Material melting auxiliary device, single crystal furnace system and material melting process

Abstract

The invention provides a material auxiliary device, a single crystal furnace system and a material melting process, the material auxiliary device comprises a connecting chuck, a connecting rod connected with the connecting chuck and a heat preservation assembly connected with the connecting rod, the heat preservation assembly comprises a cover body and a tray which are connected, the cover body is connected with the tray, the cover body and the tray can move relative to the connecting rod, the tray is connected with the connecting rod in a clamped mode, and the connecting rod is connected with the heat preservation assembly. The connecting chuck is clamped with the connecting rod, and a containing space is formed between the cover body and the tray. The device has the beneficial effects that auxiliary material melting is carried out, and hot air in the single crystal furnace is gathered in the quartz crucible, so that abnormal phenomena such as temperature rise in the single crystal furnace, silicon raw material melting acceleration, edge hanging and bridging are obviously reduced, the material melting time is shortened, meanwhile, the material melting auxiliary device moves up and down in the single crystal furnace, the flowing direction of protective gas is changed, and the material melting efficiency is improved. The dust impurities are discharged along with the protective gas or blown into the quartz crucible, and the impurities in the silicon melt are removed in combination with a slag bonding process, so that the crystal growth success rate and the single crystal quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor preparation, and in particular relates to a material-making auxiliary device, a single crystal furnace system and a material-making process. Background Art

[0002] The heat source transfers heat to the outer wall of the graphite crucible through heat radiation, and then the graphite crucible, quartz crucible and silicon raw material transfer heat through heat conduction until the temperature of the silicon material rises to 1685K (silicon melting point) and the silicon material changes from solid to liquid. The current mainstream method of melting materials is to melt the materials at high temperature in a closed furnace chamber, which is prone to abnormal phenomena such as hanging edges and bridging during the melting process. Summary of the invention

[0003] In view of the above problems, the present invention provides a material smelting auxiliary device, a single crystal furnace system and a material smelting process to solve the above or other former problems existing in the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a chemical material auxiliary device, including a connecting chuck, a connecting rod connected to the connecting chuck, and an insulation component connected to the connecting rod, the insulation component includes a connected cover body and a tray, the cover body is connected to the tray, the cover body and the tray can be moved relative to the connecting rod, the tray is clamped with the connecting rod, the connecting chuck is clamped with the connecting rod, and there is a accommodating space between the cover body and the tray.

[0005] Furthermore, the connecting rod includes a rod body and a first abutment and a second abutment arranged at both ends of the rod body. The first abutment, the rod body and the second abutment are coaxially arranged, and the outer diameter of the second abutment is greater than the outer diameter of the rod body.

[0006] Furthermore, the cover body is provided with a first connecting through hole, and the cover body is penetrated on the connecting rod through the first connecting through hole.

[0007] Furthermore, the first connecting through hole is coaxially arranged with the cover body, and the outer diameter of one axial end of the cover body is greater than the outer diameter of the other axial end.

[0008] Furthermore, the tray is provided with a second connecting through hole and a first abutment hole, the second connecting through hole is connected to the first abutment hole, the diameter of the first abutment hole is larger than the diameter of the second connecting through hole, the outer diameter of the first abutment piece is larger than the second connecting through hole, the tray is passed through the second connecting through hole and the first abutment hole on the connecting rod, the first abutment piece is located in the first abutment hole, and the first abutment piece abuts and cooperates with the first abutment hole.

[0009] Furthermore, the connecting chuck includes a chuck body, a mounting channel provided on the chuck body, a second abutment hole provided on the chuck body, and a mounting hole, the mounting channel is connected to the second abutment hole, the mounting channel is provided on the peripheral side wall of the chuck body, the second abutment hole is connected to the outside of one axial end of the chuck body, the second abutment hole is coaxially arranged with the chuck body, so that the second abutment member passes through the mounting channel into the second abutment hole, and the second abutment member abuts and cooperates with the second abutment hole.

[0010] Furthermore, the length of the mounting channel along the axial direction of the chuck body is not less than the length of the second abutment hole along the axial direction of the chuck body, the width of the mounting channel along the circumferential direction of the chuck body is not less than the maximum outer diameter of the second abutment, and the width of the mounting channel along the circumferential direction of the chuck body at the intersection with the second abutment hole is not greater than the diameter of the second abutment hole.

[0011] Further, the mounting hole is coaxially arranged with the second abutting hole, and the mounting hole is communicated with the second abutting hole, and the mounting hole is communicated with the outside of the other axial end of the chuck body so as to be connected with the seed crystal chuck.

[0012] Furthermore, a heat-insulating component is provided in the accommodating space, and the heat-insulating component is connected to the connecting rod.

[0013] Furthermore, the connecting rod, the connecting clamp, the thermal insulation component and the thermal insulation part are all made of graphite.

[0014] A single crystal furnace system comprises a single crystal furnace body and a material-making auxiliary device as described above arranged in the single crystal furnace body. The material-making auxiliary device is connected to a seed crystal chuck in the single crystal furnace body and is suspended in the single crystal furnace body.

[0015] Furthermore, the distance between the peripheral side wall of the insulation component of the material auxiliary device and the inner side wall of the guide tube in the single crystal furnace body is 20-60 mm.

[0016] Furthermore, the distance from the bottom side of the insulation component of the material auxiliary device to the surface of the melt in the quartz crucible in the single crystal furnace body is 10-30 mm.

[0017] A chemical process, using the above-mentioned single crystal furnace system to pull a single crystal, comprises:

[0018] In the initial stage of the material charging, the protective gas is introduced at a first flow rate, and the distance between the side of the material charging auxiliary device facing the quartz crucible and the surface of the melt in the quartz crucible is always kept at a first distance to perform the material charging;

[0019] In the first stage of material processing, the protective gas is introduced at a first flow rate, and the material processing auxiliary device is controlled to move up and down to purge the dust in the single crystal furnace;

[0020] In the second stage of material processing, slag sticking is carried out.

