Doping mechanism and monocrystalline silicon production equipment
By designing a doping mechanism, using the drive member to move the input state of the dopant, and passing gas through the air pipe, the problems of uneven distribution of dopant and serious losses in single crystal silicon production are solved, and high efficiency is achieved. Uniform doping effect.
Patent Information
- Application Number
- CN202421067907.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-16
- Publication Date
- 2025-02-21
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
During the production process of single crystal silicon, the dopant is put into the silicon melt at one time in the prior art, resulting in excessive local concentration, partial dopant volatilization, serious losses, and uneven distribution.
A doping mechanism is designed to switch the feeding state and feeding state of the dopant through the movement of the driving member in the feeding barrel, and add the dopant to the silicon melt in multiple times to avoid excessive local concentration and pass The air pipe is penetrated with inert gas and reducing gas to improve the distribution uniformity of the dopant.
The volatility loss of dopants is effectively avoided, the utilization rate and doping efficiency of dopants are improved, the uniform distribution of dopants in the silicon melt is ensured, and the quality of single crystal silicon is improved.
Smart Images
Figure CN222512997U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of single crystal silicon production, and in particular to a doping mechanism and single crystal silicon production equipment. Background Art
[0002] Solar monocrystalline silicon wafers are divided into N-type and P-type, which are used to make solar cells. In the production process of monocrystalline silicon, the silicon material must be doped to grow N-type monocrystalline silicon or P-type monocrystalline silicon.
[0003] In the related art, dopants or heavily-doped master alloys are added into silicon melt at one time for doping. However, when doping or heavily-doped master alloys are added at one time, there is a situation where the concentration of dopants in the silicon melt is too high locally. In addition, due to the saturation effect, part of the dopant with excessive concentration will volatilize, and the volatilized dopant cannot enter the silicon melt, thereby increasing the loss of the dopant. Utility Model Content
[0004] In order to overcome the deficiencies in the prior art, the present application provides a doping mechanism and single crystal silicon production equipment.
[0005] In the first aspect, the present application provides a doping mechanism, comprising: a feeding barrel, a driving member and a limiting assembly, wherein the feeding barrel is arranged on a crucible, the driving member is sleeved in the feeding barrel, and the limiting assembly is arranged on the driving member, and the driving member is used to move in the feeding barrel so that the limiting assembly is in a feeding state and / or a material holding state, when the limiting assembly is in a material holding state, the bearing surface of the limiting assembly abuts against the feeding barrel to enclose a material holding space with the feeding barrel, and the material holding space is used to hold doped material, and when the limiting assembly is in the feeding state, the bearing surface is detached from the feeding barrel.
[0006] In combination with the first aspect, in a possible implementation, the supporting surface is a conical surface, and an air pipe is provided on the feeding barrel, one end of the air pipe is connected to a gas source, and the other end of the air pipe extends into the silicon melt in the crucible, and the gas source includes an inert gas and a reducing gas.
[0007] In combination with the first aspect, in a possible embodiment, the limit assembly includes at least two limit members, when the driving member moves to the first position, the limit member on the first end of the driving member is in the feeding state, and the limit member on the middle end of the driving member is in the material holding state, when the driving member moves to the second position, the limit member on the first end and the limit member on the middle end are both in the feeding state, and the first end is located at one end of the driving member close to the crucible.
[0008] In combination with the first aspect, in a possible embodiment, a connecting rod, one end of the connecting rod is connected to the limiting member, and a pressing member is provided on the other end of the connecting rod, and the driving member is sleeved in the connecting rod, and the driving member is used to move along the connecting rod to the first position, and the driving member in the first position is used to drive the pressing member to move to the second position.
[0009] In combination with the first aspect, in a possible implementation, the doping mechanism further includes: a barrel cover, which is arranged on an end of the feeding barrel away from the crucible, the connecting rod is sleeved in the barrel cover, and an elastic member is arranged on the barrel cover, one end of the elastic member abuts against the barrel cover, and the other end of the elastic member abuts against the pressing member.
