Low-oxygen heater for single crystal furnace

Abstract

The utility model discloses a low-oxygen heater for a single crystal furnace, which comprises an annular heating body and a group of heater foot plates uniformly arranged at the bottom of the heating body, and the annular heating body is formed by sequentially connecting a group of heating bodies end to end in series; the heating body comprises a middle heating body and an end heating body. The upper side and the lower side of the middle heating body are connected with the two end heating bodies respectively, and the end heating bodies on the two sides of the middle heating body are symmetrically distributed up and down and integrally formed. The whole heating body adopts the structural design with the uniform cross section size, the local heating value is increased by locally adopting a mode of increasing the transverse radiation heat size, and meanwhile, the problem that the service life of a main family is greatly shortened due to the fact that the local resistance of an existing low-oxygen heater is increased by locally reducing the size is solved.

Description

Technical Field

[0001] This utility model belongs to the field of monocrystalline silicon production, specifically relating to a low-oxygen heater for monocrystalline furnaces. Background Technology

[0002] The oxygen in a single-crystal silicon rod mainly originates from silicon monoxide produced by the reaction of molten silicon with a quartz crucible. Slowing down this reaction can effectively reduce the oxygen content in the rod. The graphite heater in a single-crystal furnace is a crucial component of the furnace's thermal field, its primary function being to provide a stable heat source for the molten silicon, ensuring successful growth. Currently, optimizing the heater structure to reduce the reaction rate between molten silicon and the quartz crucible primarily involves the following technical solutions: First, shortening the heating element length to reduce the silicon monoxide produced by the reaction, thereby lowering the oxygen content in the rod. However, due to limitations in material resistance, shortening the heating element has reached its limit, making it impossible to further slow down the reaction by shortening the heating element length. Second, increasing the local resistance of the heating element to raise the temperature in the crystalline region and lower the temperature in the amorphous region can also slow down the reaction. While this increases the local heat output of the heating element, the increased resistance means a smaller local cross-sectional area and a significantly increased ablation rate, leading to a substantial decrease in the furnace's lifespan. Summary of the Invention

[0003] Purpose of this utility model: The technical problem to be solved by this utility model is to provide a heater with a special structure to address the shortcomings of the existing technology. It adopts a solution of increasing the area of ​​the local heating element to increase the heat generation in the crystallization region and reduce the heat generation in the non-crystalline region. Under the background that the existing technical solution can no longer continue to shorten the length of the heating element, it can achieve a continuous reduction in the oxygen content of the crystal rod. At the same time, it solves the technical problems of excessively high local resistance of the existing heating element, excessively fast ablation rate, and short service life.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A low-oxygen heater for a single crystal furnace includes an annular heating element and a set of heater feet uniformly arranged at the bottom of the heating element. The annular heating element is composed of a set of heating elements connected in series end to end. The heating element includes a middle heating element and an end heating element.

[0006] Specifically, the upper and lower sides of the central heating element are respectively connected to two end heating elements.

[0007] Specifically, the central heating element and the two end heating elements are integrally formed.

[0008] Furthermore, the ratio of the width of the middle heating element to the width of the end heating element is 1.5-2.5:1.

[0009] Furthermore, the ratio of the thickness of the middle heating element to the thickness of the end heating element is 1:1.5-2.5.

[0010] Furthermore, the longitudinal cross-sectional areas of the central heating element and the end heating element are equal.

[0011] Furthermore, the resistivity of the middle heating element and the end heating element are equal.

[0012] Preferably, the transverse centerline of the central heating element coincides with the surface of the molten silicon in the quartz crucible.

[0013] Specifically, the grooved portion of the central heating element is opposite to the quartz crucible.

[0014] Specifically, the end heating elements on both sides of the central heating element are symmetrically distributed vertically. Beneficial effects

[0015] (1) The low oxygen heater for single crystal furnace of this utility model adopts an equal cross-sectional size structure design for the heating element as a whole. The local heating element is increased by increasing the size of the transverse radiant heat. At the same time, it solves the problem that the existing low oxygen heaters use local size reduction to increase local resistance, which leads to a significant decrease in the life of the main body.

[0016] (2) The low oxygen heater for single crystal furnace of this utility model adopts the method of increasing the size of the lateral radiant heat heating element and aligning the center of the molten silicon with the surface of the molten silicon, so as to get as close as possible to the quartz crucible. The special design of this structure can realize the high heat heating element to locally and accurately heat the surface of the molten silicon, increase the temperature of the crystallization area, reduce the temperature of the non-crystallization area, slow down the reaction rate between the molten silicon and the quartz crucible, and ultimately achieve the purpose of reducing the oxygen content of the crystal rod. Attached Figure Description

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0018] Figure 1 This is a schematic diagram of the overall structure of the low-oxygen heater used in the single crystal furnace.

[0019] Figure 2 This is a diagram showing the operating status of the low-oxygen heater used in the single crystal furnace.