[0021] Furthermore, the first flow rate of the protective gas is 120-160 slpm.

[0022] Furthermore, the first distance is 10-30 mm.

[0023] Furthermore, when the material-making auxiliary device moves up and down, it is set that: along the direction from the quartz crucible to the auxiliary chamber, the distance from the surface of the melt in the quartz crucible is 10-30 mm as the initial position, the distance from the lower edge of the auxiliary chamber to the middle of the auxiliary chamber is 100-2000 mm as the first position, the material-making auxiliary device moves at a first speed between the initial position and the lower edge of the auxiliary chamber, and moves at a second speed between the lower edge of the auxiliary chamber and the first position, and the second speed is greater than the first speed.

[0024] Furthermore, the first speed is 200-350 mm / h, and the second speed is 350-550 mm / h.

[0025] Furthermore, when the slag is stuck, it includes:

[0026] Lowering the seed crystal, and when the seed crystal contacts the impurities in the melt, continuing to lower the seed crystal by a second distance and staying for the first time, so that the seed crystal and the impurity block are welded;

[0027] After the seed crystal is fused with the impurity block, the seed crystal is raised at a third speed, and when the seed crystal rises to the second position, it stays for a second time;

[0028] It is determined whether the impurity block has fallen off from the seed crystal. If not, the seed crystal is raised at the fourth speed, and the seed crystal is cooled after entering the auxiliary chamber. After cooling, the impurity block is taken out.

[0029] Furthermore, the second distance is 2-10 mm, and the first time is 2-10 min.

[0030] Furthermore, the third speed is 100-150 mm / h, the second position is 5-10 mm above the melt surface in the quartz crucible, and the second time is 2-10 min.

[0031] Furthermore, the fourth speed is 400-600 mm / h, and the cooling time is 30-60 min.

[0032] Furthermore, from the start of the material-making process to the last re-feeding, until all the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials remain on the surface of the silicon melt, this stage is set as the initial stage of material-making;

[0033] From the last re-addition until the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials on the surface of the silicon melt remain until 10%-20% of the silicon raw materials on the surface of the silicon melt remain, this stage is set as the first stage of material melting;

[0034] The stage from when 10%-20% of the silicon raw material remains on the surface of the silicon melt to the end of the material-making process is set as the second material-making stage.

[0035] Due to the adoption of the above technical solution, the cover of the material-making auxiliary device is buckled and connected with the tray, the cover is inserted into the connecting rod, the connecting rod is clamped with the tray, and the connecting rod is clamped with the connecting chuck, and no bolts or other connecting parts are required for fixed connection, the structure is simple, and installation and disassembly are convenient; the material-making auxiliary device is installed in the single crystal furnace during the material-making stage, located above the quartz crucible, to assist in material-making, and to gather the hot air flow in the single crystal furnace into the quartz crucible, so that the temperature in the single crystal furnace is increased, the melting of silicon raw materials is accelerated, and abnormal phenomena such as edge hanging and bridging are significantly reduced, thereby shortening the material-making time; at the same time By moving the material auxiliary device up and down in the single crystal furnace, the flow direction of the protective gas is changed, so that dust impurities are discharged with the protective gas or blown into the quartz crucible. Combined with the slag sticking process, impurities in the silicon melt are removed to avoid the phenomenon of impurity bulging during the single crystal pulling process, effectively reducing the amount of dissolution of the inner wall of the quartz crucible, increasing the service life of the quartz crucible, and reducing the probability of silicon leakage and deformation during crystal growth. At the same time, it can reduce the introduction of impurities into the melt due to the dissolution of the inner wall of the quartz crucible, thereby improving the success rate of crystal growth and the quality of single crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the three-dimensional structure of a material auxiliary device according to an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the main structure of a material auxiliary device according to an embodiment of the present invention;

[0038] Figure 3 yes Figure 2 AA cross-sectional structural diagram;

[0039] Figure 4 is a schematic diagram of the three-dimensional structure of a cover body according to an embodiment of the present invention;

[0040] Figure 5 is a schematic cross-sectional structural diagram of a cover body according to an embodiment of the present invention;

[0041] Figure 6 is a schematic diagram of the three-dimensional structure of a tray according to an embodiment of the present invention;

[0042] Figure 7 is a schematic cross-sectional structural diagram of a tray according to an embodiment of the present invention;

[0043] Figure 8 is a schematic structural diagram of a connecting rod according to an embodiment of the present invention;

[0044] Fig. 9 is a schematic structural diagram of a connecting clamp according to an embodiment of the present invention;

[0045] Fig.10 is a schematic diagram of a top view of a connecting clamp according to an embodiment of the present invention;

[0046] Fig.11 yes Fig.10 BB cross-sectional structure diagram;

[0047] Fig.12 is a bottom view of the structure of a connecting clamp according to an embodiment of the present invention;

[0048] Fig.13 yes Fig.12 Schematic diagram of the CC cross-sectional structure.

[0049] In the figure:

[0050] 1. Connecting chuck 2. Connecting rod 3. Cover

[0051] 4. Tray 5. Insulation 10. Chuck body

[0052] 11. Installation channel 12. Installation hole 20. Rod body

[0053] 21, first abutting member 22, second abutting member 30, first connecting through hole

[0054] 40, boss 41, second connecting through hole 42, first abutting hole

[0055] 13. Second abutment hole DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0057] Figure 1 A structural schematic diagram of an embodiment of the present invention is shown. This embodiment relates to a material charging auxiliary device, a single crystal furnace system and a charging process. During the charging process, the material charging auxiliary device is suspended in the single crystal furnace, located above the quartz crucible, and the hot air flow in the furnace is gathered in the quartz crucible to seal the hot air flow, thereby increasing the temperature in the single crystal furnace, accelerating the melting of silicon raw materials, and shortening the charging time. The material charging auxiliary device is moved up and down to change the flow direction of the protective gas, and combined with the slag sticking process, the crystal growth success rate and the single crystal quality are improved.

