WO2022267302A1

WO2022267302A1 - Silicon material feeding method

Info

Publication number: WO2022267302A1
Application number: PCT/CN2021/129494
Authority: WO
Inventors: 周声浪; 汪晨; 张华利; 周洁
Original assignee: 江苏协鑫硅材料科技发展有限公司
Priority date: 2021-06-25
Filing date: 2021-11-09
Publication date: 2022-12-29
Also published as: CN113430639A

Abstract

A method for feeding a silicon material, comprising: S1, selecting silicon material having a size within a first preset range as a first type of silicon material, and selecting silicon material having a size within a second preset range and having a smooth surface as a second type of silicon material, a minimum value of the first preset range being greater than a maximum value of the second preset range; S2, loading the first type of silicon material and the second type of silicon material into a loading space, the second type of silicon material at least partially occupying a void between the first type of silicon material; S3, feeding the first type of silicon material and the second type of silicon material from the charging space into a crucible; S4, if the feeding does not meet a preset feeding requirement of the crucible, repeating steps S2 and S3 until the feeding requirement is met, and then stopping feeding. The described feeding method improves the output efficiency of a Czochralski monocrystalline silicon process.

Description

Feeding method of silicon material

technical field

The invention relates to the technical field of Czochralski single crystal silicon technology, in particular to a method for feeding silicon material.

Background technique

The Czochralski monocrystalline silicon process is a commonly used process in single crystal growth, and it is widely used in semiconductor integrated circuits, diodes, solar photovoltaics and other fields. The process of the Czochralski monocrystalline silicon process usually includes the initial installation of the crucible, re-injection and rod pulling, and after the initial installation of the crucible, the processes of re-injection and rod pulling will be repeated alternately for many times. It can be seen that the efficiency of the re-investment process can have a direct impact on the output efficiency of the Czochralski monocrystalline silicon process.

At present, a re-injection process usually includes multiple alternate charging steps and feeding steps, that is, firstly load the bulk silicon material into the charging space of the re-injection device, fill the charging space, and then place the massive silicon material When the material is put into the crucible to meet the feeding demand of a single single crystal silicon rod, a re-dosing process is completed.

However, in the above-mentioned re-introduction process, bulk silicon materials are loaded into the charging space, and there are large gaps between the bulk silicon materials, resulting in a large waste of space, and the amount of silicon materials injected at a time is small. The efficiency of the re-investment process is reduced, and the number of re-investments is increased, which in turn reduces the output efficiency of the Czochralski monocrystalline silicon process. On the other hand, bulk silicon material is prone to material jamming during the feeding step, that is, the silicon material fails to fall into the crucible, and the re-injection device needs to be lifted out and reloaded to carry out the re-injection process. The unfallen silicon material needs to be taken out and re-cleaned before it can be used again. It can be seen that the material jam phenomenon will adversely affect the output efficiency of the Czochralski monocrystalline silicon process. In addition, in the feeding step, quartz slag will be produced between the block silicon material and the re-introduction device, such as the block silicon material and the quartz cylinder, due to extrusion, and the quartz slag will increase the oxygen content in the silicon liquid after falling into the silicon liquid , affecting the quality of the silicon rods pulled out, in addition, it will also have a relatively large adverse effect on the service life of the re-throwing device.

Contents of the invention

Based on this, it is necessary to provide a silicon material for the problems of low single feeding amount and low output efficiency caused by material jams in the Czochralski monocrystalline silicon process, which have a relatively large adverse effect on the service life of the re-injection device. feeding method.

A method for feeding silicon material, which is used for feeding a re-injection device to a crucible, the re-injection device includes a charging space, and the method for feeding silicon material comprises the steps of:

S1. Select the silicon material whose size is within the first preset range as the first type of silicon material,

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

S2. Loading the first-type silicon material and the second-type silicon material into the charging space, the second-type silicon material at least partially occupying the space between the first-type silicon materials;

S3. Putting the first type of silicon material and the second type of silicon material in the charging space into the crucible;

S4. If the feeding does not meet the preset feeding requirements of the crucible, repeat steps S2 and S3 until the feeding requirements are met and stop feeding.

