Water-cooled heat shield, single crystal furnace and crystal pulling method

Abstract

The invention relates to the field of single crystal growth, in particular to a water-cooled heat shield, a single crystal furnace and a crystal pulling method.The water-cooled heat shield comprises a water-cooled heat shield body, the water-cooled heat shield body is provided with a first part and a second part, and the first part and the second part are located on the two sides of the center of the water-cooled heat shield body; and the adjusting piece is connected with and acts on the first part and the second part, so that the water-cooling heat shield body can reach a preset posture. The technical problem of low crystal growth quality is solved, and the technical effect of improving the crystal growth quality is achieved.

Description

Technical Field

[0001] The present application relates to the field of single crystal growth, and in particular to a water-cooled heat shield, a single crystal furnace and a crystal pulling method. Background Art

[0002] In the field of single crystal furnace technology, water-cooled heat shields are a key heat exchange device, and their importance is self-evident. Single crystal furnaces, as core equipment in the fields of semiconductors and photovoltaics, melt polycrystalline materials and grow high-quality single crystal materials through the Czochralski method. However, the high temperature environment inside the single crystal furnace not only requires precise temperature control to ensure the growth quality of the single crystal, but also needs to protect the components in the furnace from high temperature damage. The water-cooled heat shield is designed to solve this problem. It uses the excellent thermal conductivity of water and a complex cooling system such as guide plates and cooling pipes to quickly cool down the high-temperature working medium and recycle it, thereby effectively regulating the temperature field inside the single crystal furnace.

[0003] In the prior art, the water-cooled heat shield is a crucial temperature control structure in the single crystal furnace. The installation and welding accuracy of the water-cooled heat shield is directly related to the stability of the thermal field inside the single crystal furnace. However, due to various factors in the processing and installation process, such as insufficient welding accuracy between water-cooled heat shield components and slight deviations in the installation position, these problems are often difficult to completely avoid. These position deviations will directly lead to a decrease in the working efficiency of the water-cooled heat shield in the single crystal furnace, which will in turn cause thermal field disorder, resulting in lower crystal growth quality.

[0004] Therefore, the technical problem of the prior art is that the crystal growth quality is low. Summary of the invention

[0005] The present application provides a water-cooled heat shield, a single crystal furnace and a crystal pulling method, which solve the technical problem of low crystal growth quality and achieve the technical effect of improving the crystal growth quality.

[0006] On the one hand, the present application provides a water-cooled heat shield, which adopts the following technical solution:

[0007] A water-cooled heat shield comprises: a water-cooled heat shield body, the water-cooled heat shield body having a first part and a second part, the first part and the second part are located on both sides of the center of the water-cooled heat shield body; an adjusting member, the adjusting member is connected to and acts on the first part and the second part, so that the water-cooled heat shield body can reach a preset posture.

[0008] Preferably, the adjusting member is flexible, and there are at least two adjusting members, and the first part and the second part are respectively connected to at least one adjusting member.

[0009] Preferably, the adjusting member is flexible, there are at least three adjusting members, and the first part and the second part are respectively connected to at least one adjusting member.

[0010] Preferably, a plurality of the adjustment members are evenly distributed on the water-cooled heat shield body.

[0011] In the second aspect, the present application provides a single crystal furnace, which adopts the following technical solution:

[0012] A single crystal furnace comprises a main furnace chamber, wherein the main furnace chamber comprises: a furnace cover; a water-cooled heat shield, wherein the water-cooled heat shield is the water-cooled heat shield described above, wherein the adjusting member is connected to the furnace cover; and a driving device, wherein the driving device is connected between the furnace cover and the water-cooled heat shield to drive the water-cooled heat shield to rise and fall, wherein the driving device is detachably connected to at least a portion of the water-cooled heat shield body so that the water-cooled heat shield body can be adjusted to a preset posture by the adjusting member.

[0013] Preferably, the driving device has a movable part, and the movable part has the freedom of movement in the vertical direction; when the movable part is moving, the water-cooled heat screen has at least a first state and a second state: in the first state, the water-cooled heat screen is abutted by the movable part; in the second state, the water-cooled heat screen is separated from the movable part.

[0014] Preferably, the adjusting member is adjustably connected to the furnace cover.

[0015] Preferably, the furnace cover has a first connecting portion, the adjusting member has a second connecting portion, the second connecting portion is passed through the first connecting portion, and the second connecting portion is threadedly connected to the first connecting portion, so that the length of the adjusting member is adjustable.

