maximum / minimum insulation of the reaction chamber. Thus, the insulating and cooling positions typically maximize and minimize the insulation of the reaction chamber "relative" to one another.

[0031] It is noted that the mobility of the insulating components relative to one another makes it possible to tailor the insulating properties of the insulating system: this effect is achieved through the movement of said components, which can be designed to create openings in the insulating system or to locally vary its thickness.

[0032] Depending on the location of the moving insulation component(s) and the reality and type of their movement (linear or rotational), a certain number of debris may be generated and reach the reaction chamber. However, the cylindrical shape of the reactor should reduce or eliminate this side effect. Indeed, any debris generated above the reaction chamber due to the movement of parts may preferentially fall towards the sides and then down the reaction chamber, thereby reducing the probability of contaminating its interior.

[0033] To further minimize possible debris, the insulating components that are coupled to the actuator (and therefore subject to movement) should preferably not carry any additional weight beyond themselves and should not be subject to any external forces, which can help minimize friction caused by movement.

[0034] In a first embodiment, the reactor according to the invention comprises at least one cover jacket positioned between the one or more separator elements and the thermal insulation system, which by providing an additional mechanical protection layer can prevent debris generated by the operation of the thermal insulation components from reaching the reaction chamber.

[0035] The cover jacket is a rigid element and can advantageously be made of graphite. Alternatively, insulating materials such as porous carbon structures can be used. It has been observed that carbon composites made from porous carbon materials such as short-cut carbon fibers, optionally interconnected in a matrix or pressed together, work particularly well in the implementation of the invention. In this case, all surfaces of the cover jacket can be coated to improve their compactness and reduce the formation of debris that can result from the separation of fibers or other particles from the bulk insulating material. The coating can be graphite-based.

[0036] In a second embodiment, which may be implemented alternatively or additionally to the first, the actuator is made of or coated with a heat-resistant material suitable for the temperatures reached in the reactor but outside the insulating chamber. Typically, such temperatures range from 400 to 800 ° C. The heat-resistant material may advantageously be chosen from borosilicate glass, sapphire glass, quartz, ceramics, graphite, or combinations thereof. These materials make it possible to place the actuator in the reactor without compromising its operation and lifespan.

[0037] In general, the actuator may be a linear actuator, causing the insulating component to move along a longitudinal axis, or may be a rotational actuator, thus causing the insulating component to rotate about a longitudinal axis.

[0038] It is advantageous for the actuator to exhibit low friction and have no seals or gaskets to avoid stick-slip phenomena that can alter the smoothness of movement imparted to the insulating component.

[0039] In a further embodiment, the actuator of the reactor according to the invention comprises a cylinder and a piston, the latter adapted to move within the cylinder from a contracted position to an extended position and vice versa, the piston being coupled, connected or connectable to at least one of the insulating components to cause its movement from a cooling position to an insulating position and vice versa.

[0040] Advantageously, but not limited to, in the above embodiments, the piston may move under the influence of a pressure differential using a single connection, thereby simplifying its assembly and operation.

[0041] For example, the piston may move from a retracted position to an extended position under pressure exerted by a flow of an inert gas in a cylinder, which may be selected from nitrogen, argon, neon, helium, xenon, or combinations thereof.

[0042] Furthermore, the piston may move from the extended position to the retracted position under a suction pressure obtained by reducing the pressure in the cylinder below the operating pressure of the reactor. Typically, reducing the pressure to below 300 mbar may make it possible to achieve the desired effect, although the exact value will depend on the actual pressure in the reactor.

[0043] It is advantageous for the actuator to have a minimal weight to reduce friction applied to the piston. It is further advantageous for the cylinder to have a large diameter to match the available space to minimize the pressure difference between the inside of the cylinder and the reactor. In this way, a relatively low suction pressure, or gas flow, can actuate the piston.

[0044] In another embodiment, a reactor according to the present invention comprises a linear actuator adapted to move at least one of the insulating components along the longitudinal axis.

