Single crystal furnace
By setting an inclined surface and a collection structure on the bottom of the support ring, the problem of silicon droplet contamination of the crystal rod was solved, achieving the effect of reducing the introduction of impurities and improving the quality of the crystal rod.
Patent Information
- Application Number
- CN202423262446.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-27
AI Technical Summary
In the traditional continuous Czochralski (CCZ) process, silicon powder and silicon vapor in granular silicon or silicon fragments volatilize onto the support ring and condense into silicon droplets, causing impurities to contaminate the crystal rod and increasing the difficulty of crystal pulling.
An inclined surface is provided on the bottom of the support ring, so that one end is higher than the other end, to guide the volatilized and condensed silicon droplets to flow to the outside of the crucible, and collect the silicon droplets through the flat surface or grooves on the auxiliary ring, reducing the amount of impurities entering the crucible.
This effectively prevents silicon droplets from entering the crucible and contaminating the molten silicon, improving the quality of the crystal rod and reducing the difficulty of crystal pulling.
Smart Images
Figure CN223576646U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of single crystal silicon technology, and in particular to a single crystal furnace. Background Technology
[0002] Czochralski (CZ) growth of monocrystalline silicon is currently the most widely used technology for producing monocrystalline silicon. The equipment used in the industry for CZ growth is the CZ furnace. Continuous CZ growth (CCZ) requires at least two crucibles: an inner crucible and an outer crucible. The crystal is pulled in the inner crucible. During the crystal pulling process, granular silicon or silicon fragments are added between the inner and outer crucibles through a feeding tube. The granular silicon or silicon fragments melt between the inner and outer crucibles and then enter the inner crucible through the holes at the bottom of the inner crucible, thus realizing the production process of adding material while pulling the crystal.
[0003] However, in the traditional continuous Czochralski (CCZ) single crystal pulling process, during the feeding process through the feeding tube, silicon powder and silicon vapor in the granular silicon or crushed silicon material will volatilize onto the support ring connected to the guide tube and condense into silicon droplets on the surface. The silicon droplets entering the inner crucible introduce impurities, which will affect the quality of the crystal rod and increase the difficulty of crystal pulling.
[0004] like Figure 1 The diagram shows a partial schematic of a traditional single crystal furnace, which has an outer crucible 11' and an inner crucible 12'. Silicon material is added from the feeding pipe 3' into the area between the outer crucible 11' and the inner crucible 12'. A support ring 4' is arranged around the periphery of the guide tube 2', and the bottom surface 40' of the support ring 4' is parallel to the horizontal plane. Silicon powder and silicon vapor in the granular silicon or crushed silicon material will volatilize onto the support ring 4' and condense into silicon droplets at the bottom of the support ring 4'. After the silicon droplets accumulate, they will drip into the inner crucible 12', causing contamination of the silicon liquid.
[0005] In view of this, it is necessary to improve the existing single crystal furnace to solve the above problems. Utility Model Content
[0006] The purpose of this invention is to provide a single crystal furnace that can effectively reduce the introduction of impurities and improve the quality of crystal rods.
[0007] To achieve the above-mentioned objectives, this utility model provides a single crystal furnace, comprising:
[0008] A crucible assembly, comprising a first crucible and a second crucible, wherein the second crucible is located inside the first crucible;
[0009] A flow guide tube is disposed on the upper part of the second crucible and located inside it;
[0010] A feeding tube, located between the first crucible and the second crucible, is used to add silicon material into the crucible assembly;
[0011] A support ring is arranged at the periphery of the draft tube to provide support for the draft tube, the bottom surface of the support ring has a first inclined surface arranged in a height direction, and the first inclined surface has a first end and a second end oppositely arranged in the inclined direction of the first inclined surface, the first end is connected with the draft tube, and the second end is connected with the feeding pipe.
[0012] As a further improvement of the utility model, the included angle between the first inclined surface and the horizontal plane is α, and 10°≤α≤20°.
[0013] As a further improvement of the utility model, the bottom surface of the support ring further has a flat surface connected with the second end and arranged parallel to the horizontal plane, and the width of the flat surface in the radial direction of the single crystal furnace ranges from 20 to 60 mm.
[0014] As a further improvement of the utility model, the bottom surface of the support ring further includes a second inclined surface, the inclined direction of the second inclined surface is opposite to the inclined direction of the first inclined surface, so that the outer end of the second inclined surface is higher than the inner end, and the inner end and the second end are respectively connected with two ends of the flat surface oppositely arranged in the radial direction.
