Monocrystalline silicon interstitial oxygen elimination system
By optimizing the argon flow and heating method in the interstitial oxygen removal system for monocrystalline silicon, the problems of uneven interstitial oxygen distribution and low removal efficiency during the Czochralski method for preparing monocrystalline silicon were solved. This achieved uniform heating and efficient removal of silicon crystals, improving the electrical properties and production stability of monocrystalline silicon.
Patent Information
- Application Number
- CN202423109247.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2026-01-06
- Estimated Expiration
- 2034-12-17
AI Technical Summary
When preparing single-crystal silicon using the Czochralski method, the uneven distribution and low removal efficiency of interstitial oxygen affect the electrical properties of the silicon crystal, and the introduction of argon gas causes temperature instability inside the single-crystal furnace.
A single-crystal silicon interstitial oxygen removal system is designed. By setting up graphite support components and gas supply channels in the single-crystal furnace, and using argon gas tanks and gas heating devices to control the flow of argon gas and the heating method, the silicon crystal is ensured to be heated uniformly. Hollow structure and support structure are used to optimize the distribution of gas outlets, prevent oxidation reaction and improve removal efficiency.
This method achieves uniform distribution and efficient removal of interstitial oxygen in single-crystal silicon, improves the electrical properties of silicon crystals, and ensures temperature stability and vacuum environment within the single-crystal furnace.
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Figure CN223766478U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of monocrystalline silicon, and more particularly to a monocrystalline silicon interstitial oxygen removal system. Background Technology
[0002] Single-crystal silicon is the substrate material for most semiconductor components. It is generally prepared using the Czochralski method, which can more effectively reduce costs in large-scale production.
[0003] Interstitial oxygen is easily generated during the Czochralski method for preparing single-crystal silicon, which can affect the electrical properties of the silicon crystal. Introducing argon gas into the single-crystal furnace can effectively prevent oxidation reactions within the furnace, ensuring the purity of the molten silicon and avoiding the introduction of impurities and oxygen. This is crucial for obtaining high-purity single-crystal silicon.
[0004] However, the introduction of argon gas may cause temperature instability inside the single crystal furnace, affecting the distribution and removal efficiency of interstitial oxygen in the silicon crystal. Utility Model Content
[0005] In view of the problems existing in the prior art, the present invention is proposed.
[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution;
[0007] A single-crystal silicon interstitial oxygen elimination system includes a single-crystal furnace, in which a crucible and a graphite support component supporting the crucible are disposed, the graphite support component including a graphite pot for accommodating the crucible and a graphite support rod for supporting the graphite pot.
[0008] The graphite support component also includes an air supply channel, which is provided with an air outlet and an air inlet. The air outlet is located on the bottom surface of the inner cavity of the graphite pot, and the air inlet is located at the lower end of the graphite support rod.
[0009] The bottom surface of the inner cavity of the graphite pot is provided with at least 8 air outlets;
[0010] The bottom structural layer of the graphite pot is provided with a hollow structure whose thickness gradually increases from the central axis to the outer periphery. The hollow structure is connected to the air outlets arranged on the inner bottom of the graphite pot, and the air inlet is connected to the hollow structure.
[0011] The bottom structural layer of the graphite pot is provided with a hollow structure whose thickness gradually increases from the central axis to the outer periphery. The bottom surface of the inner cavity of the graphite pot is provided with at least 8 air outlets. The hollow structure is connected to the air outlets arranged on the bottom inner side of the graphite pot.
[0012] It also includes a gas supply system, which includes an argon cylinder and a gas heating device. The argon cylinder is provided with a gas supply port from which argon flows out, and the gas heating device has a cold gas inlet and a hot gas outlet.
[0013] The gas supply port is connected to the cold gas inlet of the gas heating device, and the hot gas outlet of the gas heating device is connected to the gas inlet.