[0010] In combination with the first aspect, in a possible embodiment, a push plate is provided on the driving member, and the pressing member includes a first contact surface and a second contact surface that are relatively arranged, the elastic member abuts against the first contact surface, and when the driving member moves along the connecting rod to the first position, the push plate fits against the second contact surface.
[0011] In combination with the first aspect, in a possible implementation, a first opening and a second opening are provided on the barrel cover, the connecting rod is inserted into the first opening, the second opening is provided at two opposite sides of the first opening, and the second opening is an inlet for the doping material.
[0012] In combination with the first aspect, in a possible embodiment, a first buffer plate and a second buffer plate are provided in the feeding barrel, the first buffer plate is provided between the crucible and the driving member, and a first preset angle exists between the first buffer plate and the feeding barrel, the second buffer plate is provided at an end of the crucible away from the first buffer plate, and a second preset angle exists between the second buffer plate and the feeding barrel, and the second preset angle is equal to the first preset angle.
[0013] In combination with the first aspect, in a possible implementation, the feeding cylinder includes: a first feeding cylinder and a second feeding cylinder, the first feeding cylinder is arranged along a first preset direction, the second feeding cylinder is arranged along the first preset direction, and the second feeding cylinder is sleeved in the first feeding cylinder.
[0014] In a second aspect, the present application provides a single crystal silicon production device, comprising the above-mentioned doping mechanism.
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] The doping mechanism provided in the present application is characterized in that the driving member moves in the feeding tube so that the bearing surface abuts against the feeding tube and / or the bearing surface is separated from the feeding tube. The bearing surface abuts against the feeding tube and can be combined with the feeding tube to form a material holding space for holding doping material. The bearing surface is separated from the feeding tube and can put the doping material into the silicon melt in the crucible. The position of the driving member moving in the feeding tube is adjusted to switch the feeding state and the material holding state of the doping material, so that the doping material can be added to the silicon melt in multiple times, which can effectively avoid the situation where the concentration of the doping material in the silicon melt is locally too high due to the one-time addition of the doping material, improves the uniformity of the distribution of the doping material in the silicon melt, improves the doping efficiency, reduces the volatilization loss of the doping material, and improves the utilization rate of the doping material. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.
[0018] Figure 1 A schematic cross-sectional structure diagram of a doping mechanism is shown;
[0019] Figure 2 A schematic cross-sectional structure diagram showing a feeding state of a doping mechanism;
[0020] Figure 3 A schematic cross-sectional structure diagram showing another feeding state of the doping mechanism;
[0021] Figure 4 A schematic cross-sectional structure diagram of a cylinder cover of a doping mechanism is shown;
[0022] Figure 5 A schematic cross-sectional structure diagram of the air pipe of the doping mechanism is shown.
[0023] Description of main component symbols:
[0024] 100-feeding barrel; 110-first feeding barrel; 111-feeding end; 112-discharging end; 120-second feeding barrel; 130-third feeding barrel; 200-driving member; 210-first end; 220-second end; 230-middle end; 300-limiting assembly; 310-first limiting member; 311-first bearing surface; 320-second limiting member; 321-second bearing surface; 400-barrel cover; 410-first opening; 420-second opening; 500-connecting rod; 510-pressing member; 511-first contact surface; 512-second contact surface; 600-push plate; 700-elastic member; 800-trachea; 900-buffer plate; 910-first buffer plate; 920-second buffer plate. DETAILED DESCRIPTION
[0025] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0028] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 or an electrical connection; it can be a direct connection or an indirect connection 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 specific circumstances.
[0029] 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.