[0058] A material auxiliary device, such as Figure 1-3As shown, it includes a connecting chuck 1, a connecting rod 2 connected to the connecting chuck 1, and a thermal insulation component connected to the connecting rod 2. The setting of the connecting rod 2 plays the role of connecting the skeleton, connecting the connecting chuck 1 and the thermal insulation component together to construct the overall structure of the material-making auxiliary device. The connecting chuck 1 is used to connect with the seed crystal chuck in the single crystal furnace to realize the suspension of the material-making auxiliary device in the single crystal furnace, and the thermal insulation component plays the role of assisting the material-making.

[0059] When in use, the auxiliary device for melting materials is connected to the seed crystal chuck in the single crystal furnace, suspended in the single crystal furnace, and located above the quartz crucible. The insulation component has a certain volume and can gather the hot air flow in the single crystal furnace into the quartz crucible. Due to the sealing of the hot air flow, the temperature in the single crystal furnace will gradually increase. The high temperature helps to melt the silicon raw material quickly, shortening the melting time, thereby reducing the melting power and reducing production costs.

[0060] In some feasible embodiments, preferably, the above-mentioned connecting chuck 1, connecting rod 2 and insulation component are coaxially arranged so that the material auxiliary device is always in a force balance state during the up and down movement in the single crystal furnace and maintains a stable state during the movement.

[0061] The above-mentioned heat preservation assembly includes a cover body 3 and a tray 4 connected to each other. The cover body 3 is connected to the tray 4. Both the cover body 3 and the tray 4 can move relative to the connecting rod. The tray 3 is clamped with the connecting rod 2. The connecting chuck 1 is clamped with the connecting rod 2. There is a accommodating space between the cover body 3 and the tray 4, which can be used for heat preservation and shielding the top of the quartz crucible, thereby gathering the hot air flow in the single crystal furnace. In some feasible embodiments, the cover body 3 and the tray 4 are snap-fitted, such as directly snapping the cover body 3 on the tray 4, or the cover body 3 and the tray 4 are connected by threads, or other detachable connection methods, which are selected according to actual needs and are not specifically required here.

[0062] In some feasible embodiments, preferably, the cover body 3 and the tray 4 are coaxially arranged, and the cover body 3 and the connecting rod 2 are coaxially arranged.

[0063] Specifically, Figure 4-5As shown, the cover body 3 is a shell structure with one end open, with a space inside, and the cover body 3 is provided with a first connecting through hole 30, through which the cover body 3 is inserted on the connecting rod 2. When the cover body 3 is installed on the connecting rod 2, one end of the connecting rod 2 passes through the first connecting through hole 30, so that the cover body 3 is inserted on the connecting rod 2, and the cover body 3 can move along the axial direction of the connecting rod 2. The outer diameter of one axial end of the cover body 3 is greater than the outer diameter of the other axial end, that is, the cover body 3 is a cone structure, and the peripheral side surface of the cover body 3 is a curved surface structure, and its cross-sectional shape is a straight line or an arc, which is selected according to actual needs, and no specific requirements are made here. In some feasible embodiments, preferably, the cross-sectional shape of the peripheral side surface of the cover body 3 is a straight line, that is, the cover body 3 is a frustum structure, the large diameter end of the cover body 3 is an open structure, so that the large diameter end of the cover body 3 is connected to the tray 4, the small diameter end of the cover body 3 is a planar structure, and the first connecting through hole 30 is provided on the end surface of the small diameter end, the first connecting through hole 30 is a through hole, which penetrates the small diameter end of the cover body 3, so that the two sides of the small diameter end of the cover body 3 are connected, so that the connecting rod 2 is connected to the cover body 3.

[0064] A cover body 3 with different diameters at both ends of the axial direction is used to affect the flow direction of the protective gas. The flow direction of the protective gas is changed so that the dust impurities in the single crystal furnace are discharged with the protective gas or blown into the quartz crucible. The slag sticking process is used to stick the slag and remove impurities in the melt in the quartz crucible, thereby avoiding the impurity bulging phenomenon during the single crystal pulling process, thereby improving the crystal growth success rate and the single crystal quality.

[0065] In order to ensure that the auxiliary device for material charging is stably suspended in the single crystal furnace, the first connecting through hole 30 is coaxially arranged with the cover body 3, that is, the cover body 3 is an axisymmetric structure, so that the auxiliary device for material charging is subjected to balanced force.

[0066] The cover body 3 has a certain height along the axial direction, so that the cover body 3 has a certain internal space, so that after the cover body 3 and the tray 4 are buckled and connected, a receiving space is formed.

[0067] The shape of the first connecting through hole 30 can be circular, square, polygonal, or other shapes, which can be selected according to actual needs, and no specific requirements are made here. In some feasible embodiments, preferably, the shape of the first connecting through hole 30 is adapted to the shape of the connecting rod 2, and the diameter of the first connecting through hole 30 is not less than the outer diameter of the connecting rod 2, so that the connecting rod 2 passes through the first connecting through hole 30, so that the cover body 3 is penetrated on the connecting rod 2.

[0068] like Figure 8As shown, the above-mentioned connecting rod 2 includes a rod body 20 and a first abutment 21 and a second abutment 22 arranged at both ends of the rod body 20. The first abutment 21, the rod body 20 and the second abutment 22 are coaxially arranged. The outer diameter of the first abutment 21 is greater than the outer diameter of the rod body 20. The rod body 20 is a rod structure with a certain length. The cross-sectional shape of the rod body 20 can be circular, square, or other shapes, which can be selected according to actual needs. No specific requirements are made here. The first abutment 21 and the second abutment 22 are both fixedly connected to the rod body 20. The fixed connection method is preferably integrally formed, so that the structure of the connecting rod 2 is stable and the service life of the connecting rod 2 is extended.

[0069] The first abutment 21 is provided so that the connecting rod 2 is connected to the tray 4 , and the first abutment 21 abuts and cooperates with the tray 4 . The second abutment 22 is provided so that the connecting rod 2 is connected to the connecting clamp 1 , and the second abutment 22 abuts and cooperates with the connecting clamp 1 .

