CN113430639A - Feeding method of silicon material - Google Patents

Abstract

The invention relates to a feeding method of a silicon material, which comprises the following steps: s1, selecting a silicon material with the size within a first preset interval range as a first type of silicon material, selecting a silicon material with the size within a second preset interval range and smooth surface as a second type of silicon material, wherein the minimum value of the first preset interval range is larger than the maximum value of the second preset interval range; s2, loading the first silicon materials and the second silicon materials into a loading space, wherein the second silicon materials at least partially occupy gaps among the first silicon materials; s3, feeding the first silicon material and the second silicon material in the charging space into a crucible; and S4, if the feeding does not meet the preset feeding requirement of the crucible, repeating the step S2 and the step S3 until the feeding requirement is met, and stopping feeding. The invention improves the output efficiency of the czochralski silicon process.

Description

Feeding method of silicon material

Technical Field

The invention relates to the technical field of czochralski silicon technology, in particular to a silicon material feeding method.

Background

The Czochralski monocrystalline silicon process is a commonly used process in monocrystalline growth and is widely applied to the fields of semiconductor integrated circuits, diodes, solar photovoltaics and the like. The process of the czochralski silicon technology generally comprises the steps of initial loading of a crucible, re-feeding and pulling a rod, and after the initial loading of the crucible is finished, the process of re-feeding and pulling the rod is repeated alternately for a plurality of times. Therefore, the efficiency of the re-feeding process can directly influence the output efficiency of the czochralski silicon process.

At present, a re-feeding process usually comprises a charging step and a feeding step which are alternately carried out for a plurality of times, namely, a massive silicon material is firstly charged into a charging space of a re-feeding device, and then the massive silicon material is charged into a crucible after the charging space is filled, so that when the feeding requirement of a single silicon single crystal rod is met, the re-feeding process is completed.

However, in the above-mentioned re-feeding process, the bulk silicon material is loaded into the loading space, and there are large gaps between the bulk silicon materials, which results in large space waste, the amount of silicon material fed in a single time is small, the efficiency of the re-feeding process is reduced, the number of re-feeding times is increased, and further the output efficiency of the czochralski silicon process is reduced. On the other hand, the block silicon material is easy to be blocked in the feeding step, i.e. the silicon material cannot fall into the crucible, and the re-feeding device needs to be lifted out for re-feeding and the re-feeding process is carried out. The silicon material which cannot fall off needs to be taken out and cleaned again before being reused, so that the material blocking phenomenon can cause adverse effect on the output efficiency of the process of pulling the monocrystalline silicon. In addition, in the feeding step, quartz slag is generated between the massive silicon material and the re-feeding device, such as the massive silicon material and the quartz cylinder, due to extrusion, and the quartz slag falls into the silicon liquid to increase the oxygen content in the silicon liquid, so that the quality of the pulled silicon rod is affected, and in addition, the service life of the re-feeding device is greatly affected.

Disclosure of Invention

Therefore, a silicon material feeding method is needed to solve the problems of low single feeding amount and low output efficiency caused by material blocking in the czochralski silicon process and great adverse effect on the service life of a re-feeding device.

A feeding method of a silicon material is used for feeding the crucible by a re-feeding device, the re-feeding device comprises a charging space, and the feeding method of the silicon material comprises the following steps:

s1, selecting the silicon material with the size within the first preset interval range as a first type of silicon material,

selecting a silicon material with the size within a second preset interval range and smooth surface as a second type of silicon material, wherein the minimum value of the first preset interval range is larger than the maximum value of the second preset interval range;

s2, loading the first silicon materials and the second silicon materials into a loading space, wherein the second silicon materials at least partially occupy gaps among the first silicon materials;

s3, feeding the first silicon material and the second silicon material in the charging space into a crucible;

and S4, if the feeding does not meet the preset feeding requirement of the crucible, repeating the step S2 and the step S3 until the feeding requirement is met, and stopping feeding.

