Single crystal shoulder expanding control method and system and single crystal shoulder expanding device

Abstract

The invention provides a single crystal shoulder expanding control method and system and a single crystal shoulder expanding device. The single crystal shoulder expansion control method comprises the following steps: providing a seed crystal, and placing the seed crystal in a reaction furnace; setting a target shoulder shape, and obtaining a target diameter according to the target shoulder shape; introducing protective gas into the reaction furnace, and carrying out shoulder expansion on the single crystal; the real-time diameter of the single crystal is obtained, and the actual diameter difference delta D1 between the real-time diameter D1 and the target diameter D0 is calculated according to the target diameter corresponding to the shoulder expanding length L; whether the actual diameter difference delta D1 meets the range of the preset diameter difference delta D0 or not is judged; and if the actual diameter difference deltaD1 does not meet the range of the preset diameter difference deltaD0, the flow of the protective gas is adjusted so that the actual diameter difference deltaD1 can meet the range of the preset diameter difference deltaD0. According to the present invention, the real-time regulation is performed according to the real-time shoulder type in the shoulder expanding process, such that the heat on the single crystal surface can be timely adjusted, the regulation reaction speed is rapid, and the dislocation and the supercooling problem are not easily generated.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor technology, and specifically relates to a single crystal shoulder expansion control method and system, and a single crystal shoulder expansion device. Background Art

[0002] The production process of single crystal silicon rod includes the melting of silicon materials, temperature stabilization, seeding, shoulder release, shoulder expansion, growth, finishing, cooling and other process. Among them, the shoulder expansion process relies on the heater temperature setting combined with the growth rate setting to complete the growth of single crystal shoulder expansion.

[0003] During the shoulder expansion process, the shoulder shape and survival rate will be affected by factors such as temperature and inert atmosphere. The shoulder expansion angle can be controlled by controlling the heater temperature to quickly rise and fall or adjusting the growth rate: on the one hand, the heater takes a long time to react to the temperature rise and fall of the silicon solution and it is not easy to stably control the temperature. The thermal shock caused by the temperature fluctuation of the silicon solution can easily cause dislocations in the crystal. On the other hand, when growing heavily doped single crystals, due to the high impurity concentration, the rapid fluctuations in the growth rate will lead to compositional overcooling or dislocations and broken buds at the solid-liquid interface.

[0004] Therefore, how to control the process parameters so that the shoulder expansion can obtain the ideal shoulder shape without dislocation, broken bud or composition overcooling is a technical problem that needs to be solved at present. Summary of the invention

[0005] The present invention provides a single crystal shoulder expansion control method and system, and a single crystal shoulder expansion device, aiming to solve the problems of dislocation and bud breakage occurring in the existing single crystal silicon rod shoulder expansion process.

[0006] The first embodiment of the present application provides a single crystal shoulder expansion control method, comprising the following steps:

[0007] Providing a seed crystal, placing the seed single crystal in a reaction furnace, and growing a single crystal;

[0008] Set the target shoulder shape and obtain the target diameter D according to the target shoulder shape 0 ;

[0009] Introducing protective gas into the reaction furnace to expand the shoulders of the single crystal;

[0010] Get the real-time diameter D of the single crystal 1 And real-time shoulder length L 1 , according to the real-time shoulder length L 1 Corresponding target diameter D 0 , calculate the real-time diameter D 1 and the target diameter D 0 The actual diameter difference ΔD 1 ;

[0011] Determine the actual diameter difference ΔD 1Whether the preset diameter difference ΔD is met 0 scope;

[0012] If the actual diameter difference ΔD 1 The preset diameter difference ΔD is not satisfied 0 range, the flow rate of the protective gas is adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 range.

[0013] In some embodiments, the flow rate of the protective gas is adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 The scope of the steps further includes:

[0014] If the actual diameter difference ΔD 1 Greater than the preset diameter difference ΔD 0 is the maximum value, then the flow rate of the protective gas is reduced;

[0015] If the actual diameter difference ΔD 1 Smaller than the preset diameter difference ΔD 0 If the minimum value is reached, the flow rate of the shielding gas is increased.

