WO2023178955A1 - 一种高品质石英坩埚的制作方法 - Google Patents

一种高品质石英坩埚的制作方法 Download PDF

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WO2023178955A1
WO2023178955A1 PCT/CN2022/119998 CN2022119998W WO2023178955A1 WO 2023178955 A1 WO2023178955 A1 WO 2023178955A1 CN 2022119998 W CN2022119998 W CN 2022119998W WO 2023178955 A1 WO2023178955 A1 WO 2023178955A1
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Prior art keywords
graphite electrode
crucible
residence time
quartz crucible
time
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PCT/CN2022/119998
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English (en)
French (fr)
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陈曼
李宗辉
朱剑
王也
王震
张治强
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锦州佑鑫石英科技有限公司
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Publication of WO2023178955A1 publication Critical patent/WO2023178955A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B20/00—Processes specially adapted for the production of quartz or fused silica articles, not otherwise provided for
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B19/00—Other methods of shaping glass
    • C03B19/06—Other methods of shaping glass by sintering, e.g. by cold isostatic pressing of powders and subsequent sintering, by hot pressing of powders, by sintering slurries or dispersions not undergoing a liquid phase reaction
    • C03B19/066—Other methods of shaping glass by sintering, e.g. by cold isostatic pressing of powders and subsequent sintering, by hot pressing of powders, by sintering slurries or dispersions not undergoing a liquid phase reaction for the production of quartz or fused silica articles
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
    • C30B15/10—Crucibles or containers for supporting the melt
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements
    • C30B29/06—Silicon

Definitions

  • the present invention relates to the technical field of single crystal silicon production, specifically a method for manufacturing a quartz crucible used when manufacturing silicon single crystal by the Czochralski method (hereinafter referred to as CZ Czochralski method).
  • Silicon single crystal is one of the most important raw materials for making silicon-based semiconductor materials and solar cells. Silicon single crystal is mainly produced by CZ Czochralski method. In the CZ Czochralski method, the polycrystalline silicon raw material is placed in a quartz crucible to heat the molten silicon melt. The pull rod drives the seed crystal down to contact the silicon melt, and then slowly pulls the seed crystal upward to form a silicon single crystal rod. Quartz crucibles generally have a double-layer structure. The inner wall is a transparent layer without bubbles, and the outer wall is an opaque layer with more bubbles. Because the inner wall is in contact with the silicon melt, if there are bubbles on the inner wall at high temperatures, the bubbles will burst due to erosion by the silicon melt.
  • the quality of quartz crucible has a great influence on the quality of silicon single crystal. For example, the content of bubbles on the inner wall of the quartz crucible, the purity of the quartz crucible, the high temperature deformation resistance of the quartz crucible, etc.
  • Quartz crucibles are generally manufactured using the vacuum arc method.
  • the high-purity quartz sand raw material is poured into a graphite mold or a metal mold, and the quartz sand raw material is evenly formed on the inner surface of the mold through a forming device, and then passed through a high-temperature arc (usually three-phase electric arc furnaces) Graphite electrode)
  • the quartz sand is melted at a high temperature above 3000°C, and finally formed into a quartz (glass) crucible by rapid cooling.
  • the temperature of the arc has a great influence on the quality of the quartz crucible, such as the bubble content of the inner wall of the crucible, purity, high temperature deformation resistance, vitrification degree, etc. Therefore, how to optimize the control of the arc is very important. important.
  • the position of the graphite electrode (the position of the electrode end relative to the upper end of the mold) will greatly improve the production quality of the quartz crucible under the condition that the current is constant (the power equipment remains unchanged).
  • the current electrode positioning in the process of making quartz crucibles generally still adopts the fixed position melting method (referred to in this application as the fixed positioning method or Fixed Type Method, referred to as the FT method).
  • the position of the graphite electrode in the FT method is fixed, and only the consumption of the graphite electrode is periodically compensated (dropped a certain distance to compensate for the loss of the electrode).
  • the existing preparation method only improves the production quality of the quartz crucible by adjusting the current size. .
  • the present invention provides a method for manufacturing a high-quality quartz crucible.
  • This method mainly produces a high-quality quartz crucible by controlling the position of the graphite electrode and the time allocation of each position. , including improving the high-temperature resistance strength of the crucible, improving the purity of the transparent layer, reducing bubbles on the inner wall of the crucible, etc. It solves the technical problems caused by the existing technology to improve the quality of the crucible by changing the current under fixed movement.
  • the main technical solutions adopted by the present invention include:
  • the present invention provides a method for manufacturing a high-quality quartz crucible.
  • the manufacturing method adopts a vacuum arc method and includes the steps:
  • the end of the graphite electrode is marked as + above the zero point and as - below the zero point; during the melting process, the starting position of the graphite electrode is + (0.10 ⁇ 0.30) times the outer diameter of the crucible , the residence time is ⁇ 2 minutes, and then the positions are lowered sequentially according to the ladder movement method. Each lowered position stays for a period of time. The graphite electrode continues to release high-temperature arcs to melt the crucible blank during the corresponding period of time at the corresponding position.
  • the movement is at least 3 After several times, it reaches the bottom polishing position; the bottom polishing position is the lowest position that the graphite electrode reaches and enters the inside of the crucible blank (the position is negative), 300-550mm away from the bottom of the crucible; at the bottom polishing position, the graphite electrode stays for a predetermined time to perform polishing on the bottom of the crucible High temperature polishing and volatile impurity removal;
  • the graphite electrode leaves the bottom polishing position and then rises to the tailing station.
  • the tailing station is + (0.05 ⁇ 0.07) times the outer diameter of the crucible.
  • the upper inner wall of the quartz crucible is polished at high temperature and evaporated to remove impurities.
  • the height difference between two adjacent positions is ⁇ 50mm; and when the number of moves from the starting position to the bottom polishing position is greater than 3 times, then There is no need for the height difference between every two steps to be ⁇ 50mm.
  • the position of the graphite electrode includes a starting position, a second position, a third position, a fourth position, a fifth position, a bottom polishing position and a finishing position. position, where the starting position to the bottom polishing position is a step-wise descent and stays at each position for a period of time.
  • the residence time of the graphite electrode in each position is distributed as follows: the sum of the residence time at the starting position, the second position and the third position is 0.4-0.5t, and the residence time at the fourth position is 0.1- 0.2t, the residence time at the fifth position is 0.1t, the residence time at the bottom polishing position is 0.2-0.3t, and the residence time at the finishing station is 0.1t; t is the total melting time of the target quartz crucible.