[0014] The above design firstly involves setting up a gas supply channel. Argon gas enters through the inlet and then exits through the outlet into the graphite pot, replacing the air in the single crystal furnace and preventing oxidation reactions within the furnace. Secondly, a gas heating device is installed in the gas supply system to heat the argon gas before it is introduced into the gas supply channel, ensuring uniform heating of the silicon crystal and improving the removal efficiency of interstitial oxygen. Finally, a hollow structure is set at the bottom of the graphite pot. The thickness of the hollow structure gradually increases from the central axis to the outer periphery. The hollow structure is connected to multiple outlets, allowing for a more uniform distribution of hot gas when gas is introduced into the bottom of the crucible, resulting in better distribution and higher removal efficiency of interstitial oxygen in the single crystal silicon.
[0015] Preferably, the vent on the bottom surface of the graphite pot's inner cavity is larger the further away from the center of the graphite pot; this reduces the direct impact of high-temperature argon gas on the bottom of the crucible, making the argon gas heating at the bottom of the crucible more uniform and improving the removal efficiency of interstitial oxygen.
[0016] Preferably, at least four support structures are arranged in the hollow structure, and the support structures are connected to the upper and lower walls of the hollow structure; at least four support structures are arranged around the center of the graphite pot; the support strength of the hollow structure.
[0017] Preferably, a gas inlet is provided at the bottom of the hollow structure, and at least four supporting structures are arranged around the outer edge of the inlet, forming a gas flow channel. The gas outlet is located above the gas flow channel. The inlet is located in the middle of the hollow structure, and the upper gas outlet of the gas flow channel avoids direct impact of high-temperature argon gas, creating a turbulent flow structure within the hollow structure.
[0018] Preferably, the bottom of the graphite pot is provided with support bars that support the crucible, and the support bars form a heating channel for gas flow. The support bars facilitate the flow of high-temperature argon gas.
[0019] Preferably, there is a gap between the inner wall of the graphite pot and the outer wall of the crucible, and the gap is connected to the heating channel. Argon gas flows out from the gap between the crucible and the graphite, so that the silicon crystal is in an argon atmosphere, which improves the distribution and removal efficiency of interstitial oxygen in the silicon crystal.
[0020] Preferably, the single crystal furnace is provided with an exhaust port located below the single crystal furnace, and the height of the exhaust port is lower than the height of the gas outlet. The exhaust port is also connected to a vacuum pumping device. The exhaust port located below the single crystal furnace floats upward when high-temperature argon gas is introduced, which facilitates the sinking and discharge of cold air. The vacuum pumping device can effectively improve the air discharge efficiency, reduce the oxygen content of the gas in the single crystal furnace, and improve the removal efficiency of interstitial oxygen in the silicon crystal.
[0021] Preferably, a one-way valve is also provided in the exhaust port, and the one-way valve is oriented from the exhaust port to the vacuum pumping device; the presence of the one-way valve prevents gas from being drawn back into the single crystal furnace, thereby improving the single crystal furnace's ability to maintain a vacuum. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:
[0023] Figure 1 A schematic diagram of the overall assembly structure of the monocrystalline silicon interstitial oxygen elimination system according to an embodiment of this utility model;
[0024] Figure 2 A schematic diagram of the internal structure of the graphite support component and crucible of the single-crystal silicon interstitial oxygen elimination system according to an embodiment of this utility model;
[0025] Figure 3 A schematic diagram of the graphite support component structure of the monocrystalline silicon interstitial oxygen elimination system according to an embodiment of this utility model;
[0026] Figure 4 A schematic diagram of the internal structure of the graphite support component of the monocrystalline silicon interstitial oxygen removal system according to an embodiment of this utility model. Detailed Implementation
[0027] To make the above-mentioned objectives, features and advantages of this utility model more readily understood, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.
[0028] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0029] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.
[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in less than one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.
[0031] Example 1
[0032] Reference Figures 1-3 A single-crystal silicon interstitial oxygen elimination system includes a single-crystal furnace 1, a crucible 11 disposed in the single-crystal furnace 1 and a graphite support component supporting the crucible 11, the graphite support component including a graphite pot 13 for accommodating the crucible 11 and a graphite support rod 12 for supporting the graphite pot 13.
