Method for manufacturing a quartz glass crucible

Abstract

To provide a quartz glass crucible that is used to grow silicon single crystals and has the number of excessive oxygen defects at least on the inner face side reduced to a prescribed value or less.SOLUTION: The present invention relates to a method for producing a quartz glass crucible 1 in which, at least on the inner face of the crucible, an area of 3 mm from the inner face contains excessive oxygen defects of 3×1011 / g or less. The method has a step of keeping the inner face temperature of the crucible-shaped body at a temperature between 950°C to 1200°C. In the step, a reactive gas to react with oxygen contained in the crucible-shaped body is applied at least to the inner face of the crucible-shaped body.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a quartz glass crucible and a method for manufacturing the same, and more particularly to a quartz glass crucible for pulling a silicon single crystal, which suppresses bubble swelling during pulling of a silicon single crystal, and a method for manufacturing the same.

Background Art

[0002] It is known that oxygen excess defects (for example, NBOHC (Non Bridge Oxygen Hole Center)) in quartz glass cause bubble swelling. When the quartz glass is applied to a quartz glass crucible used for pulling a silicon single crystal, when the silicon raw material is melted in the crucible, oxygen contained in the oxygen excess defect is released by the generated heat, and residual bubbles trapped in the oxygen excess defect expand, causing bubble swelling in the crucible. When such bubble swelling occurs near the inner surface of the crucible, there is a problem that fragments of quartz glass are mixed into the silicon melt when the bubbles burst. Furthermore, there is a risk that bubbles detach from the inner surface of the crucible and are mixed into the growing silicon single crystal. If the oxygen excess defects in quartz glass can be measured non-destructively, it is possible to provide a quartz glass member and a quartz glass crucible with guaranteed quality based on the results.

[0003] As a method for non-destructively measuring oxygen excess defects in quartz glass, there is a laser Raman spectroscopy method as disclosed in Patent Document 1. According to this laser Raman spectroscopy method, fluorescence at 650 nm detected at 4000 cm -1 ~4100 cm -1 is attributed to oxygen excess defects. By measuring the distribution of the present fluorescence intensity (calculated by dividing the area intensity of red fluorescence (4000~100 cm -1 ) by the area intensity of the internal standard peak (700~900 cm -1 ) of quartz glass) in a minute region, it is possible to grasp the general tendency of the amount of oxygen excess defects depending on the location.

[0004] However, in the evaluation of oxygen excess defects using the laser Raman spectroscopy method disclosed in Patent Document 1, it was only indirectly evaluated in the form of the red fluorescence intensity ratio. That is, even though it is non-destructive, the amount of oxygen excess defects cannot be measured, and there is a problem that the result cannot be reflected as a specific numerical value in terms of defect analysis and quality assurance.

[0005] In response to such problems, the applicant of the present application has proposed an evaluation method in Patent Document 2 that can non-destructively measure the amount of oxygen excess defects in fused silica in a micro-region. This method includes a step of obtaining a calibration curve of the red fluorescence intensity ratio and oxygen excess defects in a fused silica member using the laser Raman spectroscopy method and the electron spin resonance method, and a step of calculating the number of oxygen excess defects per unit weight using the calibration curve from the red fluorescence intensity ratio of the fused silica member measured by the laser Raman spectroscopy method.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] If the fused silica member is evaluated based on the amount of oxygen excess defects in fused silica obtained by the evaluation method of Patent Document 2 proposed by the applicant of the present application, the generation of bubble swelling in the fused silica crucible can be effectively suppressed. However, in Patent Document 2 proposed by the applicant of the present application, a method for forming the amount of oxygen excess defects in a fused silica member (fused silica crucible) to a desired value has not been provided yet.

[0008] The inventors of the present application conducted intensive research and found that by exposing the surface of a quartz glass crucible (crucible-shaped body) maintained in a high-temperature state after melt molding to a predetermined reactive gas that reacts with oxygen contained in the surface region, the amount of oxygen excess defects present in the surface layer of the quartz glass crucible can be suppressed, and thus the present invention was completed.

[0009] An object of the present invention is to provide a quartz glass crucible used for growing a single crystal of silicon, in which the amount of oxygen excess defects is reduced to a predetermined value or less at least on the inner surface side thereof, and a method for manufacturing the same.