  • the residence time of the graphite electrode in each position is distributed as follows: quartz crucible with an outer diameter of 24 inches: the sum of the residence time of the starting position, the second position and the third position is 0.4 t, the residence time at the fourth position is 0.2t, the residence time at the fifth position is 0.1t, the residence time at the bottom polishing position is 0.2t; the residence time at the finishing station is 0.1t; the total melting time is 14-16 minutes, preferably 15 minutes;
  • Quartz crucible with an outer diameter of 26 inches the sum of the residence time at the starting position, the second position and the third position is 0.45t, the residence time at the fourth position is 0.15t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.2t; the residence time of the finishing station is 0.1t; the total melting time is 17-19 minutes, preferably 18 minutes;
  • Quartz crucible with an outer diameter of 28 inches the sum of the residence time at the starting position, the second position and the third position is 0.45t, the residence time at the fourth position is 0.1t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.25t; the residence time of the finishing station is 0.1t; the total melting time is 22-26 minutes, preferably 24 minutes;
  • Quartz crucible with an outer diameter of 32 inches the sum of the residence time at the starting position, the second position and the third position is 0.4t, the residence time at the fourth position is 0.1t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.3t; the residence time of the finishing station is 0.1t; the total melting time is 28-32 minutes, preferably 30 minutes.
  • the positioning accuracy of each position is ⁇ 5mm.
  • the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa; the power of the graphite electrode is 500-2000KW.
  • the graphite electrode power when melting a quartz crucible with an outer diameter of 24 inches, the graphite electrode power is 750-850KW; when melting a quartz crucible with an outer diameter of 26 inches, the graphite electrode power is 850-950KW; When melting a quartz crucible with an outer diameter of 28 inches, the graphite electrode power is 1000-1100KW; when melting a quartz crucible with an outer diameter of 32 inches, the graphite electrode power is 1300-1400KW.
  • the graphite electrode is blown to remove dust, and the volatile matter deposited on the surface of the graphite electrode is purged and removed.
  • the height difference between the bottom polishing position (or called the bottoming position, which is also the lowest position reached by the graphite electrode) and the fifth position is more than 100 mm.
  • the produced quartz crucible blank is cut, inspected, cleaned, dried, packaged and stored in sequence.
  • the position of the graphite electrode of the present invention is programmed and controlled by the PLC module.
  • the present invention provides a high-quality quartz crucible, which is manufactured using the manufacturing method of any of the above embodiments.
  • the present invention can greatly improve quartz
  • the quality of the crucible includes reducing bubbles on the inner wall of the quartz crucible, improving the purity of the transparent layer of the crucible, enhancing high temperature deformation resistance, reducing the collapse rate of the crucible wall during the crystal pulling process, etc., in order to improve the yield and yield of silicon single crystal produced by the CZ Czochralski method. Production quality is supported.
  • the present invention does not simply improve the quality of the crucible by increasing the working current of the graphite electrode. It does not need to change the hardware of the quartz crucible production equipment. It has a greater flexibility margin and is suitable for producing various specifications.
  • crucible Lower the graphite electrode at least 3 times from the starting position to the bottom polishing position to reach the inside of the crucible and close to the bottom of the crucible blank.
  • the graphite electrode gradually approaches the inner center of the crucible blank, and the distribution of the electrode residence time at each position makes the crucible blank
  • the inner surface including the straight wall surface, arc-shaped transition parts and bottom, is evenly distributed to the heat, and the local area is subjected to extremely high temperature and concentrated treatment, so that the impurities contained in the inner surface of the crucible are evaporated at high temperature and the transparent layer of the crucible is improved. Purity thus ensures the quality of silicon single crystals.
  • the top of the crucible mold is then raised to the cleaning station, which is used to process the upper part of the crucible opening to remove impurities that have volatilized and then deposited on the upper part of the inner wall of the crucible.
  • the present invention can effectively reduce the impurity content on the inner wall surface of the crucible, improve the high-temperature deformation resistance of the crucible, and reduce the collapse rate of the crucible wall surface during the crystal pulling process.
  • Figure 1 is a schematic structural diagram of a quartz crucible.
  • Figure 2 is a schematic diagram of quartz crucible production using high-temperature arc melting.
  • Figure 3 is a schematic diagram of the starting position and zero point position of the graphite electrode during the production of quartz crucible using high-temperature arc melting.
  • Figure 4 shows the graphite electrode positioning diagram and the time distribution at each position when making a 26-inch quartz crucible in Example 1.
  • Figure 5 shows the graphite electrode positioning diagram and the time distribution at each position when making a 26-inch quartz crucible in Example 2.
  • Figure 6 shows the graphite electrode positioning diagram and the time distribution at each position when making a 26-inch quartz crucible in Example 3.
  • Figure 7 shows the graphite electrode positioning diagram and the time distribution at each position when making a 24-inch quartz crucible in Example 4.
  • Figure 8 shows the graphite electrode positioning diagram and the time distribution at each position when making a 28-inch quartz crucible in Example 5.
  • Figure 9 shows the graphite electrode positioning diagram and the time distribution at each position when making a 32-inch quartz crucible in Example 6.
  • Figure 10 is a schematic diagram of the end surface of the quartz crucible collapsing after it is used to produce silicon single crystal by the CZ method.
  • Figure 1 shows a schematic diagram of a quartz crucible, which includes an inner transparent layer 1 and an outer non-transparent layer 2.
  • the transparent layer 1 is in direct contact with the silicon melt.
  • the transparent layer 1 includes a straight wall surface H, an arc transition surface L and a bottom surface W.
  • FIG. 2 it is a schematic diagram of using high-temperature arc melting to produce quartz crucibles in the prior art.
  • the graphite electrode 3 enters the inside of the crucible mold, and the graphite electrode 3 releases a high-temperature arc to melt the quartz raw material.
  • the graphite electrode 3 is lost in the process of releasing high-temperature arc, the graphite electrode 3 continues to move downward, but the distance between the lower end of the graphite electrode and the bottom of the crucible remains unchanged during the entire melting process.
  • This technology can be defined as fixed movement method in this application. Fixed positioning means that the distance from the lower end of the graphite electrode to the upper end face (zero point) of the mold opening remains unchanged.
  • the present invention is based on the existing technology and improves the heat distribution during the melting process of quartz crucible by changing the position of the lower end of the graphite electrode. Specifically, it changes the position of the lower end of the graphite electrode relative to the mold opening in a stepwise manner.