[0016] In a third aspect, the present application provides a crystal pulling method, which adopts the following technical solution:

[0017] A crystal pulling method comprises: adjusting an adjusting part to make a water-cooled heat shield body reach a preset posture; and pulling the crystal.

[0018] Preferably, before the "adjusting the adjusting member", the method further includes: driving the water-cooled heat shield body to descend so that the water-cooled heat shield body is separated from the driving device.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] The water-cooled heat shield proposed in this application is provided with an adjustment part, which can accurately adjust the posture of the water-cooled heat shield body to a preset state, effectively solving the problems caused by insufficient welding accuracy and slight deviation of the installation position during the processing and installation of the traditional water-cooled heat shield, such as thermal field disorder and inaccurate temperature control; by adjusting the water-cooled heat shield body with the adjustment part, the optimal working state of the water-cooled heat shield in the single crystal furnace is ensured, and the stability and uniformity of the temperature field inside the single crystal furnace are significantly improved; the crystal growth environment is optimized, the crystal defects caused by thermal field fluctuations are reduced, and the quality and yield of crystal growth are greatly improved. The technical problem of low crystal growth quality is solved, and the technical effect of improving the quality of crystal growth is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the layout of the water-cooled heat screen described in this application;

[0022] Figure 2 It is a schematic diagram of the water-cooled heat shield described in this application;

[0023] Figure 3 It is a schematic diagram of the connection of the water-cooled heat shield described in this application;

[0024] Figure 4 , 5 It is a schematic diagram of the coordination between the water-cooled heat shield and the driving device described in the present application;

[0025] Figure 6 is a cross-sectional view of the furnace cover and water-cooled heat shield described in the present application;

[0026] Figure 7 yes Figure 6 A is an enlarged view of the middle image.

[0027] Description of reference numerals:

[0028] 100, water-cooled heat shield; 110, water-cooled heat shield body; 111, first part; 112, second part; 113, connecting piece; 120, adjusting piece; 121, second connecting part; 200, furnace cover; 210, first connecting part; 300, driving device; 310, movable part. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] The embodiment of the present application provides a water-cooled heat shield 100 and a single crystal furnace, which solves the technical problem of low crystal growth quality and achieves the technical effect of improving crystal growth quality.

[0032] 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.

[0033] The water-cooled heat shield 100 plays a vital role in the single crystal furnace. The excellent heat exchange performance of the water-cooled heat shield 100 has a profound impact on the growth process of single crystal materials. The high temperature environment inside the single crystal furnace has extremely high requirements for the growth quality of single crystal materials, and the water-cooled heat shield 100 uses its efficient water cooling system and the excellent thermal conductivity of water to quickly cool down and recycle the high-temperature working medium inside the single crystal furnace. In this process, the water-cooled heat shield 100 not only effectively regulates the temperature field in the furnace, but also ensures the stable temperature environment required for single crystal growth. In addition, the precise design and installation of the water-cooled heat shield 100 further improves the uniformity of the thermal field of the single crystal furnace, reduces the adverse effects of thermal stress on crystal growth, and thus significantly improves the growth quality and yield rate of single crystal materials.

[0034] like Figure 1 As shown, the water-cooled heat shield body 110 generally has two connectors 113, which serve as a supporting and connecting structure. The connector 113 is connected to the driving device 300. Under the drive of the driving device 300, the water-cooled heat shield body 110 can be lifted and lowered in the vertical direction. The water-cooled heat shield body 110 is processed as a whole by welding and other processes. There are unavoidable minor errors in the processing and installation process, which makes the position deviation from the upper position (connecting member 113) to the lower position (water-cooled heat shield body 110) amplified. This causes the position of the water-cooled heat shield body 110 to shift, thereby affecting the uniformity of the thermal field in the single crystal furnace. Due to the existence of the connector 113, the left-right direction of the connector 113 can be adjusted through parameters such as the connection height and angle between the connector 113 and the drive device 300. However, the front-to-back direction of the connector 113 is difficult to adjust, that is, the water-cooled heat shield body 110 will lower or raise its head in the front-to-back direction of the connector 113, causing a disordered thermal field in the single crystal furnace, thereby affecting the quality of crystal growth. This technical problem needs to be solved urgently.

[0035] The present application proposes a water-cooled heat shield 100, such as Figure 1 , 2 As shown, for solving the above technical problems, the water-cooled heat shield 100 includes a water-cooled heat shield body 110 and an adjustment member 120; the posture of the water-cooled heat shield body 110 is adjusted by the adjustment member 120 so that the water-cooled heat shield body 110 reaches a preset posture.