[0020] Figure 3 This refers to the lateral radiant heat dimension of the heating element in the embodiment.

[0021] Figure 4 This refers to the longitudinal cross-sectional dimension of the heating element in the embodiment.

[0022] Figure 5This refers to the longitudinal height dimension of the heating element in the embodiment. Detailed Implementation

[0023] The present invention can be better understood from the following embodiments.

[0024] The structures, proportions, and sizes shown in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0025] Combination Figure 1 and Figure 2 As shown, the low-oxygen heater for the single crystal furnace in this embodiment includes an annular heating body and a set of heater feet 1 uniformly arranged at the bottom of the heating body. The annular heating body is composed of a set of heating elements connected in series end to end. The heating element includes a middle heating element 3 and an end heating element 2.

[0026] The upper and lower sides of the central heating element 3 are connected to two end heating elements 2 respectively, and the end heating elements 2 on the upper and lower sides of the central heating element 3 are symmetrically distributed.

[0027] The central heating element 3 and the two end heating elements 2 are integrally formed.

[0028] The heater is supported by two (or four) heater feet 1, with heating elements symmetrically distributed on both sides of the upper end of the heater feet 1, forming a parallel structure. Each heating element consists of an end heating element 2 and a middle heating element 3, which are connected in series.

[0029] Combination Figure 3 In this embodiment, the design features of the lateral radiant heat of the heating element are as follows: two end heating elements 2 are symmetrically distributed at the upper and lower ends of the middle heating element 3, symmetrical along the center. The width of the end heating elements 2 is 40mm, and the width of the middle heating element 3 is 80mm. This special design of dimensions allows the lateral width of the main local (central) heating element to be twice that of the upper and lower end heating elements, thereby increasing the local heat generation.

[0030] Combination Figure 4In this embodiment, the longitudinal cross-sectional dimensions of the heating element are designed as follows: it has an overall U-shaped structure, is symmetrical along the center, has a thickness of 40mm at the top and bottom ends (heating element 2), a thickness of 20mm at the middle (heating element 3), and a cross-sectional dimension of 40*40=1600mm at the ends (heating element 2). 2 The cross-sectional dimensions of the central heating element 3 are 80*20=1600mm. 2 The end heating element 2 and the middle heating element 3 have the same cross-sectional dimensions. Of course, the end heating element 2 and the middle heating element 3 can adopt other dimensions, as long as the cross-sectional dimensions are consistent. With the same heating element, the resistivity is consistent, and with the same cross-sectional area, the resistance is also the same. This special structural design ensures the uniformity and consistency of the heater's heating element resistance. While increasing the area of ​​the local heating element to increase heat generation, it solves the problem of existing low-oxygen heaters that use localized size reduction to increase local resistance, leading to a significant decrease in the heater's lifespan.

[0031] Combination Figure 5 As shown, in this embodiment, the longitudinal height dimension design of the heating element is as follows: the overall structure is U-shaped, the height of the middle heating element 3 is 100mm, the central part coincides with the surface of the molten silicon, ensuring that the surface of the molten silicon is in the center of the middle heating element 3, the grooved part of the heating element faces outward, the middle heating element 3 can be as close as possible to the quartz crucible, and the lateral width of the middle heating element 3 is twice that of the end heating element 2. This special design of the structure can realize the localized and precise heating of the molten silicon surface by the middle heating element 3, increase the temperature of the crystallization area, reduce the temperature of the non-crystallization area (the area where the end heating element 2 is located), slow down the reaction rate between the molten silicon and the quartz crucible, and ultimately achieve the purpose of reducing the oxygen content of the crystal rod.

[0032] This utility model provides a concept and method for a low-oxygen heater for a single crystal furnace. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. A low-oxygen heater for a single crystal furnace, characterized in that, It includes an annular heating element and a set of heater feet (1) evenly arranged at the bottom of the heating element. The annular heating element is composed of a set of heating elements connected in series from end to end. The heating element includes a middle heating element (3) and an end heating element (2).

2. The low-oxygen heater for a single crystal furnace according to claim 1, characterized in that, The upper and lower sides of the central heating element (3) are respectively connected to the two end heating elements (2).

3. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The central heating element (3) and the two end heating elements (2) are integrally formed.

4. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The width ratio of the middle heating element (3) to the width of the end heating element (2) is 1.5-2.5:

1.

5. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The thickness ratio of the middle heating element (3) to the end heating element (2) is 1:1.5-2.

5.

6. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The longitudinal cross-sectional areas of the middle heating element (3) and the end heating element (2) are equal.

7. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The resistivity of the middle heating element (3) and the end heating element (2) is equal.

8. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The transverse centerline of the central heating element (3) coincides with the surface of the molten silicon in the quartz crucible.

9. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The groove portion of the central heating element (3) is opposite to the quartz crucible.

10. The low-oxygen heater for a single crystal furnace according to claim 2, characterized in that, The heating elements (2) at the ends of the central heating element (3) are symmetrically distributed on both sides.

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