Means for Solving the Problems

[0010] The quartz glass crucible according to the present invention made to solve the above problems is a quartz glass crucible used for growing a single crystal of silicon, and the content of oxygen excess defects in the region from the inner surface of the crucible to a depth of 3 mm at least on the inner surface of the crucible is 3×10 11 per g or less, which is characterized. By using the quartz glass crucible configured as described above, when the silicon raw material is melted in the crucible, even if the residual bubbles trapped in the oxygen excess defects expand due to the generated heat, since the amount of oxygen excess defects on the inner surface of the crucible is small, the generation of bubble swelling on the inner surface of the crucible is suppressed, and the dissolution of bubbles into the silicon melt can be prevented.

[0011] The method for manufacturing a quartz glass crucible according to the present invention, which is made to solve the problems, is a method for manufacturing a quartz glass crucible having the above-described features, and includes a step of rotating an inner member of a crucible forming mold around an axis and supplying glass raw material powder into the inner member, a step of pressing the glass raw material powder against the inner surface of the inner member rotating around the axis by suction force and centrifugal force to form a raw material powder laminate composed of at least one layer, a step of heating and melting the inside of the raw material powder laminate to vitrify the entire raw material powder laminate into a crucible-shaped body, and a step of maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C. In the step of maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C, it is characterized in that a reactive gas that reacts with oxygen contained in the crucible-shaped body is exposed at least to the inner surface of the crucible-shaped body. In addition, in the step of maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C, it is desirable to spray a reactive gas that reacts with oxygen contained in the crucible-shaped body onto the inner surface of the crucible-shaped body at 10 L / second for 60 minutes or more. Further, it is desirable that the reactive gas is hydrogen gas.

[0012] By such a method, a quartz glass crucible in which the content of oxygen excess defects in the region from the inner surface of the crucible to a depth of 3 mm is 3×10 11 or less per g can be obtained, and the above-described effects can be achieved.

Effects of the Invention

[0013] According to the present invention, it is possible to provide a quartz glass crucible in which the amount of oxygen excess defects is reduced to a predetermined value or less at least on the inner surface side thereof, and a method for manufacturing the same, for use in growing a silicon single crystal.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the fused silica crucible and its manufacturing method according to the present invention will be described with reference to the drawings. Figure 1 is a cross-sectional view of the fused silica crucible according to the present invention, and Figure 2 is a schematic diagram of an apparatus for manufacturing the fused silica crucible of Figure 1.

[0016] The fused silica crucible 1 is formed, for example, with a diameter of 100 to 950 mm, and has a bottom portion 13 having a predetermined curvature, a corner portion 12 formed around the bottom portion 13 and having a predetermined curvature, and a straight body portion 11 extending upward from the corner portion 12. At the upper end of the straight body portion 11, a crucible opening (referred to as an upper end opening or a mouth portion 1a) is formed. In the present embodiment, the fused silica crucible 1 has a two-layer structure of an opaque outer layer 2 (opaque layer) and a transparent inner layer 3 (transparent layer) as shown in Figure 1.

[0017] Among these, the opaque outer layer 2 is made of natural raw material fused silica, and the transparent inner layer 3 is made of high-purity synthetic raw material fused silica that comes into contact with molten silicon during the pulling of a single crystal of silicon. Here, "opaque" means a state in which a large number of air bubbles (pores) are present in the fused silica, and it appears cloudy. Also, "natural raw material fused silica" means silica glass manufactured by melting natural raw materials such as quartz crystals, and "synthetic raw material fused silica" means silica glass manufactured by melting synthetic raw materials synthesized, for example, by hydrolysis of silicon alkoxide.

[0018] The opaque outer layer 2 made of natural raw material quartz glass has a thickness dimension in the straight barrel portion 11 of, for example, 10 to 40 mm before heating, a thickness dimension in the corner portion 12 of 10 to 40 mm, and a thickness dimension in the bottom portion 13 of 10 to 40 mm. Also, the transparent inner layer 3 made of synthetic raw material quartz glass (or natural raw material quartz glass) has a thickness dimension in the straight barrel portion 11 of 3 to 30 mm, a thickness dimension in the corner portion 12 of 3 to 30 mm, and a thickness dimension in the bottom portion 13 of 3 to 30 mm.

[0019] Also, in the region within 2 to 3 mm from the inner surface of the transparent inner layer 3, the content of its oxygen excess defects is 3×10 11 pieces / g or less. In this way, by forming the content of oxygen excess defects on the inner surface side of the crucible to be 3×10 11 pieces / g or less, the generation of bubble swelling in the quartz glass crucible 1 can be effectively suppressed. That is, when the silicon raw material is melted in the crucible, even if the residual bubbles trapped in the oxygen excess defects expand due to the generated heat, since the amount of oxygen excess defects on the inner surface of the crucible is small, the generation of bubble swelling on the inner surface of the crucible is suppressed, and the dissolution of bubbles into the silicon melt can be prevented.