[0045] In this case, the insulating component may advantageously comprise an upper component located substantially above the bottom of the reaction chamber, and two lower components located substantially below the bottom of the reaction chamber. A linear actuator is coupled to one of the two lower components for moving it along the longitudinal axis. The movable lower component can be moved from an insulating position where the two lower components are adjacent along the longitudinal axis to a cooling position where a gap is formed between them, and vice versa. The gap of the insulating system allows for faster cooling of the reactor.

[0046] The above design reduces the risk of debris contaminating the reaction chamber since movement of the insulating components involves the lower half of the reactor, especially in the absence of a cover jacket.

[0047] However, the above embodiment can be modified to have one lower component and two upper components to create a gap in the top half of the reactor, with one of the upper components being moved by a linear actuator as described above.

[0048] According to a further embodiment, the insulating component of the reactor according to the invention comprises an outer component and an inner component that are substantially concentric with each other. They may exhibit different radii but have the same or different lengths in the longitudinal direction. The linear actuator is adapted to move the outer component linearly from an insulating position that maximizes the cladding with the inner component to a cooling position that minimizes the cladding with the inner component. The term "cladding" in this context means the overlap or projection of the inner and outer components relative to each other along the longitudinal direction.

[0049] In this embodiment, the effects of debris resulting from movement of the outer components is offset by the protective effect of the inner components, and regardless of whether the movement occurs at the top or bottom of the reactor.

[0050] Additionally, both the outer component and the inner component may include at least one through hole on a major surface thereof. The outer component and the inner component may advantageously be arranged such that, in a cooled position, a linear actuator moves the outer component such that the through holes of the outer component and the inner component are substantially aligned, thereby forming a through hole in the insulation system.

[0051] On the other hand, in the insulating position, the through holes are not aligned, thereby limiting heat dispersion.

[0052] In a further embodiment, the at least one actuator of the reactor according to the invention is a rotational actuator adapted to rotate the at least one insulating component about a longitudinal axis.

[0053] In a non-limiting example, the rotation actuator may be a pneumatic actuator adapted to rotate in a first direction under pressure applied by flowing an inert gas through an inlet. The actuator may also rotate in a second direction opposite to the first direction under suction pressure applied through the same inlet, thereby minimizing the number of connections. The suction pressure may be generated by reducing the pressure inside the actuator relative to the pressure of the reaction chamber. A pressure of 300 mbar or less is usually sufficient.

[0054] Alternatively, the rotary actuator may comprise a cylinder and a piston kinematically coupled to one or more mechanical elements suitable for converting linear motion to rotary motion, for example the piston may be connected to a cam, a slotted link, or a crankshaft mechanism.

[0055] In the case of a rotary actuator, the insulating component may advantageously be comprised of outer and inner components that are substantially concentric with one another, such that the outer component may overlap in whole or in part with the inner component.

[0056] In this embodiment, the rotational actuator may be adapted to rotate the inner or outer component about a longitudinal axis from a cooling position (where the outer and inner components partially or completely overlap) to an adiabatic position (where their overlap is minimized or zero).

[0057] The above embodiment allows opening up a large area of ​​the insulation system in the cooling position to facilitate cooling of the reactor. In fact, the movement of the insulation components (upper and / or lower) is not constrained by the limited movement available longitudinally in the reactor. This allows reducing the insulation surface by up to 50% during the cooling operation, thereby making full use of the circular cross section of the reactor and significantly speeding up the process.

[0058] The above effect can be achieved, for example, if the rotary actuator is adapted to move both the inner and outer components substantially below the bottom of the reaction chamber when in the cooling position, such that the top of the reaction chamber is fully exposed, thereby reducing the cooling time of the reactor.

[0059] In another embodiment, the reactor according to the invention further comprises a reactor enclosure surrounding the thermal insulation system. The enclosure may advantageously be a double-walled enclosure featuring a space suitable for the flow of a cooling fluid such as water. For example, the enclosure may comprise two concentric quartz tubes that are connected or connectable at their ends.

[0060] Advantageously, in the reactor according to the invention, at least one separating element is made of a material with high sensitivity, such as graphite.