[0016] In some embodiments, the flow rate of the protective gas is adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 The scope of the steps further includes:

[0017] According to the real-time diameter D 1 and the target diameter D 0 , adjust the flow rate of the protective gas to the protective gas flow correction value Q 1 , the protective gas flow correction value Q 1 satisfy:

[0018]

[0019] Among them, Q 0 is the initial flow setting value of the protective gas; β is the correction coefficient, 0.2≤β≤2.

[0020] In some embodiments, the target shoulder shape has an end diameter D f and the terminal shoulder length L f ,satisfy:

[0021] 40mm≤D f ≤440mm.

[0022] In some embodiments, 5 mm ≤ L f≤700mm.

[0023] In some embodiments, the preset diameter difference ΔD 0 Satisfy: -10mm≤ΔD 0 ≤10mm.

[0024] In some embodiments, the protective gas flow correction value Q 1 Satisfy: -100Torr≤Q 1 -Q 0 ≤100Torr.

[0025] In some embodiments, the shielding gas includes at least one of argon, helium, and nitrogen.

[0026] In some embodiments, the growth rate of the single crystal is 15-150 mm / h.

[0027] In some embodiments, the single crystal shoulder expansion control method further includes the following steps:

[0028] Set the end diameter D f ;

[0029] Determine the real-time diameter D 1 Whether the end point diameter D is met f scope;

[0030] If the real-time diameter D 1 Does not meet the end point diameter D f If the range is within the range of , the shoulder expansion of the single crystal continues;

[0031] If the real-time diameter D 1 Satisfy the end point diameter D f range, then the shoulder expansion of the single crystal is finished.

[0032] In some embodiments, the terminal diameter D f Satisfaction: D b -30mm≤D f ≤D b +30mm, where the single crystal D b is the equal diameter target diameter in mm.

[0033] The second embodiment of the present application provides a single crystal shoulder expansion control system, which is used to implement the single crystal shoulder expansion control method in any of the above embodiments, including:

[0034] A first acquisition module, wherein the first acquisition module is configured to acquire a target diameter D according to a target shoulder shape 0 ;

[0035] A gas delivery module, wherein the gas delivery module is configured to control a protective gas diffuser to introduce protective gas into the reaction furnace;

[0036] A second acquisition module, the second acquisition module is configured to acquire the real-time diameter D of the single crystal 1 And real-time shoulder length L 1 ;

[0037] The calculation module is configured to calculate the shoulder length L according to the real-time shoulder length L 1 Corresponding target diameter D 0 , calculate the real-time diameter D 1 and the target diameter D 0 The actual diameter difference ΔD 1 ;

[0038] A judgment module configured to judge the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 scope;

[0039] A control module configured to respond to the actual diameter difference ΔD 1 The preset diameter difference ΔD is not satisfied 0 The flow rate of the protective gas is controlled and adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 range.

[0040] A third embodiment of the present application provides a single crystal shoulder expansion device, comprising:

[0041] A reaction furnace, the reaction furnace is used to accommodate the single crystal;

[0042] A protective gas diffuser, wherein the protective gas diffuser is arranged in the reaction furnace;

[0043] A control device, wherein the control device is arranged at one side of the reactor and connected to the protective gas diffuser, the control device comprises a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the single crystal shoulder expansion control method as described in any one of claims 1 to 9.

[0044] In some embodiments, the protective gas diffuser comprises:

[0045] A diffuser body, the diffuser body being arranged on one side of the single crystal;

[0046] An air intake pipe, one end of which is connected to the diffuser body, and the other end of which is connected to the control device.

[0047] In some embodiments, there is a minimum distance R between the diffuser body and the single crystal, satisfying:

[0048] 20mm≤R≤200mm.

[0049] The present application provides a single crystal shoulder expansion control method, comprising the following steps: providing a seed crystal, placing the seed crystal in a reaction furnace, and growing a single crystal; setting a target shoulder shape, and obtaining a target diameter D according to the target shoulder shape. 0 ; Introduce protective gas into the reactor to expand the shoulders of the single crystal; obtain the real-time diameter D of the single crystal 1 And real-time shoulder length L 1 , according to the real-time shoulder length L 1 Corresponding target diameter D 0 , calculate the real-time diameter D 1 and target diameter D 0 The actual diameter difference ΔD 1 ; Determine the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 range; if the actual diameter difference ΔD 1 Does not meet the preset diameter difference ΔD 0 If the actual diameter difference is within the range of ΔD, the flow rate of the protective gas is adjusted to make 1 Meet the preset diameter difference ΔD 0 The present application can timely adjust the heat on the surface of the single crystal by real-time regulation according to the real-time shoulder shape during the shoulder expansion process. Compared with regulating the shoulder shape by adjusting the temperature through a heater, the shoulder shape reaction speed is faster, and compared with regulating the shoulder shape by the growth rate, the shoulder shape is less likely to produce dislocation and compositional overcooling problems. The shaped shoulder shape is more consistent with the standard set shoulder shape, ensuring the liquid level distance and the initial crucible position in the equal-diameter stage, which is beneficial to improving the consistency of V / G in the equal-diameter stage and improving the overall quality of the single crystal. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0051] Figure 1 A flow chart of a single crystal shoulder expansion control method provided in an embodiment of the present application;

[0052] Figure 2 A flow chart of a single crystal shoulder expansion control method provided by another embodiment of the present application;

[0053] Figure 3 A schematic diagram of the structure of a single crystal shoulder expansion device provided in an embodiment of the present application;

[0054] Reference numerals:

[0055] 10-reaction furnace, 20-protective gas diffuser, 21-diffuser body, 22-intake pipe, 30-control device, 40-support foot, 50-clamping piece, 100-single crystal. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0057] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0058] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0059] The first embodiment of the present application provides a method for controlling shoulder expansion of a single crystal 100, such as Figure 1 As shown, the following steps are included:

[0060] Providing a seed crystal, placing the seed crystal in a reaction furnace 10, and growing a single crystal 100;

[0061] Set the target shoulder shape and obtain the target diameter D according to the target shoulder shape 0 ;

[0062] A protective gas is introduced into the reaction furnace 10 to expand the shoulders of the single crystal 100;

[0063] Get the real-time diameter D of the single crystal 100 1 And real-time shoulder length L 1, according to the real-time shoulder length L 1 Corresponding target diameter D 0 , calculate the real-time diameter D 1 and target diameter D 0 The actual diameter difference ΔD 1 ;

[0064] Determine the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 scope;

[0065] If the actual diameter difference ΔD 1 Does not meet the preset diameter difference ΔD 0 If the actual diameter difference is within the range of ΔD, the flow rate of the protective gas is adjusted to make 1 Meet the preset diameter difference ΔD 0 range.

[0066] During the shoulder expansion process, the shoulder shape and survival rate are greatly affected by the stabilization temperature. Different starting temperatures of shoulder expansion, the same set cooling range and growth rate may cause the shoulder shape to be too cold or too hot. Changes in shoulder shape will affect the quality parameters of the crystal equal diameter position, and even cause the shoulder to break. During the shoulder expansion process, adjusting the heating temperature or the pulling speed of shoulder expansion can adjust the shoulder shape, but the temperature reaction slows down with the increase of silicon solution, which takes about 30 to 60 minutes, and the speed of temperature fluctuation is also affected by the crucible rotation and magnetic field. If the process crucible rotates slowly or the magnetic field intervenes, the temperature reaction time becomes longer, which also delays the adjustment of the shoulder shape and makes it impossible to form an ideal shoulder shape. If the temperature is adjusted by pulse power, the rapid thermal shock change is restricted by the crucible rotation and magnetic field, and the heat convection cannot be evenly distributed in the silicon solution, which will cause a sudden change in the shoulder temperature, resulting in broken bracts or dislocations; the shoulder can be controlled by adjusting the pulling speed of the shoulder expansion. Although the adjustment speed of the shoulder type is fast, for 111 crystal orientation products or heavily doped products, the shoulder expansion stress itself is large and slip lines are easily generated. Under the rapid fluctuation adjustment of the pulling speed, the stress near the triple point of the 111 crystal orientation increases sharply, especially when the impurity concentration of the heavily doped agent is high. The change in the growth rate of the single crystal 100 will directly lead to the problem of composition supercooling, resulting in dislocation, poor grain penetration or broken buds of the single crystal 100. The stable shoulder type can ensure that the feed amount is fixed, and the liquid level distance and crucible position entering the equal diameter stage are relatively fixed, which is conducive to the control of V / G consistency in the equal diameter stage and improves the overall quality of the single crystal 100.