[0070] In order to facilitate the preparation of the first abutment 21 and the second abutment 22 , the first abutment 21 is fixedly connected to the rod body 20 via a transition portion, and the second abutment 22 is fixedly connected to the rod body 20 via a transition portion, and the transition portion is a conical structure.

[0071] To facilitate the second abutment 22 to pass through the first connecting hole 30 and move along the rod body 20 , the diameter of the first connecting hole 30 is not less than the maximum outer diameter of the second abutment 22 , and the diameter of the first connecting hole 30 is not less than the maximum outer diameter of the rod body 20 .

[0072] like Figure 6-7 As shown, the above-mentioned tray 4 is a box structure with an open end, having an internal space, and its cross-sectional shape can be circular, square, or other shapes, which can be selected according to actual needs, and no specific requirements are made here. The shape of the open end of the tray 4 is adapted to the shape of the large diameter end (open end) of the cover body 3. A stopper structure is provided on the axial end face of the open end of the tray 4, and a corresponding stopper structure is provided on the end face of the large diameter end of the cover body 3, so that the large diameter end of the cover body 3 is buckled at the open end of the tray 4, realizing the buckling connection between the cover body 3 and the tray 4. With the help of the internal space of the tray 4 and the internal space of the cover body 3, a accommodating space between the cover body 3 and the tray 4 is constructed.

[0073] In order to realize the connection between the connecting rod 2 and the tray 4, the tray 4 is provided with a second connecting through hole 41 and a first abutment hole 42. The second connecting through hole 41 is connected to the first abutment hole 42. The diameter of the first abutment hole 42 is larger than the diameter of the second connecting through hole 41. The outer diameter of the first abutment member 21 is larger than the diameter of the second connecting through hole 41. The tray 4 is passed through the second connecting through hole 41 and the first abutment hole 42 on the connecting rod 2, and the first abutment member 21 is located in the first abutment hole 42, and the first abutment member 21 abuts and cooperates with the first abutment hole 42. In order to realize the second abutment member 22 passing through the second connecting through hole 41, the diameter of the second connecting through hole 41 is not less than the maximum outer diameter of the second abutment member 22.

[0074] In some feasible embodiments, preferably, the second connecting through hole 41 and the first abutting hole 42 are coaxially arranged with the tray 4 so that the tray 4 is subjected to balanced force during movement.

[0075] A boss 40 is provided on the inner side surface of the bottom wall of the tray 4, and the boss 40 is protruding from the inner side surface of the bottom wall of the tray 4. A second connecting through hole 41 and a first abutting hole 42 are provided on the boss 40. The second connecting through hole 41 is formed by the inward depression of the free end surface of the boss 40, and the diameter of the second connecting through hole 41 is larger than the outer diameter of the rod body 20. At the same time, the diameter of the second connecting through hole 41 is larger than the maximum outer diameter of the second abutting member 22, and the diameter of the second connecting through hole 41 is larger than the maximum outer diameter of the transition portion between the second abutting member 22 and the rod body 20, so that the rod body 20, the second abutting member 22 and the transition portion can pass through the second connecting through hole 41, so that the tray 4 is passed through the connecting rod 2 and moves along the connecting rod 2. The first abutment hole 42 is formed by the other side surface of the boss 40 being recessed inwardly, that is, the first abutment hole 42 is a hole structure formed by the outer surface of the bottom wall of the tray 4 being recessed inwardly, and the first abutment hole 42 is connected to the second connecting through hole 41, and the diameter of the first abutment hole 42 is larger than the diameter of the second connecting through hole 41, and the first abutment hole 42 and the second connecting through hole 41 form a stepped hole structure, and the shape of the first abutment hole 42 is adapted to the shape of the first abutment member 21, and the size of the first abutment hole 42 is not smaller than the size of the first abutment member 21, so that the first abutment member 21 can be located in the first abutment hole 42, and the first abutment member 21 is abutted in the first abutment hole 42 and will not enter the second connecting through hole 41, thereby installing the tray 4 on the connecting rod 2.

[0076] In some feasible embodiments, preferably, the second connecting through hole 41 is a tapered hole so as to accommodate the transition portion between the first abutment member 21 and the rod body 20 .

[0077] The second connecting through hole 41 , the first abutting hole 42 , and the boss 40 are coaxially arranged with the tray 4 .

[0078] like Figure 9-13As shown, the above-mentioned connecting chuck 1 includes a chuck body 10, a mounting channel 11 provided on the chuck body 10, a second abutment hole 13 provided on the chuck body 10, and a mounting hole 12. The mounting channel 11 is provided on the peripheral side wall of the chuck body 10, and the mounting channel 11 is connected with the second abutment hole 13. The second abutment hole 13 is connected with the outside of one axial end of the chuck body 10, so that the connecting rod 2 passes through the mounting channel 11 and enters the second abutment hole 13, and the second abutment member 22 abuts and cooperates with the second abutment hole 13. The chuck body 10 is a columnar structure, so as to facilitate the arrangement of the mounting channel 11, the second abutment hole 13 and the mounting hole 12. The cross-sectional shape of the chuck body 10 can be circular, square, or other shapes, which can be selected according to actual needs. No specific requirements are made here. Preferably, in some feasible embodiments, the cross-sectional shape of the chuck body 10 is circular, and the chuck body 10 is a cylindrical structure.

[0079] The arrangement of the above-mentioned mounting channel 11 facilitates the connection between the connecting rod 2 and the connecting chuck 1. The mounting channel 11 is arranged on the peripheral side wall of the chuck body 10, and is arranged along the axial direction of the chuck body 10, and has a certain length, and is recessed inward from the peripheral side surface of the chuck body 10 until it is connected with the second abutment hole 13, forming a mounting channel 11 structure, and the length of the mounting channel 11 along the axial direction of the chuck body 10 is not less than the length of the second abutment hole 13 along the axial direction of the chuck body 10, and the width of the mounting channel 11 along the circumferential direction of the chuck body 10 is not less than the maximum outer diameter of the second abutment member 22, so that the second abutment member 22 can pass through the mounting channel 11 into the second abutment hole 13, and abut against the second abutment hole 13, thereby realizing the connection between the connecting rod 2 and the connecting chuck 1.