[0020] Subsequently, the manufacturing method of the quartz glass crucible according to the present invention will be described. The manufacturing method of the quartz glass crucible according to the present invention is performed, for example, using a quartz glass crucible manufacturing apparatus 20 as shown in FIG. 2. The crucible forming mold 21 of the quartz glass crucible manufacturing apparatus 20 is composed of, for example, an inner member 22 formed of a mold having a plurality of through holes (not shown) drilled therein, and a holding body 24 provided with a ventilation portion 23 on its outer periphery for holding the inner member 22.

[0021] Also, a rotary shaft 25 connected to a rotating means (not shown) is fixed to the lower part of the holder 24, and the crucible forming die 21 is rotatably supported. The vent part 23 is connected to an exhaust port 26 provided at the center of the rotary shaft 25 through an opening 27 provided in the lower part of the holder 24, and this vent part 23 is connected to a decompression mechanism 28. Above the upper part facing the inner member 22, there are an arc electrode 29 for arc discharge, a raw material supply nozzle 31, a nozzle 32 for injecting nitrogen gas, helium gas, or argon gas and spraying the gas to a predetermined part of the crucible, and further a nozzle 34 for injecting a reactive gas that reacts with oxygen (O 2 ) in the quartz glass, for example, hydrogen gas (H 2 ) and spraying it on the inner surface of the crucible.

[0022] To manufacture a crucible using this quartz glass crucible manufacturing apparatus 20, a rotary drive source (not shown) is operated to rotate the rotary shaft 25 in the direction of the arrow, thereby rotating the crucible forming die 21 at a predetermined speed (step S1 in FIG. 3). Then, the atmosphere is set to atmospheric pressure, and the vent part 23 is decompressed by the operation of the decompression mechanism 28. While sucking the inner surface side of the inner member 22 through a large number of through holes formed in the inner member 22 of the crucible forming die 21, quartz glass raw material powder is supplied from the raw material supply nozzle 31 into the inner member 22.

[0023] When loading quartz glass raw material powder into the rotated crucible forming die 21, this raw material supply nozzle 31 is configured to first load, for example, coarse-grained natural quartz glass raw material powder, and then load, for example, fine-grained synthetic silica raw material powder on its inner surface. In addition, two raw material supply nozzles may be provided to supply raw material powder separately.

[0024] The natural quartz glass raw material powder supplied into the crucible forming die 21 is pressed against the inner member 22 of the crucible forming die 21 by the suction force to the inner surface side of the inner member 22 and the centrifugal force, and a single layer (natural quartz glass raw material powder layer 5) is formed (step S2 in FIG. 3). Subsequently, synthetic silica raw material powder is supplied into the crucible molding die 21 following the natural quartz glass raw material powder. This synthetic silica raw material powder is pressed onto the natural quartz glass raw material powder layer 5 by suction force and centrifugal force, forming one layer (synthetic silica raw material powder layer 6), and as a whole, a two-layer raw material powder laminate 7 in the shape of a crucible is formed (step S3 in FIG. 3).

[0025] After forming the raw material powder laminate 7, the decompression by the operation of the decompression mechanism 28 is continued. After a predetermined time has elapsed, the carbon electrode 29 is energized to heat from the inside of the raw material powder laminate, melting the raw material powder laminate 7 from the inside and vitrifying the surface layer (to form a synthetic silica glass layer).

[0026] Furthermore, the decompression by the operation of the decompression mechanism 28 is continued, and suction is performed from the raw material powder laminate 7 for a predetermined time through a plurality of through holes formed in the inner member 22. Furthermore, the carbon electrode 29 is energized to heat and melt from the inside of the raw material powder laminate 7, forming a vitrified crucible-shaped body 8 (step S4 in FIG. 3).

[0027] Here, the temperature of the crucible-shaped body 8 is maintained at 950°C to 1200°C, and a reactive gas, which is a reactive gas, is sprayed onto the entire inner surface of the crucible at a flow rate of 10 L / second from the nozzle 34 for 60 to 180 minutes (step S5 in FIG. 3). By this treatment, the reactive gas reacts with the oxygen component on the crucible surface, removing excess oxygen in the inner surface region of the crucible (the region from the surface to a depth of 3 mm), and suppressing the content of oxygen excess defects to 3×10 11 per gram or less.