[0061] In a second aspect, the present invention provides a method for controlling the insulation of a reactor according to any of the above-mentioned embodiments, comprising: - moving at least one actuator into mechanical engagement with at least one insulating component to an insulating position when the reactor is in operation; - moving the at least one actuator into mechanical engagement with the at least one insulating component to a cooling position when the reactor is cooled after operation.

[0062] This provides the reactor with an insulation system whose efficiency can be adjusted based on pre-deposition, during-deposition, and post-deposition insulation requirements. This adjustability allows for the reactor cooling downtime to be reduced by over 50%, thereby improving the overall efficiency and throughput of the reactor. Additionally, the particular geometry of the reactor and the above embodiments limits the impact of any debris formed as a result of moving parts.

[0063] In a third aspect, the present invention relates to the use of the reactor described above for hot-wall, cross-flow, homoepitaxial, or heteroepitaxial deposition of silicon, silicon carbide, or gallium arsenide films on semiconductor substrates.

[0064] Description of the drawings The illustrations presented herein are not meant to be the actual appearance of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of the present disclosure. In particular, 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 the system may not be described in detail. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical connections between the various elements. Many alternative or additional functional relationships or physical connections may be present in an actual system and / or may not be present in some embodiments.

[0065] It is noted that in Figures 1-3, the longitudinal axis X is shown below the reactor to illustrate its orientation relative to the elements and parts shown and to improve the clarity of the figures, however, the longitudinal axis X should be construed as being positioned along the center of the reaction chamber, especially when discussed in relation to the rotation of the insulating elements.

[0066] FIG. 1 shows three schematic diagrams of a first embodiment of a hot-wall cross-flow reactor (1) for SiC deposition, having a cylindrical shape and extending along a longitudinal axis.

[0067] FIG. 1(a) shows a cross-section of the reactor in a plane perpendicular to the longitudinal axis (X). The reactor is characterized by a reaction chamber (10) having a bottom (30). The chamber in which the epitaxial deposition takes place is defined by an assembly of four partition elements (21, 22, 23, 24) housed in a thermal insulation system. The latter comprises three thermal insulation components (110, 120 shown, 130 not shown). The half-moon shaped partition elements (21, 22) can advantageously be made of a highly susceptible material such as graphite to ensure that temperatures of up to 1800° C. can be reached when exposed to a suitable electromagnetic field. The field can be generated via an induction coil (not shown) wound around the reactor. The partition elements (23, 24) can advantageously be made of SiC to ensure that the current generated in the partition elements (21, 22) circulates along the entire half-moon contour. The reactor (1) is typically protected by an enclosure (not shown), such as a double-walled quartz tube, that is placed between the insulating components and the induction coil used to heat the reactor.

[0068] Figure 1(b) shows a cross section of the reactor along the longitudinal axis (X) with the insulation components (110, 120, 130) located in the insulation position. In this position, all the partition elements (21, 22 shown, 23 and 24 not shown) surrounding the reaction chamber (10) at the bottom (30) are completely surrounded by the insulation system. This maximizes the insulation of the reactor. The reactor is equipped with a linear actuator (200) coupled to the movable insulation component (120).

[0069] Figure 1(c) shows the same transverse cross section of Figure 1(b) with the insulation components (110, 120, 130) moved in a cooling position. In this position, a gap in the insulation system is created by the movement of the insulation component (120) under the tension of the actuator (200). This exposes an area of ​​the lower partition element (22) that relatively minimizes the insulation of the reactor and speeds up the reactor cooling process.

[0070] FIG. 2 shows three views of a second embodiment of a reactor (1) according to the invention, having a cylindrical shape extending along a longitudinal axis (X).

[0071] 2(a) shows the cross section of the reactor in a plane perpendicular to the longitudinal axis (X). The reactor is characterized by three insulating components (120, 140, 150), specifically an outer component (140) and an inner component (150), which are located at the top of the reactor, i.e., substantially above the bottom (30) of the reaction chamber (10), and which are concentric with each other.