[0033] The graphite support component also includes an air supply channel 14, which is provided with an air outlet 142 and an air inlet 141. The air outlet 142 is located on the bottom surface of the inner cavity of the graphite pot 13, and the air inlet 141 is located at the lower end of the graphite support rod 12. The bottom surface of the inner cavity of the graphite pot 13 is provided with at least eight air outlets 142. A hollow structure 15 with gradually increasing thickness from the central axis to the outer periphery is provided in the bottom structural layer of the graphite pot. The hollow structure 15 is connected to the air outlets 142 arranged on the bottom inner side of the graphite pot, and the air inlet 141 is connected to the hollow structure 15. The graphite pot 13 has a hollow structure 15 in its bottom structural layer, with the thickness gradually increasing from the central axis to the outer periphery. The bottom surface of the inner cavity of the graphite pot 13 has at least 8 air outlets 142, and the hollow structure 15 is connected to the air outlets 142 arranged on the bottom of the inner side of the graphite pot. It also includes a gas supply system, which includes an argon tank 2 and a gas heating device 3. The argon tank 2 is provided with a gas supply port for argon flow, and the gas heating device 3 has a cold gas inlet and a hot gas outlet. The gas supply port is connected to the cold gas inlet of the gas heating device 3, and the hot gas outlet of the gas heating device 3 is connected to the gas inlet 141. First, argon gas enters the gas supply channel 14 through the inlet 141 and then passes through the outlet 142 into the graphite pot 13, replacing the air in the single crystal furnace 1 and preventing oxidation reactions within the furnace. Second, a gas heating device 3 is installed in the gas supply system to heat the argon gas before it is introduced into the gas supply channel 14, ensuring uniform heating of the silicon crystal and improving the removal efficiency of interstitial oxygen. Finally, a hollow structure 15 is installed at the bottom of the graphite pot 13. The thickness of the hollow structure 15 gradually increases from the central axis to the outer periphery. The hollow structure 15 is connected to multiple outlets 142, so that when the gas is introduced into the bottom of the crucible 11 through the outlets 142, the hot gas is distributed more evenly, resulting in better distribution and higher removal efficiency of interstitial oxygen in the single crystal silicon.
[0034] The vent 142 on the bottom surface of the inner cavity of the graphite pot 13 is larger the farther away from the center of the graphite pot 13; this reduces the direct impact of high-temperature argon gas on the bottom of the crucible 11, making the argon gas heating at the bottom of the crucible 11 more uniform and improving the removal efficiency of interstitial oxygen.
[0035] The single crystal furnace 1 is equipped with an exhaust port located below the furnace 1, with the height of the exhaust port being lower than that of the gas outlet 142. The exhaust port is also connected to a vacuum device 4. The exhaust port located below the single crystal furnace 1 floats upward when high-temperature argon gas is introduced, facilitating the downward discharge of cold air. The vacuum device 4 can effectively improve the air discharge efficiency, reduce the oxygen content of the gas inside the single crystal furnace 1, and improve the removal efficiency of interstitial oxygen in the silicon crystal.
[0036] A one-way valve is also installed in the exhaust port, and the direction of conduction of the one-way valve is from the exhaust port to the vacuum pumping device 4; the presence of the one-way valve prevents gas from being drawn back into the single crystal furnace 1, thereby improving the ability of the single crystal furnace 1 to maintain a vacuum.
[0037] In use, after the silicon crystal raw material is added to the crucible 11, the vacuum pump 4 is turned on to evacuate the single crystal furnace 1. After the pressure is reduced to a certain level, the argon tank 2 and the gas heating device 3 are turned on. After the gas is heated, it is injected into the single crystal furnace 1 through the gas supply channel 14 to fill the air in the furnace. The vacuum pump 4 continues to run for a period of time and then turns off. The heated argon gas continues to be introduced. When the high-temperature argon gas is introduced, it is evenly heated to the bottom of the crucible 11 through at least 8 gas outlets 142, so that the silicon crystal in the crucible 11 is heated evenly, and the interstitial oxygen distribution in the single crystal silicon is better and the removal efficiency is higher.
[0038] Example 2
[0039] Reference Figure 3 and Figure 4 This is the second embodiment of the present invention, which is based on the previous embodiment.
[0040] The hollow structure 15 has at least four support structures 151 arranged in a row, and the support structures 151 connect the upper and lower walls of the hollow structure 15; at least four support structures 151 are arranged around the center of the graphite pot; the support strength of the hollow structure 15.