In order to improve the output efficiency of the Czochralski monocrystalline silicon process, the feeding method of the above-mentioned silicon material, firstly, select the first type of silicon material and the second type of silicon material with different sizes for charging, and the second type of silicon material at least partially occupies the second type of silicon material. The gap between the first type of silicon materials increases the charging volume of the charging space, that is, increases the amount of silicon materials that are put into the crucible at a time, thereby reducing the number of times of feeding required to meet the feeding requirements, and improving the Czochralski unit. Yield efficiency of crystalline silicon process. Second, the silicon material whose size is within the second preset range and has a smooth surface is selected as the second type of silicon material, so that the second type of silicon material is filled in the gap between the first type of silicon material In addition to increasing the charging capacity of the charging space, it can also play a lubricating role in favor of the sliding of the first type of silicon material when feeding into the crucible in the charging space, reducing the possibility of the first type of silicon material jamming performance, further improving the output efficiency of the Czochralski monocrystalline silicon process.

The technical scheme of the present application is described further below:

In one embodiment, step S1 includes: selecting spherical or ellipsoidal silicon material as the second type of silicon material.

In one of the embodiments, step S1 includes:

S101. Determine the maximum value of the first preset interval according to the size of the feeding inlet of the charging space;

S102. Determine the maximum value of the second preset interval range according to the maximum value of the first preset interval range.

In one of the embodiments, step S101 includes:

Controlling the size of the feeding inlet of the charging space where the maximum value of the selected first preset range is less than or equal to half.

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

In one of the embodiments, step S2 includes:

S202. Load the first type of silicon material into the charging space, and form gaps between the first type of silicon materials;

S203. Load the second type of silicon material into the charging space, so that the second type of silicon material at least partially falls/slides into the gap between the first type of silicon materials.

In one embodiment, step S2 includes: S204, step S202 and step S203 are alternately performed until the preset loading requirement of the loading space is met, and step S2 is ended.

In one embodiment, step S2 includes: S201, loading the second type of silicon material into the charging space, and laying it in an area of the charging space close to the feeding outlet.

In one of the embodiments, step S2 includes:

S201. Mix the first type of silicon material with the second type of silicon material to obtain a mixed silicon material;

S202. Load the mixed silicon material in step S201 into the charging space.

In one of the embodiments, the re-introduction device includes a quartz cylinder with openings at both ends, a quartz thin tube fixed to the quartz cylinder and arranged coaxially with the quartz cylinder, located in the quartz thin tube A metal connecting rod inside and protruding from the opening at one end of the quartz cylinder, and a quartz cone head fixed to the metal connecting rod and positioned below the opening at the other end of the quartz cylinder; the metal The connecting rod can drive the quartz cone to move relative to the opening at the other end of the quartz cylinder;

Step S2 includes: when the quartz cone abuts against the opening at the other end of the quartz cylinder, the surface of the quartz cone close to the quartz cylinder, the inner wall of the quartz cylinder, and the quartz capillary The outer wall of the tank forms a charging space;

Step S3 includes: when the quartz conical head breaks away from the opening at the other end of the quartz cylinder and a gap appears, the first type of silicon material and the second type of silicon material in the charging space are separated by the Put the gap into the crucible.

Description of drawings

Fig. 1 is a schematic structural view of a re-throwing device and a single crystal furnace in an embodiment of the present invention;

Fig. 2 is a partial enlarged schematic diagram when the quartz cylinder falls on the upper surface of the quartz cone in an embodiment of the present invention;

Fig. 3 is a partial enlarged schematic diagram of position A (silicon material falling into the crucible) in Fig. 1;

Fig. 4 is a partial enlarged schematic diagram when silicon material is housed in the charging space (the second type of silicon material is spherical silicon material) in an embodiment of the present invention;

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

Reference signs:

10. Silicon liquid; 100. Crucible; 200. Re-injection device; 210. Quartz cylinder; 220. Metal connecting rod; 230. Quartz cone head; 240. Quartz thin tube; Crystal furnace auxiliary room; 500, seed crystal weight; 20, first-class silicon material; 30, second-class silicon material.

detailed description

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In the current Czochralski monocrystalline silicon process, a crucible 100 usually needs to be used for about 300 hours, and the process of re-injection and rod pulling will be repeated about 10 times alternately, and then about 10 monocrystalline silicon rods will be produced. Each re-injection process usually includes multiple alternate charging steps and feeding steps. When the feeding requirements of a single single crystal silicon rod are met, a re-injection process is completed and the ingot pulling process is performed. After the rod pulling process of a single single crystal silicon rod is completed, the above-mentioned re-throwing process is repeated.