  • the distance between the end faces hereinafter referred to as the position of the graphite electrode.
  • the present invention adopts a step-down mode, which is programmed by the PLC module.
  • the bottom polishing position When the graphite electrode reaches the inside of the crucible for high-temperature polishing of the bottom of the crucible, this position is called the bottom polishing position.
  • the step-like descent includes two meanings.
  • the first is that the position of the graphite electrode is continuously descending.
  • the second layer is that it stays at each position for a period of time. During this time, the graphite electrode continues to release high-temperature arcs to carry out damage to the crucible blank. Heating, melting and high temperature volatilization remove impurities. When high-temperature arc is released, the temperature can reach 3000-3600 degrees. Some metal impurities will volatilize at this temperature, thereby purifying the transparent layer 1 of the crucible and ensuring the production quality of silicon single crystal.
  • the graphite electrode After the graphite electrode is finished working at the bottom polishing position, it is then raised above the mold opening to volatilize the impurities deposited on the upper part of the inner wall of the crucible at high temperature (during bottom polishing, some impurities will volatilize and be re-deposited at a lower temperature location). After the melting is completed, it is cooled to obtain the quartz crucible blank, which is then cut, inspected, cleaned, dried, and packaged for storage.
  • the starting position of the graphite electrode is + (0.10 ⁇ 0.30) times the outer diameter of the crucible, and the residence time is ⁇ 2 minutes. After that, the graphite electrode descends in sequence according to the ladder positioning method, and stays for a period of time at each lowered position.
  • the electrode continuously releases high-temperature arc to melt the crucible blank during the corresponding period of time at the corresponding position, and reaches the bottom polishing position after moving at least 3 times;
  • the bottom polishing position is the lowest position reached by the graphite electrode and enters the inside of the crucible blank (the position is negative) , 300-550mm away from the bottom of the crucible;
  • the graphite electrode stays for a predetermined time to perform high-temperature polishing and volatile impurity removal on the bottom of the crucible;
  • the graphite electrode leaves the bottom polishing position and then rises to the tailing station.
  • the tailing station is + (0.05 ⁇ 0.07) times the outer diameter of the crucible.
  • the upper inner wall of the quartz crucible is polished at high temperature and evaporated to remove impurities.
  • the position of the graphite electrode includes the starting position, the second position, the third position, the fourth position, the fifth position, the bottom polishing position and the finishing position, where the starting position to the bottom polishing position is Descend step by step and stay at each position for a period of time; the positioning accuracy of the graphite electrode at each position is ⁇ 5mm.
  • the graphite electrode's residence time at each position is distributed as follows: the sum of the residence time at the starting position, the second position, and the third position is 0.4-0.5t, the residence time at the fourth position is 0.1-0.2t, and the residence time at the fifth position is 0.1-0.2t. is 0.1t, the residence time at the bottom polishing position is 0.2-0.3t, and the residence time at the tailing station is 0.1t; t is the total melting time of the target quartz crucible.
  • the residence time of the graphite electrode at each position is distributed as follows: quartz crucible with an outer diameter of 24 inches: the sum of the residence time at the starting position, the second position and the third position is 0.4t, and the residence time at the fourth position is 0.4t.
  • the time is 0.2t
  • the residence time at the fifth position is 0.1t
  • the residence time at the bottom polishing position is 0.2t
  • the residence time at the finishing station is 0.1t
  • the total melting time is 14-16 minutes, preferably 15 minutes;
  • Quartz crucible with an outer diameter of 26 inches the sum of the residence time at the starting position, the second position and the third position is 0.45t, the residence time at the fourth position is 0.15t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.2t; the residence time of the finishing station is 0.1t; the total melting time is 17-19 minutes, preferably 18 minutes;
  • Quartz crucible with an outer diameter of 28 inches the sum of the residence time at the starting position, the second position and the third position is 0.45t, the residence time at the fourth position is 0.1t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.25t; the residence time of the finishing station is 0.1t; the total melting time is 22-26 minutes, preferably 24 minutes;
  • Quartz crucible with an outer diameter of 32 inches the sum of the residence time at the starting position, the second position and the third position is 0.4t, the residence time at the fourth position is 0.1t, the residence time at the fifth position is 0.1t, and the residence time at the bottom polishing position is 0.3t; the residence time of the finishing station is 0.1t; the total melting time is 28-32 minutes, preferably 30 minutes.
  • the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa; the power of the graphite electrode is 500-2000KW.
  • the graphite electrode power when melting a quartz crucible with an outer diameter of 24 inches, the graphite electrode power is 750-850KW; when melting a quartz crucible with an outer diameter of 26 inches, the graphite electrode power is 850-950KW; when melting a quartz crucible with an outer diameter of 28 inches When melting a quartz crucible with an outer diameter of 32 inches, the graphite electrode power is 1300-1400KW.
  • the graphite electrode is blown to remove dust, and the volatile matter deposited on the surface of the graphite electrode is purged and removed.
  • the height difference between the bottom polishing position (or called the bottoming position, which is also the lowest position reached by the graphite electrode) and the fifth position is more than 100 mm.
  • the raw materials in the following examples are all from the same batch of quartz raw materials, and the purity of high-purity quartz sand is ⁇ 99.99%.
  • This embodiment provides a high-quality quartz crucible manufacturing method, which is used to manufacture a quartz crucible with an outer diameter of 26 inches, using the vacuum arc method.
  • the steps are as follows:
  • the power of the graphite electrode is controlled to 900KW, the accuracy at each position is ⁇ 5mm, and the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa.
  • the graphite electrode is blown to remove dust. , purge to remove deposited volatiles.
  • This embodiment is based on Embodiment 1.
  • the PLC program controls the position of the graphite electrode as shown in Figure 5 to melt the quartz crucible.
  • the graphite electrode works in a total of 7 positions. It stays at the starting position for 3 minutes, the second position for 2 minutes, the third position for 3.1 minutes, the fourth position for 2.7 minutes, the fifth position for 1.8 minutes, and the bottom polishing position. 3.6min (300mm from the bottom of the crucible), and stay at the finishing position for 1.8min.
  • This embodiment is based on Embodiment 1.
  • the PLC program controls the position of the graphite electrode as shown in Figure 6 to melt the quartz crucible.
  • the graphite electrode works in a total of 7 positions. It stays at the starting position for 3 minutes, the second position for 2 minutes, the third position for 2.2 minutes, the fourth position for 3.6 minutes, the fifth position for 1.8 minutes, and the bottom polishing position. 3.6min (350mm from the bottom of the crucible), and stay at the finishing station for 1.8min.