[0041] A gas inlet is provided below the hollow structure 15, and at least four support structures 151 are arranged around the outer edge of the inlet, forming a gas flow channel. An outlet 142 is located above the gas flow channel. The inlet is situated in the middle of the hollow structure 15, and the outlet 142 above the gas flow channel prevents direct inflow of high-temperature argon gas, thus creating a turbulent flow structure within the hollow structure 15.
[0042] The bottom of the graphite pot 13 is provided with support bars 131 that support the crucible 11, and the support bars 131 form a heating channel for gas flow. The support bars 131 facilitate the flow of high-temperature argon gas.
[0043] A gap exists between the inner wall of the graphite pot 13 and the outer wall of the crucible 11, and this gap is connected to the heating channel. Argon gas flows out from the gap between the crucible 11 and the graphite, placing the silicon crystal in an argon atmosphere and improving the distribution and removal efficiency of interstitial oxygen in the silicon crystal.
[0044] In use, a support structure 151 is set in the hollow structure 15 to facilitate the passage of high-temperature argon gas, thereby improving the mechanical strength of the graphite pot 13 and preventing it from collapsing. The support bar 131 creates a gap between the graphite pot 13 and the crucible 11 to facilitate the flow of argon gas, so that the silicon crystal is in an argon atmosphere, which improves the distribution and removal efficiency of interstitial oxygen in the silicon crystal.
[0045] It should be noted that the above description illustrates the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A single crystal silicon interstitial oxygen elimination system, comprising a single crystal furnace, a crucible and a graphite support component supporting the crucible in the single crystal furnace, the graphite support component comprising a graphite pot containing the crucible and a graphite support rod supporting the graphite pot, characterized in that: the graphite support component further comprises a gas supply channel, the gas supply channel is provided with a gas outlet and a gas inlet, the gas outlet is arranged on the inner cavity bottom surface of the graphite pot, and the gas inlet is arranged on the lower end of the graphite support rod; the inner cavity bottom surface of the graphite pot is provided with at least 8 gas outlets; the graphite pot bottom structure layer is provided with a hollow structure with gradually increasing thickness from the central axis to the outer periphery, the hollow structure is in communication with the gas outlets arranged on the inner bottom of the graphite pot, and the gas inlet is in communication with the hollow structure; the system further comprises a gas supply system, the gas supply system comprises an argon tank and a gas heating device, the argon tank is provided with a gas outlet, and the gas heating device has a cold gas inlet and a hot gas outlet; the gas outlet is connected to the cold gas inlet of the gas heating device, and the hot gas outlet of the gas heating device is connected to the gas inlet. The distance between the gas outlet on the inner cavity bottom surface of the graphite pot and the center of the graphite pot is greater, and the size is greater. The hollow structure is arranged with at least 4 support structures, and the support structures are connected to the upper and lower walls of the hollow structure. At least four support structures are arranged around the center of the graphite pot. The lower part of the hollow structure is provided with a gas inlet, at least 4 support structures are arranged around the outer edge of the gas inlet, at least 4 support structures form a gas flow channel, and the gas outlet is arranged above the gas flow channel. The bottom of the graphite pot is arranged with at least a support bar supporting the crucible, and the support bars form a heating channel for gas flow.
2. The single crystal silicon gap oxygen abatement system of claim 1, wherein: The gap between the inner cavity sidewall of the graphite pot and the outer wall of the crucible is in communication with the heating channel.
3. The single crystal silicon gap oxygen abatement system of claim 1, wherein: The single crystal furnace is provided with an exhaust port, the exhaust port is located below the single crystal furnace, and the height of the exhaust port is lower than the height of the gas outlet. The exhaust port is further connected to a vacuum pumping device.
4. The single crystal silicon gap oxygen abatement system of claim 3, wherein: The exhaust port is further provided with a one-way valve, and the one-way valve is in a direction from the exhaust port to the vacuum pumping device.
5. The single crystal silicon gap oxygen abatement system of claim 1, wherein: 6. The single crystal silicon gap oxygen abatement system of claim 5, wherein: 7. The single crystal silicon gap oxygen abatement system of claim 1, wherein: 8. The single crystal silicon gap oxygen abatement system of claim 7, wherein: