Water-cooled jacket and single crystal furnace

Abstract

The water cooling jacket is applied to a crystal pulling furnace and comprises a cylindrical body, the cylindrical body comprises a first end and a second end which are oppositely arranged in the axial direction of the cylindrical body, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the cylindrical body is gradually reduced from the first end to the second end. The invention also relates to the single crystal furnace. The water cooling jacket comprises a cylindrical body, the cylindrical body comprises a first end and a second end which are oppositely arranged in the axial direction of the cylindrical body, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the cylindrical body is gradually reduced from the first end to the second end. The flow rate of argon is increased, and the cooling efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor product manufacturing, and in particular to a water cooling jacket and a single crystal furnace. Background Art

[0002] CZ (Czochralski, direct-pull single crystal manufacturing method) crystal growth method is a method widely used in the semiconductor industry to pull single crystal ingots. Its essence is to solidify molten polysilicon at the solid-liquid interface and grow single crystal silicon epitaxially. The whole process includes seeding, shoulder release, shoulder rotation, equal diameter growth, finishing and cooling. Among them, the water cooling jacket is a key component of the crystal pulling furnace chamber. It can optimize the crystal growth process by providing a stable cooling environment and promoting the flow of argon gas, thereby producing high-quality crystal materials.

[0003] First, the water-cooling jacket can promote the flow of argon gas, and its channel is usually designed to be in a shape that is conducive to airflow, thereby improving the cooling effect of argon gas on the crystal. Secondly, the water-cooling jacket can improve the cooling efficiency, because the specific heat capacity of cooling water is large and it can absorb more heat, making the environment for crystal growth more stable. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a water cooling jacket and a single crystal furnace to improve cooling efficiency and thus improve production efficiency.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted in an embodiment of the present invention is: a water-cooling jacket, applied to a crystal pulling furnace, comprising a tubular body, along the axial direction of the tubular body, the tubular body comprises a first end and a second end arranged opposite to each other, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the tubular body gradually decreases from the first end to the second end.

[0006] Optionally, a wavy concave-convex structure is provided on the inner wall of the cylindrical body.

[0007] Optionally, the concave-convex structure includes a plurality of annular protrusions arranged on the inner wall of the cylindrical body along the axial direction of the cylindrical body.

[0008] Optionally, the thickness of the annular protrusion in the radial direction of the cylindrical body gradually increases from the first end to the second end.

[0009] Optionally, in the axial direction of the cylindrical body, the distance between the center points of any two adjacent protrusions is the same.

[0010] Optionally, in the axial direction of the cylindrical body, the protrusion includes a first sub-protrusion and a second sub-protrusion that are staggered, and in the axial direction of the cylindrical body, the width of the first sub-protrusion is different from the width of the second sub-protrusion.

[0011] Optionally, the convex surface of the protrusion away from the inner wall of the cylindrical body is a smooth curved surface.

[0012] Optionally, a heat-absorbing coating is provided on a side of the protrusion away from the inner wall of the cylindrical body.

[0013] Optionally, a cooling pipe for accommodating a cooling medium is provided on the side wall of the cylindrical body, and in the axial direction of the cylindrical body, the cooling pipe is distributed on the side wall of the cylindrical body in a spiral shape.

[0014] An embodiment of the present invention further provides a single crystal furnace, comprising the above-mentioned water cooling jacket.

[0015] The beneficial effects of the present invention are as follows: the water cooling jacket provided by the present invention comprises a cylindrical body, along the axial direction of the cylindrical body, the cylindrical body comprises a first end and a second end arranged opposite to each other, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the cylindrical body gradually decreases from the first end to the second end. The flow rate of argon gas is increased, and the cooling efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram showing the structure of a water cooling jacket in an embodiment of the present invention;

[0017] Figure 2 A schematic diagram showing the structure of a water cooling jacket in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] The features such as "parallel", "perpendicular", and "same" used in the embodiments of the present disclosure include the features such as "parallel", "perpendicular", and "same" in a strict sense, as well as the cases where "approximately parallel", "approximately perpendicular", "approximately the same", etc. include certain tolerances, taking into account the tolerances associated with the measurement of specific quantities (e.g., the limitations of the measurement system), and represent the acceptable deviation range for a specific value determined by ordinary technicians in the field. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of the value.