Referring to Fig. 1, the reinvestment device 200 adopted in the reinvestment process includes a quartz cylinder 210, a metal connecting rod 220 and a quartz cone 230, wherein the quartz cylinder 210 is a cylinder with openings at both ends, and the inner cavity of the quartz cylinder 210 A metal connecting rod 220 is arranged in the axial direction. One end of the metal connecting rod 220 protrudes from the upper opening of the quartz cylinder 210 and can be connected with the seed crystal weight 500, and the other end of the metal connecting rod 220 is connected to the quartz cone 230, which is located at the lower end of the quartz cylinder 210 below the opening. In addition, in order to avoid contact between the metal connecting rod 220 and the silicon material, a quartz thin tube 240 is arranged inside the quartz cylinder 210 , and the metal connecting rod 220 is located inside the quartz thin tube 240 .

During use, referring to Fig. 1-Fig. 3, the quartz cylinder 210 falls on the upper surface of the quartz cone 230 to support the quartz cylinder 210, the upper surface of the quartz cone 230, the inner wall of the quartz cylinder 210, and the quartz fine The outer wall of the tube 240 constitutes a space for containing the silicon material, and the silicon material is loaded into the above-mentioned space. After charging, move the re-injection device 200 to the lower end of the auxiliary chamber 400 of the single crystal furnace, then lower the seed crystal weight 500 and connect the metal connecting rod 220 so that the seed crystal weight 500 is suspended by the metal connecting rod 220 for re-injection The device 200 rises and slowly lifts into the sub-chamber 400 of the single crystal furnace. Then the sub-chamber 400 of the single crystal furnace is turned back to the top of the main room 300 of the single crystal furnace, and the sub-chamber 400 of the single crystal furnace is lowered to connect with the main room 300 of the single crystal furnace. The throwing 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 will stop falling, and the metal connecting rod 220 and the quartz cone 230 will continue to descend under the drive of the seed crystal weight 500, and the upper surface of the quartz cone 230 will break away from the quartz The lower end of the cylinder 210 is open, and the silicon material leaks from the quartz cylinder 210 through the gap between the upper surface of the quartz cone 230 and the lower end of the quartz cylinder 210 , and falls into the crucible 100 . After the silicon material is completely removed, the re-injection device 200 is lifted into the sub-chamber 400 of the single crystal furnace, and the re-injection device 200 is taken out to complete the single-cylinder feeding process. Each re-injection requires multiple single-cylinder charging and single-cylinder feeding, namely Carry out the above operation steps several times until the feeding weight reaches the feeding requirement for re-dosing.

In the traditional process, more than 90% of the silicon material used for single crystal re-investment comes from dense rod-shaped material and single crystal circulating material. Since the diameter of the above two silicon materials is more than 150mm, the inner wall radius of the quartz cylinder 210 is usually about 110mm, so the dense Both rod-shaped material and single crystal recycled material need to be crushed before they can be used as silicon materials for re-use. Due to the high hardness of silicon, it is more difficult to crush dense rod-shaped materials and single crystal recycled materials. The smaller the crushing size, the higher the man-hours and energy consumption required, 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 silicon material in the quartz cylinder 210 cannot fall down due to mutual extrusion, which greatly increases the possibility of material jamming. Therefore, in order to take into account the cost of crushing the silicon material and the possibility of a material jam accident, the size of the silicon material used for single crystal re-use is usually limited to 50mm.