[0072] Figure 2(b) shows an exterior side view of the reactor (1) along the longitudinal axis (X) with the insulating components (120, 140, 150) located in an insulating position. The reactor comprises a linear actuator (200) mechanically coupled to a movable outer component (140), which features three through-holes (501, 502, 503). The inner component (150) also comprises three through-holes (551, 552, 553) positioned below the outer component and not visible (identified by dashed lines).

[0073] In the insulating position of Figure 2(b), the through-holes (501, 502, 503) of the outer component (140) and the through-holes (551, 552, 553) of the inner component (150) are not aligned, thus providing insulation over the entire outer surface of the partition element (21).

[0074] It is noted that in this embodiment, the through-holes (551, 552, 553) in the inner component have substantially the same shape and spacing as the through-holes (501, 502, 503) in the outer component. This is generally advantageous, as will become apparent below, regardless of the shape and number of the through-holes.

[0075] Figure 2(c) shows the same transverse section of figure 2(b) with the thermal insulation components (110, 140, 150) moved in a cooling position. In this position, the through holes (501, 502, 503) of the outer component (140) are aligned with the through holes (551, 552, 553) of the inner component (150), forming gaps in the thermal insulation system under the tension of the actuator (200), thereby exposing three areas of the upper partition element (21). These exposed areas make it possible to speed up the cooling process of the reactor by relatively minimizing its thermal insulation.

[0076] FIG. 3 shows three views of a further embodiment of a reactor (1) according to the invention, having a cylindrical shape extending along a longitudinal axis (X).

[0077] Figure 3(a) shows a cross-section of the reactor in a plane perpendicular to the longitudinal axis (X). The reactor is characterized by two insulating components (140, 150), specifically an outer component (140) and an inner component (150), which are located at the upper and lower parts of the reactor, i.e., substantially above and below the bottom (30) of the reaction chamber, respectively.

[0078] Figure 3(b) shows a transverse cross-section of the reactor in a vertical plane along the longitudinal axis (X). In this view, the insulating components (140, 150) are located in an insulating position, with the outer component (140) and the inner component (150) located on the top and bottom of the reactor, respectively. In this position, the entire outer surface of the partition elements (21, 22) is surrounded by the insulating components. Thus, insulation is maximized, since there are no exposed areas. The reactor further comprises a rotation actuator (200) mechanically coupled to the movable outer component (140).

[0079] Figure 3(c) shows the same transverse section of Figure 3(b) with the insulating components (140, 150) moving to a cooling position. In this position, the actuator (200) rotates the outer component (140) about its longitudinal axis, thereby exposing the outer surface of the upper partition element (21). This exposed area makes it possible to speed up the cooling process of the reactor.

[0080] The subject matter of the present disclosure includes all novel and non-obvious combinations and subcombinations of the various processes, systems, and configurations, as well as other features, functions, operations, and / or properties disclosed herein, as well as all equivalents thereof.

[0081] In the description and claims of this application, the term "comprise" and variations thereof, such as "comprising" and "comprises", do not exclude the presence of other additional elements, components or steps.

[0082] The discussion of documents, acts, materials, devices, articles and the like is presented in the text solely for the purpose of providing a background for the invention, and not all of this material, or any portion thereof, should be understood to constitute common general knowledge in the art relative to the invention prior to the priority date of each of the claims appended to this application.

Claims

1. A reactor suitable for epitaxial deposition of semiconductor films on substrates, comprising: (i) a reaction chamber (10) formed by at least one separation element (21, 22, 23, 24) and having a bottom (30) adapted to receive a substrate holder; and (ii) a thermal insulation system adapted to provide thermal insulation for said reaction chamber, said reactor is characterised in that it extends along a longitudinal axis (X) and has a substantially circular cross section in a plane perpendicular to said longitudinal axis; A reactor, characterized in that the thermal insulation system comprises a number of thermal insulation elements (110, 120, 130, 140, 150) with a circular or arc-shaped cross section in a plane perpendicular to the longitudinal axis, and at least one actuator (200), The at least one actuator is adapted to move at least one of the insulating components from an insulating position to a cooling position and vice versa, the insulating position and the cooling position being adapted to relatively maximize and minimize the insulation of the reaction chamber, respectively.