[0021] The water cooling jacket is a key component of the crystal pulling furnace chamber. It can optimize the crystal growth process by providing a stable cooling environment and promoting the flow of argon gas, thereby producing high-quality crystal materials.

[0022] The water-cooling jacket can promote the flow of argon gas, and its channel is usually designed to be in a shape that is conducive to airflow, thereby improving the cooling effect of argon gas on the crystal. Secondly, the water-cooling jacket can improve the cooling efficiency, because the specific heat capacity of cooling water is large, it can absorb more heat, making the environment for crystal growth more stable.

[0023] In order to improve the cooling efficiency of the crystal ingot and the production efficiency of the crystal ingot, we can increase the argon flow rate and the cooling rate:

[0024] Increase the argon flow rate: A higher flow rate helps to carry and disperse impurities on the molten surface, reduce the contact time between impurities and the melt, and reduce the oxidation of the crystal, which is important for improving the purity of the crystal. At the same time, the increase in the argon flow rate will enhance thermal convection, which helps to distribute heat more evenly, thereby improving the temperature control accuracy during the crystal pulling process, reducing thermal stress, and making the crystal grow more uniformly. In addition, increasing the argon flow rate can take away the heat from the melt surface faster, thereby increasing the growth rate of the single crystal, which can improve production efficiency to a certain extent.

[0025] Increase cooling speed: Increasing cooling speed means that longer crystals can be obtained in the same amount of time, thus improving production efficiency. Increasing cooling speed can speed up the cooling of the melt, thereby increasing the growth rate of the crystal. At the same time, increasing cooling speed is of great significance for reducing costs and increasing efficiency of enterprises.

[0026] refer to Figure 1-Figure 2 This embodiment provides a water-cooling jacket, which is applied to a crystal pulling furnace, and includes a cylindrical body 1, along the axial direction of the cylindrical body 1 (reference Figure 1 The cylindrical body 1 includes a first end and a second end that are arranged opposite to each other, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the cylindrical body 1 gradually decreases from the first end to the second end.

[0027] By adopting the above scheme, a longitudinal (i.e., axial direction of the tubular body 1) gradient water cooling effect can be formed. Since the temperature of the crystal rod in the longitudinal direction (i.e., axial direction of the crystal rod) changes gradiently (the lower end is hot and the upper end is cold, the end close to the silicon melt is the lower end, and the end away from the silicon melt is the upper end), the heat of the crystal rod is mainly transmitted to the surrounding object with low temperature in the form of radiation. The intensity of radiation heat transfer is inversely proportional to the cube of the distance, that is, the closer the distance, the stronger the radiation heat transfer, and the better the corresponding water cooling effect. The inner diameter of the tubular body 1 gradually decreases from the first end to the second end. Along the longitudinal direction, the distance between the inner wall of the tubular body 1 and the crystal rod in the radial direction of the crystal rod changes gradiently, which can achieve a gradient water cooling effect, that is, a longitudinal asymmetric effect, thereby achieving radial and axial gradient temperature gradient changes, greatly improving the axial and radial heat dissipation of the crystal rod, reducing internal heat accumulation, changing the thermal history of the crystal rod, reducing the generation of misalignment and other crystal defects, and improving the quality of the crystal rod. The inclination angle of the inner wall of the inner cylinder can be adjusted according to the requirements of the pulling process, which can greatly adjust the longitudinal (ie axial) and radial temperature gradients of the crystal rod, control the reaction rate of defects in the crystal rod, and adjust the defect distribution.

[0028] Furthermore, the inner diameter of the cylindrical body 1 gradually decreases from the first end to the second end. According to fluid mechanics, the flow rate of the gas can be increased and the cooling efficiency can be improved.

