Thermal insulation cylinder for reducing single crystal oxygen content

Abstract

The utility model provides a thermal insulation cylinder for reducing single crystal oxygen content, which comprises an upper thermal insulation cylinder, a middle thermal insulation cylinder and a lower thermal insulation cylinder, the inner diameter of the upper thermal insulation cylinder and the inner diameter of the lower thermal insulation cylinder are smaller than the inner diameter of the middle thermal insulation cylinder, and a heater blade is arranged between the upper thermal insulation cylinder and the lower thermal insulation cylinder relative to the middle thermal insulation cylinder. The device has the beneficial effects that the convection and transmission of heat are reduced, the reaction rate of molten silicon and the quartz crucible and the volatilization of impurities are reduced, the generation of oxygen is reduced, the oxygen content is reduced, the oxygen is prevented from entering a crystalline region and entering single crystals along with the growth of the single crystals, the quality of the single crystals is improved, the structure is simple, and the operation is convenient and fast.

Description

TECHNICAL FIELD

[0001] The utility model belongs to single crystal silicon manufacturing technical field, especially, it relates to a heat preservation cylinder of reducing single crystal oxygen content. BACKGROUND

[0002] In the single crystal pulling process, quartz crucible and fused silicon react to generate oxygen under the action of high temperature, part of the oxygen will escape from the fused silicon and be discharged from the furnace body along with the furnace gas circulation system, part of the oxygen not discharged in time will melt into the fused silicon again, part of the oxygen will move to the crystallization zone along with the convection of the fused silicon and enter the single crystal along with the growth of the single crystal. The general heat preservation cylinder cannot reduce the reaction rate of the quartz crucible, resulting in high single crystal oxygen content, which affects the quality of the single crystal. SUMMARY

[0003] To solve the above technical problems, the utility model provides a heat preservation cylinder of reducing single crystal oxygen content, which effectively solves the technical problems that the heat preservation cylinder cannot reduce the reaction rate of the quartz crucible, resulting in high single crystal oxygen content, and overcomes the deficiencies of the prior art.

[0004] The utility model discloses the technical scheme that a kind of heat preservation cylinder of reducing single crystal oxygen content, including upper heat preservation cylinder, middle heat preservation cylinder and lower heat preservation cylinder, the inner diameter of the upper heat preservation cylinder and lower heat preservation cylinder is less than the inner diameter of the middle heat preservation cylinder, so that heater blade is relatively arranged between the upper heat preservation cylinder and lower heat preservation cylinder in the middle heat preservation cylinder.

[0005] Further, the inner diameter of the upper heat preservation cylinder and lower heat preservation cylinder is same with the inner diameter of the heater blade.

[0006] Further, the upper of the heater blade and the bottom of the upper heat preservation cylinder and the lower of the heater blade and the top of the lower heat preservation cylinder are all equipped with safety distance.

[0007] Further, the safety distance is equipped between the heater blade and the middle heat preservation cylinder.

[0008] Further, the lower heat preservation cylinder is equipped with groove relative to the position of electrode foot.

[0009] Further, the safety distance is equipped between the groove and the electrode foot.

[0010] Further, the safety distance is greater than or equal to 20mm.

[0011] Further, the top of the middle heat preservation cylinder is equipped with first support ring, and the bottom of the upper heat preservation cylinder is placed on the first support ring.

[0012] Further, the top of the lower heat preservation cylinder is equipped with second support ring, and the bottom of the middle heat preservation cylinder is placed on the second support ring. Further, the top of the lower heat preservation cylinder is equipped with second support ring, and the bottom of the middle heat preservation cylinder is placed on the second support ring.

[0013] Further, the upper heat preservation cylinder, the middle heat preservation cylinder and the lower heat preservation cylinder are externally provided with heat preservation layers, and the heat preservation layers are connected through concave-convex joints.

[0014] The utility model discloses has the advantages and positive effect is: because adopt above -mentioned technical scheme, reduced the convection and transmission of heat, reduced the reaction rate of fused silica and quartz crucible and the volatilization of impurity, reduced the generation of oxygen, reduced oxygen content, avoided oxygen to enter the crystallization area with the growth of single crystal enters single crystal, improved the quality of single crystal, simple structure, convenient operation. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a kind of heat preservation cylinder overall structure schematic diagram of reducing the oxygen content of single crystal of the utility model embodiment.

[0016] Figure 2 It is a kind of heat preservation cylinder lower heat preservation cylinder structure schematic diagram of reducing the oxygen content of single crystal of the utility model embodiment.