[0030] Embodiment 1
[0031] See also Figure 1, an embodiment of the present application provides a doping mechanism. The doping mechanism includes: a feeding barrel 100, a driving member 200 and a limiting assembly 300. The feeding barrel 100 is arranged on a crucible. The driving member 200 is sleeved in the feeding barrel 100. The limiting assembly 300 is arranged on the driving member 200, and the driving member 200 is used to move in the feeding barrel 100 so that the limiting assembly 300 is in a feeding state and / or a material holding state. When the limiting assembly 300 is in a material holding state, the bearing surface of the limiting assembly 300 abuts against the feeding barrel 100 to enclose a material holding space with the feeding barrel 100, and the material holding space is used to hold doped materials. When the limiting assembly 300 is in a feeding state, the bearing surface is separated from the feeding barrel 100. The driving member 200 moves in the feeding cylinder 100 so that the bearing surface abuts against the feeding cylinder 100 and / or the bearing surface is separated from the feeding cylinder 100. The bearing surface abuts against the feeding cylinder 100 and can be combined with the feeding cylinder 100 to form a material storage space for containing dopants, and the bearing surface is separated from the feeding cylinder 100 to drop the dopants into the silicon melt in the crucible. The position of the driving member 200 in the feeding cylinder 100 is adjusted to switch the feeding state and the material storage state of the dopants, so that the dopants can be added to the silicon melt in multiple times, which can effectively avoid the situation where the concentration of the dopants in the silicon melt is too high locally due to the one-time addition of the dopants, improve the uniformity of the distribution of the dopants in the silicon melt, improve the doping efficiency, reduce the volatilization loss of the dopants, and improve the utilization rate of the dopants.
[0032] In some embodiments, the dopant is a dopant or a heavily doped master alloy.
[0033] See also Figure 1 In some embodiments, the feeding cylinder 100 includes: a first feeding cylinder 110, a second feeding cylinder 120 and a third feeding cylinder 130. The first feeding cylinder 110 is arranged along a first preset direction. The second feeding cylinder 120 is arranged along the first preset direction, and the second feeding cylinder 120 is sleeved in the first feeding cylinder 110. The third feeding cylinder 130 is arranged along the first preset direction, and the third feeding cylinder 130 is detachably connected to the first feeding cylinder 110, and the third feeding cylinder 130 is located at one end of the first feeding cylinder 110 close to the crucible.
[0034] In some embodiments, the central axis of the first feeding cylinder 110 coincides with the central axis of the second feeding cylinder 120 , and the central axis of the first feeding cylinder 110 coincides with the central axis of the third feeding cylinder 130 .
[0035] See also Figure 1and Figure 2 In some embodiments, the first feeding cylinder 110 includes an inlet end 111 and an outlet end 112. The inlet end 111 is located at one end of the first feeding cylinder 110 close to the second feeding cylinder 120. The outlet end 112 is located at one end of the first feeding cylinder 110 close to the third feeding cylinder 130. The third feeding cylinder 130 is detachably connected to the outlet end 112.
[0036] In some embodiments, the length of the feeding end 111 along the second preset direction is greater than the length of the second feeding cylinder 120 along the second preset direction. The second preset direction is perpendicular to the first preset direction.
[0037] See also Figure 2 and Figure 4 In some embodiments, a barrel cover 400 is provided on the feeding end 111. The barrel cover 400 is provided on the feeding end 111, and the barrel cover 400 is detachably connected to the first feeding barrel 110, and a first opening 410 and a second opening 420 are provided on the barrel cover 400. The central axis of the first opening 410 coincides with the central axis of the barrel cover 400, and a connecting rod 500 is sleeved in the first opening 410. The driving member 200 is sleeved in the connecting rod 500, and the driving member 200 is used to move in the connecting rod 500 or drive the connecting rod 500 to move. The second opening 420 is provided at two opposite sides of the first opening 410.
[0038] In some embodiments, the barrel cover 400 is connected to the first feeding barrel 110 by a method.
[0039] In some embodiments, one end of the third feeding barrel 130 away from the discharge end 112 extends into the silicon melt in the crucible. The doping material enters the second feeding barrel 120 through the second opening 420, and the driving member 200 moves to the first position in the connecting rod 500 so that the doping material enters the first feeding barrel 110 from the second feeding barrel 120. The driving member 200 in the first position drives the connecting rod 500 to move along the first preset direction so that the doping material enters the third feeding barrel 130 from the second feeding barrel 120 and falls from the third feeding barrel 130 into the silicon melt, and the driving member 200 is in the second position.
[0040] See also Figure 2In some embodiments, the driving member 200 is a driving rod, and the driving member 200 includes a first end 210, a second end 220, and a middle end 230. The first end 210 is located at an end of the driving member 200 close to the crucible. The second end 220 is located at an end of the driving member 200 away from the crucible, and a push plate 600 is disposed on the second end 220.