[0015] As a further improvement of the utility model, the flat surface is located at the middle position between the first crucible and the second crucible in the radial direction, and the distance between the flat surface and the top surface of the support ring in the height direction ranges from 20 to 80 mm.
[0016] As a further improvement of the utility model, the bottom surface of the support ring further has a second inclined surface, the second inclined surface is arranged on the two sides of the feeding pipe in the radial direction with the first inclined surface, and the inclined direction of the second inclined surface is the same as that of the first inclined surface.
[0017] As a further improvement of the utility model, the second inclined surface is arranged coplanarly with the first inclined surface.
[0018] As a further improvement of the utility model, the single crystal furnace further has an auxiliary ring connected with the outer side of the support ring, and the auxiliary ring has a groove located below the outer end of the second inclined surface to collect silicon droplets.
[0019] As a further improvement of the utility model, the auxiliary ring and the support ring are connected through a connecting structure, and the groove is located on the outer side of the first crucible in the radial direction.
[0020] As a further improvement of the utility model, the support ring is made of an isostatic pressing graphite material or a carbon ceramic material or a carbon-carbon material.
[0021] The utility model discloses a beneficial effect: the utility model discloses single crystal furnace through setting up the first inclined plane that inclines in the height direction on the bottom surface of support ring 4, and the first inclined plane 41 has the first end 41a and the second end 41b of opposite setting in its inclined direction, the first end 41a is with the one end of being connected with the flow guide cylinder 2, the second end 41b is with the one end of being connected with the feeding pipe 3, the first end 41a is higher than the second end 41b, thereby through the setting of first inclined plane 41 to the flow direction of the silicon drop that volatilizes and condenses on the bottom surface of support ring 4 is guided, avoids the silicon drop to fall into the second crucible 12 inside and pollutes the silicon liquid that it contains, reduces the introduction of impurity and the influence to the crystal pulling, in addition, the utility model discloses single crystal furnace 100 through the flat surface 43 of setting up of support ring 4 bottom or the groove 51 of setting up on auxiliary ring 5 to be more reliable to collect silicon drop. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 It is the partial schematic view of traditional single crystal furnace.
[0023] Figure 2 It is the structure schematic view of the first embodiment of the utility model discloses single crystal furnace.
[0024] Figure 3 It is the structure schematic view of the second embodiment of the utility model discloses single crystal furnace.
[0025] In the drawing:
[0026] 100, single crystal furnace;
[0027] 1, crucible assembly;11, first crucible;12, second crucible;
[0028] 2, flow guide cylinder;
[0029] 3, feeding pipe;
[0030] 4, support ring;41, first inclined plane;41a, first end;41b, second end;42, second inclined plane;43, flat surface;
[0031] 5, auxiliary ring;51, groove. DETAILED DESCRIPTION
[0032] The utility model will be described in detail in the following in conjunction with the embodiment shown in the drawing. But this embodiment does not limit the utility model, the conversion of structure, method or function that the ordinary skill in the art makes according to this embodiment is included in the protection scope of the utility model.
[0033] The terms such as "upper", "lower", "left", "right", "front", "back", etc. used herein to indicate spatial relative positions are for the purpose of facilitating illustration to describe the relationship of one feature relative to another feature as shown in the drawings. It can be understood that the terms of spatial relative positions can be intended to include different orientations other than the one shown in the drawings, and should not be construed as limiting the claims. In addition, the descriptive word "horizontal" used herein is not completely equivalent to along the direction perpendicular to the gravity direction, and a certain angle of inclination is allowed.
[0034] Please refer to Figures 2 to 3 The structure schematic diagram of the single crystal furnace of the utility model is shown, wherein Figure 2 The structure schematic diagram of the first embodiment of the single crystal furnace 100 of the utility model is shown, Figure 3 The structure schematic diagram of the second embodiment of the single crystal furnace 100 of the utility model is shown.
[0035] Please refer to Figure 2 And Figure 3 The single crystal furnace 100 of the utility model, as shown, comprises:
[0036] The crucible assembly 1 comprises a first crucible 11 and a second crucible 12, and the second crucible 12 is located inside the first crucible 11;
[0037] The flow guide cylinder 2 is arranged at the upper part of the second crucible 12 and located inside it;
[0038] The charging pipe 3 is located between the first crucible 11 and the second crucible 12 to add silicon material into the crucible assembly 1;
[0039] The support ring 4 is arranged at the periphery of the flow guide cylinder 2 to provide support for it, the bottom surface of the support ring 4 is provided with a first inclined surface 41 inclined in the height direction, and the first inclined surface 41 is provided with a first end 41a and a second end 41b oppositely arranged in the inclined direction, the first end 41a is connected with the flow guide cylinder 2, the second end 41b is connected with the charging pipe 3, and the first end 41a is higher than the second end 41b.