[0029] It should be noted that in order to achieve a gradual decrease in the inner diameter of the cylindrical body 1 from the first end to the second end, it can be achieved by gradually increasing the thickness of the side wall of the cylindrical body 1 from the first end to the second end. The outer wall of the cylindrical body 1 is a columnar structure, that is, the outer wall of the cylindrical body 1 is a straight cylindrical structure. By gradually increasing the thickness of the side wall of the cylindrical body 1 from the first end to the second end, that is, from the first end to the second end, the distance between the outer wall and the inner wall gradually increases, so that the inner diameter of the cylindrical body 1 gradually decreases from the first end to the second end.

[0030] It should be noted that Figure 1 and Figure 2 Only part of the structure of the water cooling jacket is shown.

[0031] In some embodiments, the inner wall of the cylindrical body 1 may be a smooth conical surface.

[0032] In an exemplary embodiment, a wave-shaped concave-convex structure 11 is provided on the inner wall of the cylindrical body 1 .

[0033] According to the Bernoulli effect in fluid dynamics, the water-cooled screen with a wave structure has a smaller aperture at the second end, so the velocity of the argon gas flowing through it will be relatively larger, which can take away more impurities and make the crystal rod purer. At the same time, the higher flow rate can take away more heat per unit time, which can enhance the cooling efficiency of the crystal rod to a certain extent.

[0034] The arrangement of the concave-convex structure 11 can increase the surface area of ​​the inner wall of the cylindrical body 1, that is, increase the heat absorption area of ​​the water cooling jacket. Compared with a smooth surface, such a surface has a better heat absorption effect and has a good effect of cooling the crystal rod.

[0035] In an exemplary embodiment, the concavo-convex structure 11 includes a plurality of annular protrusions disposed on the inner wall of the cylindrical body 1 along the axial direction of the cylindrical body 1 .

[0036] In an exemplary embodiment, a plurality of the annular protrusions are arranged along the axial direction of the cylindrical body 1 , and the cross-sectional shape of a single annular protrusion may be a triangle, a trapezoid, an arc, or the like.

[0037] In an exemplary embodiment, the thickness of the annular protrusion in the radial direction of the cylindrical body 1 gradually increases from the first end to the second end.

[0038] In an exemplary embodiment, in the axial direction of the cylindrical body 1, the distance between the center points of any two adjacent protrusions is the same.

[0039] In an exemplary embodiment, in the axial direction of the cylindrical body 1, the protrusion includes a first sub-protrusion and a second sub-protrusion that are staggered, and in the axial direction of the cylindrical body 1, the width of the first sub-protrusion is different from the width of the second sub-protrusion.

[0040] In a specific embodiment, the outer diameter of the cylindrical body 1 is 400 mm, the total length of the three adjacent protrusions in the axial direction of the cylindrical body 1 is 400 mm, and along the axial direction of the cylindrical body, the three protrusions are respectively a first protrusion 101, a second protrusion 102 and a third protrusion 103, the length of the first protrusion 101 in the axial direction of the cylindrical body 1 is 160 mm, the first protrusion 101 includes a third end close to the second protrusion 102 and a fourth end away from the second protrusion 102, and in the axial direction of the cylindrical body 1, the center point of the second protrusion 102 The distance from the center point of the first protrusion 101 to the center point of the second protrusion 102 is 120 mm, and the distance from the center point of the second protrusion 102 to the center point of the third protrusion 103 is 120 mm. That is to say, the distance from the center point of the first protrusion 101 to the center point of the second protrusion 102 and the distance from the center point of the second protrusion 102 to the center point of the third protrusion 103 are the same. Such a setting is conducive to the formation of the concave-convex structure 11 and simplifies the process.

[0041] In an exemplary embodiment, the minimum inner diameter of the cylindrical body 1 at the first protrusion 101 is 320 mm, the minimum inner diameter of the cylindrical body 1 at the second protrusion 102 is 340 mm, and the minimum inner diameter of the cylindrical body 1 at the third protrusion 103 is 360 mm.