Specifically, taking the quartz cylinder 210 with an inner wall radius of 110mm and a height of 185cm as an example, because the size of the quartz thin tube 240 is relatively small compared to the quartz cylinder 210, when the influence of the quartz thin tube 240 on the charging space is ignored, then The loading space of the quartz cylinder 210 is about 11*11*3.14*185=70288.9cm ³ , and the density of solid silicon is calculated as 2.329g/cm3, then the theoretical loading space can be loaded with a silicon material weight of 70288.9*2.329/1000= 160kg. However, in actual production, only 70-75 kg of bulk silicon material with a size of 50 mm can be loaded, and the gap between silicon materials in the loading space accounts for more than 50% of the volume of the loading space, so there is a large space waste. Taking the 30-inch crucible 100 as an example, about 300 kg of silicon material needs to be re-introduced each time, and each cylinder can only hold about 70 kg of silicon material, that is, 5 cylinders of silicon material are required for each re-injection process. It takes 30-40 minutes of process time to add a single cylinder of silicon material, and it takes more than 2 hours of process time to add 5 cylinders of silicon material each time. It can be seen that the amount of material loaded in a single cylinder is small and the number of cylinders is large during each re-injection, resulting in a long process time and affecting production efficiency. In addition, during the charging process and the process of the silicon material falling into the crucible 100, because the silicon material collides and squeezes in the quartz cylinder, it will cause some of the silicon material to scratch the quartz cylinder 210 at a sharp angle, causing the inner surface of the quartz cylinder 210 to The quartz falls off and falls into the silicon liquid 10 in the crucible 100 as the silicon material falls, resulting in an increase in the oxygen content in the silicon liquid 10 , which affects subsequent crystal pulling and also affects the service life of the quartz cylinder 210 .

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

S1. Select a silicon material with a size within the first preset range as the first type of silicon material 20,

A silicon material whose size is within a second preset range and has a smooth surface is selected as the second type of silicon material 30 , wherein the minimum value of the first preset range is greater than the maximum value of the second preset range.

S2. Loading the first-type silicon material 20 and the second-type silicon material 30 into the charging space, the second-type silicon material 30 at least partially occupies the space between the first-type silicon materials 20 .

S3. Put the first-type silicon material 20 and the second-type silicon material 30 in the charging space into the crucible.

S4. If the input does not meet the preset feeding requirements of the crucible, repeat steps S2 and S3 until the feeding requirements are met and stop feeding.

The feeding method of the above-mentioned silicon material, in order to improve the output efficiency of the Czochralski monocrystalline silicon process, one, select the first type silicon material 20 and the second type silicon material 30 with different sizes for charging, and the second type silicon material 30 Occupying at least part of the space between the first type of silicon materials 20 increases the amount of material in the charging space, that is, increases the amount of silicon material that is put into the crucible at a time, thereby reducing the number of times of feeding required to meet the feeding requirements. The output efficiency of the Czochralski monocrystalline silicon process is improved. Second, the silicon material with a size within the second preset range and with a smooth surface is selected as the second type silicon material 30, so that the second type silicon material 30 is filled between the first type silicon materials 20. The way of the gap, in addition to the effect of increasing the charging amount of the charging space, can also play a lubricating role in favor of the sliding of the first type of silicon material 20 when the charging space feeds the crucible, reducing the amount of the first type of silicon. The probability of collision and extrusion between the materials 20 reduces the possibility of the first type of silicon material 20 jamming, and further improves the output efficiency of the Czochralski monocrystalline silicon process. In addition, two types of silicon materials in different size ranges are mixed and charged, and then mixed and added into the crucible 100, which avoids the accumulation of smaller-sized silicon materials in the crucible 100, which is conducive to the rapid melting of silicon materials and shortens the chemical process. At the same time, it is also conducive to the heat transfer inside the silicon material, reducing the possibility of hydrogen jump due to uneven temperature.

The Czochralski monocrystalline silicon process includes alternate re-injection processes and rod-drawing processes, wherein the re-injection process includes the above-mentioned feeding method of silicon material, and the rod-drawing process includes: when the input in step S4 meets the preset feeding requirements of the crucible, Stop feeding, pull rods, and produce monocrystalline silicon rods. After the rod pulling process is completed, the above steps S1-S4 are repeated.

It should be noted that, referring to FIG. 1 , in one embodiment, the charging space includes a space formed by the upper surface of the quartz cone 230 , the inner wall of the quartz cylinder 210 , and the outer wall of the quartz thin tube 240 . In one embodiment, in step S1, the silicon material whose size is within the first predetermined range is selected as the first type of silicon material 20, and the silicon material whose size is within the second predetermined range is selected as the second type of silicon material The specific manner of 30 may be to use screens of different meshes to screen the silicon material. That is, use the sieve corresponding to the maximum value of the first/second preset interval to screen the silicon material, select the silicon material that can pass through the sieve, and use the sieve corresponding to the minimum value of the first/second preset interval The silicon material is screened, and the silicon material that cannot pass through the sieve is selected. For example, the first preset interval range is 40mm-50mm, that is, the silicon material with a size larger than 40mm and smaller than 50mm is selected as the first type of silicon material 20, and the silicon material is screened with a screen with an aperture of 50mm. The silicon material of the screen. Further use a sieve with an aperture of 40mm to screen the silicon material, and select the silicon material that cannot pass through the sieve. It should be noted that the first preset range can also be set in other ways according to requirements.