[0041] In some embodiments, the driving member 200 at the first position pushes the connecting rod 500 to move along the first preset direction through the pushing plate 600 .
[0042] In some embodiments, the third end 220 of the driving member 200 is connected to a weight system in the single crystal furnace.
[0043] See also Figure 2 In some embodiments, the position limiting assembly 300 includes: a position limiting member. The number of the position limiting members is two. The first position limiting member 310 is arranged on the first end 210. The first position limiting member 310 abuts against the discharge end 112 to form a first material holding space with the first feeding barrel 110. The second position limiting member 320 is arranged on the middle end 230. The second position limiting member 320 abuts against the second feeding barrel 120 to form a second material holding space with the second feeding barrel 120. The middle end 230 is located between the first end 210 and the second end 220.
[0044] In other embodiments, the number of the limiting members can be three, four, five, six, etc., to form a third material holding space, a fourth material holding space, a fifth material holding space, a sixth material holding space, etc., which are not listed one by one here.
[0045] In some embodiments, the length of the first limiting member 310 along the second preset direction is equal to the length of the second limiting member 320 along the second preset direction.
[0046] In some embodiments, the first stopper 310 is made of quartz stone, is conical, and has a first bearing surface 311. The first bearing surface 311 is a conical surface, and the first bearing surface 311 abuts against the discharge end 112 to form a first material holding space with the first feeding barrel 110. Figure 2When the driving member 200 moves to the first position in the connecting rod 500, the first limiting member 310 is in the feeding state, and the second limiting member 320 is in the holding state, that is, the first bearing surface 311 of the first limiting member 310 is separated from the discharge end 112, so that the doping material in the first holding space falls into the third feeding barrel 130 and the silicon melt in turn to complete the first doping feeding, and the second bearing surface 321 of the second limiting member 320 abuts against the second feeding barrel 120.
[0047] In some embodiments, the second stopper 320 is made of quartz, is conical, and has a second bearing surface 321. The second bearing surface 321 is a conical surface, and abuts against an end of the second feeding barrel 120 away from the barrel cover 400 to form a second material holding space with the second feeding barrel 120.
[0048] See also Figure 2 In some embodiments, one end of the connecting rod 500 is connected to the second stopper 320, and a pressing member 510 is disposed on the other end of the connecting rod 500. An elastic member 700 is disposed between the pressing member 510 and the cylinder cover 400. The elastic member 700 is sleeved on the connecting rod 500, and one end of the elastic member 700 abuts against the cylinder cover 400, and the other end of the elastic member 700 abuts against the pressing member 510.
[0049] See also Figure 2 and Figure 3 In some embodiments, the pressing member 510 includes a first contact surface 511 and a second contact surface 512 that are arranged opposite to each other. The elastic member 700 abuts against the first contact surface 511. When the driving member 200 is in the first position, the push plate 600 abuts against the second contact surface 512.
[0050] In some embodiments, the elastic member 700 is a spring. Figure 3When the driving member 200 in the first position moves to the second position, the first limiting member 310 is in the feeding state, and the second limiting member 320 is in the feeding state, that is, the driving member 200 pushes the pressing member 510 through the push plate 600 to squeeze the elastic member 700, and drives the connecting rod 500 to move synchronously, so that the second bearing surface 321 of the second limiting member 320 is separated from the second feeding cylinder 120, so that the doping material in the second material holding space falls into the first feeding cylinder 110, the third feeding cylinder 130, and the silicon melt in turn to complete the second doping treatment. By adding the doping material to the silicon melt in two batches, the situation of excessively high concentration of the doping material in the local silicon melt caused by the one-time addition of the doping material can be avoided, the uniformity of the distribution of the doping material in the silicon melt is improved, and the volatilization of the doping material caused by the excessively high concentration of the doping material in the local silicon melt can be reduced, and the utilization rate of the doping material is improved.
