Bell jar for a silicon carbide CVD deposition furnace

Abstract

The utility model discloses a bell jar for silicon carbide CVD deposition furnace, it is bell jar body, be provided with a liquid outlet pipe in the bell jar inside middle position, be provided with a plurality of spiral upward liquid passage between the liquid outlet pipe and the bell jar body inside, and each liquid passage leads to the top, and the top is provided with the drainage passage that spirals to the middle, and the drainage passage all leads to the top export of the middle liquid outlet pipe, and the bottom of liquid passage is provided with the passage entrance, the utility model discloses whole simple and reasonable structure, practical safe, stable operation, high structural strength, temperature is even, improves deposition effect.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor equipment technology, specifically relating to a bell jar for a silicon carbide CVD deposition furnace. Background Technology

[0002] In recent years, with the rapid growth in demand for high-frequency, high-power radio frequency and power electronics such as 5G and new energy, third-generation semiconductor materials, led by silicon carbide, have gradually moved from scientific research to industrialization. High-purity silicon carbide raw materials prepared by CVD (chemical vapor deposition) have characteristics such as high purity, good uniformity, and low defect density. Therefore, CVD preparation of high-purity silicon carbide raw materials has enormous potential in the high-end electronics field.

[0003] The bell-type reduction furnace is a commonly used CVD deposition apparatus. The deposition reaction needs to be carried out at a high temperature of 1400℃~1600℃. Due to the extremely high reaction temperature inside the furnace, the inner cylinder needs to be cooled to prevent high-temperature deformation or damage. In the prior art, the inner wall of the bell-shaped furnace and the jacket of the CVD deposition furnace are cooled by water using a single spiral cooling channel. However, as the diameter of the CVD furnace increases, the fluid flow path in the single spiral cooling channel becomes longer, the fluid resistance increases, and the cooling load increases. This can easily lead to uneven temperature distribution in the vertical direction, causing deformation of the bell-shaped inner cylinder. At the same time, the temperature field in the vertical direction inside the furnace is prone to change, resulting in deterioration of deposition quality and product failure.

[0004] To address this issue, a bell jar for a silicon carbide CVD deposition furnace was designed to overcome the aforementioned problems. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a bell jar for a silicon carbide CVD deposition furnace that is simple and reasonable in structure, practical and safe, stable in operation, high in structural strength, uniform in temperature, and improves the deposition effect.

[0006] This utility model is achieved through the following technical solution: a bell jar for a silicon carbide CVD deposition furnace, which includes a bell jar body. A liquid outlet pipe is provided in the middle of the interior of the bell jar. Multiple spiraling upward liquid channels are provided between the liquid outlet pipe and the interior of the bell jar body. Each liquid channel leads to the top. A spiraling guide channel is provided at the top, which leads to the top outlet of the middle liquid outlet pipe. A channel inlet is provided at the bottom of the liquid channel.

[0007] Preferably, there are two spiraling upward liquid channels arranged symmetrically. The channel inlets are located on both sides of the bottom of the liquid channel, and the top ends of the channels lead to the top outlet of the middle liquid outlet pipe. Each outlet is provided with a baffle or guide edge.

[0008] Preferably, the spiral upward liquid channel is a spiral channel, with two spiral channels on opposite sides spiraling alternately to the top, and the top drainage channel is also provided with a double spiral channel. The ends of the double spiral channels are symmetrically arranged on opposite sides of the liquid outlet pipe, and the height of the liquid outlet pipe is less than the height of the double spiral channels, so that the ends of the double spiral channels form opposite side baffles, which facilitates the accurate flow of liquid into the liquid outlet pipe.

[0009] Preferably, the spiraling upward liquid channel is a stepped channel, with two stepped channels on opposite sides spiraling alternately to the top. An upward transition slope is provided between the lower and upper channels. The top drainage channel is also provided with a double spiral channel, and a guide plate is provided on the double spiral channel. The guide plate connects the inner and outer channels, making the entire drainage channel a progressive drainage channel. A semi-circular water-blocking ring is provided at the end of the progressive drainage channel, and a circular water-blocking ring is formed between the two semi-circular water-blocking rings. The liquid outlet pipe is located in the middle of the water-blocking ring, and its height is less than the height of the water-blocking ring, so that the liquid can flow accurately into the liquid outlet pipe.

[0010] Preferably, each layer of the liquid channel is provided with an arc-shaped buffer wall that is concave inward and convex outward on the bell body, and the liquid channel is arranged in the bell body as a reinforcing rib, making the entire bell body more robust.

[0011] The beneficial effects of this utility model are as follows:

[0012] The bell jar for silicon carbide CVD deposition furnace designed in this invention can effectively solve the problem of uneven temperature distribution in the vertical direction of the inner cylinder caused by excessively long cooling channel paths in the existing CVD deposition furnace bell jar. Through the double helix guide plate structure, the cooling channel paths inside the bell jar are shortened, reducing fluid resistance and single-channel cooling load, resulting in uniform cooling temperature, avoiding inner cylinder deformation, and improving deposition effect. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the first structure of this utility model.

[0014] Figure 2 for Figure 1 A schematic diagram of the drainage channel at the top of the middle section.

[0015] Figure 3 This is a schematic diagram of the second structure of this utility model.

[0016] Figure 4 for Figure 3 A schematic diagram of the drainage channel at the top of the middle section. Detailed Implementation

[0017] To enable those skilled in the art to more clearly understand the purpose, technical solution and advantages of this utility model, the present utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "horizontal", and "vertical" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0019] The present invention will now be described in detail with reference to the accompanying drawings: Figures 1-2 As shown, a bell jar for a silicon carbide CVD deposition furnace includes a bell jar body. Inside the bell jar 1, a liquid outlet pipe 2 is located in the middle. Between the liquid outlet pipe 2 and the inside of the bell jar body, multiple spiraling upward liquid channels 3 are arranged. Each liquid channel 3 leads to the top, and a spiraling guide channel 4 is provided at the top, which leads to the top outlet 5 of the middle liquid outlet pipe 2. A channel inlet 6 is opened at the bottom of the liquid channels.

[0020] There are two spiraling upward liquid channels 3 arranged symmetrically. The channel inlets 6 are located on both sides of the bottom of the liquid channel, and the top ends of the channels lead to the top outlet 5 of the middle liquid outlet pipe 2. Each outlet is provided with a baffle 7 or a guide edge 8.

[0021] This invention utilizes two symmetrically arranged liquid channels. Its ingenious design saves overall equipment area while increasing the flow area of ​​the liquid channels inside the bell jar. It also shortens the cooling channel path inside the bell jar, reduces fluid resistance, lowers the cooling load per channel, and makes the cooling temperature more uniform, thereby improving the deposition effect.

[0022] The spiral upward liquid channel 3 can be a spiral channel, with two spiral channels on opposite sides spiraling alternately to the top. The top drainage channel 4 is also provided with a double spiral channel. The ends of the double spiral channels are symmetrically arranged on opposite sides of the liquid outlet pipe, and the height of the liquid outlet pipe 2 is less than the height of the double spiral channels, so that the ends of the double spiral channels form opposite side baffles 7, which facilitates the accurate flow of liquid into the liquid outlet pipe 2.

[0023] like Figures 3-4As shown, the spiraling upward liquid channel 3 is a stepped channel, with two stepped channels on opposite sides spiraling alternately to the top. An upward-sloping transition ramp 9 is provided between the lower and upper channels. The top drainage channel 4 also has a double spiraling channel, with a guide plate 10 on it. This guide plate 10 connects the inner and outer channels, making the entire drainage channel a progressive drainage channel. A semi-circular water-blocking ring 11 is provided at the end of the progressive drainage channel, forming a circular water-blocking ring 12 between the two semi-circular water-blocking rings 11. The liquid outlet pipe 2 is located in the center of the water-blocking ring 12, and its height is less than the height of the water-blocking ring 12, facilitating accurate liquid flow into the outlet pipe 2. Each layer of the liquid channel 3 on the bell jar 1 body is provided with an inwardly concave and outwardly convex arc-shaped buffer wall 13, and the liquid channel is arranged within the bell jar 1 body as a reinforcing rib, making the entire bell jar 1 body more robust.

[0024] This utility model, through the design of an arc-shaped buffer wall with concave interior and convex exterior, can not only play a certain buffering role when liquid flows, but also serve as a reinforcing rib to improve the overall strength of the bell jar, thereby increasing its service life.

[0025] The bell jar for silicon carbide CVD deposition furnace designed in this invention can effectively solve the problem of uneven temperature distribution in the vertical direction of the inner cylinder caused by excessively long cooling channel paths in the existing CVD deposition furnace bell jar. Through the double helix guide plate structure, the cooling channel paths inside the bell jar are shortened, reducing fluid resistance and single-channel cooling load, resulting in uniform cooling temperature, avoiding inner cylinder deformation, and improving deposition effect.

[0026] The specific embodiments described herein are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A bell jar for a silicon carbide CVD deposition furnace, comprising a bell jar body, characterized in that: A liquid outlet pipe is located in the middle of the inside of the bell jar. Multiple spiraling upward liquid channels are located between the liquid outlet pipe and the inside of the bell jar body. Each liquid channel leads to the top, and a spiraling drainage channel is located at the top, which leads to the top outlet of the middle liquid outlet pipe. A channel inlet is opened at the bottom of the liquid channel.

2. The bell jar for a silicon carbide CVD deposition furnace according to claim 1, characterized in that: There are two spiraling upward liquid channels arranged symmetrically. The channel inlets are located on both sides of the bottom of the liquid channel, and the top ends of both channels lead to the top outlet of the middle liquid outlet pipe. Each outlet is equipped with a baffle or guide edge.

3. The bell jar for a silicon carbide CVD deposition furnace according to claim 2, characterized in that: The spiral upward liquid channel is a spiral channel with two spiral channels on opposite sides spiraling alternately to the top. The top drainage channel is also equipped with a double spiral channel. The ends of the double spiral channels are symmetrically arranged on opposite sides of the liquid outlet pipe, and the height of the liquid outlet pipe is less than the height of the double spiral channels, so that the ends of the double spiral channels form opposite side baffles, which facilitates the accurate flow of liquid into the liquid outlet pipe.

4. The bell jar for a silicon carbide CVD deposition furnace according to claim 2, characterized in that: The spiraling upward liquid channel is a stepped channel, with two stepped channels on opposite sides spiraling alternately to the top. An upward-sloping transition ramp is provided between the lower and upper channels. The top drainage channel also has a double spiraling channel with a guide plate on it. This guide plate connects the inner and outer channels, making the entire drainage channel a progressive drainage channel. At the end of the progressive drainage channel, a semi-circular water-blocking ring is provided, forming a circular water-blocking ring between the two semi-circular water-blocking rings. The liquid outlet pipe is located in the middle of the water-blocking ring, and its height is less than that of the water-blocking ring, facilitating accurate liquid flow into the liquid outlet pipe.

5. The bell jar for a silicon carbide CVD deposition furnace according to claim 1, 2, 3, or 4, characterized in that: Each layer of the liquid channel is provided with an arc-shaped buffer wall that is concave inward and convex outward on the bell body, and the liquid channel is arranged in the bell body as a reinforcing rib, making the entire bell body more robust.

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