2. 10. The reactor of claim 1 further comprising at least one cover jacket positioned between said at least one partition element and said insulation system.

3. 3. The reactor of claim 2, wherein the cover jacket is made of graphite or a thermal insulating material.

4. 4. The reactor according to any one of claims 1 to 3, wherein the at least one actuator is substantially made of or coated with a heat resistant material, preferably ceramic, quartz, borosilicate glass, sapphire glass, graphite, or a combination thereof.

5. the at least one actuator adapted to move at least one insulating component along the longitudinal axis; a cylinder (210), a piston (220) adapted to move in said cylinder from a retracted position to an extended position and vice versa, The reactor of any one of claims 1 to 3, wherein the piston is connected or connectable to at least one of the thermal insulation components.

6. - the piston moves from the retracted position to the extended position under pressure exerted in the cylinder by a flow of inert gas; A reactor as claimed in claim 5, wherein said piston moves from said extended position to said retracted position under a suction pressure obtained by reducing said pressure in said cylinder below the operating pressure of said reactor.

7. The reactor according to any one of claims 1 to 3, wherein the actuator is a linear actuator.

8. 8. The reactor of claim 7, wherein the plurality of insulating components comprises an upper component (110) located substantially above the bottom of the reaction chamber and two lower components (120, 130) located substantially below the bottom of the reaction chamber, and the linear actuator is adapted to move one of the two lower components linearly along the longitudinal axis from an insulating position where the two lower components are adjacent along the longitudinal axis to a cooling position where a gap is formed between the two lower components along the longitudinal axis, and vice versa.

9. The plurality of insulating components comprises an outer component (140) and an inner component (150) that are substantially concentric with one another; - the outer component is adapted to provide, in whole or in part, an outer covering for the inner component; The reactor of claim 7, wherein the linear actuator is adapted to linearly move the outer component from an insulating position in which coating of the inner component is relatively maximized to a cooling position in which coating is relatively minimized, and vice versa.

10. - said outer component comprises at least one through hole (501, 502, 503) on its main surface, - said inner component comprises at least one through hole (551, 552, 553) on its main surface, 10. The reactor of claim 9, wherein the inner and outer components are positioned such that (i) in the cooling position, the at least one through hole of the outer component and the at least one through hole of the inner component are substantially aligned to form at least one through hole in the insulation system, and (ii) in the insulating position, the at least one through hole of the outer component and the at least one through hole of the inner component are not aligned.

11. The reactor of any one of claims 1 to 3, wherein the at least one actuator is a rotational actuator adapted to rotate at least one insulating component about the longitudinal axis.

12. 12. The reactor of claim 11, wherein the rotational actuator is pneumatically controlled and adapted to rotate in a first direction under pressure exerted by a gas flow and to rotate in a second direction opposite the first direction under suction pressure.

13. 6. The reactor of claim 5, wherein said at least one actuator is a rotary actuator, and said piston is kinematically coupled to one or more mechanical elements suitable for converting linear motion to rotary motion.

14. The plurality of insulating components comprises at least one outer component (140) and at least one inner component (150) that are substantially concentric with one another; - the outer component is adapted to provide, in whole or in part, an outer covering for the inner component; The reactor of claim 11, wherein the rotational actuator is adapted to rotate the inner component and / or the outer component about the longitudinal axis from a cooling position to an insulating position.

15. The reactor of any one of claims 1 to 3, further comprising a reactor enclosure surrounding said insulation system.

16. 16. The reactor of claim 15, wherein the reactor enclosure is a double-walled enclosure characterized by spaces suitable for flowing a cooling fluid.

17. Reactor according to any one of claims 1 to 3, wherein at least one separation element (21, 22) is a susceptor.

18. - moving at least one actuator (200) into mechanical engagement with at least one insulating component (110, 120, 130, 140, 150) to an insulating position when the reactor is in operation; - mechanically engaging at least one actuator with at least one insulating component to move it to a cooling position when the reactor is cooled after operation.

19. Use of the reactor of any one of claims 1 to 3 for hot-wall, cross-flow deposition of silicon, silicon carbide or gallium arsenide films on semiconductor substrates.

Images