[0051] See also Figure 2 and Figure 5 In some embodiments, the doping mechanism further includes: an air pipe 800. The air pipe 800 is disposed on the third feeding barrel 130, and one end of the air pipe 800 is connected to the air source, and the other end of the air pipe 800 extends into the silicon melt, and the end surface of the air pipe 800 extending into the silicon melt is flush with the end surface of the third feeding barrel 130 extending into the silicon melt.
[0052] In some embodiments, an electromagnetic switch is provided on the air pipe, and the electromagnetic switch is used to control the on and off of the gas in the air pipe.
[0053] In some embodiments, the gas source includes an inert gas and a reducing gas. During the first doping treatment and the second doping treatment, the gas pipe 800 introduces the inert gas into the silicon melt to stir the silicon melt, thereby improving the uniformity of the distribution of the dopant in the silicon melt. After completing the first doping treatment, the gas pipe 800 introduces the reducing gas into the silicon melt so that the reducing gas reacts with the silicon oxide in the silicon melt, thereby reducing the content of oxygen impurities in the silicon melt, reducing the oxygen content in the single crystal silicon rod, and improving the quality of the single crystal silicon rod.
[0054] See also Figure 1 and Figure 2In some embodiments, the doping mechanism further includes: a buffer plate 900. The buffer plate 900 includes: a first buffer plate 910 and a second buffer plate 920. The number of the first buffer plates 910 is four, and the first buffer plates 910 are arranged in the third feeding cylinder 130, and there is a first preset angle between the first buffer plate 910 and the third feeding cylinder 130. The second buffer plate 920 is arranged in the second feeding cylinder 120, and there are two second buffer plates 920, and there is a second preset angle between the second buffer plate 920 and the first feeding cylinder 110. The second preset angle is equal to the first preset angle.
[0055] In some embodiments, the first preset angle is 40° C. to 50° C. The doping material in the first material holding space falls into the silicon melt after being buffered by the first buffer plate 910, and the doping material in the second material holding space falls into the silicon melt after being buffered by the second buffer plate 920 and the first buffer plate 910. The buffering of the first buffer plate 910 and the second buffer plate 920 can reduce the falling speed of the doping material, reduce the impact of the falling doping material on the silicon melt liquid surface, and reduce the splashing of the silicon melt.
[0056] Part of the doping material is put into the second material holding space through the second opening 420, and then the pressing member 510 is pressed to make the second bearing surface 321 separate from the second feeding tube 120, so that the doping material falls into the first material holding space, and the pressing member 510 is stopped. The connecting rod 500 pulls the second limiting member 320 to move under the action of the rebound force of the elastic member 700, so that the second bearing surface 321 abuts against the second feeding tube 120, and the remaining part of the doping material is put into the second material holding space through the second opening 420 to complete the filling of the doping material. In the conventional doping equipment, during the doping process, the doping equipment needs to be placed in the single crystal furnace to complete the first doping feeding, and then the doping equipment is taken out to fill the dopant, and then placed in the single crystal furnace for the second doping feeding. Compared with the conventional doping equipment, the doping mechanism only needs to perform one filling operation when performing two doping operations, which has high filling efficiency, eliminates the step of taking out the doping equipment, and simplifies the filling operation.
[0057] The driving member 200 moves to the first position in the connecting rod 500 in the direction close to the crucible, so that the first supporting surface 311 is separated from the first feeding tube 110, so that the doping material on the first supporting surface 311 falls into the silicon melt in the crucible through the third feeding tube 130 to complete the first doping treatment, and during the first doping treatment, the gas pipe 800 introduces the inert gas into the silicon melt to stir the silicon melt.
[0058] After the first doping treatment is completed, the reducing gas is introduced into the silicon melt through the gas pipe 800, and then the second doping treatment is performed, and an inert gas is introduced into the silicon melt through the gas pipe 800, and the second doping treatment is: the driving member 200 in the first position is pushed by the push plate 600 to move the connecting rod 500 toward the direction close to the crucible, so that the driving member 200 is in the second position, and the second bearing surface 321 is separated from the second feeding cylinder 120, so that the doping material on the second bearing surface 321 passes through the first feeding cylinder 110 and the third feeding cylinder 130 in sequence and then falls into the silicon melt. Putting the doping material into the silicon melt twice can avoid the situation where the concentration of the local doping material in the silicon melt is too high due to the one-time addition of the doping material, can effectively improve the uniformity of the distribution of the doping material in the silicon melt, and reduce the volatilization loss of the doping material caused by the saturation effect, thereby improving the utilization rate and doping efficiency of the doping material.
