Growth equipment of monocrystalline silicon

Abstract

The invention provides monocrystalline silicon growth equipment, which comprises a crucible assembly used for accommodating a silicon material; the heating assembly is arranged on the outer side of the crucible assembly to heat the silicon material contained in the crucible assembly and comprises a first heater located on the periphery of the crucible assembly; the heat insulation assembly is annularly arranged on the outer side of the crucible assembly and extends in the height direction, and the heat insulation assembly upwards extends to the lower side of the first heater and downwards extends out of the bottom end of a crucible support of the crucible assembly. The growth equipment for monocrystalline silicon can effectively reduce the temperature of the bottom of the crucible and reduce the content of oxygen impurities.

Description

Technical Field

[0001] The present invention relates to the technical field of single crystal silicon, and in particular to a single crystal silicon growth device. Background Art

[0002] At present, with the pursuit of high photoelectric conversion efficiency and the requirement of reducing costs in solar energy technology, N-type monocrystalline silicon wafers are widely used, and topcon (Tunnel Oxide Passivated Contact) technology is constantly developing. However, topcon battery technology will produce a certain proportion of oxygen rings, which has high requirements for oxygen content. Therefore, reducing the oxygen content in silicon rods has become the main technical difficulty at present. The main method to reduce the oxygen content is to reduce the temperature of the inner surface of the crucible in contact with the silicon material, especially the temperature of the bottom of the crucible. Therefore, how to reduce the temperature of the bottom of the crucible is an urgent problem that the industry needs to solve.

[0003] In view of this, it is necessary to improve the existing single crystal silicon growth equipment to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a single crystal silicon growth device which can effectively lower the crucible bottom temperature and reduce the oxygen impurity content.

[0005] To achieve the above-mentioned object of the invention, the present invention provides a single crystal silicon growth device, comprising:

[0006] A crucible assembly for containing silicon material;

[0007] A heating assembly, disposed outside the crucible assembly to heat the silicon material contained in the crucible assembly, comprising a first heater located outside the crucible assembly;

[0008] The heat insulation component is annularly arranged outside the crucible component and extends in the height direction. The heat insulation component extends upward to the lower side of the first heater and extends downward beyond the bottom end of the crucible support of the crucible component.

[0009] As a further improvement of the present invention, the single crystal silicon growth equipment also includes an insulation component arranged on the outside of the crucible assembly, the insulation component includes a bottom insulation wall located on the lower side of the crucible assembly, the insulation component includes a first insulation ring supported on the bottom insulation wall, and the first insulation ring extends upward from the bottom insulation wall beyond the top of the crucible support.

[0010] As a further improvement of the present invention, the heating assembly further comprises a second heater located at the lower side of the crucible assembly, and the first insulation ring extends downwardly beyond the second heater.

[0011] As a further improvement of the present invention, the first thermal insulation ring includes an upper thermal insulation ring and a lower thermal insulation ring connected up and down, the outer diameter of the upper thermal insulation ring is not larger than the outer diameter of the first heater, the inner diameter of the upper thermal insulation ring is larger than the outer diameter of the crucible of the crucible assembly, and the upper thermal insulation ring extends upward to the outside of the crucible.

[0012] As a further improvement of the present invention, the bottom end of the upper insulation ring is lower than the bottom end of the crucible support, and the inner diameter of the lower insulation ring is larger than the outer diameter of the crucible support.

[0013] As a further improvement of the present invention, in the up and down directions, the upper insulation ring is in the shape of a straight cylinder with the same inner diameter and outer diameter, the lower insulation ring is also in the shape of a straight cylinder with the same inner diameter and outer diameter, and the upper insulation ring extends straight upward from the lower insulation ring.

[0014] As a further improvement of the present invention, the upper insulation ring and the lower insulation ring have different inner diameters and outer diameters, the outer diameter of the lower insulation ring is smaller than the inner diameter of the first heater, and the first insulation ring also has a connecting ring connecting the upper insulation ring and the lower insulation ring.