  • a fixed movement method is used to manufacture a quartz crucible with an outer diameter of 26 inches. The steps are as follows:
  • This embodiment provides a high-quality quartz crucible manufacturing method, which is used to manufacture a quartz crucible with an outer diameter of 24 inches, using the vacuum arc method.
  • the steps are as follows:
  • the power of the graphite electrode is controlled to 800KW, the accuracy at each position is ⁇ 5mm, and the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa.
  • the graphite electrode is blown and dusted. , purge to remove deposited volatiles.
  • This embodiment provides a high-quality quartz crucible manufacturing method, which is used to manufacture a quartz crucible with an outer diameter of 28 inches, using the vacuum arc method.
  • the steps are as follows:
  • the power of the graphite electrode is controlled to 1050KW, the accuracy at each position is ⁇ 5mm, and the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa.
  • the graphite electrode is blown to remove dust and dust, and the deposits are removed by blowing. of volatile matter.
  • This embodiment provides a high-quality quartz crucible manufacturing method, which is used to manufacture a quartz crucible with an outer diameter of 32 inches, using the vacuum arc method.
  • the steps are as follows:
  • the power of the graphite electrode is controlled to 1400KW, the accuracy at each position is ⁇ 5mm, and the vacuum degree is controlled at -0.093Mpa ⁇ -0.1Mpa.
  • the graphite electrode is blown and dusted. , purge to remove deposited volatiles.
  • Example 1 0.5 0.6 0.5 0.9 0.1 0.8 0.4 0.05 Comparative example 1 0.9 0.8 1.0 1.1 0.7 1.8 0.8 0.1 Example 2 0.4 0.4 0.7 0.8 0.2 0.9 0.3 0.04 Example 3 0.4 0.5 0.8 0.7 0.2 0.8 0.2 0.06 Example 4 0.6 0.3 0.9 0.8 0.3 0.7 0.2 0.05 Example 5 0.7 0.4 0.5 0.6 0.2 0.6 0.4 0.08 Example 6 0.5 0.6 0.5 0.8 0.1 0.7 0.4 0.05
  • the surface impurity content of the inner transparent layer 1 of the quartz crucible prepared in Examples 1-6 of the present invention is lower and purer, which reduces the introduction of impurities in the process of pulling crystals to produce silicon single crystals to ensure the quality of silicon single crystals. Production quality.
  • the quartz glass crucibles of Examples 1-6 were inspected and found to have no cracks or pits on the surface, and no bubbles or protruding spots by naked eye observation.

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Abstract

本发明涉及一种高品质石英坩埚的制作方法，采用真空电弧法熔制，石墨电极的走位和每个位置上的停留时间满足：以模具上口端面位置为零点，石墨电极的末端在零点以上为+，在零点以下为-；石墨电极的起始位置为+0.10～0.30倍的坩埚外径，停留时间≥2分钟，之后依次按阶梯走位法依次下降位置，每下降一个位置停留一段时间，走位至少3次后到达底部抛光位置；底部抛光位置为石墨电极到达的最低位置且进入坩埚坯内部，距离坩埚底部300-550mm；在该位置上，石墨电极停留并对坩埚底部进行高温抛光和挥发除杂；之后再上升到扫尾工位，该扫尾工位为+0.05～0.07倍的坩埚外径，在该位置上对石英坩埚的内壁上部进行高温挥发除杂。本发明用于提高坩埚透明层的纯度，增强耐高温变形性能等。

Description

一种高品质石英坩埚的制作方法 技术领域
本发明涉及单晶硅生产技术领域，具体是一种由丘克拉斯基法(Czochralski，以下简称为CZ直拉法)制造硅单晶时所使用的石英坩埚的制作方法。
背景技术
硅单晶是制作硅基半导体材料、太阳能电池片最主要的原材料之一。硅单晶主要由CZ直拉法制得。在CZ直拉法中，将多晶硅原料放置于石英坩埚内加热熔融状硅熔体，拉杆带动籽晶下降使其接触硅熔体，然后缓慢的向上提拉籽晶从而形成硅单晶棒。石英坩埚一般为双层结构，内壁为不含气泡的透明层，外壁为气泡含量较多的非透明层。内壁因为与硅熔体接触，在高温状态下，若内壁存在气泡，气泡会由于硅熔体侵蚀而破裂，破裂的碎片如果溶于硅熔体中，会影响硅单晶的成品率和品质。外壁需要把来自加热器的热量均匀散射，所以需要规定数量和大小的气泡，从而对硅熔体均匀加热。作为唯一与硅溶液接触的材料，石英坩埚的质量对硅单晶的品质有很大影响。譬如石英坩埚内壁气泡的含量、石英坩埚的纯度、石英坩埚的耐高温变形性能等。