[0059] Embodiment 2
[0060] An embodiment of the present application provides a single crystal silicon production device (not shown in the figure), which includes the doping mechanism in any one of the above embodiments, and therefore has all the beneficial effects of the doping mechanism in any one of the above embodiments, which will not be elaborated here.
[0061] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0062] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A doping mechanism, characterized in that: include: A feeding cylinder, wherein the feeding cylinder is arranged on the crucible; A driving member, wherein the driving member is sleeved in the feeding cylinder; A limit assembly, wherein the limit assembly is arranged on the driving member, and the driving member is used to move in the feeding barrel so that the limit assembly is in a feeding state and / or a material holding state. When the limit assembly is in the material holding state, the bearing surface of the limit assembly abuts against the feeding barrel to enclose a material holding space with the feeding barrel, and the material holding space is used to hold doped materials. When the limit assembly is in the feeding state, the bearing surface is separated from the feeding barrel.
2. The doping mechanism according to claim 1, characterized in that: The bearing surface is a conical surface, and the feeding barrel is provided with an air pipe, one end of which is connected to a gas source, and the other end of which extends into the silicon melt in the crucible, and the gas source includes an inert gas and a reducing gas.
3. The doping mechanism according to claim 1, characterized in that: The limiting assembly includes at least two limiting members. When the driving member moves to the first position, the limiting member on the first end of the driving member is in the feeding state, and the limiting member on the middle end of the driving member is in the material holding state. When the driving member moves to the second position, the limiting member on the first end and the limiting member on the middle end are both in the feeding state, and the first end is located at one end of the driving member close to the crucible.
4. The doping mechanism according to claim 3, characterized in that: The doping mechanism further comprises: A connecting rod, one end of which is connected to the limiting member, a pressing member is provided on the other end of the connecting rod, the driving member is sleeved in the connecting rod, the driving member is used to move along the connecting rod to the first position, and the driving member in the first position is used to drive the pressing member to move to the second position.
5. The doping mechanism according to claim 4, characterized in that: The doping mechanism further comprises: The cylinder cover is arranged on one end of the feeding cylinder away from the crucible, the connecting rod is sleeved in the cylinder cover, and an elastic member is arranged on the cylinder cover, one end of the elastic member abuts against the cylinder cover, and the other end of the elastic member abuts against the pressing member.
6. The doping mechanism according to claim 5, characterized in that: The driving member is provided with a push plate, and the pressing member includes a first contact surface and a second contact surface which are arranged opposite to each other, the elastic member abuts against the first contact surface, and when the driving member moves along the connecting rod to the first position, the push plate fits against the second contact surface.
7. The doping mechanism according to claim 5, characterized in that: The cylinder cover is provided with a first opening and a second opening, the connecting rod is inserted into the first opening, the second opening is provided at two opposite sides of the first opening, and the second opening is an inlet for the doping material.
8. The doping mechanism according to any one of claims 1 to 7, characterized in that: A first buffer plate and a second buffer plate are provided in the feeding barrel, the first buffer plate is provided between the crucible and the driving member, and a first preset angle is formed between the first buffer plate and the feeding barrel, the second buffer plate is provided at one end of the crucible away from the first buffer plate, and a second preset angle is formed between the second buffer plate and the feeding barrel, and the second preset angle is equal to the first preset angle.
9. The doping mechanism according to any one of claims 1 to 7, characterized in that: The feeding cylinder comprises: A first feeding cylinder, wherein the first feeding cylinder is arranged along a first preset direction; The second feeding cylinder is arranged along the first preset direction, and the second feeding cylinder is sleeved in the first feeding cylinder.
10. A production device for single crystal silicon, characterized in that: The invention comprises the doping mechanism as claimed in any one of claims 1 to 9.