[0067] The solution provided by the present application achieves control of the shoulder shape and quality assurance of the shoulder expansion process by adjusting the flow rate of the protective gas in the reactor 10. During the growth of the single crystal 100, as the shoulder expansion length increases, the shoulder expansion area also increases, the heat exchange area with the protective gas also increases, and the heat carried away by the heat exchange increases. By adjusting the flow rate of the protective gas in real time, the heat dissipation on the surface of the single crystal 100 can be controlled in time, thereby ensuring that the crystal grows according to the preset shoulder shape, and at the same time ensuring that the shoulder expansion shoulder shape will not be affected by excessive temperature changes to cause edge dislocations, thereby improving the quality of the finished single crystal 100.

[0068] In some embodiments, the flow rate of the shielding gas is adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 The scope of the steps further includes:

[0069] If the actual diameter difference ΔD 1 Greater than the preset diameter difference ΔD 0 If the maximum value of the protective gas is reached, the flow rate of the protective gas is reduced;

[0070] If the actual diameter difference ΔD 1 Smaller than the preset diameter difference ΔD 0 If the minimum value is reached, increase the flow rate of the shielding gas.

[0071] During the shoulder expansion process, the diameter of the single crystal 100 does not increase uniformly, but is slow at the beginning and then increases rapidly. For details, please refer to the energy conservation equation:

[0072]

[0073] A=πr 2

[0074] Where A is the cross-sectional area of ​​the single crystal 100, is heat loss, which refers to the heat dissipated by the crystal and the environment per unit time. is the heat transferred from the melt to the solid-liquid interface, L is the latent heat of solidification, v is the pulling rate of the single crystal 100, ρ s is the crystal density of the single crystal 100, and r is the crystal radius at the solid-liquid interface. During the shoulder release process, the heat loss On the one hand, heat is conducted through the seed crystal chuck Heat dissipation per fixed chuck area On the other hand, the heat is dissipated through the conical surface of the shoulder of the single crystal 100 Proportional to the cone area S, when the pulling speed and melt temperature gradient remain unchanged, the shoulder area S of the single crystal 100 increases exponentially with time Where a and b are constants.

[0075] Conical surface heat dissipation It is mainly taken away by the shielding gas. According to the calculation formula of fluid heat Q = cmΔT, c is the specific heat of the shielding gas, m is the mass of the shielding gas, and ΔT is the temperature change. Therefore, the flow rate of the shielding gas is proportional to the fluid heat Q, proportional to the shoulder expansion cone area S, and exponentially related to the radius r. When the shoulder area of ​​the single crystal 100 increases too fast, the actual diameter difference ΔD 1 Greater than the preset diameter difference ΔD 0 The maximum value of the protective gas flow rate needs to be reduced to reduce heat dissipation; when the shoulder area of ​​the single crystal 100 is insufficient, the actual diameter difference ΔD 1 Smaller than the preset diameter difference ΔD 0 To achieve the minimum value, it is necessary to increase the flow rate of the shielding gas to increase heat dissipation.

[0076] In some embodiments, the flow rate of the shielding gas is adjusted so that the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 The scope of the steps further includes:

[0077] According to the real-time diameter D 1 and the target diameter D 0 , adjust the flow rate of the protective gas to the protective gas flow correction value Q 1 , the protective gas flow correction value Q 1 satisfy:

[0078]

[0079] Among them, Q 0 is the initial flow setting value of the protective gas; β is the correction coefficient, 0.2≤β≤2.

[0080] It is understandable that the value of β can be any value among 0.2, 0.5, 1, 1.5, 2 or a range between any two values. In actual operation, the correction coefficient β can be fine-tuned at different shoulder expansion lengths. For example, when performing the first correction of the shielding gas flow rate, β is set to a minimum value of 0.2, and then according to the actual diameter difference ΔD 1 The value of the correction coefficient β is adjusted according to the change of ; or when making the first correction of the shielding gas flow rate, β is set to the maximum value of 2, and then according to the actual diameter difference ΔD 1 The value of the correction coefficient β is adjusted according to the change of .