石英坩埚的制作一般采用真空电弧法制作。采用该方法时，将高纯的石英砂原料倒入石墨模具或金属模具内，通过成型装置将石英砂原料均匀的成型在模具的内表面，然后通过高温电弧(一般是用三相电弧炉三根石墨电极)将石英砂在3000℃以上的高温下熔化，最后通过快速冷却形成石英(玻璃)坩埚。在真空电弧法制作石英坩埚的过程中，电弧的温度对石英坩埚的质量影响甚大，譬如坩埚的内壁气泡含量、纯度、抗高温变形性能、玻璃化程度等等，所以如何优化电弧的控制，十分重 要。
在对电弧温度的控制中，石墨电极的位置走位(电极末端位置相对于模具上口端面的位置)会在电流一定的情况下(功率设备不变)，极大地提升石英坩埚的制作质量。但是，目前制作石英坩埚过程中的电极位置走位一般仍采用固定位置熔制法(本申请在称之为固定走位法或Fixed Type Method，简称FT法)。FT法石墨电极的位置走位是固定的，仅针对石墨电极的消耗定期做下降补偿(下降一段距离以补偿电极的损耗)，同时现有制备方法仅通过调整电流大小来改善石英坩埚的生产质量。然而实际生产中发现，仅通过调整电流大小对石英坩埚质量的改善十分有限，且生产设备一旦搭建完成其组成硬件能够承载的电流大小是有限的，故难以通过更换大电流来改善坩埚的生产质量，而改变硬件重新搭建设备的成本也非常高昂。至此，一种提高石英坩埚品质的生产方法仍是业内研究者亟待解决的技术问题。
发明内容
(一)要解决的技术问题
鉴于现有技术的上述缺点、不足，本发明提供一种高品质石英坩埚的制作方法，该方法主要是通过控制石墨电极的位置走位和每个位置的时间分配以制得高品质的石英坩埚，包括提高适应坩埚的耐高温强度，提高透明层的纯度，减少坩埚内壁气泡等，其解决了现有技术在固定走位下通过改变电流改善坩埚品质所带来的技术问题。
(二)技术方案
为了达到上述目的，本发明采用的主要技术方案包括：
第一方面，本发明提供一种高品质石英坩埚的制作方法，所述制作方法为采用真空电弧法，包括步骤：
将高纯的石英砂原料倒入坩埚模具内，通过成型装置将石英砂原料均匀的成型在模具的内表面以成型坩埚坯，然后将坩埚模具整体移入电弧熔制炉内，通过石墨电极释放高温电弧使石英砂熔化，最后快速冷却 形成石英坩埚毛坯；在使用石墨电极释放高温电弧的过程中，控制石墨电极在高度方向上的位置走位和每个位置上的停留时间，使其满足如下条件：
以模具上口端面位置为零点，石墨电极的末端在零点以上记为+，在零点以下记为-；熔制过程中，石墨电极的起始位置为+(0.10～0.30)倍的坩埚外径，停留时间≥2分钟，之后依次按阶梯走位法依次下降位置，每下降一个位置停留一段时间，石墨电极在该相应位置的相应时段内持续释放高温电弧来熔制坩埚坯，走位至少3次后到达底部抛光位置；底部抛光位置为石墨电极到达的最低位置且进入坩埚坯内部(位置为负)，距离坩埚底部300-550mm；在底部抛光位置上，石墨电极停留预定时间对坩埚底部进行高温抛光和挥发除杂；
石墨电极从底部抛光位置离开后再上升到扫尾工位，该扫尾工位为+(0.05～0.07)倍的坩埚外径，在该位置上对石英坩埚的内壁上部进行高温抛光和挥发除杂。
其中，当起始位置到底部抛光位置的走位次数为3次时，相邻两个位置之间的高度差≥50mm；而起始位置到底部抛光位置的走位次数大于3次时，则不需要每两步之间高度差达≥50mm。
根据本发明的较佳实施例，其中，在整个熔制过程中，石墨电极的走位包括起始位置，第二位置、第三位置、第四位置、第五位置、底部抛光位置和扫尾工位，其中起始位置到底部抛光位置为阶梯式下降且在每个位置上停留一段时间。
根据本发明的较佳实施例，其中，石墨电极在各位置停留时间分配如下：起始位置和第二位置及第三位置停留时间之和为0.4-0.5t，第四位置停留时间为0.1-0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2-0.3t，扫尾工位的停留时间为0.1t；t为目标石英坩埚的总熔制时间。
根据本发明的较佳实施例，依据不同规格石英坩埚，石墨电极在各 位置的停留时间分配为：外径24寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.4t，第四位置停留时间为0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为14-16分钟，优选是15分钟；
外径26寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.15t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为17-19分钟，优选是18钟；
外径28寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.25t；扫尾工位停留时间为0.1t；总熔制时间为22-26分钟，优选是24分钟；
外径32寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.4t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.3t；扫尾工位停留时间为0.1t；总熔制时间为28-32分钟，优选是30分钟。
根据本发明的较佳实施例，石墨电极在走位过程中，每个位置的定位精度为±5mm。
根据本发明的较佳实施例，在整个熔制过程中，真空度控制在-0.093Mpa～-0.1Mpa；石墨电极的功率是500-2000KW。
根据本发明的较佳实施例，熔制外径24寸的石英坩埚时，石墨电极功率为750-850KW；熔制外径26寸的石英坩埚时，石墨电极功率为850-950KW；熔制外径28寸的石英坩埚时，石墨电极功率为1000-1100KW；熔制外径32寸的石英坩埚时，石墨电极功率为1300-1400KW。
根据本发明的较佳实施例，在所述石墨电极走位过程中，每个位置熔制结束时，对石墨电极进行吹风除灰，对石墨电极表面沉积的挥发物进行吹扫去除。
根据本发明的较佳实施例，底部抛光位置(或称为打底位置，也是石墨电极到达的最低位置)与第五位置之间的高度差在100mm以上。
根据本发明的较佳实施例，制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包装入库。
本发明的石墨电极的走位由PLC模块程序化控制。
第二方面，本发明提供一种高品质石英坩埚，其采用上述任一实施例的制作方法制得。
(三)有益效果
本发明通过精确控制石墨电极的起始位置和后续按照阶梯走位法依次下降到底底部抛光位置(位置为负)，配合每个位置上的停留时间(释放高温电弧的时间)，可以大幅改善石英坩埚的质量，包括减少石英坩埚内壁气泡，提高坩埚透明层的纯度，增强耐高温变形性能，减少在拉晶过程坩埚壁面下塌率等，为提高CZ直拉法生产硅单晶的成品率和生产质量提供支持。
相比固定走位法，本发明不是单纯通过增大石墨电极的工作电流来改善坩埚的品质，无需改变生产石英坩埚设备的各硬件，具有更大的灵活裕度和适于制作多种规格的坩埚。从起始位置到底部抛光位置至少下降3次使石墨电极到达坩埚内部并靠近坩埚坯底部，整个熔制过程中石墨电极逐渐靠近坩埚坯的内部中心，配合各位置电极停留时间的分配使坩埚坯内表面，包括直壁面、弧形过度部位和底部等各处都被均匀分配到热量，而局部又受极高温集中处理，使坩埚内表面所含杂质在高温下挥发殆尽，提高坩埚透明层纯度进而保证硅单晶的品质。在石墨电极到达最低位置对坩埚底部进行高温抛光之后，再升高坩埚模具上方到扫尾工位，用于处理坩埚开口上部以去除挥发后又沉积到坩埚内壁上部的杂质。经比较，本发明可以有效降低坩埚内壁表面的杂质含量，并提高坩埚的耐高温变形性能，减少拉晶过程坩埚壁面下塌率。
