A novel re-feeding device for Czochralski grown monocrystalline and an operating method thereof

Abstract

A novel re-feeding device for Czochralski grown monocrystalline is provided, including a re-feeding cylinder, a quartz umbrella disposed at the lower end of the re-feeding cylinder and a fixed frame at the upper end of the re-feeding cylinder. The re-feeding cylinder sequentially includes, from one end close to the fixed frame, a first cylinder part, a second cylinder part and a third cylinder part. The first, second and third cylinder parts are integrally connected, the inner diameter of the first cylinder part is greater than the inner diameter of the third cylinder part, and the height of the first cylinder part is not less than the height of the third cylinder part. The re-feeding device can increase the re-feeding amount of each cylinder, can reduce the oxygen content of head gaps ofmonocrystalline silicon rods, and can improve monocrystalline silicon quality. The service lifetime of the re-feeding device is prolonged, the production efficiency is increased and the production cost is reduced. The invention also provides an operating method of the novel re-feeding device for Czochralski grown monocrystalline. The method is particularly suitable for re-feeding for monocrystalline silicon with a large size and a large feeding amount. Through the method, quality of monocrystalline silicon rods can be ensured, and the crystal yield is increased by about 4%.

Description

technical field [0001] The invention belongs to the technical field of accessories used in Czochralski silicon single crystal furnaces, and in particular relates to a novel re-introducer for Czochralski single crystals and a method for using the same. Background technique [0002] With the increase in the size of the thermal field of the Czochralski single crystal furnace, the amount of single crystal feed increases, the existing quartz re-introduction device cannot meet the re-injection amount used in large-scale single crystal furnaces, and due to the limitations of the existing re-introduction device structure itself, The amount of re-injection each time is fixed, and it needs to be loaded and re-injected many times to meet the demand of the input amount, which seriously affects the production efficiency; and each additional re-injection will increase the silicon material’s impact on the quartz umbrella set at the bottom of the re-injection cylinder. The impact force will...

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Problems solved by technology

[0002] With the increase in the size of the thermal field of the Czochralski single crystal furnace, the amount of single crystal feed increases, the existing quartz re-introduction device cannot meet the re-injection amount used in large-scale single crystal furnaces, and due to the limitations of the existing re-introduction device structure itself, The amount of re-injection each time is fixed, and it needs to be loaded and re-injected many times to meet the demand of the input amount, which seriously affects the production efficiency; and each additional re-injection will increase the silicon material’s impact on the quartz umbrella set at the bottom of the re-injection cylinder. The impact force will reduce the protective effect of the quartz umbrella when it is severe, and it is easy to bring in impurities, thereby reducing the quality of crystal pulling; at the same time, due to the unreasonable structural design of the conical quartz umbrella, the quartz umbrella is prone to stress concentration in the high-temperature single crystal furnace. , so that the life of the quartz umbrella is low, and it needs to be replaced many times, which increases the production cost

[0003] Simultaneously, with the whereabouts of existing re-casting cylinder silicon material, as figure 1 As shown, because the quartz umbrella with a conical structure is gradually separated from the bottom of the re-injection cylinder, the position close to the inner wall of the re-injection cylinder is separated from the quartz umbrella first, so that the silicon material near the edge of the inner wall of the re-injection cylinder falls first, and the compound The silicon material in the middle of the casting cylinder is then replenished to its inner wall, and then the silicon material falls down along the inner wall of the re-casting cylinder. The contact will cause the silicon material to carry the quartz on the re-casting cylinder into the melt in the single crystal furnace, and the silicon solution will react with the quartz re-casting cylinder (Si (liquid) + SiO2 (solid) = 2SiO (liquid)), The oxygen content of the silicon solution increases, and finally the oxygen content of the drawn single crystal silicon increases, and the quality of the single crystal decreases

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