[0081] Set the limit Q of the shielding gas flow correction c =Q 1 -Q 0 , Q cIt can be reduced as the shoulder area increases, preventing the shoulder shape from getting out of control due to the rapid increase in heat dissipation as the shoulder area increases. c The range can be -100slpm≤Q c ≤100slpm. When the protective gas flow correction value Q 1 Difference ΔD from actual diameter 1 When the above relationship is met, a more ideal shoulder shape can be ensured in the end.

[0082] Among them, the target shoulder type is at each shoulder expansion length L 1 With a corresponding target diameter D 0 , the target diameter can be designed in a table by corresponding the shoulder expansion length. The target shoulder shape can be drawn by referring to the historical successful shoulder shape or it can be a user-defined shoulder shape.

[0083] In some embodiments, the target shoulder has an end diameter D f , meet: 40mm≤D f ≤440mm; further, the end diameter D f Meets: 40mm≤D f ≤430mm.

[0084] It can be understood that the terminal diameter D f The value (unit: mm) can be any value among 40, 80, 160, 240, 320, 380, 440 or a range between any two values, and is preferably any value among 50, 100, 150, 200, 250, 300, 350, 400, 430 or a range between any two values.

[0085] In some embodiments, the target shoulder has an end shoulder length L f , meet: 5mm≤L f ≤700mm.

[0086] It is understandable that the terminal shoulder length L f The value (unit: mm) can be any value among 5, 10, 25, 50, 100, 200, 300, 400, 500, 600, 700 or a range between any two values.

[0087] When the target shoulder type D f and the terminal shoulder length L f When the above value range is met, the target shoulder shape has a relatively ideal aspect ratio and can reduce dislocation or bract breakage during shoulder expansion.

[0088] In some embodiments, the preset diameter difference ΔD 0 Satisfy: -10mm≤ΔD 0 ≤10mm.

[0089] It is understandable that the preset diameter difference ΔD 0 The value (unit: mm) can be any value among -10, -8, -6, -4, -2, 0, 2, 4, 6, 8, 10 or a range between any two values. 0 Meeting the above value range can ensure that the overall dimensional error between the shoulder shape finally formed by the single crystal 100 and the target shoulder shape is within a reasonable range.

[0090] In some embodiments, the protective gas flow correction value Q 1 Satisfy: -100Torr≤Q 1 -Q 0 ≤100Torr. It is understandable that the protective gas flow correction value Q 1 The value (unit: Torr) can be any value among -100, -70, -50, -10, 0, 10, 50, 70, 100 or a range between any two values.

[0091] In some embodiments, the shielding gas includes at least one of argon, helium, and nitrogen.

[0092] In some embodiments, the growth rate of the single crystal 100 in the reactor 10 is consistent with the preset pulling speed of the single crystal 100 and no additional correction is required.

[0093] By keeping the growth rate of the single crystal 100 in the shoulder expansion process consistent with the preset pulling speed of the single crystal 100, it is possible to avoid sudden changes in the shoulder expansion temperature due to the inability of heat convection to be evenly distributed in the silicon solution, resulting in breakage or dislocation, and to avoid quality problems such as slip lines and dislocations of the single crystal 100 caused by pulling speed fluctuations.

[0094] In some embodiments, the growth rate of the single crystal 100 is 15-150 mm / h.

[0095] It can be understood that the value (unit: mm / h) of the growth rate of the single crystal 100 can be any value among 15, 30, 45, 60, 75, 90, 105, 120, 135, 150 or a range between any two values. When the growth rate of the single crystal 100 meets the above value range, it can ensure that the single crystal 100 has a relatively uniform quality and shape during the growth process.

[0096] In some embodiments, the method for controlling shoulder expansion of the single crystal 100 further includes the following steps:

[0097] Set the end diameter D f ;

[0098] Determine the real-time diameter D 1 Whether the end diameter D is met f scope;

[0099] If the real-time diameter D 1 Does not meet the end diameter D f If the range is within the range of , the shoulder expansion of the single crystal 100 continues;

[0100] If the real-time diameter D 1 Meet the end diameter D f , the shoulder expansion of the single crystal 100 is completed.

[0101] By setting the end diameter D f , further ensuring that the single crystal 100 forms an ideal shoulder shape.

[0102] In some embodiments, the end diameter D f Satisfaction: D b -30mm≤D f ≤D b +30mm, of which D b It is the equal diameter target diameter at the end of the shoulder expansion process, 70mm≤D b ≤410mm.