In addition, the preset feeding demand of the crucible can satisfy the feeding amount (weight) of a single single crystal silicon rod or rod, or other settings as required.

Referring to FIG. 4 and FIG. 5 , in an embodiment, step S1 includes: selecting a spherical or ellipsoidal silicon material as the second type of silicon material 30 . It should be noted that the size ratio between the first type of silicon material 20 and the second type of silicon material 30 in the figure is only for illustration, and the size of the second type of silicon material 30 actually used is much smaller than that of the first type of silicon material 20 . For example, the second type of silicon material 30 can be granular silicon material with a size within 4 mm and an average particle size of about 2 mm. The granular silicon material is usually spherical or ellipsoidal, and has a smooth surface. In this way, when the material is fed into the crucible in the charging space, it can lubricate the first type of silicon material 20 to slide down. Specifically, referring to Fig. 1 and Fig. 2, when the metal connecting rod 220 and the quartz cone 230 continue to descend under the drive of the seed crystal weight 500, and the upper surface of the quartz cone 230 is separated from the lower opening of the quartz cylinder 210, the first type The silicon material 20 and the second type silicon material 30 leak from the quartz cylinder 210 through the gap between the upper surface of the quartz cone 230 and the lower opening of the quartz cylinder 210. During the feeding process, the upper surface of the quartz cone 230 and the quartz The gap between the lower openings of the cylinder body 210 is constantly increasing, that is, in the initial stage when the upper surface of the quartz cone 230 is separated from the lower opening of the quartz cylinder body 210, due to the small gap, the second type of silicon material 30 is relatively small to the first type of silicon. The lubricating effect of the material 20 is particularly critical, which is conducive to the smooth input of the first type silicon material 20 at the bottom into the crucible. Certainly in the whole process of feeding intake, the second type of silicon material 30 all has a certain lubricating effect on the first type of silicon material 20. The second type of silicon material 30 can be between the first type of silicon material 20, between the first type of silicon material 20 and the re-injection device 200, especially between the first type of silicon material 20 and the cone surface on the top of the quartz cone head 230 Play a lubricating role, reduce the possibility of 20 jams of the first type of silicon material, and improve the output efficiency of the Czochralski monocrystalline silicon process.

In one embodiment, step S1 includes:

In the feeding method of the above-mentioned silicon material, in order to reduce the possibility of jamming of the first type of silicon material 20, step S101 determines the maximum value of the first preset interval according to the size of the feeding inlet of the charging space. Preferably, in an embodiment, step S101 includes: controlling the maximum value of the selected first preset interval to be less than or equal to half of the feeding inlet size of the charging space. It should be noted that the size of the feeding inlet refers to the minimum cross-sectional size of the feeding inlet, and re-feeding devices 200 of different sizes have different feeding inlet sizes. Specifically, in one embodiment, when the charging space is the space enclosed by the inner wall of the quartz cylinder, the size of the feeding inlet is the radius of the space enclosed by the inner wall of the quartz cylinder. In another embodiment, when the charging space includes the space surrounded by the upper surface of the quartz cone head 230, the inner wall of the quartz cylinder 210, and the outer wall of the quartz thin tube 240, the size of the feeding inlet is the radius of the inner wall of the quartz cylinder 210 The difference from the outer wall radius of the quartz thin tube 240. Taking the inner wall radius of the quartz cylinder 210 as 110mm and the outer wall radius of the quartz thin tube 240 as 10mm as an example, that is, the feeding inlet size of the charging space is 110mm-10mm, then it can be determined that the maximum value of the first preset interval is less than or It is equal to 50mm, that is, the size of the first type silicon material 20 is controlled below half of the size of the feeding inlet of the charging space, so that two pieces of the first type silicon material 20 can freely fall in the quartz cylinder, thereby reducing the size to a certain extent. The possibility of material jam phenomenon is small. Of course, in addition to the above determination methods, the specific determination method in step S101 can also be selected according to needs. In addition, in order to reduce the possibility of jamming of the first type of silicon material 20 and at the same time increase the loading capacity of the loading space, step S102 determines the second preset interval according to the maximum value of the first preset interval the maximum value. Taking the maximum value of the first preset interval as 50 mm as an example, determine the maximum value of the second preset interval to control the average particle size of the second type of silicon material 30 within the selected second preset interval is 2mm. In this way, the second type of silicon material 30 can easily enter the gap between the first type of silicon material 20 .