According to the silicon material feeding method, in order to improve the output efficiency of the Czochralski silicon crystal process, firstly, the first type of silicon material and the second type of silicon material with different sizes are selected for feeding, the second type of silicon material at least partially occupies the gap between the first type of silicon material, the feeding amount of the feeding space is increased, namely, the silicon material amount which is fed into the crucible at a single time is increased, the feeding times required for meeting the feeding requirement are reduced, and the output efficiency of the Czochralski silicon crystal process is improved. Secondly, the silicon material with the size within the range of the second preset interval and smooth surfaces is selected as the second silicon material, so that the mode of filling the second silicon material into the gap between the first silicon material not only plays a role in increasing the charging amount of the charging space, but also plays a role in lubricating the first silicon material when the charging space charges the crucible, reduces the possibility of material blockage of the first silicon material, and further improves the output efficiency of the czochralski silicon process.

The technical solution of the present application is further explained as follows:

in one embodiment, step S1 includes: and selecting spherical or ellipsoidal silicon materials as the second type of silicon materials.

In one embodiment, step S1 includes:

s101, determining the maximum value of a first preset interval range according to the size of a feeding inlet of the charging space;

s102, determining the maximum value of the second preset interval range according to the maximum value of the first preset interval range.

In one embodiment, step S101 includes:

controlling the maximum value of the first selected preset interval range to be less than or equal to one half of the charging space charging inlet size.

In one embodiment, the mass ratio of the first type silicon material to the second type silicon material in step S1 is 15: 11-15: 7.

in one embodiment, step S2 includes:

s202, charging the first type of silicon materials into the charging space, and forming gaps among the first type of silicon materials;

s203, charging the second silicon materials into the charging space, so that the second silicon materials at least partially fall/slide down to gaps among the first silicon materials.

In one embodiment, step S2 includes: and S204, alternately performing the step S202 and the step S203 until the preset charging requirement of the charging space is met, and ending the step S2.

In one embodiment, step S2 includes: s201, the second-type silicon materials are loaded into the loading space and are laid in the area, close to the feeding outlet, of the loading space.

In one embodiment, step S2 includes:

s201, mixing the first-class silicon material and the second-class silicon material to obtain a mixed silicon material;

s202, charging the mixed silicon material in the step S201 into the charging space.

In one embodiment, the re-throwing device comprises a quartz cylinder body with openings at two ends, a quartz tubule fixed on the quartz cylinder body and coaxially arranged with the quartz cylinder body, a metal connecting rod positioned in the quartz tubule and extending out of the opening at one end of the quartz cylinder body, and a quartz conical head fixed on the metal connecting rod and positioned below the opening at the other end of the quartz cylinder body; the metal connecting rod can drive the quartz conical head to move relative to the opening at the other end of the quartz cylinder;

step S2 includes: when the quartz conical head abuts against the opening at the other end of the quartz cylinder body, a charging space is formed on the surface, close to the quartz cylinder body, of the quartz conical head, the inner wall of the quartz cylinder body and the outer wall of the quartz tubule;

step S3 includes: and when the quartz conical head is separated from the opening at the other end of the quartz cylinder body and a gap is formed, the first silicon material and the second silicon material in the charging space are charged into the crucible from the gap.

Drawings

FIG. 1 is a schematic structural diagram of a multiple-feeding apparatus and a single crystal furnace according to an embodiment of the present invention;

FIG. 2 is a partially enlarged view of the quartz cylinder falling on the upper surface of the quartz cone head according to an embodiment of the present invention;

FIG. 3 is an enlarged partial schematic view of the location A in FIG. 1 (silicon material falling into the crucible);

FIG. 4 is an enlarged partial view of a charging space filled with a silicon material (the second type of silicon material is a spherical silicon material) according to an embodiment of the present invention;

FIG. 5 is an enlarged view of a portion of the charging space containing silicon material (the second type of silicon material includes spherical silicon material and ellipsoidal silicon material) according to an embodiment of the present invention.

Reference numerals:

10. silicon liquid; 100. a crucible; 200. a re-throwing device; 210. a quartz cylinder; 220. a metal connecting rod; 230. a quartz conical head; 240. a quartz tubule; 300. a main chamber of the single crystal furnace; 400. a single crystal furnace auxiliary chamber; 500. seed crystal heavy hammer; 20. a first type of silicon material; 30. and a second type of silicon material.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the current czochralski silicon crystal pulling process, one crucible 100 is generally used for about 300 hours, the process of repeatedly feeding and pulling the silicon rod is alternately repeated for about 10 times, and about 10 silicon single crystal rods are produced. Each re-feeding process usually comprises a charging step and a feeding step which are alternately carried out for a plurality of times, and when the feeding requirement of a single silicon single crystal rod is met, the re-feeding process is completed once to carry out a rod pulling process. And repeating the re-feeding process after the rod pulling process of the single silicon single crystal rod is completed.

Referring to fig. 1, the re-feeding device 200 used in the re-feeding process includes a quartz cylinder 210, a metal connecting rod 220 and a quartz conical head 230, wherein the quartz cylinder 210 is a cylinder with openings at two ends, and the metal connecting rod 220 is axially disposed in an inner cavity of the quartz cylinder 210. One end of the metal connecting rod 220 extends out from the opening at the upper end of the quartz cylinder 210 and can be connected with the seed crystal weight 500, the other end of the metal connecting rod 220 is connected with the quartz conical head 230, and the quartz conical head 230 is positioned below the opening at the lower end of the quartz cylinder 210. In order to prevent the metal link 220 from contacting the silicon material, a narrow quartz tube 240 is provided inside the quartz cylinder 210, and the metal link 220 is located inside the narrow quartz tube 240.

In use, referring to fig. 1-3, the quartz cylinder 210 falls on the upper surface of the quartz conical head 230 to support the quartz cylinder 210, and the upper surface of the quartz conical head 230, the inner wall of the quartz cylinder 210 and the outer wall of the quartz tubule 240 form a space for containing silicon material, and the silicon material is filled into the space. After the loading is finished, the re-feeding device 200 is moved to the lower end of the auxiliary chamber 400 of the single crystal furnace, and then the seed crystal weight 500 is lowered and connected with the metal connecting rod 220, so that the seed crystal weight 500 is lifted by hanging the re-feeding device 200 through the metal connecting rod 220 and is slowly lifted to the auxiliary chamber 400 of the single crystal furnace. Then the auxiliary chamber 400 of the single crystal furnace is rotated back to the upper part of the main chamber 300 of the single crystal furnace, the auxiliary chamber 400 of the single crystal furnace is descended to be connected with the main chamber 300 of the single crystal furnace, after the auxiliary chamber 400 of the single crystal furnace is pumped out and purified, the seed crystal weight 500 is descended, and the re-feeding device 200 slowly enters the main chamber 300 of the single crystal furnace. When the single crystal furnace supports the quartz cylinder 210, the quartz cylinder 210 stops descending, the metal connecting rod 220 and the quartz conical head 230 continue descending under the driving of the seed crystal heavy punch 500, the upper surface of the quartz conical head 230 is separated from the lower end opening of the quartz cylinder 210, and silicon leaks out of the quartz cylinder 210 through a gap between the upper surface of the quartz conical head 230 and the lower end of the quartz cylinder 210 and falls into the crucible 100. And after the silicon material is completely dropped, lifting the re-feeding device 200 into the auxiliary chamber 400 of the single crystal furnace, taking out the re-feeding device 200, and completing the single-cylinder feeding process, wherein multiple times of single-cylinder charging and single-cylinder feeding are required for each time of re-feeding, namely, the operation steps are carried out for multiple times until the charging weight reaches the feeding requirement of re-feeding.

In the traditional process, more than 90% of the silicon materials for single crystal re-casting come from compact rod-shaped materials and single crystal circulating materials, and because the diameters of the two silicon materials are more than 150mm and the radius of the inner wall of the quartz cylinder 210 is about 110mm, the compact rod-shaped materials and the single crystal circulating materials can be used as the silicon materials for re-casting after being crushed. Because the hardness of silicon is high, the difficulty of crushing compact rod-shaped materials and single crystal circulating materials is high, the smaller the crushing size is, the higher the working hour and the energy consumption are needed, and the more easily the silicon materials are polluted by the environment and crushing tools. On the contrary, if the crushing size is too large, the possibility of material jamming due to the silicon material in the quartz cylinder 210 failing to fall due to mutual extrusion is greatly increased. Therefore, in order to achieve both the cost of breaking the silicon material and the possibility of occurrence of a material sticking accident, the size of the silicon material for single crystal compound delivery is generally limited to 50 mm.

Specifically, taking the quartz cylinder 210 with an inner wall radius of 110mm and a height of 185cm as an example, since the size of the quartz tubule 240 is small compared to the quartz cylinder 210, when the influence of the quartz tubule 240 on the loading space is neglected, the loading space of the quartz cylinder 210 is about 11 × 3.14 × 185 — 70288.9cm³If the density of solid silicon is calculated as 2.329g/cm3, the loading space can theoretically be loaded with a silicon charge weight of 70288.9 x 2.329/1000-160 kg. In practical production, only 70-75 kg of block silicon materials with the size limited to 50mm can be loaded, and the gaps among the silicon materials in the loading space account for more than 50% of the volume of the loading space and existA large space waste. Taking a 30-inch crucible 100 as an example, about 300 kilograms of silicon material needs to be charged again each time, and each cylinder can only contain about 70 kilograms of silicon material, namely 5 cylinders of silicon material need to be charged in each repeated charging process. The addition of a single cylinder of silicon material requires 30-40 minutes of process time, and the process time of more than 2 hours is required for each repeated feeding of 5 cylinders of silicon material. It can be seen that the single barrel charging amount is small and the number of barrels is large during each repeated feeding, which results in long process time and influences production efficiency. In addition, during the charging process and the process of the silicon material falling into the crucible 100, because the silicon material is collided and extruded in the quartz cylinder, a part of sharp corners of the silicon material scratches the quartz cylinder 210, so that the quartz on the inner surface of the quartz cylinder 210 falls off, and the silicon material falls into the silicon liquid 10 in the crucible 100 along with the silicon material, so that the oxygen content in the silicon liquid 10 is increased, the subsequent crystal pulling is affected, and the service life of the quartz cylinder 210 is also affected.

Referring to fig. 1 to fig. 3, a method for feeding silicon material according to an embodiment of the present invention is used for feeding a re-feeding device to a crucible, the re-feeding device includes a charging space, and includes the steps of:

s1, selecting the silicon material with the size within the first preset interval range as the first type silicon material 20,

selecting a silicon material with a size within a second preset interval range and a smooth surface as the second type silicon material 30, wherein the minimum value of the first preset interval range is larger than the maximum value of the second preset interval range.

And S2, loading the first silicon material 20 and the second silicon material 30 into the loading space, wherein the second silicon material 30 at least partially occupies the gaps between the first silicon material 20.

S3, the first silicon material 20 and the second silicon material 30 in the charging space are charged into the crucible.

And S4, if the feeding does not meet the preset feeding requirement of the crucible, repeating the step S2 and the step S3 until the feeding requirement is met, and stopping feeding.

In order to improve the output efficiency of the czochralski silicon technology, the first silicon material 20 and the second silicon material 30 with different sizes are selected for loading, and the second silicon material 30 at least partially occupies the gap between the first silicon materials 20, so that the loading amount of the loading space is increased, namely the silicon material amount which is fed into the crucible once is increased, the feeding times required for meeting the feeding requirement is reduced, and the output efficiency of the czochralski silicon technology is improved. Secondly, the silicon materials with the size within the range of the second preset interval and smooth surfaces are selected as the second silicon materials 30, so that the mode of filling the second silicon materials 30 into the gaps between the first silicon materials 20 is realized, the effect of increasing the charging amount of the charging space is realized, the lubricating effect of facilitating the first silicon materials 20 to slide down can be realized when the charging space charges the crucible, the collision and extrusion probability between the first silicon materials 20 is reduced, the possibility of clamping the first silicon materials 20 is reduced, and the output efficiency of the czochralski silicon process is further improved. In addition, the two types of silicon materials in different size ranges are mixed and charged, and then are mixed and added into the crucible 100, so that the silicon materials with smaller sizes are prevented from being accumulated into a cluster in the crucible 100, the silicon materials are rapidly melted, the material melting process time is shortened, the heat transfer in the silicon materials is facilitated, and the possibility of hydrogen jump caused by uneven temperature is reduced.

The Czochralski silicon crystal pulling process comprises a re-feeding process and a rod pulling process which are alternately carried out, wherein the re-feeding process comprises the silicon material feeding method, and the rod pulling process comprises the following steps: and (S4) stopping feeding when the feeding meets the preset feeding requirement of the crucible in the step S4, and pulling the rod to obtain the silicon single crystal rod. After the rod pulling process is completed, the above steps S1-S4 are repeated.

It should be noted that, referring to fig. 1, in an embodiment, the loading space includes a space formed by an upper surface of the quartz conical head 230, an inner wall of the quartz cylinder 210, and an outer wall of the quartz tubule 240. In an embodiment, in the step S1, the specific manner of selecting the silicon material with the size within the first preset range as the first type silicon material 20 and selecting the silicon material with the size within the second preset range as the second type silicon material 30 may be to screen the silicon materials by using screens with different mesh numbers. The method comprises the steps of screening silicon materials by using a screen corresponding to the maximum value of a first/second preset interval range, selecting the silicon materials capable of passing through the screen, screening the silicon materials by using the screen corresponding to the minimum value of the first/second preset interval range, and selecting the silicon materials incapable of passing through the screen. For example, the first preset interval range is 40mm to 50mm, that is, a silicon material with a size greater than 40mm and a size smaller than 50mm is selected as the first type silicon material 20, a screen with an aperture of 50mm is used to screen the silicon material, and the silicon material capable of passing through the screen is selected. And further screening the silicon material by using a screen with the aperture of 40mm, and selecting the silicon material which cannot pass through the screen. It should be noted that the first preset interval range may be set according to other requirements.

In addition, the preset feeding requirement of the crucible can be the feeding amount (weight) of a single crystal silicon rod pulling rod, or other settings according to the requirement.

Referring to fig. 4 and 5, in an embodiment, step S1 includes: spherical or ellipsoidal silicon materials are selected as the second type silicon material 30. It should be noted that the size ratio between the first type silicon material 20 and the second type silicon material 30 in the drawing is only schematic, and the size of the second type silicon material 30 actually used is much smaller than that of the first type silicon material 20. For example, the second type silicon material 30 may be selected as a granular silicon material having a size of up to 4mm and an average particle diameter of about 2 mm. The particulate silicon material is generally spherical or ellipsoidal in shape with a smooth surface so as to provide lubrication to facilitate the sliding off of the first type of silicon material 20 as it is fed into the crucible from the loading space. Specifically, referring to fig. 1 and fig. 2, when the metal connecting rod 220 and the quartz conical head 230 continue to descend under the driving of the seed crystal weight 500 and the upper surface of the quartz conical head 230 is separated from the lower opening of the quartz cylinder 210, the first type silicon material 20 and the second type silicon material 30 leak out from the quartz cylinder 210 through the gap between the upper surface of the quartz conical head 230 and the lower opening of the quartz cylinder 210, during the feeding process, the gap between the upper surface of the quartz conical head 230 and the lower opening of the quartz cylinder 210 is continuously increased, that is, at the initial stage when the upper surface of the quartz conical head 230 is separated from the lower opening of the quartz cylinder 210, since the gap is small, the lubricating effect of the second type silicon material 30 on the first type silicon material 20 is particularly critical, which is favorable for the bottommost first type silicon material 20 to be smoothly fed into the crucible. Of course, the second-type silicon material 30 has a certain lubricating effect on the first-type silicon material 20 in the whole feeding process. The second-type silicon material 30 can play a role in lubricating the first-type silicon material 20, the first-type silicon material 20 and the re-feeding device 200, particularly the first-type silicon material 20 and the conical surface at the upper part of the quartz conical head 230, so that the possibility of material blockage of the first-type silicon material 20 is reduced, and the output efficiency of the czochralski silicon crystal process is improved.

In one embodiment, step S1 includes:

s101, determining the maximum value of a first preset interval range according to the size of a feeding inlet of a loading space;

and S102, determining the maximum value of the second preset interval range according to the maximum value of the first preset interval range.

In the feeding method of the silicon materials, in order to reduce the possibility of material jamming of the first type of silicon materials 20, step S101 determines the maximum value of the range of the first preset interval according to the feeding inlet size of the charging space. Preferably, in an embodiment, the step S101 includes: controlling the maximum value of the selected first preset interval range to be less than or equal to one half of the feeding inlet size of the loading space. It should be noted that the size of the feeding inlet refers to the smallest cross-sectional size of the feeding inlet, and that different sized multiple feeding devices 200 have different feeding inlet sizes. Specifically, in one embodiment, when the charging space is a space surrounded by the inner wall of the quartz cylinder, the feeding inlet is sized to be the radius of the space surrounded by the inner wall of the quartz cylinder. In another embodiment, when the loading space comprises a space surrounded by the upper surface of the quartz cone 230, the inner wall of the quartz cylinder 210 and the outer wall of the quartz tubule 240, the feeding inlet has a size of a difference between a radius of the inner wall of the quartz cylinder 210 and a radius of the outer wall of the quartz tubule 240. Taking the radius of the inner wall of the quartz cylinder 210 as 110mm and the radius of the outer wall of the quartz tubule 240 as 10mm as an example, that is, the size of the feeding inlet of the charging space is 110mm-10mm, it can be determined that the maximum value of the first preset interval range is less than or equal to 50mm, that is, the size of the first type silicon material 20 is controlled to be less than one half of the size of the feeding inlet of the charging space, so that the two first type silicon materials 20 can freely fall in the quartz cylinder, thereby reducing the possibility of material blocking to a certain extent. Of course, besides the above determination method, the specific determination method in step S101 may also be selected as needed. In addition, in order to increase the charging amount of the charging space while reducing the possibility of occurrence of seizing of the first type silicon material 20, step S102 determines the maximum value of the second preset interval range from the maximum value of the first preset interval range. Taking the maximum value of the first preset interval range as 50mm as an example, the maximum value of the second preset interval range is determined, so as to control the average particle size of the second type of silicon material 30 in the selected second preset interval range to be 2 mm. In this way, the second type silicon material 30 can easily enter the gaps between the first type silicon materials 20.

In one embodiment, the mass ratio of the first type silicon material 20 to the second type silicon material 30 in the step S1 is 15: 11-15: 7. the charging method of the silicon material can greatly increase the charging amount of the charging space. For example, a method for feeding silicon material comprises the following steps: s1, selecting a massive silicon material with the size within 50mm (namely, the maximum value of the first preset interval range is 50mm) as a first-class silicon material 20, and selecting a granular silicon material with the size within 4mm and the average grain size of 2mm as a second-class silicon material 30; when the mass ratio of the first-type silicon material 20 to the second-type silicon material 30 is 15: 7, 75 kg of the first type silicon material 20 and 35 kg of the second type silicon material 30 can be filled in a quartz cylinder 210 with the inner wall radius of 110mm and the height of 185cm, namely 110 kg of the second type silicon material can be filled in a single cylinder. When the mass ratio of the first-type silicon material 20 to the second-type silicon material 30 is 15: 11, 75 kg of the first type silicon material 20 and 55 kg of the second type silicon material 30 can be filled in a quartz cylinder 210 with the inner wall radius of 110mm and the height of 185cm, namely 130 kg of the second type silicon material can be filled in a single cylinder. Compared with the traditional process that only 70-75 kilograms of block silicon materials with the size limited to 50mm can be loaded, the method is more favorable for reducing the space waste, namely, the silicon material amount input at a single time is increased, the feeding times required for meeting the feeding requirement are reduced, and the output efficiency of the czochralski silicon process is further improved.

In one embodiment, step S2 includes:

s202, loading the first-type silicon materials 20 into a loading space, and forming gaps among the first-type silicon materials 20;

and S203, charging the second-type silicon materials 30 into the charging space, so that the second-type silicon materials 30 at least partially fall/slide down into the gaps among the first-type silicon materials 20.

The feeding method of the silicon materials comprises the steps of firstly feeding the first-class silicon materials 20, and then feeding the second-class silicon materials 30 after gaps are formed among the first-class silicon materials 20, so that at least part of the second-class silicon materials 30 fall/slide down to the gaps among the first-class silicon materials 20. On one hand, the charging amount of the charging space is increased, and on the other hand, the second-type silicon material 30 plays a certain lubricating role between the first-type silicon materials 20; thereby improving the output efficiency of the Czochralski silicon process from two aspects. Preferably, in an embodiment, step S2 includes: and S204, alternately performing the step S202 and the step S203 until the preset charging requirement of the charging space is met, and ending the step S2. The above-mentioned feeding method of the silicon material is beneficial to the mixing between the first type silicon material 20 and the second type silicon material 30. In the above method for feeding silicon material, in an embodiment, the step S2 further includes: dividing the first-type silicon material 20 selected in the step S1 into at least two parts according to the size, and preferentially adding the first-type silicon material 20 with a smaller size in the process of alternately performing the step S202 and the step S203. Taking the 30mm-50mm block silicon material selected in step S1 as an example, the silicon material can be divided into four parts of 30mm-35mm, 35mm-40mm, 40mm-45mm and 45mm-50mm, the 30mm-35mm block silicon material is preferentially added, and finally the 45mm-50mm block silicon material is added. Considering that the opening degree of the feeding outlet is gradually increased along with time, on the basis that the second-class silicon material 30 plays a lubricating role, the first-class silicon material 20 with a small size and loaded at the bottom can be mixed with the second-class silicon material 30 to enter the crucible within a relatively small opening degree time, so that feeding is smoother, the possibility of material blocking is further reduced, and the feeding efficiency is improved.

Further, in an embodiment, step S2 includes: s201, charging the second-type silicon materials 30 into a charging space, and paving the charging space in a region close to a charging outlet. The feeding method of the silicon materials is beneficial to the sliding of the first type silicon materials 20 at the bottommost part of the charging space, and the possibility of material blocking is further reduced. And (3) loading the second silicon material 30 into the loading space between the first silicon material 20 and the loading space to form a first silicon material layer laid at the bottommost part of the loading space, and lubricating the first silicon material 20 at the bottom in the feeding process. The placement area of the second type silicon material 30 may be selected according to the type of the charge outlet of the charge space.

In another embodiment, step S2 includes:

s201, mixing the first-class silicon material 20 and the second-class silicon material 30 to obtain a mixed silicon material;

s202, the mixed silicon material in the step S201 is loaded into a loading space.

According to the feeding method of the silicon materials, the first type of silicon materials 20 and the second type of silicon materials 30 are mixed and then are loaded into the loading space, compared with the mode that the first type of silicon materials 20 are loaded firstly, and the second type of silicon materials 30 are loaded after gaps are formed, the mode that two silicon materials with different sizes are mixed more uniformly is adopted, on one hand, the loading amount of the loading space is further increased, and on the other hand, the second type of silicon materials 30 can play a better lubricating role between the first type of silicon materials 20.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A feeding method of a silicon material is used for feeding the crucible by a re-feeding device, the re-feeding device comprises a charging space, and the feeding method of the silicon material is characterized by comprising the following steps:

s1, selecting the silicon material with the size within the first preset interval range as a first type of silicon material,

selecting a silicon material with the size within a second preset interval range and smooth surface as a second type of silicon material, wherein the minimum value of the first preset interval range is larger than the maximum value of the second preset interval range;

s2, loading the first silicon materials and the second silicon materials into a loading space, wherein the second silicon materials at least partially occupy gaps among the first silicon materials;

s3, feeding the first silicon material and the second silicon material in the charging space into a crucible;

and S4, if the feeding does not meet the preset feeding requirement of the crucible, repeating the step S2 and the step S3 until the feeding requirement is met, and stopping feeding.

2. The method for feeding the silicon material as claimed in claim 1, wherein the step S1 comprises: and selecting spherical or ellipsoidal silicon materials as the second type of silicon materials.

3. The method for feeding the silicon material as claimed in claim 1, wherein the step S1 comprises:

s101, determining the maximum value of the range of the first preset interval according to the size of a feeding inlet of the loading space;

s102, determining the maximum value of the second preset interval range according to the maximum value of the first preset interval range.

4. The method for feeding the silicon material according to claim 3, wherein the step S101 comprises:

controlling the maximum value of the first selected preset interval range to be less than or equal to one half of the charging space charging inlet size.

5. The silicon material feeding method as claimed in any one of claims 1 to 4, wherein the mass ratio of the first type silicon material to the second type silicon material in step S1 is 15: 11-15: 7.

6. the method for feeding the silicon material according to any one of claims 1 to 4, wherein the step S2 comprises:

s202, charging the first type of silicon materials into the charging space, and forming gaps among the first type of silicon materials;

s203, charging the second silicon materials into the charging space, so that the second silicon materials at least partially fall/slide down to gaps among the first silicon materials.

7. The method for feeding the silicon material as claimed in claim 6, wherein the step S2 comprises: and S204, alternately performing the step S202 and the step S203 until the preset charging requirement of the charging space is met, and ending the step S2.

8. The method for feeding the silicon material as claimed in claim 7, wherein the step S2 comprises: s201, the second-type silicon materials are loaded into the loading space and are laid in the area, close to the feeding outlet, of the loading space.

9. The method for feeding the silicon material according to any one of claims 1 to 4, wherein the step S2 comprises:

s201, mixing the first-class silicon material and the second-class silicon material to obtain a mixed silicon material;

s202, charging the mixed silicon material in the step S201 into the charging space.

10. The feeding method of silicon material according to any one of claims 1 to 4, wherein the re-feeding device comprises a quartz cylinder body with two open ends, a quartz tubule fixed to the quartz cylinder body and coaxially arranged with the quartz cylinder body, a metal connecting rod located inside the quartz tubule and extending out of the opening at one end of the quartz cylinder body, and a quartz cone fixed to the metal connecting rod and located below the opening at the other end of the quartz cylinder body; the metal connecting rod can drive the quartz conical head to move relative to the opening at the other end of the quartz cylinder; it is characterized in that the preparation method is characterized in that,

step S2 includes: when the quartz conical head abuts against the opening at the other end of the quartz cylinder body, a charging space is formed on the surface, close to the quartz cylinder body, of the quartz conical head, the inner wall of the quartz cylinder body and the outer wall of the quartz tubule;

step S3 includes: and when the quartz conical head is separated from the opening at the other end of the quartz cylinder body and a gap is formed, the first silicon material and the second silicon material in the charging space are charged into the crucible from the gap.

Images