Smelting device for preparing semiconductor silicon crystal

Abstract

The utility model discloses a smelting device for preparing semiconductor silicon crystals, which comprises a furnace shell, a quartz crucible is arranged in the middle of an inner cavity of the furnace shell, a graphite heating body and an induction coil are sequentially arranged on the periphery of the quartz crucible, a liftable supporting plate is arranged at the bottom of the quartz crucible, and a plurality of cooling channels distributed circumferentially are arranged in the supporting plate. The bottom of the supporting plate is connected with a hollow spindle which penetrates through the bottom of the furnace shell in the vertical direction. A speed reducer is fixedly installed below the furnace shell, the hollow main shaft is arranged in the speed reducer in a penetrating mode in the vertical direction, a lifting table is arranged under the speed reducer, a rotating supporting piece used for installing a shaft head at the bottom of the hollow main shaft is arranged in the lifting table, and a hydraulic cylinder and a sliding rod are installed between the lifting table and the speed reducer. According to the utility model, the silicon material can be smelted in the dynamically rotating quartz crucible, and each part of the quartz crucible can be in contact with an external heat source in the rotating process, so that the uniform absorption and distribution of heat are facilitated, and the smelting speed and uniformity of the silicon material are improved.

Description

Technical Field

[0001] This utility model relates to a melting apparatus for preparing semiconductor silicon crystals, belonging to the field of semiconductor silicon crystal preparation technology. Background Technology

[0002] Silicon crystals are crystalline forms of silicon, including polycrystalline and monocrystalline silicon, and are a good semiconductor material.

[0003] The smelting and purification of polycrystalline silicon raw materials often employs directional solidification purification. Directional solidification utilizes the significant difference in segregation coefficients between silicon and metallic impurities in polycrystalline silicon raw materials. During solidification, the molten silicon at the bottom of the quartz crucible begins to solidify first. To achieve segregation equilibrium, impurities with lower segregation coefficients diffuse and separate from the solidified silicon into the liquid state and accumulate there. As solidification continues, the concentration of metallic impurities in the liquid state increases, eventually solidifying at the top of the ingot. Finally, the end with higher metallic impurity content is removed, resulting in a purified polycrystalline silicon ingot.

[0004] Application number CN201320435296.0 discloses a low-energy-consumption polycrystalline silicon directional solidification device, including a furnace body, a quartz crucible placed inside the furnace body, a graphite heating element, an insulation sleeve and an induction coil arranged sequentially from the inside to the outside of the outer wall of the quartz crucible, a water-cooled ingot pulling mechanism connected to the bottom of the furnace body is provided at the bottom of the quartz crucible, a graphite support plate is provided between the quartz crucible and the water-cooled ingot pulling mechanism, and a movable support that can move laterally is provided at equal intervals between the bottom of the graphite support plate and the bottom of the furnace body along the outer periphery.

[0005] The technical solutions disclosed in the aforementioned patent documents still have the following technical problems, based on practical experience:

[0006] During the melting process of silicon material inside the quartz crucible, the quartz crucible remains static. Different parts of the quartz crucible do not come into uniform contact with the external heat source, affecting the uniform absorption and distribution of heat, resulting in a slow and uneven melting speed of silicon material.

[0007] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0008] This invention addresses the shortcomings of the prior art by providing a melting device for semiconductor silicon crystal preparation, which enables silicon material to be melted in a dynamically rotating quartz crucible. During the rotation of the quartz crucible, all parts come into contact with external heat sources, which helps to uniformly absorb and distribute heat, thereby improving the melting speed and uniformity of silicon material.

[0009] To solve the above technical problems, the present invention adopts the following technical solution:

[0010] A melting apparatus for preparing semiconductor silicon crystals includes a furnace shell, a quartz crucible installed in the center of the furnace shell cavity, and a graphite heating element and an induction coil arranged sequentially around the quartz crucible; a liftable support plate is installed at the bottom of the quartz crucible, and multiple cooling channels are arranged in a circular pattern inside the support plate. The bottom of the support plate is connected to a hollow main shaft, which is installed vertically through the bottom of the furnace shell, and a sliding sleeve is installed at the penetration point.

[0011] A speed reducer is fixedly installed below the furnace shell. The hollow main shaft passes through the speed reducer in a vertical direction. A lifting platform is set directly below the speed reducer. The lifting platform is equipped with a rotating support for installing the bottom shaft head of the hollow main shaft. A hydraulic cylinder and a slide rod are installed between the lifting platform and the speed reducer.

[0012] Furthermore, the sliding sleeve is fixedly installed at the bottom of the furnace shell, and a rotating seal is installed inside the top part of the sliding sleeve.