[0042] Flow rate calculation formula: Flow rate (v) = flow rate / area (Q / A);

[0043] The unit of flow rate is usually cubic meter per second (m 3 / s), the unit of area is usually square meters (m 2 ). Assume that in actual production, the flow rate of argon is 120L / min (0.002m 3 / s), according to Figure 1 The inner diameters shown are: 360mm, 340mm, 320mm, and the calculated areas are 0.102m 2 、0.091m 2 、0.08m 2Therefore, according to the above flow rate formula, it can be calculated that the flow rate of argon from top to bottom is 0.02m / s, 0.022m / s, and 0.025m / s. According to the data, the argon flow rate at the minimum inner diameter position is 25% higher than the argon flow rate at the maximum inner diameter position.

[0044] In an exemplary embodiment, the convex surface of the protrusion away from the inner wall of the cylindrical body 1 is a smooth curved surface, but the present invention is not limited thereto.

[0045] In an exemplary embodiment, each of the protrusions includes a center line extending in the radial direction of the cylindrical body 1, and the distance from the convex surface of the protrusion away from the inner wall of the cylindrical body 1 to the outer wall of the cylindrical body 1 gradually decreases from the center line to both sides, that is, for each of the protrusions, the position of the center line is the position of the minimum inner diameter.

[0046] The concave-convex structure 11 includes a plurality of protrusions, a concave portion is formed between two adjacent protrusions, and along the axial direction of the cylindrical body 1, from the first end to the second end, the thickness of the concave portion (the size in the radial direction of the cylindrical body 1) can be gradually increased. Along the axial direction of the cylindrical body 1, from the first end to the second end, the thickness of the concave portion (the size in the radial direction of the cylindrical body 1) can also be the same, as long as the change in the thickness of the plurality of protrusions in the radial direction of the cylindrical body 1 makes the inner diameter of the cylindrical body 1 gradually decrease from the first end to the second end.

[0047] It should be noted that in order to improve the stability of the argon gas flow rate, the smaller the difference in thickness between the protrusion and the recess in the radial direction of the cylindrical body 1, the better. Therefore, in this embodiment, preferably, along the axial direction of the cylindrical body 1, from the first end to the second end, the thickness of the recess (the dimension in the radial direction of the cylindrical body 1) gradually increases.

[0048] In the axial direction of the cylindrical body 1, the length of the first protrusion 101 is 160 mm, the length of the second protrusion 102 is 80 mm, and the length of the third protrusion 103 is 160 mm, that is, the first protrusion 101 and the third protrusion 103 are the first sub-protrusions, and the second protrusion 102 is the second sub-protrusion. In the axial direction of the cylindrical body 1, the lengths of the first sub-protrusion and the second sub-protrusion are different, and the first sub-protrusion and the second sub-protrusion are staggered.

[0049] In an exemplary embodiment, a heat absorbing coating is provided on a side of the protrusion away from the inner wall of the cylindrical body 1 .

[0050] The heat-absorbing coating is arranged on one side of the concave-convex structure 11 close to the center of the cylindrical body 1, and the shape of the heat-absorbing coating is consistent with the shape of the concave-convex structure 11, that is, the connecting surface of the heat-absorbing coating connected to the side wall of the cylindrical body 1 and the inner surface arranged opposite to the connecting surface are both the concave-convex structure 11.

[0051] The heat-absorbing coating has a heat-absorbing effect. The bonding strength between the heat-absorbing coating and the cylindrical body 1 is high, which can effectively alleviate the thermal stress of the heat-absorbing coating interface (the connecting surface between the heat-absorbing coating and the cylindrical body 1). The thermodynamic properties are stable. The cylindrical body 1 can well take away the heat transmitted by the crystal rod in real time, greatly improve the cooling rate of the crystal rod, increase the pulling speed, and increase the crystal pulling efficiency.

[0052] In an exemplary embodiment, the thickness of the heat absorbing coating layer in the radial direction of the cylindrical body 1 gradually increases in a direction from the first end of the cylindrical body 1 to the second end of the cylindrical body 1 .

[0053] In an exemplary embodiment, the heat absorbing coating is made of ceramic, but is not limited thereto.

[0054] In an exemplary embodiment, the outer side wall of the cylindrical body 1 is provided with a heat insulation coating.

[0055] The heat-insulating coating has the function of reflecting and shielding heat, preventing the external heat from being transmitted from the cylindrical body 1 to the inside of the water-cooling jacket (ie, the inside of the cylindrical body 1), thereby maintaining a constant temperature inside the water-cooling jacket.

[0056] In an exemplary embodiment, the outer wall of the cylindrical body 1 is provided with a thermal insulation coating, and the thickness of the thermal insulation coating in the radial direction of the cylindrical body 1 gradually increases from the top of the cylindrical body 1 to the bottom of the cylindrical body 1 (i.e., from the first end of the cylindrical body 1 to the second end of the cylindrical body 1).

[0057] In an exemplary embodiment, the thermal insulation coating is made of high temperature resistant thermal insulation zirconia ceramics.

[0058] In an exemplary embodiment, a cooling pipe for accommodating a cooling medium is disposed on the side wall of the cylindrical body 1 , and in the axial direction of the cylindrical body 1 , the cooling pipe is distributed on the side wall of the cylindrical body 1 in a spiral shape.

[0059] In an exemplary embodiment, a cooling pipe for containing a cooling medium is disposed on the outer circumferential surface of the cylindrical body 1 .

[0060] In an exemplary embodiment, the side wall of the cylindrical body 1 may be hollow, and the cooling pipe is distributed in the side wall of the cylindrical body 1 .

[0061] The specific structural form of the cooling pipe is not limited thereto. For example, the cooling pipe may be serpentine and distributed on the outer wall of the cylindrical body 1. The cooling pipe may be serpentine and include a plurality of straight pipes extending along the axial direction of the cylindrical body 1 and a bent pipe arranged between two adjacent straight pipes.

[0062] In an exemplary embodiment, the diameter of the cooling pipe gradually increases in a direction from the top end of the cylindrical body 1 to the bottom end of the cylindrical body 1 .

[0063] By adopting the above solution, the water cooling effect of the cooling pipe changes gradually along the axial direction of the cooling pipe, which is beneficial to the regulation of radial and axial gradient temperatures.

[0064] In summary, the water cooling jacket provided in this embodiment has the following advantages:

[0065] Increasing the flow rate of argon gas: by reducing the diameter (ie, the inner diameter of the cylindrical body 1), the flow rate of argon gas is relatively increased, which makes it easier to remove impurities on the surface of the silicon melt, thereby making the purity of the silicon melt higher.

[0066] Increase the surface area: The arrangement of the wavy concave-convex structure 11 can increase the surface area of ​​the water cooling jacket in contact with the crystal rod, so that more heat can enter the cooling water through heat transfer.

[0067] Promoting heat dissipation: The water cooling jacket provided with the wavy concave-convex structure 11 can make the argon gas generate more turbulence, which can more effectively take away the heat, thereby accelerating the cooling speed of the crystal rod.

[0068] Improve cooling uniformity: The provision of the wavy concave-convex structure 11 helps to form a more uniform heat flux distribution on the growth surface of the crystal rod, reduces the temperature gradient, and helps to grow a crystal rod without defects or with fewer defects.

[0069] An embodiment of the present invention further provides a single crystal furnace, comprising the above-mentioned water cooling jacket.

[0070] Preferably, the single crystal furnace may further include:

[0071] a furnace body, the furnace body defining a chamber;

[0072] A crucible assembly is arranged in the inner cavity of the furnace body, the crucible assembly comprises a sleeved quartz crucible and a graphite crucible, and the quartz crucible contains a silicon solution;

[0073] A guide tube, the guide tube is used to guide the inert gas to the top of the silicon melt, wherein the guide tube is arranged on the periphery of the water cooling jacket;

[0074] A heating component is arranged around the crucible assembly and is used to heat the crucible assembly. The heating component is fixed to the bottom of the furnace body through electrode bolts and is connected to the heating electrode at the bottom of the furnace body.