[0080] The shape of the projection of the mounting channel 11 on the plane where the axis of the chuck body 10 is located (the plane perpendicular to the axial end face) can be square, that is, the side wall of the mounting channel 11 is perpendicular to the plane where the axis of the chuck body 10 is located, or the shape of the projection of the mounting channel 11 on the plane where the axis of the chuck body 10 is located (the plane perpendicular to the axial end face) can be trapezoidal, that is, the side wall of the mounting channel 11 is arranged to be obliquely intersected with the plane where the axis of the chuck body 10 is located, the side wall of the mounting channel 11 is an inclined surface, the opening width of the mounting channel 11 on the outer side surface of the chuck body 10 (along the circumferential direction of the chuck body 10) is greater than the opening width of the mounting channel 11 at the intersection with the second abutment hole 13, and the specific structure of the mounting channel 11 is selected and set according to actual needs, and no specific requirements are made here. Regardless of the structure of the mounting channel 11 , the width of the mounting channel 11 at the intersection with the second abutment hole 13 is smaller than the diameter of the second abutment hole 13 , so that the second abutment member 22 can be snapped into the second abutment hole 13 to achieve effective connection between the connecting rod 2 and the connecting clamp 1 .

[0081] The second abutment hole 13 is a hole structure, and the second abutment hole 13 is coaxially arranged with the chuck body 10, and the shape of the second abutment hole 13 is adapted to the shape of the second abutment member 22, and the second abutment hole 13 is formed by an inward depression of an axial end surface of the chuck body 10. Since the second abutment member 22 includes an abutment portion and a connecting portion connected to each other, the abutment portion and the connecting portion are coaxially arranged, the abutment portion is arranged at one end of the connecting portion, the other end of the connecting portion is connected to the transition portion, and the other end of the transition portion is connected to the rod body 20, therefore, the second abutment hole 13 includes a first accommodating hole for accommodating the abutment portion and a second accommodating hole for accommodating the connecting portion, the first accommodating hole is connected with the second accommodating hole, and the first accommodating hole is coaxially arranged with the second accommodating hole, the shape and size of the first accommodating hole are adapted to the shape of the abutment portion, the shape and size of the second accommodating hole are adapted to the shape and size of the connecting portion, the connecting portion is located in the second accommodating hole, and the connecting portion extends out of the second accommodating hole, so that the connecting portion is connected to the transition portion, and the transition portion does not contact the chuck body 10, and does not interfere.

[0082] The above-mentioned mounting hole 12 is coaxially arranged with the second abutment hole 13, and the mounting hole 12 is communicated with the second abutment hole 13, and the mounting hole 12 is communicated with the outside of the other axial end of the chuck body 10, so that the mounting hole 12 is connected to the seed crystal chuck. The mounting hole 12 is a hole structure formed by the inward recess of the end surface of the other axial end of the chuck body 10. In order to facilitate the connection between the mounting hole 12 and the seed crystal chuck, the mounting hole 12 is preferably a threaded hole, so that the connecting chuck 1 is threadedly connected to the seed crystal chuck.

[0083] In order to maintain the force balance of the connecting chuck 1 during the movement, the chuck body 10, the mounting hole 12, and the second abutting hole 13 are coaxially arranged.

[0084] A further optimization scheme is adopted. In order to enhance the heat preservation function of the chemical auxiliary device, a heat preservation component 5 is provided in the accommodation space between the cover body 3 and the tray 4. The shape of the heat preservation component 5 is adapted to the shape of the accommodation space, and the heat preservation component 5 is provided with a through hole so that the connecting rod 2 can pass through the through hole. The heat preservation component 5 is connected to the connecting rod 2 to avoid interference of the heat preservation component 5 with the connection between the connecting rod 2 and the tray 4 and the cover body 3.

[0085] The materials of the connecting rod 2, the connecting chuck 1, the heat-insulating assembly and the heat-insulating member 5 are all graphite, so as to avoid the introduction of new impurities during the single crystal pulling process.

[0086] When the chemical auxiliary device is in use, it is first assembled, the heat preservation member 5 is placed on the tray 4, and then the cover body 3 is buckled on the tray 4, so that the heat preservation member 5 is located in the accommodating space between the tray 4 and the cover body 3, the first abutting hole 42, the second connecting through hole 41, the through hole on the heat preservation member 5 and the first connecting through hole 30 on the cover body 3 are coaxially arranged, and the first abutting hole 42, the second connecting through hole 41, the through hole on the heat preservation member 5 and the first connecting through hole 30 on the cover body 3 are connected, and one end of the connecting rod 2 provided with the second abutting member 22 passes through the first abutting hole 42, the second connecting through hole 41, the through hole and the first connecting through hole 30 in sequence. The connecting hole 30 is extended out of the cover body 3 until the first abutment member 21 is located in the first abutment hole 42, and the first abutment member 21 abuts against the first abutment hole 42, and the second abutment member 22 passes through the installation channel 11 of the connecting clamp 1 until it is located in the second abutment hole 13, and the second abutment member 22 abuts against the second abutment hole 13, forming a chemical auxiliary device structure, and utilizing the gravity of the cover body 3, the tray 4 and the thermal insulation member 5, and the connecting rod 2, so that the assembly structure composed of the cover body 3, the tray 4 and the thermal insulation member 5 is suspended under the connecting clamp 1 through the connecting rod 2, and no bolts or other connecting parts are required for fixed assembly, the structure is simple, and installation and disassembly are convenient.

[0087] A single crystal furnace system includes a single crystal furnace main body and a material charging auxiliary device as described above, which is arranged in the single crystal furnace main body. The material charging auxiliary device is connected to a seed crystal chuck in the single crystal furnace main body and is suspended in the single crystal furnace main body. When the material charging auxiliary device is connected to the seed crystal chuck, the seed crystal chuck is connected to a mounting hole 12 through a threaded connection, and the seed crystal chuck is connected to a steel cable. The material charging auxiliary device is suspended in the single crystal furnace, and the steel cable is connected to a crystal lifting mechanism. Under the driving action of the crystal lifting mechanism, the material charging auxiliary device can be raised and lowered in the single crystal furnace.

[0088] The distance between the outer wall of the insulation component of the above-mentioned material-chemical auxiliary device and the inner wall of the guide tube in the single crystal furnace body is 20-60mm, that is, the outer diameter of the material-chemical auxiliary device is smaller than the inner diameter of the guide tube in the single crystal furnace, so that when the material-chemical auxiliary device moves up and down in the single crystal furnace, the material-chemical auxiliary device will not touch the guide tube, and there will be no movement interference between the material-chemical auxiliary device and the guide tube.

[0089] The distance from the bottom side of the insulation component of the above-mentioned material-chemical auxiliary device to the surface of the melt in the quartz crucible in the single crystal furnace main body is 10-30mm, that is, the distance between the side of the material-chemical auxiliary device facing the silicon melt in the quartz crucible and the liquid level of the silicon melt is 10-30mm. This distance is also the lowest position of the material-chemical auxiliary device during its movement in the main chamber of the single crystal furnace, which prevents the material-chemical auxiliary device from contacting the silicon melt in the quartz crucible during its up and down movement, and at the same time blocks the hot air flow, thereby facilitating the gathering of the hot air flow in the single crystal furnace in the quartz crucible.

[0090] A chemical process, using the above-mentioned single crystal furnace system to pull a single crystal, comprises:

[0091] Before the material is chemically processed, the chemically processed auxiliary device is installed in the single crystal furnace, and then the single crystal is pulled and the chemically processed process is carried out;

[0092] In the initial stage of the material smelting, the protective gas is introduced at a first flow rate, where the protective gas is argon, and the first flow rate of the protective gas is 120-160slpm. The flow rate of the protective gas is selected and set according to actual needs, and no specific requirements are made here. At the same time, in the initial stage of the material smelting, the distance from the side of the material smelting auxiliary device facing the quartz crucible to the surface of the melt in the quartz crucible is always kept at a first distance to carry out the material smelting, that is, in the initial stage of the material smelting, the material smelting auxiliary device remains stationary, and the material smelting auxiliary device is located above the quartz crucible to block the rise of the hot air flow, and gather the hot air flow in the single crystal furnace in the quartz crucible. Since the hot air flow is sealed between the material smelting auxiliary device and the quartz crucible, the temperature in the single crystal furnace gradually increases, which is conducive to accelerating the melting of the silicon raw material and shortening the material smelting time.

[0093] The above-mentioned first distance is 10-30 mm. The size of the first distance is selected according to actual needs and no specific requirements are made here.

[0094] After the initial stage of the material smelting is completed, the first stage of the material smelting is entered. In the first stage of the material smelting, the protective gas is introduced at a first flow rate, and the auxiliary device for material smelting is controlled to move up and down to purge the dust in the single crystal furnace. Here, the first flow rate of the protective gas is 120-160slpm. The flow rate of the protective gas is selected and set according to actual needs, and no specific requirements are made here. Since the cover body 3 of the auxiliary device for material smelting is a cone structure, the flow direction of the protective gas entering from the top of the auxiliary chamber of the single crystal furnace is changed, which affects the airflow direction of the protective gas in the single crystal furnace, and the excess dust impurities in the single crystal furnace are purged, so that the impurities flow with the protective gas, and the impurities are purged out along the outlet of the protective gas, or the dust impurities are blown into the quartz crucible, and the impurities are cleaned out in combination with the subsequent slag sticking process to avoid the phenomenon of impurity bulging during the single crystal pulling process and improve the crystallization rate.

[0095] The material-making auxiliary device moves up and down along the axial direction of the auxiliary chamber through the crystal lifting mechanism and the steel cable, and moves up and down in the main chamber and the auxiliary chamber of the single crystal furnace. When the material-making auxiliary device moves up and down, it is set as follows: along the direction from the quartz crucible to the auxiliary chamber, the distance from the surface of the melt in the quartz crucible to 10-30mm is the initial position, and the distance from the lower edge of the auxiliary chamber to the middle of the auxiliary chamber to 100-2000mm is the first position. Between the initial position and the lower edge of the auxiliary chamber, the material-making auxiliary device moves at a first speed, and between the lower edge of the auxiliary chamber and the first position, the material-making auxiliary device moves at a second speed, and the second speed is greater than the first speed, that is, in the main chamber of the single crystal furnace, it moves slowly, and the material-making auxiliary device changes the flow direction of the protective gas while keeping warm. In the auxiliary chamber of the single crystal furnace, it moves at a higher speed, changes the flow direction of the protective gas, and purges the dust and impurities in the auxiliary chamber.

[0096] The above-mentioned first speed is 200-350 mm / h. The size of the first speed is selected according to actual needs and no specific requirements are made here.

[0097] The above-mentioned second speed is 350-550 mm / h. The size of the second speed is selected according to actual needs and no specific requirements are made here.

[0098] After the first stage of material processing, the second stage of material processing begins. In the second stage of material processing, slag sticking is performed to remove impurities in the silicon melt to improve the crystallization rate of single crystals. In the second stage of material processing, the silicon raw material is completely melted. As the material block melts, some flake and block impurities flow with the rotation of the quartz crucible, thereby floating at the center of the melt surface. Slag sticking is required to remove impurities and remove impurities in the silicon melt to improve the crystallization rate. In the second stage of material processing, the auxiliary device for material processing is removed and the seed crystal is installed. When the slag sticking is performed, it includes:

[0099] Lower the seed crystal. When the seed crystal contacts the impurities in the melt, continue to lower the seed crystal by a second distance and stay for the first time, so that the seed crystal and the impurity block are fused. The second distance is the distance that the contact point of the seed crystal with the impurities in the silicon melt moves downward. The second distance is 2-10 mm, and the first time is 2-10 min. The second distance and the first time are selected according to actual needs, and no specific requirements are made here.

[0100] After the seed crystal is fused with the impurity block, the seed crystal is raised at a third speed. When the seed crystal rises to the second position, it stays for a second time. The third speed is 100-150 mm / h. The third speed is selected according to actual needs. No specific requirements are made here. The second position is 5-10 mm above the melt surface in the quartz crucible. The second time is 2-10 min. The second time is selected according to actual needs. No specific requirements are made here.

[0101] Determine whether the impurity block falls off from the seed crystal, and observe whether the impurity block falls off from the seed crystal through the window of the single crystal furnace. If not, the seed crystal is raised at the fourth speed, and the seed crystal is cooled after entering the sub-chamber. After cooling, the impurity block is taken out. The fourth speed is 400-600 mm / h, and the cooling time is 30-60 min. Preferably, the fourth speed is 500 mm / h. The fourth speed and the cooling time are selected according to actual needs, and no specific requirements are made here;

[0102] If the impurity blocks fall off, repeat the above steps to remove the slag again.

[0103] From the beginning of the material-making process to the last re-dosing, until all the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials remain on the surface of the silicon melt, this stage is set as the initial material-making stage, that is, multiple re-dosing is required in the material-making stage to reach the required weight of silicon melt. The initial material-making stage is the process from the beginning of the material-making process to the first time node. The first time node is: after the last re-dosing is completed, until all the silicon raw materials in contact with the inner wall of the quartz crucible in the quartz crucible are melted, the silicon raw materials in the silicon melt are not in contact with the inner wall of the quartz crucible, and at the same time, 70%-80% of the silicon raw materials remain on the surface of the silicon melt. At the first time node, the initial material-making stage ends and enters the first material-making stage. The first time node divides the initial material-making stage and the first material-making stage;

[0104] From the last re-addition until the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials on the surface of the silicon melt remain until 10%-20% of the silicon raw materials on the surface of the silicon melt remain, this stage is set as the first stage of material initiation, that is, after the initial stage of material initiation ends, the first stage of material initiation begins, until 10%-20% of the silicon raw materials on the surface of the silicon melt remain, the first stage of material initiation ends, and the second stage of material initiation begins;

[0105] From the time when 10%-20% of silicon raw materials remain on the surface of the silicon melt to the end of the material-making process, this stage is set as the second material-making stage, that is, after the end of the first material-making stage, the second material-making stage is entered, and slag sticking is carried out in the second material-making stage until the end of the material-making process, the slag sticking is completed, and the next process (crystal seeding process) is entered.

[0106] Compared with the existing process without the auxiliary device for material smelting, the above-mentioned material smelting device is used for material smelting and combined with the slag sticking process. Under the conditions of using the same furnace, the same heat field size and pulling single crystals of the same size, without changing the single crystal growth process, growth equipment and growth environment, the average difference in the thickness of the inner wall of the quartz crucible before and after use, the material smelting power, the average material smelting time, the average oxygen content of the crystal and the average carbon content of the crystal are all reduced, and the success rate of crystal growth is improved. The specific parameter analysis is shown in the following table:

[0107]

[0108] From the above table, we can know that the material fusion time is reduced by about 3 hours, the material fusion power is reduced by about 13Kw, abnormal phenomena such as edge hanging and bridging are significantly reduced, and the crystal growth success rate is increased from 50% to 75%.

[0109] Due to the adoption of the above technical solution, the cover of the material-making auxiliary device is buckled and connected with the tray, the cover is inserted into the connecting rod, the connecting rod is clamped with the tray, and the connecting rod is clamped with the connecting chuck, and no bolts or other connecting parts are required for fixed connection, the structure is simple, and installation and disassembly are convenient; the material-making auxiliary device is installed in the single crystal furnace during the material-making stage, located above the quartz crucible, to assist in material-making, and to gather the hot air flow in the single crystal furnace into the quartz crucible, so that the temperature in the single crystal furnace is increased, the melting of silicon raw materials is accelerated, and abnormal phenomena such as edge hanging and bridging are significantly reduced, thereby shortening the material-making time; at the same time By moving the material auxiliary device up and down in the single crystal furnace, the flow direction of the protective gas is changed, so that dust impurities are discharged with the protective gas or blown into the quartz crucible. Combined with the slag sticking process, impurities in the silicon melt are removed to avoid the phenomenon of impurity bulging during the single crystal pulling process, effectively reducing the amount of dissolution of the inner wall of the quartz crucible, increasing the service life of the quartz crucible, and reducing the probability of silicon leakage and deformation during crystal growth. At the same time, it can reduce the introduction of impurities into the melt due to the dissolution of the inner wall of the quartz crucible, thereby improving the success rate of crystal growth and the quality of single crystals.

[0110] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A material auxiliary device, characterized in that: It includes a connecting clamp, a connecting rod connected to the connecting clamp, and an insulation component connected to the connecting rod. The insulation component includes a cover body and a tray connected to each other. The cover body is connected to the tray. Both the cover body and the tray can move relative to the connecting rod. The tray is clamped with the connecting rod, the connecting clamp is clamped with the connecting rod, and there is a accommodating space between the cover body and the tray.

2. The material auxiliary device according to claim 1, characterized in that: The connecting rod comprises a rod body and a first abutment and a second abutment arranged at two ends of the rod body. The first abutment, the rod body and the second abutment are coaxially arranged, and the outer diameter of the second abutment is greater than the outer diameter of the rod body.

3. The material auxiliary device according to claim 2, characterized in that: The cover body is provided with a first connecting through hole, and the cover body is penetrated on the connecting rod through the first connecting through hole.

4. The material auxiliary device according to claim 3, characterized in that: The first connecting through hole is coaxially arranged with the cover body, and the outer diameter of one axial end of the cover body is larger than the outer diameter of the other axial end.