[0040] The support ring 4 is arranged at the periphery of the flow guide cylinder 2, and in the utility model, the first inclined surface 41 is arranged at the bottom of the support ring 4, and the first end connected with the flow guide cylinder 2 is higher and the first end connected with the charging pipe 3 is lower, so that the silicon drops volatilized and condensed on the bottom surface of the support ring 4 can flow to the outside of the second crucible 12 under the guidance of the first inclined surface 41, and the pollution caused by the introduction of impurities into the second crucible 12 is avoided.
[0041] The first end 41a of the first inclined surface 41 is directly connected with the flow guide cylinder 2, and there is no horizontal surface connection between the two, so the silicon droplets will not gather at the connection between the first end of the first inclined surface 41 and the flow guide cylinder 2, but will flow down along the first inclined surface 41 from the high place to the low place, and then flow into the space between the first crucible 11 and the second crucible 12 or flow to the outside of the first crucible 11.
[0042] In the embodiment, the included angle between the first inclined surface 41 and the horizontal surface is α, and 10°≤α≤20°, that is, the included angle between the first inclined surface 41 and the top surface of the support ring 4 is α, so that the silicon droplets condensed at the bottom of the support ring 4 can be better received, and the silicon droplets can flow down along the first inclined surface 41 to the space between the first crucible 11 and the second crucible 12 or flow to the outside of the first crucible 11, thereby preventing the silicon droplets from falling into the second crucible 12 to affect the quality of the crystal bar and reduce the difficulty of crystal pulling.
[0043] Please refer to Figure 2 As shown in the first embodiment of the single crystal furnace 100 of the utility model, the bottom surface of the support ring 4 further has a flat surface 43 connected with the second end 41b and arranged parallel to the horizontal surface, and the width range of the flat surface 43 in the radial direction of the single crystal furnace 100 is 20-60 mm, so that the flat surface 43 with a certain width is used to collect the silicon droplets volatilized and condensed to the bottom of the support ring 4, reduce the pollution of the silicon droplets to the silicon liquid in the second crucible 12, and avoid the introduction of impurities in the crystal pulling area.
[0044] In the embodiment, the bottom surface of the support ring 4 further includes a second inclined surface 42, the inclined direction of the second inclined surface 42 is opposite to the inclined direction of the first inclined surface 41, so that the outer end of the second inclined surface 42 is higher than the inner end, the inner end and the second end 41b are respectively connected with two ends of the flat surface 43 arranged opposite in the radial direction, so that the first and second inclined surfaces 41 and 42 are respectively located on both sides of the charging pipe 3 in the radial direction.
[0045] Further, in an embodiment of the first embodiment of the single crystal furnace 100 of the utility model, the flat surface 43 is located at the middle position between the first crucible 11 and the second crucible 12 in the radial direction, and the distance between the flat surface 43 and the top surface of the support ring 4 in the height direction is 20-80 mm.
[0046] In the embodiment, the support ring 4 is made of isostatic graphite or carbon ceramic or carbon-carbon material, the single crystal furnace 100 guides the silicon droplet through the flow guiding effect of the first inclined surface 41 arranged at the bottom of the support ring 4 and makes the silicon droplet converge at the flat surface 43 located in the middle of the first crucible 11 and the second crucible 12, and finally drips into the first crucible 11 and the second crucible 12, thereby reducing the introduction of impurities in the crystal pulling area of the second crucible 12 and causing pollution, and reducing the influence of the silicon droplet entering the second crucible 12 on the stability of the crystal pulling.
[0047] Please refer to Figure 3 In the second embodiment of the single crystal furnace 100, the bottom surface of the support ring 4 further has a second inclined surface 42, and the second inclined surface 42 and the first inclined surface 41 are arranged on the two sides of the charging pipe 3 in the radial direction, and the difference between the first embodiment is that, in the example, the inclination direction of the second inclined surface 42 is the same as that of the first inclined surface 41.
[0048] Further, in the embodiment, the second inclined surface 42 is arranged coplanarly with the first inclined surface 41. In other embodiments of the utility model, the second inclined surface 42 can be arranged at a certain angle with the first inclined surface 41, as long as the overall inclination trend is the same, that is, the second inclined surface 42 can also be arranged non-coplanarly with the first inclined surface 41, as long as the outer end edge of the second inclined surface 42 is lower than the inner end edge.