[0103] Understandably, D b The value (unit: mm) can be any value among 70, 150, 200, 300, 410 or a range between any two values.

[0104] Specifically, Figure 2 As shown, the above embodiment can be implemented by the following steps:

[0105] Providing a single crystal 100, and placing the single crystal 100 in a reaction furnace 10;

[0106] Set the target shoulder shape, and obtain the target diameter according to the target shoulder shape;

[0107] Set the end diameter D f ;

[0108] A protective gas is introduced into the reaction furnace 10 to expand the shoulders of the single crystal 100;

[0109] Obtain the real-time diameter of the single crystal 100 and determine whether the real-time diameter meets the end-point diameter D f scope;

[0110] If the actual diameter does not meet the end point diameter D f The actual diameter difference ΔD between the real-time diameter and the target diameter is calculated based on the target diameter corresponding to the time point. 1 ;

[0111] Determine the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 scope;

[0112] If the actual diameter difference ΔD 1 Does not meet the preset diameter difference ΔD 0 If the actual diameter difference is within the range of ΔD, the flow rate of the protective gas is adjusted to make 1 Meet the preset diameter difference ΔD 0 scope;

[0113] Repeat the above steps until the real-time diameter meets the end-point diameter D f range, and the shoulder expansion of the single crystal 100 is completed.

[0114] The second embodiment of the present application provides a single crystal 100 shoulder expansion control system, which is used to implement the single crystal 100 shoulder expansion control method in any of the above embodiments, including:

[0115] A first acquisition module, the first acquisition module is configured to acquire a target diameter according to a target shoulder shape;

[0116] A gas delivery module, the gas delivery module is configured to control the protective gas diffuser 20 to pass the protective gas into the reaction furnace 10;

[0117] A second acquisition module, the second acquisition module is configured to acquire a real-time diameter of the single crystal 100;

[0118] The calculation module is configured to calculate the actual diameter difference ΔD between the real-time diameter and the target diameter according to the target diameter corresponding to the time point. 1 ;

[0119] The judging module is configured to judge the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 scope;

[0120] A control module configured to respond to the actual diameter difference ΔD 1 Does not meet the preset diameter difference ΔD 0 The flow rate of the protective gas is controlled and adjusted to make the actual diameter difference ΔD 1 Meet the preset diameter difference ΔD 0 range.

[0121] The third embodiment of the present application provides a shoulder expansion device for a single crystal 100, such as Figure 3 As shown, including:

[0122] A reaction furnace 10, the reaction furnace 10 is used to accommodate a single crystal 100;

[0123] A protective gas diffuser 20, wherein the protective gas diffuser 20 is disposed in the reaction furnace 10;

[0124] The control device 30 is arranged at one side of the reaction furnace 10 and connected to the protective gas diffuser 20. The control device 30 includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor executes the single crystal 100 shoulder expansion control method.

[0125] On the basis of the above-mentioned embodiment, the single crystal 100 is fixed in the reaction furnace 10 by the clamping member 50 to perform shoulder expansion growth.

[0126] In some embodiments, the shielding gas diffuser 20 comprises:

[0127] A diffuser body 21, which is disposed on one side of the single crystal 100;

[0128] The air intake pipe 22 has one end connected to the diffuser body 21 and the other end connected to the control device 30 .

[0129] Based on the above embodiment, the diffuser body 21 has a plurality of through holes for diffusing the protective gas into the reactor 10. There may be a plurality of groups of air inlet pipes 22. One end of the air inlet pipes 22 is connected to the diffuser body 21 for inputting the protective gas into the diffuser body 21, and the other end is fixed to the furnace cover of the reactor 10 through the supporting legs 40.

[0130] By setting the air inlet pipe 22 and the diffuser body 21, the protective gas diffuser 20 can be brought closer to the single crystal 100 and take effect locally. Therefore, while ensuring the stable operation of the protective gas system of the single crystal 100 furnace, a small flow of protective gas can be additionally controlled to achieve the purpose of precise control.

[0131] In some embodiments, there is a minimum distance R between the diffuser body 21 and the single crystal 100, satisfying:

[0132] 20mm≤R≤200mm.