[0013] Furthermore, the reducer is a hollow reducer, and the hollow main shaft is connected to the reducer via a flat key.

[0014] Furthermore, the tail end of the hydraulic cylinder is fixedly connected to the bottom of the reducer, and the head end of the hydraulic cylinder is fixedly connected to the lifting platform.

[0015] Furthermore, the top of the slide rod is fixedly connected to the bottom of the reducer, and the main body of the slide rod is inserted vertically inside the lifting platform, with the slide rod slidably connected to the lifting platform.

[0016] Furthermore, the cooling channel has a U-shaped structure.

[0017] Furthermore, a cooling water inlet pipe is fixedly connected to the hollow spindle inside, with the top end of the cooling water inlet pipe fixed inside the support plate, and the inner cavity of the cooling water inlet pipe connected to the upper part of the cooling channel.

[0018] Furthermore, a return water channel is formed between the inner wall of the hollow spindle and the outer wall of the cooling water inlet pipe, and the lower part of the return water channel and the cooling channel are connected.

[0019] Compared with the prior art, the present invention, by adopting the above technical solution, has the following advantages:

[0020] During the silicon smelting process, the reducer drives the hollow main shaft to rotate, which in turn drives the quartz crucible to rotate slowly. During the rotation of the quartz crucible, each part comes into contact with the external heat source, which helps to absorb and distribute heat evenly.

[0021] The hollow spindle is connected to the reducer via a flat key. The reducer can transmit torque to the hollow spindle, and the hollow spindle can move up and down along the inside of the reducer. After melting is completed, the hollow spindle drives the quartz crucible to slowly descend, gradually pulling the quartz crucible out of the hot zone. At the same time, cooling water enters the tray for heat exchange, thereby causing the polycrystalline silicon to solidify in a directional manner.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] Figure 2 This is a schematic diagram of the structure of this utility model;

[0025] Figure 3 yes Figure 2 Enlarged view of the structure at point N.

[0026] In the figure, 1-furnace shell, 2-quartz crucible, 3-graphite heating element, 4-induction coil, 5-support plate, 51-cooling channel, 6-hollow main shaft, 7-sliding sleeve, 8-rotating seal, 9-reducer, 10-lifting platform, 11-hydraulic cylinder, 12-sliding rod, 13-rotating support, 14-cooling water inlet pipe. Detailed Implementation

[0027] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0028] like Figures 1-3 As shown in the figure, this utility model provides a melting device for preparing semiconductor silicon crystals, including a furnace shell 1, a quartz crucible 2 installed in the middle of the inner cavity of the furnace shell 1, a graphite heating element 3 and an induction coil 4 arranged in sequence around the quartz crucible 2, a gap of a certain width between the inner wall of the graphite heating element 3 and the outer wall of the quartz crucible 2, and a liftable support plate 5 installed at the bottom of the quartz crucible 2.

[0029] The bottom of the support plate 5 is connected to the hollow main shaft 6. The hollow main shaft 6 is set through the bottom of the furnace shell 1 in a vertical direction, and a sliding sleeve 7 is installed at the through point. The sliding sleeve 7 is fixedly installed at the bottom of the furnace shell 1.

[0030] A rotating seal 8 is installed inside the top part of the sliding sleeve 7. The rotating seal 8 is used to prevent gas from flowing along the connection between the sliding sleeve 7 and the hollow main shaft 6.

[0031] A speed reducer 9 is fixedly installed below the furnace shell 1, and a hollow main shaft 6 is vertically inserted into the speed reducer 9.

[0032] The reducer 9 is a hollow reducer. The hollow main shaft 6 is connected to the reducer 9 by a flat key. The reducer 9 can transmit torque to the hollow main shaft 6, and the hollow main shaft 6 can move up and down along the inside of the reducer 9.

[0033] A lifting platform 10 is provided directly below the reducer 9, and the lifting platform 10 is provided with a rotating support 13 for installing the bottom shaft head of the hollow main shaft 6.

[0034] A hydraulic cylinder 11 and a slide rod 12 are installed between the lifting platform 10 and the reducer 9. The tail of the hydraulic cylinder 11 is fixedly connected to the bottom of the reducer 9, and the head of the hydraulic cylinder 11 is fixedly connected to the lifting platform 10. The top of the slide rod 12 is fixedly connected to the bottom of the reducer 9. The main body of the slide rod 12 passes vertically through the lifting platform 10, and the slide rod 12 is slidably connected to the lifting platform 10. The slide rod 12 serves as a guide.

[0035] The interior is provided with multiple cooling channels 51 arranged in a circular pattern, and the cooling channels 51 have a U-shaped structure.