[0017] In the drawing,

[0018] 1, upper heat preservation cylinder 2, middle heat preservation cylinder 3, lower heat preservation cylinder

[0019] 4, groove 5, first support ring 6, second support ring

[0020] 7, heat preservation layer 8, concave-convex joint 9, heater blade

[0021] 10, electrode foot DETAILED DESCRIPTION

[0022] The utility model embodiment provides a kind of heat preservation cylinder for reducing the oxygen content of single crystal, the following with the drawings to the embodiment of the utility model is described.

[0023] In the description of the utility model embodiment, it needs to be understood that the orientation or positional relationship indicated by the terms "top", "bottom" and the like is based on the orientation or positional relationship shown in the drawing, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, so it cannot be understood as a limitation on the utility model.In the description of the utility model, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "set", "connected" should be broadly understood, for example, can be fixedly connected, can be detachably connected, or integrally connected;It can be directly connected, or indirectly connected through intermediate medium, and can be the intercommunication of two elements inside.For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood through specific circumstances.

[0024] As Figure 1As shown, the utility model discloses a kind of heat preservation cylinders for reducing monocrystal oxygen content, including upper heat preservation cylinder 1, middle heat preservation cylinder 2 and lower heat preservation cylinder 3, the inner diameter of upper heat preservation cylinder 1 and lower heat preservation cylinder 3 is less than the inner diameter of middle heat preservation cylinder 2, so that heater blade 9 is arranged between upper heat preservation cylinder 1 and lower heat preservation cylinder 3 relative to middle heat preservation cylinder 2.Upper heat preservation cylinder 1, middle heat preservation cylinder 2 and lower heat preservation cylinder 3 are aligned along the central axis arrangement.Because the inner diameter of upper heat preservation cylinder 1 and lower heat preservation cylinder 3 is less than the inner diameter of middle heat preservation cylinder 2, so that the middle part of entire heat preservation cylinder forms an annular groove, heater blade 9 is arranged relative to middle heat preservation cylinder 2, and is placed in annular groove.When heat is transmitted upwards, it is blocked by the bottom of upper heat preservation cylinder 1, when heat is transmitted downwards, it is blocked by the top of lower heat preservation cylinder 3, reduce heat convection and the heat transfer of heater, reduce the reaction rate of quartz crucible under high temperature, thereby reducing the release of oxygen.

[0025] Preferably, in order to avoid affecting the up and down movement of quartz crucible, the inner diameter of upper heat preservation cylinder 1 and lower heat preservation cylinder 3 is same with the inner diameter of heater blade 9.

[0026] Preferably, a safety distance d is provided between the top of heater blade 9 and the bottom of upper heat preservation cylinder 1, to avoid the distance between the top of heater blade 9 and the bottom of upper heat preservation cylinder 1 being too close, which causes sparking between heater and heat preservation cylinder.

[0027] Preferably, a safety distance d is provided between the bottom of heater blade 9 and the top of lower heat preservation cylinder 3, to avoid the distance between the bottom of heater blade 9 and the top of lower heat preservation cylinder 3 being too close, which causes sparking between heater and heat preservation cylinder.

[0028] Preferably, a safety distance d is provided between heater blade 9 and middle heat preservation cylinder 2, to avoid the distance between heater blade 9 and middle heat preservation cylinder 2 being too close, which causes sparking between heater and heat preservation cylinder.

[0029] Preferably, in order to avoid interference between lower heat preservation cylinder 3 and electrode foot 10 of heater, recess 4 is provided on the position of lower heat preservation cylinder 3 relative to electrode foot 10.

[0030] Preferably, a safety distance d is provided between recess 4 and electrode foot 10, to avoid the distance between recess 4 and electrode foot 10 being too close, which causes sparking between electrode foot 10 and heat preservation cylinder.

[0031] Preferably, the safety distance d is greater than or equal to 20mm.

[0032] Preferably, in order to prevent the thermal field from being disassembled and assembled, the misalignment of the heat preservation cylinder causes uneven thermal field distribution, affecting the crystallization, the top of the middle heat preservation cylinder 2 is provided with a first support ring 5, the bottom of the upper heat preservation cylinder 1 is placed on the first support ring 5, the top of the lower heat preservation cylinder 3 is provided with a second support ring 6, and the bottom of the middle heat preservation cylinder 2 is placed on the second support ring 6. The first support ring 5 is a ring-shaped groove, which is arranged on the inner side of the top of the middle heat preservation cylinder 2. The outer diameter of the upper heat preservation cylinder 1 is matched with the outer diameter of the first support ring 5, so that the bottom of the upper heat preservation cylinder 1 can be positioned in the first support ring 5. The outer side of the bottom of the upper heat preservation cylinder 1 is positioned on the first support ring 5, and the inner side of the bottom of the upper heat preservation cylinder 1 extends out of the first support ring 5 and is above the heater blade 9, which is used to block the heat upward transmission. The second support ring 6 is a ring-shaped groove, which is arranged on the outer side of the top of the lower heat preservation cylinder 3. The inner diameter of the middle heat preservation cylinder 2 is matched with the inner diameter of the second support ring 6, so that the bottom of the middle heat preservation cylinder 2 can be positioned in the second support ring 6. The outer side of the top of the lower heat preservation cylinder 3 is placed in the middle heat preservation cylinder 2, and the inner side of the top of the lower heat preservation cylinder 3 extends out of the middle heat preservation cylinder 2 and is below the heater blade 9, which is used to block the heat downward transmission.