In one embodiment, the mass ratio of the first type silicon material 20 to the second type silicon material 30 in step S1 is 15:11-15:7. The feeding method of the above-mentioned silicon material can increase the charging amount of the charging space to a large extent. For example, the feeding method of silicon material includes: S1, selecting a block silicon material with a size within 50mm (that is, the maximum value of the first preset range is 50mm) as the first type of silicon material 20, selecting a size within 4mm, And the granular silicon material with an average particle size of 2mm is used as the second type silicon material 30; when the mass ratio of the first type silicon material 20 and the second type silicon material 30 is loaded in the mode of 15:7, the inner wall radius is 110mm, The first type of silicon material 20 in the quartz cylinder 210 with a height of 185 cm can be loaded with 75 kg, and the second type of silicon material 30 can be loaded with 35 kg, that is, a single cylinder can be loaded with 110 kg. When the mass ratio of the first type of silicon material 20 to the second type of silicon material 30 is 15:11, the first type of silicon material 20 in the quartz cylinder 210 with an inner wall radius of 110 mm and a height of 185 cm can hold 75 kilograms, the second type of silicon material 30 can be loaded into 55 kilograms, that is, 130 kilograms in a single cylinder. Compared with the traditional process, which can only hold 70-75 kg of bulk silicon material with a size limited to 50mm, the above method is more conducive to reducing space waste, that is, increasing the amount of silicon material input at a time, reducing the need to meet The number of feeds required by the feeding requirements, thereby improving the output efficiency of the Czochralski monocrystalline silicon process.

In one embodiment, step S2 includes:

S202, loading the first type silicon material 20 into the charging space, and forming gaps between the first type silicon material 20;

S203 , loading the second-type silicon material 30 into the charging space, so that the second-type silicon material 30 at least partially falls/slides into the gap between the first-type silicon materials 20 .

The feeding method of the above-mentioned silicon material is to first load the first type silicon material 20, after the gap is formed between the first type silicon material 20, the second type silicon material 30 is loaded, so that the second type silicon material 30 at least partly falls/ Slide down into the gap between the first type silicon materials 20 . On the one hand, the loading capacity of the loading space is increased; on the other hand, the second type of silicon material 30 plays a certain lubricating effect between the first type of silicon material 20; The productivity of the process. Preferably, in an embodiment, step S2 includes: S204, step S202 and step S203 are alternately performed until the preset loading requirement of the loading space is met, and step S2 is ended. The feeding method of the above-mentioned 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 of feeding silicon material, in one embodiment, step S2 further includes: dividing the first type of silicon material 20 selected in step S1 into at least two parts according to size, and performing step S202 and step S203 alternately, The first type of silicon material 20 with smaller size is given priority. Taking the block silicon material of 30mm-50mm selected in step S1 as an example, it can be divided into four parts of 30mm-35mm, 35mm-40mm, 40mm-45mm, and 45mm-50mm, and the block silicon material of 30mm-35mm is given priority. Finally, put in 45mm-50mm block silicon material. Considering that the opening of the feeding outlet gradually increases with time, on the basis that the second type of silicon material 30 plays a lubricating role, the first type of silicon material with a smaller size can be loaded at the bottom within a relatively small opening. The silicon material 20 mixed with the second type of silicon material 30 enters the crucible, which makes feeding more smoothly, further reduces the possibility of material jam, and improves the efficiency of feeding.

Further, in one embodiment, step S2 includes: S201, loading the second type of silicon material 30 into the charging space, and laying it in the area of the charging space near the feeding outlet. The feeding method of the above-mentioned silicon material is to facilitate the sliding of the first-type silicon material 20 at the bottom of the charging space, and further reduce the possibility of material jamming. Between loading the first type of silicon material 20 into the charging space, the second type of silicon material 30 is loaded into the charging space to form the first type of silicon material layer laid at the bottom of the charging space. During the feeding process, Lubricate the first type silicon material 20 at the bottom. It should be noted that the laying area of the second type of silicon material 30 can be selected according to the feeding outlet form of the charging space.

