Crucible and single crystal furnace

Abstract

The invention relates to the technical field of Czochralski single crystal, in particular to a crucible and a single crystal furnace. The second crucible layer is located on the inner side of the first crucible layer, the second crucible layer is arranged on the inner wall of the first crucible layer in a composite mode, the second crucible layer comprises a bubble layer, and the bubble layer is connected to the inner wall of the first crucible layer; the transparent layer is located on the inner side of the bubble layer, and the transparent layer is connected to the inner wall of the bubble layer; wherein the air bubble layer is provided with first air bubbles, and the air bubble layer is further provided with added second air bubbles. The technical problem that the thermal stability of the crucible is low is solved, and the technical effect of improving the thermal stability of the crucible is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of Czochralski single crystals, and in particular to a crucible and a single crystal furnace. Background Art

[0002] Monocrystalline silicon is an important photovoltaic and semiconductor material, generally used to manufacture integrated circuits, electronic components and photovoltaic solar panels. At present, with the proposal of the goals of "carbon peak" and "carbon neutrality", the increased requirements for clean energy have promoted the development of the photovoltaic market. Monocrystalline silicon is the mainstream product of solar cells, and direct-pull monocrystalline silicon is an important method for producing monocrystalline silicon. With the development of monocrystalline silicon and the intensification of market competition, in order to increase the production capacity of monocrystalline silicon and reduce costs, the thermal field size of direct-pull single crystal furnaces continues to increase, and the stability and consistency of the thermal field in monocrystalline silicon are also facing challenges. It is necessary not only to optimize the growth parameters of monocrystalline silicon from the process aspect, but also to optimize the performance of the thermal field from aspects such as the components of the thermal field. Among them, the quartz crucible is one of the important components of the thermal field, serving as a quartz crucible that carries polycrystalline silicon molten material.

[0003] In the prior art, quartz crucibles are consumables. As the crystal pulling operation progresses, the performance of the crucible will deteriorate, especially the poor thermal stability of the crucible. As the size of the quartz crucible increases, the temperature difference of the melt in the crucible increases, the convection speed and mode change, and the stability of the melt in the crucible gradually deteriorates. All of these have a significant impact on the growth quality and efficiency of single crystal silicon rods, and the dislocation probability of silicon single crystals will also be greatly increased as the melt shakes.

[0004] Therefore, the technical problem of the prior art is that the crucible has low thermal stability. Summary of the invention

[0005] The present application provides a crucible and a single crystal furnace, which solve the technical problem of low thermal stability of the crucible and achieve the technical effect of improving the thermal stability of the crucible.

[0006] On the one hand, the present application provides a crucible, which adopts the following technical solution:

[0007] A crucible, comprising: a first crucible layer; a second crucible layer, wherein the second crucible layer is located on the inner side of the first crucible layer, and the second crucible layer is compositely arranged on the inner wall of the first crucible layer, and the second crucible layer comprises: a bubble layer, wherein the bubble layer is connected to the inner wall of the first crucible layer; a transparent layer, wherein the transparent layer is located on the inner side of the bubble layer, and the transparent layer is connected to the inner wall of the bubble layer; wherein the bubble layer has first bubbles, and the bubble layer also has added second bubbles.

[0008] Preferably, the second bubbles are configured to increase the bubble density of the bubble layer.

[0009] Preferably, the second bubbles are configured to increase the thickness of the bubble layer.

[0010] Preferably, the side wall of the crucible has a stable region, the stable region is arranged corresponding to the free interface of the melt, and the second bubbles are arranged in a bubble layer of the stable region.

[0011] Preferably, the stabilizing region is located at a top region of a side wall of the crucible.

[0012] Preferably, the stable region extends downward from the top edge of the crucible by between 0 and 40 cm.

[0013] Preferably, the second bubbles are configured such that the thickness of the bubble layer increases; and in the direction from the top of the crucible to the bottom of the crucible, the thickness of the bubble layer in the stable area gradually decreases.

[0014] Preferably, the second bubbles are configured such that the bubble density of the bubble layer increases; and in the direction from the top of the crucible to the bottom of the crucible, the bubble density of the bubble layer in the stable region gradually decreases.

[0015] Preferably, the height of the stable region is H∈[L-20, L+20] cm, wherein L is the height of the free interface of the melt in the welding and seeding state.

[0016] On the other hand, the present application provides a single crystal furnace, which adopts the following technical solution:

[0017] A single crystal furnace comprises a furnace body, wherein the crucible is arranged inside the furnace body.

[0018] In summary, the present application includes at least one of the following beneficial technical effects:

[0019] In the crucible provided by the present application, a second bubble is added to the bubble layer, the number of bubbles in the bubble layer is increased, and the bubble layer of the second bubble is increased, which not only enhances the heat insulation performance of the crucible and reduces heat loss, but also achieves a more uniform temperature distribution in the stable area near the free interface of the melt, effectively improves the thermal stability and melt stability of the crucible, significantly improves the growth quality and efficiency of the single crystal silicon rod, and reduces the probability of silicon single crystal dislocation. The technical problem that the low thermal stability of the crucible affects the quality of crystal growth is solved, and the technical effect of improving the thermal stability of the crucible and improving the quality of crystal growth is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a conventional crucible described in this application;

[0021] Figure 2 yes Figure 1 A magnified view of middle;

[0022] Figure 3 is a schematic diagram of the crucible described in this application;

[0023] Figure 4 yes Figure 3 Enlarged view of middle B;

[0024] Figure 5 It is a comparison chart of the liquid surface temperature fluctuations of the crucible described in the present application and the traditional crucible in the initial stage of melting and seeding.

[0025] Description of reference numerals: 100, first crucible layer; 200, second crucible layer; 210, bubble layer; 220, transparent layer; 300, stable region. DETAILED DESCRIPTION

[0026] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of this application, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0027] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] The embodiments of the present application provide a crucible and a single crystal furnace, which solve the technical problem that the low thermal stability of the crucible affects the quality of crystal growth, and achieve the technical effect of improving the thermal stability of the crucible and improving the quality of crystal growth.

[0029] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0030] As the size of the quartz crucible continues to increase, the temperature difference of the melt inside the crucible intensifies, and the convection speed and pattern change, resulting in a significant decrease in the stability of the melt (silicon), which poses a serious threat to the growth quality and efficiency of single crystal silicon rods, and also greatly increases the probability of silicon single crystal dislocation. Therefore, optimizing the stability of the melt inside the crucible and effectively reducing the vibration of the melt are crucial to improving the growth quality and efficiency of single crystal silicon. Therefore, the present application proposes a crucible and a single crystal furnace with high stability.

[0031] Before crystal pulling, the raw materials in the crucible need to be accurately heated to a molten state to convert them into silicon melt. In the process of crystal pulling, especially seeding, the bubble layer 210 inside the crucible plays a vital role. Figure 1 , 2 As shown, the original intention of the design of the bubble layer 210 is to achieve uniform scattering of the heater heat to the melt through the dense bubbles inside it, thereby ensuring that the melt is heated evenly and laying a solid foundation for the growth of high-quality crystals. As the heating temperature gradually rises, a phenomenon that cannot be ignored begins to appear: the bubbles begin to migrate from the outer layer of the crucible to the inside; in this process, the bubbles gradually expand and eventually burst. This change not only brings in tiny particle impurities such as silicon dioxide, causing direct contamination to the melt, but also leads to possible misalignment problems during the crystal pulling process. More seriously, the movement and rupture of bubbles also profoundly affect the thermal stability of the crucible. With the changes in the number, density and uniformity of bubbles, the transfer of heat in the melt becomes no longer uniform, and the temperature stability and consistency of the melt are greatly reduced, which in turn poses a severe challenge to the growth quality and efficiency of the crystal.

[0032] Therefore, how to effectively control and reduce the change in the content of bubbles in the crucible bubble layer 210 has become a key issue that we need to solve urgently. This not only requires us to deeply explore the mechanism of bubble movement and rupture, but also requires comprehensive consideration and optimization in multiple aspects such as heating process, crucible design and raw material pretreatment, so as to achieve more uniform and stable heat transfer during the crystal pulling process, thereby ensuring that the growth quality and efficiency of the crystal reach the optimal level.

[0033] The present application provides a crucible for carrying molten silicon, such as Figure 3 , 4 As shown, the crucible includes a first crucible layer 100 and a second crucible layer 200. The second crucible layer 200 is attached to the inner layer of the first crucible layer 100 and fixedly connected. The first crucible layer 100 is usually a carbon-carbon crucible; the second crucible layer 200 is usually a composite crucible layer.

[0034] like Figure 3 , 4As shown, the second crucible layer 200 includes a bubble layer 210 and a transparent layer 220. The bubble layer 210 is compositely arranged on the inner side of the first crucible layer 100, and the bubble layer 210 is connected to the inner wall of the first crucible layer 100; the transparent layer 220 is compositely arranged on the inner wall of the bubble layer 210, and the transparent layer 220 is connected to the inner wall of the bubble layer 210. Composite arrangement refers to: the connection between the first crucible layer 100 and the second crucible layer 200, so that the second crucible layer 200 is closely connected to the inner wall of the first crucible layer 100, including but not limited to chemical bonding, adhesive bonding, melting bonding, sintering bonding, etc. Among them, the bubble layer 210 has a first bubble, and the bubble layer 210 also has an increased second bubble, and the second bubble is arranged in the bubble layer so that the bubble density in the bubble layer 210 is increased and / or the thickness of the bubble layer 210 is increased; in one embodiment, the increased second bubble is arranged in the first direction of the first bubble, specifically, in the first direction, the bubble layer 210 also has an increased second bubble, that is, in the bubble layer 210, the first bubble also has an increased second bubble in the first direction, and the first direction defines the direction from the outside to the inside or from the inside to the outside of the crucible, that is, there is an angle between the first direction and the crucible wall; in other words, the present application increases the amount of bubbles in the bubble layer 210 of the crucible in a direction not parallel to the crucible wall, and increases the amount of bubbles in the bubble layer 210 to mitigate the impact of bubble movement and rupture on heat scattering; in another embodiment, the increased second bubble can also be arranged above or below the first bubble, that is, the amount of bubbles is increased in a direction parallel to the crucible wall, which can also increase the amount of bubbles in the bubble layer 210 to mitigate the impact of bubble movement and rupture on heat scattering.

[0035] It is worth noting that, based on the conventional crucible having the first bubbles in the bubble layer 210, the present application adds the second bubbles in the bubble layer 210 to increase the overall bubble content of the bubble layer 210. For example, the density of the first bubbles in the conventional crucible is x / mm 3 After the process adjustment, the thickness of the bubble layer 210 remains unchanged, and the second bubble is added on the basis of the first bubble in the bubble layer 210, so that the bubble density of the bubble layer 210 reaches x+y / mm 3 ; or, the thickness of the bubble layer 210 in the traditional crucible is αmm. After process adjustment, the density of bubbles in the bubble layer 210 remains unchanged, so that the thickness of the bubble layer 210 is increased to α+βmm; or, the addition of second bubbles increases the thickness of the bubble layer 210 or the density of bubbles in the bubble layer 210.

[0036] In one embodiment, the second bubble is configured to increase the bubble density of the bubble layer 210: this embodiment increases the density of the bubble layer 210 while maintaining the thickness of the bubble layer 210 unchanged. During the manufacturing process of the bubble layer 210, the bubble generation conditions are adjusted, such as increasing the gas injection amount, changing the gas injection rate, or optimizing the bubble formation process, so that the number of bubbles per unit volume in the bubble layer 210 is significantly increased, that is, the second bubble is added on the basis of the original first bubble. The bubble layer 210 structure formed by the newly added second bubble not only enhances the scattering and absorption capacity of the bubble layer 210 for thermal radiation, but also effectively slows down the thermal scattering fluctuations caused by the inward movement of the bubble through the interaction between the first bubble and the second bubble, thereby improving the stability of the temperature field in the crucible. In addition, the increased bubble density can also improve the thermal insulation performance of the crucible wall to a certain extent, reduce the direct transfer of heat to the outside of the crucible, which is beneficial to extend the service life of the crucible and optimize the crystallization quality of the silicon melt.

[0037] In the second embodiment, the second bubble is configured to increase the thickness of the bubble layer 210: this embodiment increases the thickness of the bubble layer 210 while keeping the bubble density unchanged. On the basis of maintaining the uniformity of bubble distribution, by extending the physical thickness of the bubble layer 210, the barrier path of the bubble layer 210 to thermal radiation is directly increased. In other words, the bubble layer 210 is thickened on the basis of the original thickness of the bubble layer 210. The bubbles in the original thickness of the bubble layer 210 are the first bubbles, and the bubbles in the thickened bubble layer 210 are the newly added second bubbles. In this way, the thermal radiation from the molten silicon can be more effectively absorbed and scattered, and the direct penetration of heat through the bubble layer 210 is reduced, thereby reducing the temperature of the outer wall of the crucible and reducing heat loss. At the same time, a thicker bubble layer 210 also means that there is more space for the bubbles to interact with each other, which helps to stabilize the bubble state, reduce the inward movement, expansion, and explosion of the bubbles, and further reduce the interference of bubble activity on thermal scattering. Therefore, increasing the thickness of the bubble layer 210 not only improves the thermal isolation performance of the crucible, but also promotes the uniform distribution of the temperature field inside the molten silicon, which is conducive to obtaining higher quality crystal growth.

[0038] In the third embodiment, the second bubbles are configured such that the bubble density of the bubble layer 210 increases, and at the same time, the thickness of the bubble layer 210 increases.

[0039] Furthermore, the above-mentioned bubble layer 210 is configured to have an increased thickness or an increased bubble density, or an increased thickness and an increased bubble density. For the increased thickness or increased bubble density of the bubble layer 210, it can be set to the entire bubble layer 210, that is, the entire bubble layer 210 is configured to have an increased thickness or an increased bubble density, or an increased thickness and an increased bubble density; it can also be set to only a portion of the bubble layer 210, that is, a portion of the bubble layer 210 is configured to have an increased thickness or an increased bubble density, or an increased thickness and an increased bubble density.

[0040] As the applicant conducted in-depth research, it was found that the impact of this phenomenon is particularly significant in the initial stage of crystal pulling, that is, during the crystal seeding process. Since this stage requires extremely high temperature control of the melt, the temperature on the free interface of the melt is often higher, which further aggravates the movement speed of the bubbles in the bubble layer 210 near the free interface. Among them, the free interface of the melt refers to the height position of the molten liquid of the melt. For example, when silicon is used as the melt, the free interface refers to the height position of the silicon liquid surface. This change not only leads to serious uneven heat scattering of the crucible, but also causes the thermal stability of the crucible to drop sharply. For this reason, the present application specifically defines a stable area 300 of the crucible, such as Figure 3 , 4 As shown, the stable region 300 is arranged on the side wall of the crucible, and the stable region 300 is determined by the free interface height of the melt, and generally covers a position within a range of 20 cm above and below the free interface height. In this region, any change in the bubble content in the bubble layer 210 may have a decisive influence on the growth of the crystal.

[0041] Therefore, in order to address the thermal stability issue in the stable area 300 of the crucible (i.e., the height position near the melt free interface, whose temperature stability and uniformity are crucial to crystal growth), the present application adds second bubbles in the bubble layer 210 on the stable area 300; it is worth noting that the height of the melt free interface is generally flush with the top edge of the first crucible layer 100.

[0042] Specifically, by precisely controlling the structure and layout of the bubble layer 210, additional bubbles (i.e., second bubbles) are added in the stable region 300, the overall thickness and / or density of the bubble layer 210 is increased (the increasing method is selected according to actual conditions), and the heat scattering and absorption path in the bubble layer 210 is further optimized. Such a design not only effectively slows down the speed at which bubbles move into the crucible due to temperature increase, reduces the risk of bubble rupture and impurities mixing into the melt, but also significantly improves the thermal stability in the stable region 300.

[0043] Further, by increasing the bubble content in the bubble layer 210 (whether by increasing the bubble density or increasing the thickness of the bubble layer 210), the crucible designed in the present application exhibits a high thermal stability. Even when the temperature rises and the bubbles move inward, expand and eventually burst, thereby reducing the number of bubbles, a sufficient amount of the first and second bubbles are still maintained in the bubble layer 210. These remaining bubbles, due to their uniform distribution in the bubble layer 210, can effectively continue to undertake the task of heat scattering and transfer. The synergistic effect of the first and second bubbles ensures the uniform distribution and effective transmission of heat in the bubble layer 210, thereby maintaining the stability of the internal temperature of the molten silicon. In addition, due to the sufficient number of bubbles in the bubble layer 210 and the uniformity of distribution, even if some bubbles burst due to the increase in temperature, it will not have a significant impact on the overall heat scattering effect.

[0044] In one embodiment, the stable region 300 is located at the top region of the crucible side wall, which is an area where temperature stability and uniformity are particularly important during crystal growth. The stable region 300 extends downward from the top of the crucible side wall, with a specific range of 0 to 40 cm. In order to further optimize the thermal stability in this critical region, the present application has specially designed the bubble layer 210. Specifically:

[0045] On the one hand, when the second bubbles are configured to increase the thickness of the bubble layer 210, the thickness of the bubble layer 210 in the stable region 300 gradually decreases in the direction from the top of the crucible to the bottom of the crucible; in the area near the top of the crucible, the temperature is higher due to the direct influence of the heater, so a thicker bubble layer 210 is required to provide sufficient heat scattering and heat insulation. As the heat is transferred to the bottom of the crucible, the temperature gradually decreases, and the thickness of the bubble layer 210 is also reduced accordingly to achieve more efficient heat transfer and more uniform temperature distribution.

[0046] On the other hand, when the second bubbles are configured to increase the bubble density of the bubble layer 210, the bubble density of the bubble layer 210 in the stable region 300 gradually decreases in the direction from the top of the crucible to the bottom of the crucible; this helps to form a denser heat scattering network in the area near the top of the crucible, effectively slowing down the heat transfer speed and reducing temperature fluctuations. As heat is transferred to the bottom of the crucible, the gradual decrease in bubble density helps the heat pass through the bubble layer 210 more smoothly, achieving a more uniform temperature distribution.

[0047] In another embodiment, Figure 3 , 4As shown, in order to more accurately define the stable region 300, its height H is associated with the free interface height L of the melt. Specifically, the height H of the stable region 300 is defined as: starting from the free interface height L of the melt inside the crucible, extending upward or downward to a certain range, that is, L-20cm≤H≤L+20cm, where L is the height of the free interface of the melt in the welding and seeding state, which is the interface between the molten silicon and the internal space of the crucible. Since the height of the free interface of the melt may change as the crystal growth process proceeds (for example, as the crystal is pulled out, the melt height will gradually decrease), by introducing the definition of H associated with L, it can be ensured that the stable region 300 is always located at a key position near the free interface of the melt.

[0048] In this range (L-20cm to L+20cm), the bubble layer 210 is designed to have a specific bubble density and / or thickness to provide sufficient heat scattering and heat insulation effects, thereby maintaining the stability and uniformity of the internal temperature of the molten silicon, especially the stability and uniformity of the melt free interface. The melt free interface temperatures of the traditional old crucible and the new crucible of the present application during operation are measured respectively, as shown in FIG. Figure 5 It can be seen that: in the early stage of melting and seeding, the temperature of the melt free interface of the traditional crucible, i.e. the old crucible, fluctuates greatly; while in the early stage of melting and seeding, the temperature of the melt free interface of the new crucible proposed in the present application fluctuates less.

[0049] Such a design helps to ensure the controllability and consistency of the temperature environment during the crystal growth process, providing a strong guarantee for obtaining high-quality crystals. It should be noted that although the height H of the stable area 300 is related to the height L of the melt free interface, in actual operation, it is necessary to monitor the height L of the melt free interface in real time through temperature sensors, image processing and other means, and adjust the position of the crucible or heater as needed to ensure that the stable area 300 is always in the correct position.

[0050] The above-mentioned crucible and its application performance will be further described through the following specific examples:

[0051] Embodiment 1:

[0052] The overall thickness of the bubble layer 210 of the crucible is set to 30 mm, that is, the thickness of the stable area 300 and the thickness of other areas of the bubble layer 210 are both 30 mm, and the bubble density in the bubble layer 210 is set to about 36 / mm 3 .

[0053] Embodiment 2:

[0054] The thickness of the stable area 300 of the bubble layer 210 in the crucible is set to 30 mm (the thickness decreases from top to bottom), and the thickness of other areas is 15 mm. The bubble density in the bubble layer 210 is set to about 36 / mm3 .

[0055] Embodiment 3:

[0056] The overall thickness of the bubble layer 210 of the crucible is set to 15 mm, that is, the thickness of the stable area 300 and the thickness of other areas of the bubble layer 210 are both 15 mm, and the bubble density in the bubble layer 210 is set to about 62 / mm 3 .

[0057] Comparative Example 1:

[0058] The overall thickness of the bubble layer 210 of the crucible is set to 15 mm, that is, the thickness of the stable area 300 and the thickness of other areas of the bubble layer 210 are both 15 mm, and the bubble density in the bubble layer 210 is set to about 36 / mm 3 .

[0059] Performance and testing:

[0060] In order to verify the influence of the crucible design proposed in Examples 1 to 3 (including the increase in the bubble density of the bubble layer 210 and the increase in the thickness of the bubble layer 210) and Comparative Example 1 on the crystal pulling process and the performance of the crucible, this test installed the above-mentioned crucible in a single crystal furnace, performed the crystal pulling process, and monitored and recorded the key process parameters and crystal quality indicators.

[0061] Seeding temperature fluctuation(℃) Lifespan (h) Crystallization rate (%) Crystal head oxygen content (ppma) Process 1 (Comparative Example 1) 0.50 380 89.50％ 13.04 Process 2 (Example 1) 0.10 500 93.40％ 11.97 Process 3 (Example 2) 0.10 460 93.20％ 11.42 Process 4 (Example 3) 0.08 410 92.10％ 11.54

[0062] Based on the above table, it can be seen that based on the crucible of the present application, increasing the thickness of the bubble layer 210 or increasing the bubble density in the bubble layer 210 can improve the performance of the crucible, reduce the fluctuation of the seeding temperature, increase the service life of the crucible, increase the crystallization rate and improve the crystal quality.

[0063] The present application proposes a single crystal furnace, comprising a main furnace chamber and an auxiliary furnace chamber. The main furnace chamber is provided with the above-mentioned crucible, which can improve the growth quality and efficiency of single crystal silicon rods and reduce the probability of dislocation of silicon single crystals.

[0064] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0065] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A crucible, characterized in that: include: First crucible layer; A second crucible layer, wherein the second crucible layer is located on the inner side of the first crucible layer, the second crucible layer is compositely arranged on the inner wall of the first crucible layer, and the second crucible layer comprises: a bubble layer connected to the inner wall of the first crucible layer; A transparent layer, the transparent layer is located inside the bubble layer, and the transparent layer is connected to the inner wall of the bubble layer; The bubble layer has first bubbles, and the bubble layer also has added second bubbles.

2. A crucible according to claim 1, characterized in that: The second bubbles are configured to increase the bubble density of the bubble layer.

3. A crucible according to claim 1 or 2, characterized in that: The second bubbles are configured to increase the thickness of the bubble layer.

4. A crucible according to claim 1, characterized in that: The side wall of the crucible has a stable region, the stable region is arranged corresponding to the free interface of the melt, and the second bubbles are arranged in the bubble layer of the stable region.

5. A crucible according to claim 4, characterized in that: The stabilization region is located in a top region of the side wall of the crucible.

6. A crucible according to claim 5, characterized in that: The stable region extends downward from the top edge of the crucible between 0 and 40 cm.

7. A crucible according to claim 5, characterized in that: The second bubbles are configured such that the thickness of the bubble layer increases; and in a direction from the top of the crucible to the bottom of the crucible, the thickness of the bubble layer in the stable region gradually decreases.

8. A crucible according to claim 5, characterized in that: The second bubbles are configured such that the bubble density of the bubble layer increases; and the bubble density of the bubble layer in the stable region gradually decreases in a direction from the top of the crucible to the bottom of the crucible.

9. A crucible according to claim 4, characterized in that: The height of the stable region is H∈[L-20, L+20] cm, wherein L is the height of the free interface of the melt in the welding and seeding state.

10. A single crystal furnace, characterized in that: include: A furnace body, wherein the crucible according to any one of claims 1 to 9 is arranged inside the furnace body.

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