附图说明
图1为石英坩埚的结构示意图。
图2为采用高温电弧熔制生产石英坩埚的示意图。
图3为采用高温电弧熔制生产石英坩埚的过程中，石墨电极的起始位置、零点位置的示意图。
图4为实施例1中制作26寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图5为实施例2中制作26寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图6为实施例3中制作26寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图7为实施例4中制作24寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图8为实施例5中制作28寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图9为实施例6中制作32寸石英坩埚时石墨电极走位图和各位置上的时间分配。
图10为石英坩埚用于CZ法生产硅单晶后坩埚端面下塌情况示意图。
具体实施方式
为了更好的解释本发明，以便于理解，下面结合附图，通过具体实施方式，对本发明作详细描述。
如图1所示为石英坩埚示意图，其包括内侧的透明层1和外侧的非透明层2。其中透明层1与硅熔液直接接触。透明层1包括直壁面H、弧形过度面L和底面W。
如图2所示，为现有技术中采用高温电弧熔制生产石英坩埚的示意图。现有技术中，石墨电极3进入坩埚模具内部，石墨电极3释放高温电弧对石英原料进行熔制。随着石墨电极3在释放高温电弧过程中的损耗，石墨电极3不断下移，但是石墨电极下部末端与坩埚底部的距离在 整个熔制过程中保持不变。该技术在本申请中可定义为固定走位法。固定走位的意思就是石墨电极的下部末端到模具开口上端面(零点)的距离保持不变。
如图3所示，本发明是在现有技术的基础上，通过改变石墨电极下部末端的位置来改善石英坩埚熔制过程中的热量分配，具体是阶梯式改变石墨电极下部末端相对模具开口上端面的距离(后述简称为石墨电极的位置)。在改变石墨电极位置的过程中，本发明采用了阶梯式下降的模式，该阶梯式下降模式由PLC模块程序化控制。当石墨电极到达坩埚内部用于对坩埚底部进行高温抛光，该位置称为底部抛光位置。所述阶梯式下降，包含两层意思，第一是石墨电极的位置是不断下降的，第二层是在每个位置上停留一段时间，在该时间内石墨电极持续释放高温电弧对坩埚坯进行加热熔制和高温挥发去除杂质。在高温电弧释放时，温度可达到3000-3600度，一些金属杂质在该温度下会挥发掉，从而使坩埚的透明层1实现纯净化，保证硅单晶的生产质量。石墨电极在底部抛光位置工作结束后，再升高到模具开口上方，用于对坩埚内壁上部沉积的杂质进行高温挥发(在底部抛光时，一些杂质会挥发到温度降低的部位重新沉积)。熔制完成后，冷却，得到石英坩埚毛坯，再依次进行切割、检查、清洗、烘干、包装入库。
如图3所示，以模具上口端面位置为零点，石墨电极的末端在零点上方记为+，在零点的下方记为-。具体地，本发明的方案如下：
熔制过程中，石墨电极的起始位置为+(0.10～0.30)倍的坩埚外径，停留时间≥2分钟，之后依次按阶梯走位法依次下降位置，每下降一个位置停留一段时间，石墨电极在该相应位置的相应时段内持续释放高温电弧来熔制坩埚坯，走位至少3次后到达底部抛光位置；底部抛光位置为石墨电极到达的最低位置且进入坩埚坯内部(位置为负)，距离坩埚底部300-550mm；在底部抛光位置上，石墨电极停留预定时间对坩埚底部进行高温抛光和挥发除杂；
石墨电极从底部抛光位置离开后再上升到扫尾工位，该扫尾工位为+(0.05～0.07)倍的坩埚外径，在该位置上对石英坩埚的内壁上部进行高温抛光和挥发除杂。
在整个熔制过程中，石墨电极的走位包括起始位置，第二位置、第三位置、第四位置、第五位置、底部抛光位置和扫尾工位，其中起始位置到底部抛光位置为阶梯式下降且在每个位置上停留一段时间；石墨电极在每个位置的定位精度为±5mm。
优选地，石墨电极在各位置停留时间分配如下：起始位置和第二位置及第三位置停留时间之和为0.4-0.5t，第四位置停留时间为0.1-0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2-0.3t，扫尾工位的停留时间为0.1t；t为目标石英坩埚的总熔制时间。
进一步地，依据不同规格石英坩埚，石墨电极在各位置的停留时间分配为：外径24寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.4t，第四位置停留时间为0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为14-16分钟，优选是15分钟；
外径26寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.15t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为17-19分钟，优选是18钟；
外径28寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.25t；扫尾工位停留时间为0.1t；总熔制时间为22-26分钟，优选是24分钟；
外径32寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.4t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.3t；扫尾工位停留时间为0.1t；总熔制时间为28-32分 钟，优选是30分钟。
优选地，在整个熔制过程中，真空度控制在-0.093Mpa～-0.1Mpa；石墨电极的功率是500-2000KW。
优选地，熔制外径24寸的石英坩埚时，石墨电极功率为750-850KW；熔制外径26寸的石英坩埚时，石墨电极功率为850-950KW；熔制外径28寸的石英坩埚时，石墨电极功率为1000-1100KW；熔制外径32寸的石英坩埚时，石墨电极功率为1300-1400KW。
优选地，在所述石墨电极走位过程中，每个位置熔制结束时，对石墨电极进行吹风除灰，对石墨电极表面沉积的挥发物进行吹扫去除。
优选地，底部抛光位置(或称为打底位置，也是石墨电极到达的最低位置)与第五位置之间的高度差在100mm以上。
以下结合本发明的较佳实施例说明本发明的特点和效果。如无特殊说明，以下实施例中原料都为同一批石英原料，高纯石英砂的纯度≥99.99％。
实施例1
本实施例提供一种高品质石英坩埚制作方法，用于制作外径26寸的石英坩埚，采用真空电弧法，步骤如下：
(1)在坩埚模具内均匀布高纯石英砂粉料，并成型；
(2)成型后的模具移入电弧熔制炉内；
(3)将模具开上端面位置设为零点，PLC程序化控制石墨电极的走位如图4所示，对石英坩埚进行熔制。图中，石墨电极共有在7个位置进行工作，起始位置停留3min、第二位置停留3min、第三位置停留3min、第四位置停留1.8min、第五位置停留1.8min、底部抛光位置停留3.6min(距离坩埚底部310mm)、扫尾工位停留1.8min。
熔制过程中，控制石墨电极的功率为900KW，每个位置上的精度为±5mm，真空度控制在-0.093Mpa～-0.1Mpa，每步位置熔制结束时，对石墨电极进行吹风除灰，吹扫去除沉积的挥发物。