[0015] As a further improvement of the present invention, the thermal insulation assembly also includes a second thermal insulation ring connected to the crucible support, the second thermal insulation ring is located on the inner side of the lower thermal insulation ring in the radial direction of the crucible assembly, and at least partially overlaps with the lower thermal insulation ring in the height direction.

[0016] As a further improvement of the present invention, the lower end edge of the second heat insulation ring is not higher than the lower end edge of the tray arranged at the top end of the support rod.

[0017] As a further improvement of the present invention, the thermal insulation component is made of one or more materials selected from the group consisting of graphite, quartz, silicon nitride, aluminum oxide, ceramic material, and graphite fiber.

[0018] Beneficial effects of the present invention: The single crystal silicon growth equipment of the present invention arranges a heat insulation component extending in the height direction on the outer side of the crucible assembly, and the heat insulation component extends upward to the lower side of the first heater and extends downward beyond the bottom end of the crucible support of the crucible assembly, thereby effectively reducing the heat radiated from the first heater to the bottom of the crucible by adding the heat insulation component at the bottom of the heat field, lowering the temperature of the bottom of the crucible, slowing down the reaction between the crucible and molten silicon, and significantly reducing the amount of silicon monoxide generated, thereby reducing the oxygen content in the crystal rod without affecting the overall structure of the existing heat field. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the first embodiment of the single crystal silicon growth equipment of the present invention.

[0020] Figure 2 It is a schematic structural diagram of a second embodiment of a single crystal silicon growth device of the present invention.

[0021] Figure 3 It is a schematic structural diagram of a third embodiment of a single crystal silicon growth device of the present invention.

[0022] In the figure:

[0023] 100. Single crystal silicon growth equipment;

[0024] 1. Crucible assembly; 11. Crucible; 12. Crucible shank; 13. Crucible support; 14. Support rod; 15. Tray;

[0025] 2. Heating assembly; 21. First heater; 23. Second heater;

[0026] 3. Insulation assembly; 31. First insulation ring; 311. Upper insulation ring; 312. Lower insulation ring; 313. Connecting ring; 32. Second insulation ring;

[0027] 4. Insulation assembly; 41. Bottom insulation wall; 42. Side insulation wall;

[0028] 5. Furnace body. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. However, the embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on the embodiments are all within the protection scope of the present invention.

[0030] The terms used herein, such as "upper", "lower", "left", "right", "front", "back", etc., which indicate relative positions in space, are used for the purpose of convenience to describe the relationship between one feature and another feature as shown in the drawings. It is understood that, depending on the placement of the product, the terms of relative positions in space may be intended to include different orientations in addition to the orientation shown in the drawings, and should not be construed as limitations on the claims. In addition, the descriptor "horizontal" used herein is not completely equivalent to being perpendicular to the direction of gravity, and a certain angle of inclination is allowed.

[0031] Please refer to Figures 1 to 3 The schematic diagrams of various embodiments of the single crystal silicon growth device of the present invention are shown, wherein Figure 1 is a schematic structural diagram of a first embodiment of a single crystal silicon growth device 100 of the present invention, Figure 2 is a schematic structural diagram of a second embodiment of a single crystal silicon growth device according to the present invention, Figure 3 It is a schematic structural diagram of a third embodiment of a single crystal silicon growth device of the present invention.

[0032] Please refer to Figures 1 to 3 As shown, the single crystal silicon growth device 100 of the present invention comprises:

[0033] A crucible assembly 1, which is used to contain silicon material;

[0034] A heating assembly 2, arranged outside the crucible assembly 1 to heat the silicon material contained in the crucible assembly 1, comprising a first heater 21 located outside the crucible assembly 1;

[0035] The heat insulation component 3 is annularly arranged outside the crucible component 1 and extends in the height direction. The heat insulation component 3 extends upward to the lower side of the first heater 21 and extends downward beyond the bottom end of the crucible support 13 of the crucible component 1.