In another embodiment, step S2 includes:

S201, mixing the first type silicon material 20 with the second type silicon material 30 to obtain a mixed silicon material;

S202. Load the mixed silicon material in step S201 into the charging space.

The feeding method of the above-mentioned silicon material is to first mix the first type silicon material 20 and the second type silicon material 30 and then load them into the charging space together. The way of the second type of silicon material 30, the mixing of two kinds of silicon materials of different sizes is more uniform in this way, on the one hand, further increases the charging capacity of the charging space, on the other hand, the second type of silicon material 30 in the second One type of silicon material 20 can play a better lubricating effect.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and therefore should not be construed as limitations on the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the 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. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or there may be an intervening element. 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. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions are for the purpose of illustration only and are not intended to represent the only embodiment.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims

A method for feeding silicon material, which is used for feeding a re-injection device to a crucible, the re-injection device includes a charging space, and is characterized in that the method for feeding silicon material comprises the steps of:

S1. Select the silicon material whose size is within the first preset range as the first type of silicon material,

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

S2. Loading the first-type silicon material and the second-type silicon material into the charging space, the second-type silicon material at least partially occupying the space between the first-type silicon materials;

S3. Putting the first type of silicon material and the second type of silicon material in the charging space into the crucible;

S4. If the feeding does not meet the preset feeding requirements of the crucible, repeat steps S2 and S3 until the feeding requirements are met and stop feeding.
The feeding method of silicon material according to claim 1, characterized in that step S1 comprises: selecting spherical or ellipsoidal silicon material as the second type of silicon material.
The feeding method of silicon material according to claim 1, characterized in that step S1 comprises:

S101. Determine the maximum value of the first preset interval according to the size of the feeding inlet of the charging space;

S102. Determine the maximum value of the second preset interval range according to the maximum value of the first preset interval range.
The feeding method of silicon material according to claim 3, characterized in that step S101 comprises:

Controlling the size of the feeding inlet of the charging space where the maximum value of the selected first preset range is less than or equal to half.
The feeding method of silicon material according to any one of claims 1-4, characterized in that the mass ratio of the first type of silicon material to the second type of silicon material in step S1 is 15:11-15:7.
The feeding method of silicon material according to any one of claims 1-4, is characterized in that, step S2 comprises:

S202. Load the first type of silicon material into the charging space, and form gaps between the first type of silicon materials;

S203. Load the second type of silicon material into the charging space, so that the second type of silicon material at least partially falls/slides into the gap between the first type of silicon materials.
The method for feeding silicon material according to claim 6, characterized in that step S2 comprises: S204, alternately performing step S202 and step S203 until the preset charging requirement of the charging space is satisfied, and step S2 is ended.
The feeding method of silicon material according to claim 7, characterized in that step S2 includes: S201, loading the second type of silicon material into the charging space, and laying it in the charging space near the charging space. export area.
The feeding method of silicon material according to any one of claims 1-4, characterized in that step S2 comprises:

S201. Mix the first type of silicon material with the second type of silicon material to obtain a mixed silicon material;

S202. Load the mixed silicon material in step S201 into the charging space.
According to the feeding method of silicon material according to any one of claims 1-4, the re-introduction device comprises a quartz cylinder with openings at both ends, fixed to the quartz cylinder and coaxial with the quartz cylinder The set quartz thin tube, the metal connecting rod that is located inside the quartz thin tube and protrudes from the opening at one end of the quartz cylinder, and the other metal connecting rod that is fixed on the metal connecting rod and is located in the quartz cylinder. A quartz cone head below the opening at one end; the metal connecting rod can drive the quartz cone head to move relative to the opening at the other end of the quartz cylinder; it is characterized in that,

Step S2 includes: when the quartz cone abuts against the opening at the other end of the quartz cylinder, the surface of the quartz cone close to the quartz cylinder, the inner wall of the quartz cylinder, and the quartz capillary The outer wall of the tank forms a charging space;

Step S3 includes: when the quartz conical head breaks away from the opening at the other end of the quartz cylinder and a gap appears, the first type of silicon material and the second type of silicon material in the charging space are separated by the Put the gap into the crucible.