(4)熔制结束后，石英坩埚冷却出炉，完成石英坩埚毛坯的制作；
(5)制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包装入库。
实施例2
本实施例是在实施例1基础上，PLC程序化控制石墨电极的走位如图5所示，对石英坩埚进行熔制。图中，石墨电极共有在7个位置进行工作，起始位置停留3min、第二位置停留2min、第三位置停留3.1min、第四位置停留2.7min、第五位置停留1.8min、底部抛光位置停留3.6min(距离坩埚底部300mm)、扫尾工位停留1.8min。
实施例3
本实施例是在实施例1基础上，PLC程序化控制石墨电极的走位如图6所示，对石英坩埚进行熔制。图中，石墨电极共有在7个位置进行工作，起始位置停留3min、第二位置停留2min、第三位置停留2.2min、第四位置停留3.6min、第五位置停留1.8min、底部抛光位置停留3.6min(距离坩埚底部350mm)、扫尾工位停留1.8min。
对比例1
本实施例采用固定走位法制作外径26寸的石英坩埚，步骤如下：
(1)在坩埚模具内均匀布高纯石英砂粉料，并成型；石英原料与实施例1为同一批原料。
(2)成型后的模具移入电弧熔制炉内；
(3)将石墨电极定位-150mm处，石墨电极的功率为900KW，真空度控制在-0.093Mpa～-0.1Mpa，每隔3分钟对石墨电极进行吹风除灰，吹扫去除沉积的挥发物。随着石墨电极损耗，适应性向下移动石墨电极，使石墨电极下部末端到模具开口上端面的距离保持在-150mm(距离坩埚底部310mm)。
(4)熔制结束后，石英坩埚冷却出炉，完成石英坩埚毛坯的制作；
(5)制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包 装入库。
实施例4
本实施例提供一种高品质石英坩埚制作方法，用于制作外径24寸的石英坩埚，采用真空电弧法，步骤如下：
(1)在坩埚模具内均匀布高纯石英砂粉料，并成型；
(2)成型后的模具移入电弧熔制炉内；
(3)将模具开上端面位置设为零点，PLC程序化控制石墨电极的走位如图7所示，对石英坩埚进行熔制：图中，石墨电极共有在7个位置进行工作，起始位置停留2min、第二位置停留2min、第三位置停留2min、第四位置停留3min、第五位置停留1.5min、底部抛光位置停留3min(距离坩埚底部340mm)、扫尾工位停留1.5min。
熔制过程中，控制石墨电极的功率为800KW，每个位置上的精度为±5mm，真空度控制在-0.093Mpa～-0.1Mpa，每步位置熔制结束时，对石墨电极进行吹风除灰，吹扫去除沉积的挥发物。
(4)熔制结束后，石英坩埚冷却出炉，完成石英坩埚毛坯的制作；
(5)制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包装入库。
实施例5
本实施例提供一种高品质石英坩埚制作方法，用于制作外径28寸的石英坩埚，采用真空电弧法，步骤如下：
(1)在坩埚模具内均匀布高纯石英砂粉料，并成型；
(2)成型后的模具移入电弧熔制炉内；
(3)将模具开上端面位置设为零点，PLC程序化控制石墨电极的走位如图8所示，对石英坩埚进行熔制：图中，石墨电极共有在7个位置进行工作，起始位置停留3.6min、第二位置停留3.6min、第三位置停留3.6min、第四位置停留2.4min、第五位置停留2.4min、底部抛光位置停留6min(距离坩埚底部420mm)、扫尾工位停留2.4min。
控制石墨电极的功率为1050KW，每个位置上的精度为±5mm，真空度控制在-0.093Mpa～-0.1Mpa，每步位置熔制结束时，对石墨电极进行吹风除灰，吹扫去除沉积的挥发物。
(4)熔制结束后，石英坩埚冷却出炉，完成石英坩埚毛坯的制作；
(5)制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包装入库。
实施例6
本实施例提供一种高品质石英坩埚制作方法，用于制作外径32寸的石英坩埚，采用真空电弧法，步骤如下：
(1)在坩埚模具内均匀布高纯石英砂粉料，并成型；
(2)成型后的模具移入电弧熔制炉内；
(3)将模具开上端面位置设为零点，PLC程序化控制石墨电极的走位如图9所示，对石英坩埚进行熔制：图中，石墨电极共有在7个位置进行工作，起始位置停留4min、第二位置停留4min、第三位置停留4min、第四位置停留3min、第五位置停留3min、底部抛光位置停留9min(距离坩埚底部500mm)、扫尾工位停留3min。
熔制过程中，控制石墨电极的功率为1400KW，每个位置上的精度为±5mm，真空度控制在-0.093Mpa～-0.1Mpa，每步位置熔制结束时，对石墨电极进行吹风除灰，吹扫去除沉积的挥发物。
(4)熔制结束后，石英坩埚冷却出炉，完成石英坩埚毛坯的制作；
(5)制作后的石英坩埚毛坯依次进行切割、检查、清洗、烘干、包装入库。
对实施例制备的石英坩埚进行性能比较，包括CZ法生产一根硅单晶(耗时100h)后，石英坩埚的下塌情况和石英坩埚透明层中杂质元素含量比较。
取实施例1-6和对比例1的石英坩埚内部透明层1，采用原子吸收法 检测最内侧杂质元素含量，如下表所示：
杂质元素含量ppm
  Ca K Na Li B Al Fe Cu
实施例1 0.5 0.6 0.5 0.9 0.1 0.8 0.4 0.05
对比例1 0.9 0.8 1.0 1.1 0.7 1.8 0.8 0.1
实施例2 0.4 0.4 0.7 0.8 0.2 0.9 0.3 0.04
实施例3 0.4 0.5 0.8 0.7 0.2 0.8 0.2 0.06
实施例4 0.6 0.3 0.9 0.8 0.3 0.7 0.2 0.05
实施例5 0.7 0.4 0.5 0.6 0.2 0.6 0.4 0.08
实施例6 0.5 0.6 0.5 0.8 0.1 0.7 0.4 0.05
经上述比较可知，本发明实施例1-6制备的石英坩埚的内侧透明层1的表面杂质含量更低，更纯净，减少在拉晶生产硅单晶过程中引入杂质，以保证硅单晶的生产品质。此外，实施例1-6的石英玻璃坩埚经检测，表面不裂纹、无凹坑，肉眼观察无气泡和凸出的点。
如图10所示为将石英坩埚用于CZ法拉晶生产单晶硅后，因高温熔化而不可避免地产生下塌现象。在生产过程中，石英坩埚放在石墨坩埚内定位，石英坩埚内盛装纯净的硅熔体。在生产一根硅单晶后，实施例1的石英坩埚下塌高度为3.6mm，对比例1为8.8mm。由此说明，对比例1制备的石英坩埚耐高温变形性能较差，而本发明提供的方案可改善这一问题。
最后应说明的是：以上各实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述各实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的范围。

Claims (10)

  1. 一种高品质石英坩埚的制作方法，所述制作方法为采用真空电弧法，其特征在于，包括步骤：
    将高纯的石英砂原料倒入坩埚模具内，通过成型装置将石英砂原料均匀的成型在模具的内表面以成型坩埚坯，然后将坩埚模具整体移入电弧熔制炉内，通过石墨电极释放高温电弧使石英砂熔化，最后快速冷却形成石英坩埚毛坯；在使用石墨电极释放高温电弧的过程中，控制石墨电极在高度方向上的位置走位和每个位置上的停留时间，使其满足如下条件：