[0036] like Figure 1 , 2 As shown, the water-cooled heat shield body 110 is used to water-cool the single crystal furnace so that the single crystal furnace has a stable and uniform thermal field. The structure of the water-cooled heat shield body 110 is a conventional setting in this field and will not be repeated in this embodiment. It is worth noting that the water-cooled heat shield body 110 has a first part 111 and a second part 112, and the first part 111 and the second part 112 are located on both sides of the center of the water-cooled heat shield body 110; if the setting positions of the two connecting members 113 are located on the same diameter, the two sides of the center of the water-cooled heat shield body 110 refer to: the two sides of the diameter where the connection position of the connecting member 113 is located; if the setting positions of the two connecting members 113 are not on the same diameter, the two sides of the center of the water-cooled heat shield body 110 refer to: the two sides of the diameter where the connection position of any one of the connecting members 113 is located; if the setting positions of the two connecting members 113 are not on the same diameter, the two sides of the center of the water-cooled heat shield body 110 may also refer to: the two sides of any diameter of the water-cooled heat shield body 110.

[0037] In the present application, an adjustment member 120 is provided on the water-cooled heat shield body 110, such as Figure 1 , 2As shown, the adjustment member 120 is connected to and acts on the water-cooled heat shield body 110. The adjustment member 120 adjusts the posture of the water-cooled heat shield body 110 so that the water-cooled heat shield body 110 reaches a preset posture. Generally, the preset posture means that the water-cooled heat shield body 110 is kept centered in the single crystal furnace so that the upper edge and the lower edge of the water-cooled heat shield 100 are horizontal, thereby making the thermal field in the single crystal furnace uniform and stable.

[0038] Specifically, there are several adjusting members 120, and the adjusting members 120 are connected between the furnace cover 200 of the single crystal furnace and the water-cooled heat shield body 110, such as Figure 1-3 As shown, the posture of the water-cooled heat shield body 110 is limited by setting the length of the adjustment member 120, so that the water-cooled heat shield body 110 reaches a preset posture. The adjustment member 120 is set as a flexible member, which refers to a non-rigid object that can be bent, deformed, and twisted, such as a metal rope, a metal chain, etc. In one embodiment, a tungsten wire rope can be used.

[0039] In one embodiment, at least two adjustment members 120 are provided, and at least one adjustment member 120 is respectively connected to the first part 111 and the second part 112 of the water-cooled heat shield body 110. By adjusting the length of the adjustment members 120 on the first part 111 and the second part 112, the posture of the water-cooled heat shield body 110 can be limited so that the water-cooled heat shield body 110 remains in a centered state.

[0040] In another embodiment, at least three adjusting members 120 are provided, at least one adjusting member 120 is connected to the first portion 111 of the water-cooled heat shield body 110, and at least two adjusting members 120 are connected to the second portion 112 of the water-cooled heat shield body 110, or at least two adjusting members 120 are connected to the first portion 111 of the water-cooled heat shield body 110, and at least one adjusting member 120 is connected to the second portion 112 of the water-cooled heat shield body 110. Preferably, the number of adjusting members 120 is set to three, and the connection positions between the three adjusting members 120 and the water-cooled heat shield body 110 form a certain plane. In this way, by adjusting the lengths of the three adjusting members 120, the posture of the water-cooled heat shield body 110 can be limited so that the water-cooled heat shield body 110 remains in a centered state.

[0041] Preferably, when a plurality of adjustment parts 120 are provided on the water-cooled heat shield body 110, the plurality of adjustment parts 120 are evenly distributed on the water-cooled heat shield body 110. In one embodiment, the adjustment parts 120 are connected to the upper edge of the water-cooled heat shield body 110 and are evenly arranged. In other embodiments, the adjustment parts 120 may also be connected to other parts of the water-cooled heat shield body 110. By adjusting the length of the adjustment parts 120, the water-cooled heat shield body 110 can be adjusted to a preset posture.

[0042] The present application also proposes a single crystal furnace, such as Figure 3 As shown, for pulling single crystal silicon, the single crystal furnace includes a main furnace chamber, which is the main place for crystal pulling. The heat field distribution in the main furnace chamber needs to be strictly controlled. The present application applies the above-mentioned water-cooled heat shield 100 to improve the crystal pulling quality of the single crystal furnace. The main furnace chamber includes a furnace cover 200, a water-cooled heat shield 100 and a driving device 300. The furnace cover 200 is located at the top of the main furnace chamber. The water-cooled heat shield 100 is connected to the furnace cover 200 through the driving device 300. The water-cooled heat shield 100 is driven to rise and fall by the driving device 300, so that the water-cooled heat shield 100 can be lifted and lowered in the main furnace chamber.