[0036] In this way, the single crystal silicon growth equipment 100 of the present invention is provided with a heat insulation component 3 extending in the height direction on the outer side of the crucible assembly 1, and the heat insulation component 3 extends upward to the lower side of the first heater 21 and extends downward beyond the bottom end of the crucible support 13 of the crucible assembly 1, thereby effectively reducing the heat radiated from the first heater 21 to the bottom of the crucible 11 by adding the heat insulation component 3 at the bottom of the hot field, lowering the temperature of the bottom of the crucible 11, slowing down the reaction between the crucible 11 and the molten silicon, and significantly reducing the amount of silicon monoxide generated, thereby reducing the oxygen content in the crystal rod without affecting the overall structure of the existing hot field.

[0037] In the present invention, the thermal insulation component 3 is additionally provided below the first heater 21 to prevent the first heater 21 from transferring heat to the bottom of the crucible 11, thereby lowering the bottom temperature of the crucible 11, reducing the reaction between the crucible 11 and the silicon liquid, and reducing the introduction of silicon monoxide, thereby achieving the purpose of reducing the oxygen content. Through the technical solution described in the present invention, the bottom temperature of the crucible 11 can be reduced by more than 1K and the oxygen content can be reduced by 1ppma.

[0038] In one embodiment of the present invention, the single crystal silicon growth device 100 further has a furnace body 5, and the crucible assembly 1 is arranged in the furnace body 5 to accommodate silicon material. The crucible assembly 1 includes the crucible 11, a crucible 12 located at the periphery of the crucible 11, a crucible support 13 located at the bottom of the crucible 11, and a support rod 14 connected to the bottom of the crucible support 13, and a tray 15 is arranged at the top of the support rod 14. The single crystal silicon growth device 100 of the present invention reduces the oxygen release at the bottom of the crucible 11 by arranging a heat insulation assembly 3 near the crucible support 13 of the crucible assembly 1, thereby reducing the oxygen content entering the crystal rod, greatly improving the quality of the crystal rod, having a good oxygen reduction effect, and being able to effectively improve the production quality of single crystal silicon.

[0039] The single crystal silicon growth equipment 100 also includes an insulation component 4 arranged on the outside of the crucible assembly 1, the insulation component 4 includes a bottom insulation wall 41 located on the lower side of the crucible assembly 1, the insulation component 3 includes a first insulation ring 31 supported on the bottom insulation wall 41, the first insulation ring 31 extends upward from the bottom insulation wall 41 beyond the top of the crucible support 13, thereby effectively isolating the bottom of the crucible 11 from thermal radiation, reducing the temperature of the bottom of the crucible 11, slowing down the reaction of the crucible 11 with molten silicon, and reducing the oxygen impurity content.

[0040] The heat insulation assembly 3 is located between the first heater 21 and the bottom insulation wall 41 in the height direction. In this way, the heat radiation is effectively blocked at the bottom of the crucible 11, thereby avoiding the problem of excessive oxygen impurity content and poor crystal rod quality caused by excessively high temperature at the bottom of the crucible 11.

[0041] The heat preservation component 4 is located inside the furnace body 5 of the single crystal silicon growth device 100 to reduce the radiation of heat generated by the heating component 2 to the furnace wall. The heat preservation component 4 also includes a side heat preservation wall 42 located on the outer side of the crucible component 1 in the circumferential direction, and the side heat preservation wall 42 surrounds the periphery of the crucible component 1.

[0042] In some embodiments of the present invention, the heating assembly 2 also includes a second heater 23 located on the lower side of the crucible assembly 1, and the first insulation ring 31 extends downward beyond the second heater 23, so as to simultaneously isolate the outward heat radiation of the second heater 23 through the first insulation ring 31, thereby better avoiding the problem of excessive oxygen impurity content caused by excessive temperature at the bottom of the crucible 11.

[0043] The first thermal insulation ring 31 further has a groove body opened thereunder, and the first heater 21 is connected to the main electrode of the single crystal silicon growth device 100 through the groove body.

[0044] like Figures 1 to 3 As shown, in the first to third embodiments of the present invention, the first thermal insulation ring 31 includes an upper thermal insulation ring 311 and a lower thermal insulation ring 312 connected up and down, the outer diameter of the upper thermal insulation ring 311 is not larger than the outer diameter of the first heater 21, the inner diameter of the upper thermal insulation ring 311 is larger than the outer diameter of the crucible 12 of the crucible assembly 1, and the upper thermal insulation ring 311 extends upward to the outside of the crucible 12.

[0045] Furthermore, the bottom end of the upper insulation ring 311 is lower than the bottom end of the crucible support 13 , and the inner diameter of the lower insulation ring 312 is greater than the outer diameter of the crucible support 13 .

[0046] Please refer to Figure 1As shown, in the up-down direction, the upper heat-insulating ring 311 is in the shape of a straight tube with the same inner diameter and the same outer diameter, and the lower heat-insulating ring 312 is also in the shape of a straight tube with the same inner diameter and the same outer diameter. In the first embodiment of the present invention, the upper heat-insulating ring 311 is formed by extending straightly upward from the lower heat-insulating ring 312, that is, the inner diameter of the upper heat-insulating ring 311 is the same as the inner diameter of the lower heat-insulating ring 312, and the outer diameter of the upper heat-insulating ring 311 is also the same as the outer diameter of the lower heat-insulating ring 312. In this embodiment, the material of the first heat-insulating ring 31 can be CC fiber material.

[0047] like Figure 2 and Figure 3 As shown, in the second and third embodiments of the present invention, the upper thermal insulation ring 311 and the lower thermal insulation ring 312 have different inner diameters and outer diameters, the outer diameter of the lower thermal insulation ring 312 is smaller than the inner diameter of the first heater 21, and the first thermal insulation ring 31 also has a connecting ring 313 connecting the upper thermal insulation ring 311 and the lower thermal insulation ring 312.

[0048] Specifically, Figure 2 As shown, in the second embodiment of the present invention, the connecting ring 313 is in an arc shape, so that the upper insulation ring 311 and the connecting ring 313 are connected to form a bowl-shaped structure, and the bowl-shaped structure is adapted to the outer contour of the crucible assembly 1, and in this case, the material of the upper insulation ring 311 and the connecting ring 313 is CC fiber material, and the material of the lower insulation ring 312 is graphite material.

[0049] like Figure 3 As shown, in the third embodiment of the present invention, the connecting ring 313 extends straight in the radial direction of the crucible assembly 1, that is, the connecting ring 313 is arranged parallel to the horizontal plane. In this embodiment, the upper and lower insulation rings 311 and 312 are made of carbon ceramic material, and the connecting ring 313 is made of CC fiber material.

[0050] The upper insulation ring 311 and the connecting ring 313 are provided with grooves at positions corresponding to the foot plate of the first heater 21, and the grooves have a depth in the radial direction, thereby increasing the distance between the upper insulation ring 311 and the connecting ring 313 at positions corresponding to the foot plate of the first heater 21, and preventing sparks between the first heater 21 and the upper insulation ring 311 and the connecting ring 313; preferably, the recessed depth of the groove in the radial direction is 15 mm.

[0051] The heat insulation assembly 3 further comprises a second heat insulation ring 32 connected to the crucible support 13, the second heat insulation ring 32 is located inside the lower heat insulation ring 312 in the radial direction of the crucible assembly 1, and at least partially overlaps with the lower heat insulation ring 312 in the height direction. Figure 3From the perspective of FIG. 1 , the lower section of the second thermal insulation ring 32 and the lower thermal insulation ring 312 will overlap in the height direction, and the upper section of the second thermal insulation ring 32 and the upper thermal insulation ring 311 will overlap in the height direction, thereby achieving a double-layer heat radiation barrier for the bottom of the crucible 11, better preventing the bottom temperature of the crucible 11 from being too high, and avoiding the problem of excessive oxygen impurity content caused by the excessively high bottom temperature of the crucible 11.

[0052] Further, in this embodiment, the lower edge of the second thermal insulation ring 32 is not higher than the lower edge of the tray 15 disposed at the top of the support rod 14. That is, the lower edge of the second thermal insulation ring 32 is flush with the lower edge of the tray 15 or lower than the lower edge of the tray 15. Further, in some embodiments of the present invention, the second thermal insulation ring 32 is made of porous ceramic material and is connected to the bottom of the crucible support 13 by a fastener (not shown).

[0053] In some embodiments of the present invention, the thermal insulation component 3 is made of one or more materials selected from graphite, quartz, silicon nitride, alumina, ceramic material, and graphite fiber, so that it has good high temperature resistance, thereby effectively isolating the heat generated by the first heater 21 from radiating downward, lowering the temperature at the bottom of the crucible 11, and reducing the content of oxygen impurities.

[0054] To summarize, in the present invention, the single crystal silicon growth equipment 100 is provided with an insulation component 3 extending in the height direction on the outer side of the crucible assembly 1, and the insulation component 3 extends upward to the lower side of the first heater 21 and extends downward beyond the bottom end of the crucible support 13 of the crucible assembly 1, thereby effectively reducing the heat radiated from the first heater 21 to the bottom of the crucible 11 by adding the insulation component 3 at the bottom of the hot field, lowering the temperature at the bottom of the crucible 11, slowing down the reaction between the crucible 11 and the molten silicon, and significantly reducing the amount of silicon monoxide generated, thereby reducing the oxygen content in the crystal rod without affecting the overall structure of the existing hot field.

[0055] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0056] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A single crystal silicon growth device, characterized in that: include: A crucible assembly for containing silicon material; A heating assembly, disposed outside the crucible assembly to heat the silicon material contained in the crucible assembly, comprising a first heater located outside the crucible assembly; The heat insulation component is annularly arranged outside the crucible component and extends in the height direction. The heat insulation component extends upward to the lower side of the first heater and extends downward beyond the bottom end of the crucible support of the crucible component.

2. The single crystal silicon growth device according to claim 1, characterized in that: The single crystal silicon growth equipment also includes an insulation component arranged on the outside of the crucible assembly, the insulation component includes a bottom insulation wall located on the lower side of the crucible assembly, the insulation component includes a first insulation ring supported on the bottom insulation wall, and the first insulation ring extends upward from the bottom insulation wall beyond the top end of the crucible support.

3. The single crystal silicon growth device according to claim 2, characterized in that: The heating assembly further includes a second heater located at a lower side of the crucible assembly, and the first insulation ring extends downwardly beyond the second heater.

4. The single crystal silicon growth device according to claim 2, characterized in that: The first thermal insulation ring includes an upper thermal insulation ring and a lower thermal insulation ring connected up and down, the outer diameter of the upper thermal insulation ring is not larger than the outer diameter of the first heater, the inner diameter of the upper thermal insulation ring is larger than the outer diameter of the crucible of the crucible assembly, and the upper thermal insulation ring extends upward to the outside of the crucible.

5. The single crystal silicon growth device according to claim 4, characterized in that: The bottom end of the upper heat-insulating ring is lower than the bottom end of the crucible support, and the inner diameter of the lower heat-insulating ring is larger than the outer diameter of the crucible support.

6. The single crystal silicon growth device according to claim 4, characterized in that: In the up and down direction, the upper insulation ring is in the shape of a straight cylinder with the same inner diameter and outer diameter, the lower insulation ring is also in the shape of a straight cylinder with the same inner diameter and outer diameter, and the upper insulation ring extends straightly upward from the lower insulation ring.

7. The single crystal silicon growth device according to claim 4, characterized in that: The upper insulation ring and the lower insulation ring have different inner diameters and outer diameters. The outer diameter of the lower insulation ring is smaller than the inner diameter of the first heater. The first insulation ring also has a connecting ring connecting the upper insulation ring and the lower insulation ring.

8. The single crystal silicon growth device according to claim 4, characterized in that: The thermal insulation assembly further comprises a second thermal insulation ring connected to the crucible support, the second thermal insulation ring being located inside the lower thermal insulation ring in the radial direction of the crucible assembly and at least partially overlapping with the lower thermal insulation ring in the height direction.

9. The single crystal silicon growth device according to claim 8, characterized in that: The lower end edge of the second heat insulation ring is not higher than the lower end edge of the tray arranged at the top end of the support rod.

10. The single crystal silicon growth device according to any one of claims 1 to 9, characterized in that: The thermal insulation component is made of one or more materials selected from graphite, quartz, silicon nitride, aluminum oxide, ceramic material, and graphite fiber.

Images