[0033] Preferably, in order to enhance the heat preservation effect, the outer part of the upper heat preservation cylinder 1, the middle heat preservation cylinder 2 and the lower heat preservation cylinder 3 is provided with a heat preservation layer 7. In order to ensure the sealing of the connecting end surface of the heat preservation layer 7, the heat preservation layer 7 is connected by a concave-convex stopper 8.

[0034] The embodiment of the application discloses a heat preservation cylinder for reducing the oxygen content of a single crystal, which comprises an upper heat preservation cylinder 1, a middle heat preservation cylinder 2 and a lower heat preservation cylinder 3, the inner diameters of the upper heat preservation cylinder 1 and the lower heat preservation cylinder 3 are smaller than the inner diameter of the middle heat preservation cylinder 2, and the heater blade 9 is arranged between the upper heat preservation cylinder 1 and the lower heat preservation cylinder 3 relative to the middle heat preservation cylinder 2.

[0035] The application has the advantages and positive effects that:

[0036] The inner diameters of the upper heat preservation cylinder and the lower heat preservation cylinder are smaller than the inner diameter of the middle heat preservation cylinder, the heater blade is arranged between the upper heat preservation cylinder and the lower heat preservation cylinder, the upper heat preservation cylinder and the lower heat preservation cylinder can block the upward and downward heat transfer, the heat convection and transmission are reduced, the reaction rate of the molten silicon and the quartz crucible and the impurity volatilization are reduced, the oxygen generation is reduced, the oxygen content is reduced, the oxygen is prevented from entering the crystallization zone and entering the single crystal along with the growth of the single crystal, and the quality of the single crystal is improved.

[0037] The above embodiment of the application is described in detail, but the content is only the preferred embodiment of the application and cannot be considered as limiting the scope of the application. Any equivalent changes and improvements within the scope of the application should still belong to the patent coverage of the application.

Claims

1. A holding furnace for reducing the oxygen content of a single crystal, comprising an upper holding furnace, a middle holding furnace and a lower holding furnace, characterized in that: The inner diameter of the upper and lower heat preservation cylinders is smaller than the inner diameter of the middle heat preservation cylinder, so that the heater blade is arranged between the upper and lower heat preservation cylinders relative to the middle heat preservation cylinder.

2. The single crystal oxygen content reduction cartridge of claim 1, wherein: The inner diameter of the upper and lower heat preservation cylinders is the same as the inner diameter of the heater blade.

3. The single crystal oxygen content reducing retort of claim 1 or 2, wherein: The upper part of the heater blade is provided with a safety distance from the bottom of the upper heat preservation cylinder, and the lower part of the heater blade is provided with a safety distance from the top of the lower heat preservation cylinder.

4. The single crystal oxygen content reduction cartridge of claim 3, wherein: The heater blade is provided with a safety distance from the middle heat preservation cylinder.

5. The single crystal oxygen content reduction cartridge of claim 3, wherein: The lower heat preservation cylinder is provided with a groove relative to the position of the electrode foot.

6. The single crystal oxygen content reduction cartridge of claim 5, wherein: The groove is provided with a safety distance from the electrode foot.

7. A holding cylinder for reducing the oxygen content of a single crystal according to any one of claims 4 to 6, characterized in that: The safety distance is greater than or equal to 20 mm.

8. A holding cylinder for reducing the oxygen content of a single crystal according to any one of claims 1 to 2 and 4 to 6, characterized in that: The top of the middle heat preservation cylinder is provided with a first support ring, and the bottom of the upper heat preservation cylinder is placed on the first support ring.

9. A holding cylinder for reducing the oxygen content of a single crystal according to any one of claims 1 to 2 and 4 to 6, characterized in that: The top of the lower heat preservation cylinder is provided with a second support ring, and the bottom of the middle heat preservation cylinder is placed on the second support ring.

10. A holding cylinder for reducing the oxygen content of a single crystal according to any one of claims 1 to 2 and 4 to 6, characterized in that: The outer part of the upper, middle and lower heat preservation cylinders is provided with a heat preservation layer, and the heat preservation layers are connected by concave-convex joints.

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