    以模具上口端面位置为零点，石墨电极的末端在零点以上记为+，在零点以下记为-；熔制过程中，石墨电极的起始位置为+0.10～0.30倍的坩埚外径，停留时间≥2分钟，之后依次按阶梯走位法依次下降位置，每下降一个位置停留一段时间，石墨电极在该相应位置的相应时段内持续释放高温电弧来熔制坩埚坯，走位至少3次后到达底部抛光位置；底部抛光位置为石墨电极到达的最低位置且进入坩埚坯内部，距离坩埚底部300-550mm；在底部抛光位置上，石墨电极停留预定时间对坩埚底部进行高温抛光和挥发除杂；
    石墨电极从底部抛光位置离开后再上升到扫尾工位，该扫尾工位为+0.05～0.07倍的坩埚外径，在该位置上对石英坩埚的内壁上部进行高温抛光和挥发除杂。
  2. 根据权利要求1所述的制作方法，其特征在于，在整个熔制过程中，石墨电极的走位包括起始位置，第二位置、第三位置、第四位置、第五位置、底部抛光位置和扫尾工位，其中起始位置到底部抛光位置为阶梯式下降且在每个位置上停留一段时间。
  3. 根据权利要求2所述的制作方法，其特征在于，石墨电极在各位置停留时间分配如下：起始位置和第二位置及第三位置停留时间之和为0.4-0.5t，第四位置停留时间为0.1-0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2-0.3t，扫尾工位的停留时间为0.1t；t为目标石英 坩埚的总熔制时间。
  4. 根据权利要求3所述的制作方法，其特征在于，依据不同规格石英坩埚，石墨电极在各位置的停留时间分配为：外径24寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.4t，第四位置停留时间为0.2t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为14-16分钟；
    外径26寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.15t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.2t；扫尾工位停留时间为0.1t；总熔制时间为17-19分钟；
    外径28寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.45t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.25t；扫尾工位停留时间为0.1t；总熔制时间为22-26分钟；
    外径32寸石英坩埚：起始位置和第二位置及第三位置停留时间之和为0.5t，第四位置停留时间为0.1t，第五位置停留时间为0.1t，底部抛光位置停留时间为0.3t；扫尾工位停留时间为0.1t；总熔制时间为28-32分钟。
  5. 根据权利要求1所述的制作方法，其特征在于，石墨电极在走位过程中，每个位置的定位精度为±5mm。
  6. 根据权利要求1所述的制作方法，其特征在于，在整个熔制过程中，真空度控制在-0.093Mpa～-0.1Mpa；石墨电极的功率是500-2000KW。
  7. 根据权利要求6所述的制作方法，其特征在于，熔制外径24寸的石英坩埚时，石墨电极功率为750-850KW；熔制外径26寸的石英坩埚时，石墨电极功率为850-950KW；熔制外径28寸的石英坩埚时，石墨电极功率为1000-1100KW；熔制外径32寸的石英坩埚时，石墨电极功率为1300-1400KW。
  8. 根据权利要求1所述的制作方法，其特征在于，在所述石墨电极走位过程中，每个位置熔制结束时，对石墨电极进行吹风除灰，对石墨电极表面沉积的挥发物进行吹扫去除。
  9. 根据权利要求2所述的制作方法，其特征在于，底部抛光位置与第五位置之间的高度差在100mm以上。
  10. 一种高品质石英坩埚，其特征在于，是采用权利要求1-9任一项所述的制作方法制得。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4646318A (en) * 1984-05-24 1987-02-24 Mannesmann Aktiengesellschaft Crucible furnace with adjustable electrodes
JP2004107163A (ja) * 2002-09-20 2004-04-08 Toshiba Ceramics Co Ltd 石英ルツボとその製造方法
JP2008162839A (ja) * 2006-12-27 2008-07-17 Japan Siper Quarts Corp 石英ガラスルツボの製造方法
CN101624258A (zh) * 2008-07-10 2010-01-13 日本超精石英株式会社 石英玻璃坩埚的制造方法
US20120137733A1 (en) * 2010-12-02 2012-06-07 Japan Super Quartz Corporation Method and apparatus for manufacturing vitreous silica crucible
CN108642560A (zh) * 2018-05-21 2018-10-12 宁晋晶兴电子材料有限公司 一种大尺寸石英坩埚的制备方法
CN114477736A (zh) * 2022-03-25 2022-05-13 锦州佑鑫石英科技有限公司 一种高品质石英坩埚的制作方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2143692A1 (en) * 2008-07-10 2010-01-13 Japan Super Quartz Corporation Method for producing quartz glass crucible

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4646318A (en) * 1984-05-24 1987-02-24 Mannesmann Aktiengesellschaft Crucible furnace with adjustable electrodes
JP2004107163A (ja) * 2002-09-20 2004-04-08 Toshiba Ceramics Co Ltd 石英ルツボとその製造方法
JP2008162839A (ja) * 2006-12-27 2008-07-17 Japan Siper Quarts Corp 石英ガラスルツボの製造方法
CN101624258A (zh) * 2008-07-10 2010-01-13 日本超精石英株式会社 石英玻璃坩埚的制造方法
US20120137733A1 (en) * 2010-12-02 2012-06-07 Japan Super Quartz Corporation Method and apparatus for manufacturing vitreous silica crucible
CN108642560A (zh) * 2018-05-21 2018-10-12 宁晋晶兴电子材料有限公司 一种大尺寸石英坩埚的制备方法
CN114477736A (zh) * 2022-03-25 2022-05-13 锦州佑鑫石英科技有限公司 一种高品质石英坩埚的制作方法

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