[0049] In the embodiment, the single crystal furnace 100 further has an auxiliary ring 5 connected to the outer side of the support ring 4, and the auxiliary ring 5 has a groove 51 located below the outer end edge of the second inclined surface 42 to collect the silicon droplet; in this way, the silicon droplet flowing from the support ring 4 can be more reliably collected through the arrangement of the groove 51.
[0050] The auxiliary ring 5 and the support ring 4 are connected through a connecting structure, and the groove 51 is located on the outer side of the first crucible 11 in the radial direction. In an embodiment of the utility model, the connecting structure can be a stepped mutual matching structure, and in other embodiments, the auxiliary ring 5 and the support ring 4 can be connected together through fasteners.
[0051] In the second embodiment of the utility model, the support ring 4 and the auxiliary ring 5 are arranged in a split structure, and the first and second inclined surfaces 41 and 42 arranged at the bottom of the support ring 4 on the inner side guide the silicon droplet to flow into the groove 51 of the auxiliary ring 5 on the outer side, thereby reducing the introduction of impurities and the influence on the crystal pulling.
[0052] In the embodiment, the support ring 4 and the auxiliary ring 5 are both made of isostatic graphite material or carbon ceramic material or carbon-carbon material.
[0053] In the single crystal furnace 100, the first inclined surface 41 is arranged on the bottom surface of the support ring 4 in the height direction, and the first inclined surface 41 has the first end 41a and the second end 41b which are oppositely arranged in the inclined direction of the first inclined surface 41, the first end 41a is one end connected with the flow guide cylinder 2, and the second end 41b is one end connected with the charging pipe 3, and the first end 41a is higher than the second end 41b, so that the flow direction of the silicon drops volatilized and condensed on the bottom surface of the support ring 4 is guided by the arrangement of the first inclined surface 41, the silicon drops are prevented from falling into the second crucible 12 to pollute the silicon liquid contained in the second crucible 12, and the introduction of impurities and the influence on the crystal pulling are reduced.
[0054] It should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.
[0055] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present application, and they are not used to limit the protection scope of the present application, and any equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.
Claims
1. A single crystal furnace characterized by comprising: The single crystal furnace comprises: a crucible assembly comprising a first crucible and a second crucible, the second crucible being located inside the first crucible; a draft tube arranged at the upper portion of the second crucible and located inside the second crucible; a feeding tube located between the first crucible and the second crucible for feeding silicon material into the crucible assembly; a support ring arranged at the periphery of the draft tube to provide support for the draft tube, the bottom surface of the support ring having a first inclined surface arranged in a height direction, the first inclined surface having a first end and a second end oppositely arranged in the inclined direction of the first inclined surface, the first end being connected to the draft tube, and the second end being connected to the feeding tube, the first end being higher than the second end.
2. The single crystal furnace of claim 1, wherein: The included angle between the first inclined surface and the horizontal plane is α, and 10°≤α≤20°.
3. The single crystal furnace of claim 2, wherein: The bottom surface of the support ring further has a flat surface connected to the second end and arranged parallel to the horizontal plane, the width of the flat surface in the radial direction of the single crystal furnace being 20-60 mm.
4. The single crystal furnace of claim 3, wherein: The bottom surface of the support ring further comprises a second inclined surface, the inclined direction of the second inclined surface being opposite to the inclined direction of the first inclined surface, so that the outer end of the second inclined surface is higher than the inner end, and the inner end and the second end are respectively connected to two ends of the flat surface oppositely arranged in the radial direction.
5. The single crystal furnace of claim 3, wherein: The flat surface is located in the middle position between the first crucible and the second crucible in the radial direction, and the distance between the flat surface and the top surface of the support ring in the height direction is 20-80 mm.
6. The single crystal furnace of claim 2, wherein: The bottom surface of the support ring further has a second inclined surface, the second inclined surface being arranged on the two sides of the feeding tube in the radial direction with the first inclined surface, and the inclined direction of the second inclined surface being the same as that of the first inclined surface.
7. The single crystal furnace of claim 6, wherein: The second inclined surface is arranged coplanarly with the first inclined surface.
8. The single crystal furnace of claim 6, wherein: The single crystal furnace further has an auxiliary ring connected to the outer side of the support ring, the auxiliary ring having a groove located below the outer end of the second inclined surface to collect silicon droplets.
9. The single crystal furnace of claim 8, wherein: The auxiliary ring and the support ring are connected through a connecting structure, and the groove is located on the outer side of the first crucible in the radial direction.
10. The single crystal furnace of any one of claims 1 to 9, wherein: The support ring is made of isostatic pressing graphite material, carbon ceramic material or carbon-carbon material.