[0133] It is understandable that the value of the minimum spacing R (unit: mm) can be any value among 20, 50, 100, 150, 200 or a range between any two values. When the minimum spacing R satisfies the above value range, it can further ensure that the protective gas diffuses within a reasonable range around the single crystal 100, thereby accurately controlling the effect of the protective gas on the growth of the single crystal 100.

[0134] The single crystal 100 shoulder expansion control method and system and the single crystal 100 shoulder expansion device provided by the present application are described as follows in conjunction with specific embodiments:

[0135] Example

[0136] This embodiment provides a single crystal 100 control method, such as Figure 2 As shown. It includes the following steps:

[0137] Providing a single crystal 100, and placing the single crystal 100 in a reaction furnace 10;

[0138] Set the target shoulder shape, and obtain the target diameter according to the target shoulder shape;

[0139] Set the end diameter D f =210mm;

[0140] A protective gas is introduced into the reaction furnace 10 to expand the shoulders of the single crystal 100;

[0141] Obtain the real-time diameter of the single crystal 100 and determine whether the real-time diameter meets the end-point diameter D f scope;

[0142] If the actual diameter does not meet the end point diameter D f The actual diameter difference ΔD between the real-time diameter and the target diameter is calculated based on the target diameter corresponding to the time point. 1 ;

[0143] Determine the actual diameter difference ΔD 1 Whether the preset diameter difference ΔD is met 0 = ±2mm range;

[0144] If the actual diameter difference ΔD 1 Does not meet the preset diameter difference ΔD 0 If the actual diameter difference is within the range of ΔD, the flow rate of the protective gas is adjusted to make 1 Meet the preset diameter difference ΔD 0 scope;

[0145] Repeat the above steps until the real-time diameter meets the end-point diameter D f range, and the shoulder expansion of the single crystal 100 is completed.

[0146] In addition, the shoulder expansion speed is set to 60mm / h, the correction coefficient β is 1.1, and the protective gas correction limit Q c ±20slpm.

[0147] Controlling the protective gas compensation flow Q during shoulder expansion 1 The values ​​are shown in Table 1.

[0148] Table 1

[0149]

[0150]

[0151] The surface of the single crystal 100 prepared in Example 1 was tested for dislocations and slip lines by means of XRT, preferential etching, etc., and the number of dislocations and slip lines on the surface of the single crystal 100 was found to meet the use standard.

[0152] It can be seen from Table 1 that the single crystal shoulder expansion control method and single crystal shoulder expansion device provided in the present application can effectively adjust the shoulder length and radius in a timely manner during the shoulder expansion process of the single crystal 100, and finally form an ideal shoulder shape.

[0153] The above is a detailed introduction to a single crystal shoulder expansion control method and system and a single crystal shoulder expansion device provided in the embodiments of the present application. Specific examples are used in the present application to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single crystal shoulder expansion control method, characterized in that: The steps include: Providing a seed crystal, placing the seed crystal in a reaction furnace (10), and growing a single crystal (100); Setting a target shoulder shape, and obtaining a target diameter D0 according to the target shoulder shape; Introducing protective gas into the reaction furnace (10) to expand the shoulders of the single crystal (100); Acquiring a real-time diameter D1 and a real-time shoulder length L1 of the single crystal (100), and calculating an actual diameter difference ΔD1 between the real-time diameter D1 and the target diameter D0 according to a target diameter D0 corresponding to the real-time shoulder length L1; Determine whether the actual diameter difference ΔD1 meets the range of the preset diameter difference ΔD0; If the actual diameter difference ΔD1 does not satisfy the range of the preset diameter difference ΔD0, the flow rate of the protective gas is adjusted so that the actual diameter difference ΔD1 satisfies the range of the preset diameter difference ΔD0.

2. A single crystal shoulder expansion control method according to claim 1, characterized in that: The step of adjusting the flow rate of the protective gas so that the actual diameter difference ΔD1 satisfies the range of the preset diameter difference ΔD0 further includes: If the actual diameter difference ΔD1 is greater than the maximum value of the preset diameter difference ΔD0, reducing the flow rate of the protective gas; If the actual diameter difference ΔD1 is smaller than the minimum value of the preset diameter difference ΔD0, the flow rate of the protective gas is increased.