[0036] The hollow spindle 6 is provided with a cooling water inlet pipe 14 that is fixedly connected to it. The top end of the cooling water inlet pipe 14 is fixed to the inside of the support plate 5, and the inner cavity of the cooling water inlet pipe 14 is connected to the upper part of the cooling channel 51.

[0037] A return water channel is formed between the inner wall of the hollow spindle 6 and the outer wall of the cooling water inlet pipe 14, and the lower part of the return water channel and the cooling channel 51 are connected.

[0038] The specific working principle of this utility model is as follows:

[0039] Silicon material is placed in a quartz crucible 2, and then the inner cavity of the furnace shell 1 is evacuated. The induction coil 4 is energized, transferring heat from the graphite heating element 3 to the quartz crucible 2 to melt the silicon material. At the same time, the reducer 9 drives the hollow spindle 6 to rotate, causing the quartz crucible 2 to rotate slowly. During the rotation, all parts of the quartz crucible 2 come into contact with the external heat source, which helps to uniformly absorb and distribute heat. After melting is completed, the hydraulic cylinder 11 extends and drives the quartz crucible 2 to slowly descend via the lifting platform 10 and the hollow spindle 6, gradually pulling the quartz crucible 2 out of the hot zone. At the same time, cooling water enters the cooling channel 51 of the support plate 5 from the cooling water inlet pipe 14 for heat exchange, thereby causing the polycrystalline silicon in the quartz crucible 2 to solidify in a directional manner. The cooled water after heat exchange flows back from the return water channel. After the polycrystalline silicon has completely solidified, it is removed from the quartz crucible 2.

[0040] The above description provides examples of the preferred embodiments of this utility model. Any aspects not detailed herein are common knowledge to those skilled in the art. The scope of protection of this utility model is determined by the claims. Any equivalent modifications based on the technical teachings of this utility model are also within the scope of protection of this utility model.

Claims

1. A melting apparatus for preparing semiconductor silicon crystals, comprising a furnace shell (1), a quartz crucible (2) installed in the middle of the inner cavity of the furnace shell (1), and a graphite heating element (3) and an induction coil (4) arranged sequentially around the quartz crucible (2), characterized in that: The bottom of the quartz crucible (2) is equipped with a liftable tray (5). The tray (5) has multiple cooling channels (51) arranged in a circular pattern inside. The bottom of the tray (5) is connected to the hollow main shaft (6). The hollow main shaft (6) is set through the bottom of the furnace shell (1) in a vertical direction, and a sliding sleeve (7) is installed at the through point. A speed reducer (9) is fixedly installed below the furnace shell (1). A hollow main shaft (6) is inserted vertically inside the speed reducer (9). A lifting platform (10) is set directly below the speed reducer (9). A rotating support (13) for installing the bottom shaft head of the hollow main shaft (6) is provided inside the lifting platform (10). A hydraulic cylinder (11) and a slide rod (12) are installed between the lifting platform (10) and the speed reducer (9).

2. The melting apparatus for semiconductor silicon crystal preparation as described in claim 1, characterized in that: The sliding sleeve (7) is fixedly installed at the bottom of the furnace shell (1), and a rotating seal (8) is installed inside the top part of the sliding sleeve (7).

3. The melting apparatus for semiconductor silicon crystal preparation as described in claim 1, characterized in that: The reducer (9) is a hollow reducer, and the hollow main shaft (6) is connected to the reducer (9) by a flat key.

4. The melting apparatus for semiconductor silicon crystal preparation as described in claim 1, characterized in that: The tail of the hydraulic cylinder (11) is fixedly connected to the bottom of the reducer (9), and the head of the hydraulic cylinder (11) is fixedly connected to the lifting platform (10).

5. The melting apparatus for semiconductor silicon crystal preparation as described in claim 1, characterized in that: The top of the slide rod (12) is fixedly connected to the bottom of the reducer (9), and the main body of the slide rod (12) is inserted vertically into the lifting platform (10). The slide rod (12) is slidably connected to the lifting platform (10).

6. The melting apparatus for semiconductor silicon crystal preparation as described in claim 1, characterized in that: The cooling channel (51) has a U-shaped structure.

7. The melting apparatus for semiconductor silicon crystal preparation as described in claim 6, characterized in that: The hollow spindle (6) is provided with a cooling water inlet pipe (14) fixedly connected to it. The top end of the cooling water inlet pipe (14) is fixed to the inside of the support plate (5). The inner cavity of the cooling water inlet pipe (14) is connected to the upper part of the cooling channel (51).

8. The melting apparatus for semiconductor silicon crystal preparation as described in claim 7, characterized in that: A return water channel is formed between the inner wall of the hollow spindle (6) and the outer wall of the cooling water inlet pipe (14), and the lower part of the return water channel and the cooling channel (51) are connected.

Images