[0043] Specifically, Figure 4 , 5 As shown, the driving device 300 is located outside the main furnace chamber, and the driving device 300 is connected to the furnace cover 200; the water-cooled heat screen 100 is arranged inside the main furnace chamber, and the connecting piece 113 of the water-cooled heat screen 100 is passed through the furnace cover 200 and connected to the driving device 300, so that the driving device 300 can drive the water-cooled heat screen 100 to rise or fall as a whole; the water-cooled heat screen 100 and the driving device 300 are at least partially detachably connected, so that the driving device 300 can achieve separation and connection with the water-cooled heat screen 100 during the process of driving the water-cooled heat screen 100 to rise and fall, and when the water-cooled heat screen 100 and the driving device 300 are separated, the water-cooled heat screen 100 is corrected to a preset posture under the length limit of the adjusting piece 120, that is, the position adjustment of the water-cooled heat screen 100 is not affected by the connection of the driving device 300.

[0044] Furthermore, the driving device 300 has a movable part 310, and the movable part 310 has a degree of freedom of movement in the vertical direction. In one embodiment, the driving device 300 has two, and the two driving devices 300 are respectively connected to the connecting piece 113 of the water-cooled heat shield 100. The driving device 300 can specifically adopt a screw rod structure, and the movable part 310 is a slider connected to the screw rod; during the movement of the movable part 310, at least a first state and a second state are formed between the water-cooled heat shield 100 and the movable part 310. In the first state, the water-cooled heat shield 100 is The heat shield 100 is connected to the movable part 310. In one embodiment, the water-cooled heat shield 100 and the movable part 310 are in contact, that is, the water-cooled heat shield 100 is supported by the movable part 310. At this time, the posture of the water-cooled heat shield 100 is fixed, so that the posture of the water-cooled heat shield 100 cannot be adjusted; in the second state, the water-cooled heat shield 100 and the movable part 310 are separated, that is, there is no contact between the water-cooled heat shield 100 and the movable part 310. At this time, the posture of the water-cooled heat shield 100 is in an active state (or at least partially movable), so that the posture of the water-cooled heat shield 100 is adjustable.

[0045] It is worth noting that the movable part 310 of one group of driving devices 300 is fixedly connected to the connecting piece 113 of the water-cooled heat shield 100, and the movable part 310 of the other group of driving devices 300 is detachably connected to the connecting piece 113 of the water-cooled heat shield 100; in this way, when the movable part 310 fixedly connected to the connecting piece 113 descends to a certain position, the movable part 310 detachably connected to the connecting piece 113 continues to descend, so that the movable part 310 and the water-cooled heat shield 100 can be separated. When the movable part 310 rises, the movable part 310 can be re-contacted with the connecting piece 113 to drive the water-cooled heat shield 100 to rise.

[0046] like Figure 6 , 7 As shown, in order to improve the adjustment accuracy and application range of the adjustment member 120, the adjustment member 120 and the furnace cover 200 are adjustable, that is, when the adjustment member 120 is connected to the furnace cover 200, the length of the adjustment member 120 can be adjusted to adjust the posture of the water-cooled heat shield 100. Specifically, the furnace cover 200 has a first connection part 210, and the adjustment member 120 has a second connection part 121, the second connection part 121 is penetrated on the first connection part 210, and the second connection part 121 is connected to the first connection part 210 by a thread, and the length of the adjustment member 120 can be adjusted by adjusting the position of the second connection part 121 on the first connection part 210; in one embodiment, the second connection part 121 is a sleeve sleeved on the adjustment member 120, and the sleeve is threadedly connected to the first connection part 210 (i.e., the furnace cover 200).

[0047] The present application also proposes a crystal pulling method, which is applied to the above-mentioned single crystal furnace, comprising: driving the water-cooled heat shield 100 to descend by a driving device 300, and separating the water-cooled heat shield 100 from a movable portion 310 of the driving device 300, so that the water-cooled heat shield 100 is in a freely adjustable posture;

[0048] Adjust the length of the adjusting member 120 to make the water-cooled heat shield 100 reach a preset posture; and pull the crystal.