5. The material auxiliary device according to claim 2, characterized in that: The tray is provided with a second connecting through hole and a first abutment hole, the second connecting through hole is connected with the first abutment hole, the diameter of the first abutment hole is larger than the diameter of the second connecting through hole, the outer diameter of the first abutment piece is larger than the second connecting through hole, the tray is passed through the second connecting through hole and the first abutment hole on the connecting rod, the first abutment piece is located in the first abutment hole, and the first abutment piece abuts and cooperates with the first abutment hole.

6. The material auxiliary device according to any one of claims 2 to 5, characterized in that: The connecting chuck includes a chuck body, a mounting channel provided on the chuck body, a second abutment hole provided on the chuck body, and a mounting hole, the mounting channel is connected with the second abutment hole, the mounting channel is provided on the peripheral side wall of the chuck body, the second abutment hole is connected with the outside of one axial end of the chuck body, the second abutment hole is coaxially arranged with the chuck body, so that the second abutment member passes through the mounting channel and enters the second abutment hole, and the second abutment member abuts and cooperates with the second abutment hole.

7. The material auxiliary device according to claim 6, characterized in that: The length of the mounting channel along the axial direction of the chuck body is not less than the length of the second abutment hole along the axial direction of the chuck body, the width of the mounting channel along the circumferential direction of the chuck body is not less than the maximum outer diameter of the second abutment piece, and the width of the mounting channel along the circumferential direction of the chuck body at the intersection with the second abutment hole is not greater than the diameter of the second abutment hole.

8. The material auxiliary device according to claim 7, characterized in that: The mounting hole is coaxially arranged with the second abutting hole, and the mounting hole is communicated with the second abutting hole. The mounting hole is communicated with the outside of the other axial end of the chuck body so as to be connected with the seed crystal chuck.

9. The material auxiliary device according to any one of claims 1-5 and 7-8, characterized in that: A heat preservation component is arranged in the accommodating space, and the heat preservation component is connected to the connecting rod.

10. The material auxiliary device according to claim 9, characterized in that: The connecting rod, the connecting clamp, the heat-insulating assembly and the heat-insulating part are all made of graphite.

11. A single crystal furnace system, characterized in that: It comprises a single crystal furnace main body and a material-forming auxiliary device as described in claims 1 to 10 arranged in the single crystal furnace main body, wherein the material-forming auxiliary device is connected to a seed crystal chuck in the single crystal furnace main body and is suspended in the single crystal furnace main body.

12. The single crystal furnace system according to claim 11, characterized in that: The distance between the peripheral side wall of the insulation component of the material auxiliary device and the inner side wall of the guide tube in the single crystal furnace body is 20-60 mm.

13. The single crystal furnace system according to claim 12, characterized in that: The distance from the bottom side of the insulation component of the material auxiliary device to the surface of the melt in the quartz crucible in the single crystal furnace body is 10-30 mm.

14. A chemical material process, characterized in that: The single crystal pulling is performed using the single crystal furnace system as claimed in any one of claims 11 to 13, comprising: In the initial stage of material charging, the protective gas is introduced at a first flow rate, and the distance from the side of the material charging auxiliary device facing the quartz crucible to the surface of the melt in the quartz crucible is always kept at a first distance to perform material charging; In the first stage of material processing, the protective gas is introduced at a first flow rate, and the material processing auxiliary device is controlled to move up and down to purge the dust in the single crystal furnace; In the second stage of material processing, slag removal is carried out.

15. The chemical process according to claim 14, characterized in that: The first flow rate of the protective gas is 120-160 slpm.

16. The chemical process according to claim 15, characterized in that: The first distance is 10-30 mm.

17. The chemical process according to any one of claims 14 to 16, characterized in that: When the material-making auxiliary device moves up and down, it is set as follows: along the direction from the quartz crucible to the auxiliary chamber, the distance from the surface of the melt in the quartz crucible to 10-30 mm is the initial position, the distance from the lower edge of the auxiliary chamber to the middle of the auxiliary chamber to 100-2000 mm is the first position, the material-making auxiliary device moves at a first speed between the initial position and the lower edge of the auxiliary chamber, and moves at a second speed between the lower edge of the auxiliary chamber and the first position, and the second speed is greater than the first speed.

18. The chemical process according to claim 17, characterized in that: The first speed is 200-350 mm / h, and the second speed is 350-550 mm / h.

19. The chemical process according to any one of claims 14 to 18, characterized in that: When carrying out slag sticking, it includes: Lowering the seed crystal, and when the seed crystal contacts the impurities in the melt, continuing to lower the seed crystal by a second distance and staying for the first time, so that the seed crystal and the impurity block are welded; After the seed crystal is fused with the impurity block, the seed crystal is raised at a third speed, and when the seed crystal rises to the second position, it stays for a second time; It is determined whether the impurity block has fallen off from the seed crystal. If not, the seed crystal is raised at the fourth speed, and the seed crystal is cooled after entering the auxiliary chamber. After cooling, the impurity block is taken out.

20. The chemical process according to claim 19, characterized in that: The second distance is 2-10 mm, and the first time is 2-10 min.

21. The chemical process according to claim 20, characterized in that: The third speed is 100-150 mm / h, the second position is 5-10 mm above the melt surface in the quartz crucible, and the second time is 2-10 min.

22. The material chemical process according to claim 21, characterized in that: The fourth speed is 400-600 mm / h, and the cooling time is 30-60 min.

23. The material chemical process according to claim 14, characterized in that: From the start of the material-making process to the last re-feeding, until all the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials remain on the surface of the silicon melt, this stage is set as the initial stage of material-making; From the last re-addition until the silicon raw materials in contact with the inner wall of the quartz crucible are melted and 70%-80% of the silicon raw materials on the surface of the silicon melt remain to 10%-20% of the silicon raw materials on the surface of the silicon melt, this stage is set as the first stage of the material smelting; The stage from when 10%-20% of the silicon raw material remains on the surface of the silicon melt to the end of the material-making process is set as the second material-making stage.

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