3. A single crystal shoulder expansion control method according to claim 1, characterized in that: The step of adjusting the flow rate of the protective gas so that the actual diameter difference ΔD1 satisfies the range of the preset diameter difference ΔD0 further includes: According to the real-time diameter D1 and the target diameter D0, the flow rate of the shielding gas is adjusted to a shielding gas flow rate correction value Q1, and the shielding gas flow rate correction value Q1 satisfies: Wherein, Q0 is the initial flow setting value of the protective gas; β is the correction coefficient, 0.2≤β≤2.

4. A single crystal shoulder expansion control method according to claim 1, characterized in that: The target shoulder has an end diameter D f and the terminal shoulder length L f ,satisfy: 40mm≤D f ≤440mm; and / or, 5mm≤L f ≤700mm。 5. The single crystal shoulder expansion control method according to claim 1, characterized in that: The preset diameter difference ΔD0 satisfies: -10 mm ≤ ΔD0 ≤ 10 mm.

6. A single crystal shoulder expansion control method according to claim 3, characterized in that: The protective gas flow correction value Q1 satisfies: -100Torr≤Q1-Q0≤100Torr.

7. The single crystal shoulder expansion control method according to claim 1, characterized in that: The protective gas includes at least one of argon, nitrogen and helium.

8. The single crystal shoulder expansion control method according to claim 1, characterized in that: The growth rate of the single crystal (100) is 15 to 150 mm / h.

9. The single crystal shoulder expansion control method according to claim 1, characterized in that: The following steps are also included: Set the end diameter D f ; Determine whether the real-time diameter D1 satisfies the end-point diameter D f scope; If the real-time diameter D1 does not meet the end point diameter D f If the single crystal (100) is within the range of , the shoulder expansion is continued; If the real-time diameter D1 satisfies the end-point diameter D f , the shoulder expansion of the single crystal (100) is terminated.

10. A single crystal shoulder expansion control method according to claim 9, characterized in that: The end point diameter D f Satisfaction: D b -30mm≤D f ≤D b +30mm; Among them, D b is the target diameter of the single crystal, in mm.

11. A single crystal shoulder expansion control method according to claim 10, characterized in that: The equal diameter target diameter D b satisfy: 70mm≤D b ≤410mm。 12. A single crystal shoulder expansion control system, used to implement the single crystal (100) shoulder expansion control method according to any one of claims 1 to 11, characterized in that: include: A first acquisition module, wherein the first acquisition module is configured to acquire a target diameter D0 according to a target shoulder shape; a gas delivery module, the gas delivery module being configured to control a protective gas diffuser (20) to introduce protective gas into the reaction furnace (10); a second acquisition module, the second acquisition module being configured to acquire a real-time diameter D1 and a real-time shoulder length L1 of the single crystal (100); A calculation module, wherein the calculation module is configured to calculate an actual diameter difference ΔD1 between the real-time diameter D1 and the target diameter D0 according to the target diameter D0 corresponding to the real-time shoulder length L1; A judgment module, the judgment module is configured to judge whether the actual diameter difference ΔD1 satisfies a range of a preset diameter difference ΔD0; A control module is configured to control and adjust the protective gas flow correction value Q1 in response to the actual diameter difference ΔD1 not satisfying the range of the preset diameter difference ΔD0, so that the actual diameter difference ΔD1 satisfies the range of the preset diameter difference ΔD0.

13. A single crystal (100) shoulder expansion device, characterized in that: include: A reaction furnace (10), the reaction furnace (10) being used to accommodate the single crystal (100); a protective gas diffuser (20), wherein the protective gas diffuser (20) is arranged in the reaction furnace (10); A control device (30), wherein the control device (30) is arranged at one side of the reaction furnace (10) and connected to the protective gas diffuser (20), wherein the control device (30) comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the single crystal (100) shoulder expansion control method as described in any one of claims 1 to 9.

14. A single crystal (100) shoulder expansion device according to claim 13, characterized in that: The protective gas diffuser (20) comprises: a diffuser body (21), the diffuser body (21) being arranged on one side of the single crystal (100); An air intake pipe (22), one end of which is connected to the diffuser body (21), and the other end of which is connected to the control device (30).

15. A single crystal (100) shoulder expansion device according to claim 14, characterized in that: There is a minimum distance R between the diffuser body (21) and the single crystal (100), satisfying: 20mm≤R≤200mm.

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