[0075] A heat-insulating layer, disposed between the heating component and the side wall of the furnace body, for preventing the heat of the heating component from radiating to the outside of the furnace body;

[0076] A support shaft is supported and connected to the bottom of the graphite crucible; a crucible tray is provided at the upper end of the support shaft, and the lower end of the support shaft passes through the bottom of the furnace body 5.

[0077] The following describes the process of crystal pulling through the above-mentioned single crystal furnace:

[0078] First, the crystal raw material is placed in the crucible assembly and melted by the high temperature generated by the heating component.

[0079] Then, the molten silicon solution is slightly cooled to produce a certain degree of supercooling.

[0080] Then, a silicon single crystal (called a seed crystal) fixed on the seed crystal axis is inserted into the melt surface. After the seed crystal and the melt are melted, the seed crystal is slowly pulled upwards, and the crystal will grow at the lower end of the seed crystal.

[0081] Next, the seed crystal is controlled to grow a thin neck with a length of about 100 mm and a diameter of 3 mm to 5 mm to eliminate the dislocation of atomic arrangement caused by the strong thermal shock of the high-temperature solution on the seed crystal. This process is called seeding.

[0082] Subsequently, the crystal diameter is enlarged to the size required by the process, generally 75mm to 300mm. This process is called shoulder release.

[0083] Next, suddenly increase the pulling speed to perform the shoulder rotation operation so that the shoulder is approximately at a right angle.

[0084] Then, the equal-diameter process is entered, and single crystal columns of a certain size are grown by controlling the thermal field temperature and the crystal lifting speed.

[0085] Finally, when most of the silicon solution has completed crystallization, the crystals are gradually shrunk to form a tail-shaped cone, which is called the finishing process.

[0086] In this way, the single crystal pulling process is basically completed and it can be taken out after a certain period of insulation and cooling.

[0087] There are a few points to note:

[0088] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0089] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0090] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0091] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A water cooling jacket, applied to a crystal pulling furnace, characterized in that: It comprises a cylindrical body, along the axial direction of the cylindrical body, the cylindrical body comprises a first end and a second end which are arranged opposite to each other, the first end is arranged close to the top of the crystal pulling furnace, and the inner diameter of the cylindrical body gradually decreases from the first end to the second end.

2. The water cooling jacket according to claim 1, characterized in that: A wave-shaped concave-convex structure is arranged on the inner wall of the cylindrical body.

3. The water cooling jacket according to claim 2, characterized in that: The concave-convex structure includes a plurality of annular protrusions arranged on the inner wall of the cylindrical body along the axial direction of the cylindrical body.

4. The water cooling jacket according to claim 3, characterized in that: The thickness of the annular protrusion in the radial direction of the cylindrical body gradually increases from the first end to the second end.

5. The water cooling jacket according to claim 3, characterized in that: In the axial direction of the cylindrical body, the distance between the center points of any two adjacent protrusions is the same.

6. The water cooling jacket according to claim 5, characterized in that: In the axial direction of the cylindrical body, the protrusion includes a first sub-protrusion and a second sub-protrusion that are staggered, and in the axial direction of the cylindrical body, a width of the first sub-protrusion is different from a width of the second sub-protrusion.

7. The water cooling jacket according to claim 3, characterized in that: The convex surface of the protrusion away from the inner wall of the cylindrical body is a smooth curved surface.

8. The water cooling jacket according to claim 3, characterized in that: A heat absorbing coating is provided on a side of the protrusion away from the inner wall of the cylindrical body.

9. The water cooling jacket according to claim 3, characterized in that: A cooling pipeline for accommodating a cooling medium is arranged on the side wall of the cylindrical body. In the axial direction of the cylindrical body, the cooling pipeline is spirally distributed on the side wall of the cylindrical body.

10. A single crystal furnace, characterized in that: Comprising the water cooling jacket according to any one of claims 1 to 9.

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