[0049] Working principle / steps:

[0050] The water-cooled heat shield 100 is used to stabilize the thermal field in the single crystal furnace, and the accuracy of its posture is crucial to the quality of crystal growth. In order to solve the problem of posture deviation of the water-cooled heat shield 100 caused by processing and installation errors, the present application proposes to set an adjustment member 120 on the water-cooled heat shield body 110. These adjustment members 120 are flexible and adjustable-length components, connected between the furnace cover 200 of the single crystal furnace and the water-cooled heat shield body 110. By adjusting the length of the adjustment member 120, the posture of the water-cooled heat shield body 110 can be limited and adjusted to reach a preset centering and horizontal state, thereby ensuring the uniformity and stability of the thermal field in the single crystal furnace. In the single crystal furnace, the water-cooled heat shield 100 is lifted and lowered by the driving device 300. When the movable part 310 of the driving device 300 is disengaged from the water-cooled heat shield 100, the adjustment member 120 plays a role, so that the water-cooled heat shield 100 is adjusted to a preset posture in a free state. The first connection part 210 on the furnace cover 200 is adjustably connected to the second connection part 121 of the adjustment member 120, so as to precisely adjust the posture of the water-cooled heat shield 100. Through the coordinated action of the driving device 300 and the adjustment member 120, and the implementation of the crystal pulling method, the present application improves the crystal pulling quality of the single crystal furnace and solves the technical problem of low crystal growth quality.

[0051] Technical effects:

[0052] The water-cooled heat shield 100 proposed in the present application is provided with an adjustment member 120, which can accurately adjust the posture of the water-cooled heat shield body 110 to a preset state, effectively solving the problems caused by insufficient welding precision and slight deviation of the installation position during the processing and installation of the traditional water-cooled heat shield 100, such as thermal field disorder and inaccurate temperature control. The adjustment of the water-cooled heat shield body 110 by the adjustment member 120 ensures the optimal working state of the water-cooled heat shield 100 in the single crystal furnace, significantly improving the stability and uniformity of the temperature field inside the single crystal furnace, optimizing the crystal growth environment, reducing crystal defects caused by thermal field fluctuations, and greatly improving the quality and yield of crystal growth. The technical problem of low crystal growth quality is solved, and the technical effect of improving the quality of crystal growth is achieved.

[0053] 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.

[0054] 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 water-cooled heat shield, characterized in that: include: A water-cooled heat shield body, the water-cooled heat shield body having a first portion and a second portion, the first portion and the second portion being located on both sides of a center of the water-cooled heat shield body; An adjusting member is connected to and acts on the first part and the second part so that the water-cooled heat shield body can reach a preset posture.

2. A water-cooled heat shield according to claim 1, characterized in that: The adjusting member is flexible, and there are at least two adjusting members. The first part and the second part are respectively connected with at least one adjusting member.

3. A water-cooled heat shield according to claim 1, characterized in that: The adjusting member is flexible, has at least three adjusting members, and at least one of the first part and the second part is connected with at least two of the adjusting members.

4. A water-cooled heat shield according to claim 2 or 3, characterized in that: A plurality of the adjustment members are evenly arranged on the water-cooled heat shield body.

5. A single crystal furnace, characterized in that: The invention comprises a main furnace chamber, wherein the main furnace chamber comprises: Furnace cover; A water-cooled heat shield, wherein the water-cooled heat shield is the water-cooled heat shield according to any one of claims 1 to 4, and the adjusting member is connected to the furnace cover; and A driving device is connected between the furnace cover and the water-cooled heat shield to drive the water-cooled heat shield to rise and fall. The driving device is detachably connected to at least a portion of the water-cooled heat shield body so that the water-cooled heat shield body can be adjusted to a preset posture by the adjustment member.

6. A single crystal furnace according to claim 5, characterized in that: The driving device has a movable part, and the movable part has a degree of freedom of movement in a vertical direction; during the movement of the movable part, the water-cooled heat shield has at least a first state and a second state: In a first state, the water-cooled heat shield is connected to the movable part; In the second state, the water-cooled heat shield is separated from the movable part.

7. The single crystal furnace according to claim 5, characterized in that: The adjusting member is adjustably connected to the furnace cover.

8. A single crystal furnace according to claim 7, characterized in that: The furnace cover has a first connection portion, and the adjusting member has a second connection portion, the second connection portion is penetrated through the first connection portion, and the second connection portion is threadedly connected to the first connection portion, so that the length of the adjusting member is adjustable.

9. A crystal pulling method, characterized in that: include: Adjust the adjustment parts to make the water-cooled heat shield body reach the preset posture; Crystal pulling.

10. A crystal pulling method according to claim 9, characterized in that: Before the "adjustment adjustment part", it also includes: The water-cooled heat shield body is driven to descend, so that the water-cooled heat shield body is separated from the driving device.

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