[0028] In addition, in the step of spraying the reactive gas, if the temperature of the crucible-shaped body 8 is lower than 950°C, the diffusion rate when the reactive gas diffuses from the inner surface of the crucible into the inside of the glass mass becomes slow, which is not preferable. Also, if it is higher than 1200°C, it exceeds the glass strain point, and there is a risk that stress will locally concentrate in the quartz glass crucible in the mold, causing the quartz glass crucible to deform, which is not preferable.

[0029] Also, if the time of blowing hydrogen gas is shorter than 60 minutes at a flow rate of 10 L / second, the diffusion effect of the reactive gas from the inner surface of the crucible into the inside of the glass body becomes weak, which is not preferable. Further, if it is longer than 180 minutes at a flow rate of 10 L / second, the diffusion of the reactive gas spreads too much, exceeding, for example, the thin transparent inner layer at the bottom and reaching the opaque outer layer. To suppress oxygen excess defects, the generation of bubbles is suppressed and the inside of the glass is overheated. When the inside of the glass is overheated in such a way, the temperature of the silicon melt inside the glass becomes non-uniform, which affects the pulling of the single crystal and is not preferable.

[0030] Furthermore, if the supply of the reactive gas is small, the speed at which the gas reaches the entire inner surface of the quartz glass crucible is slow, and as a result, the speed of diffusion into the glass body is also slow. On the other hand, if the supply amount of the reactive gas is large, the reaction field where the reactive gas diffuses from the inner surface of the glass crucible into the glass body constantly changes, which is not preferable. Therefore, the flow rate of the reactive gas is preferably 10 L / second at which the reaction field is stably maintained.

[0031] Finally, nitrogen gas or helium gas is injected and cooled at a site that tends to become high temperature, for example, the bottom of the raw material powder laminate 7, to suppress the increase in temperature of the synthetic silica glass layer at that site and suppress the concentration of aluminum and metal-based elements due to vaporization (step S6 in FIG. 3). Then, after cooling, the upper end portion of the crucible-shaped body 8 is cut to obtain the quartz glass crucible 1 shown in FIG. 1 (step S7 in FIG. 3).

[0032] As described above, according to the present embodiment, in the region within 3 mm from the inner surface of the crucible, the content of oxygen excess defects is formed to be 3×10 11 pieces / g or less. By using the quartz glass crucible formed in this way, when the silicon raw material is melted in the crucible, even if the residual bubbles trapped in the oxygen excess defects expand due to the generated heat, since the amount of oxygen excess defects on the inner surface of the crucible is small, the generation of bubble swelling on the inner surface of the crucible is suppressed, and the dissolution of bubbles into the silicon melt can be prevented. In addition, to manufacture such a quartz glass crucible, a reactive gas (e.g., hydrogen gas) is sprayed onto the inner surface of the crucible-shaped body 8 maintained at 950°C to 1200°C at a rate of 10 L / second over the entire inner surface of the crucible for 60 to 180 minutes, so as to reduce oxygen excess defects on the inner surface of the crucible.

[0033] In step S5 of FIG. 3, the reactive gas was sprayed onto the inner surface of the crucible by the nozzle 34. However, the present invention is not limited thereto. While the crucible-shaped body 8 is held in a high-temperature chamber, hydrogen gas, which is a reactive gas, may be introduced into the chamber, and the crucible surface may be exposed to hydrogen gas for 60 to 180 minutes. In the above-described embodiment, a quartz glass crucible having a two-layer structure was described as an example. However, in the present invention, the number of layers of the quartz glass crucible is not limited, and it may be one layer or three or more layers. In the above-described embodiment, the reactive gas sprayed onto the inner surface of the crucible was hydrogen gas. However, in the present invention, it is not limited to hydrogen gas, and any other gas that reacts with oxygen may be used.

Example

[0034] The quartz glass crucible and its manufacturing method according to the present invention will be further described based on examples. [Experiment 1] In Experiment 1, using the quartz glass crucible manufacturing apparatus shown in FIG. 2, a quartz glass crucible with a diameter of about 800 mm was manufactured by the manufacturing method shown in the above-described embodiment. After forming the crucible-shaped body, it was held at 1200°C in an environment of atmospheric pressure, and hydrogen gas was introduced into the chamber at a rate of 10 L / second for 60 minutes or more. Then, the crucible-shaped body was cooled to manufacture a quartz glass crucible.

[0035] At three locations indicated by reference numerals 11, 12, and 13 in FIG. 1 of the manufactured quartz glass crucible, it was verified whether there were differences in the amount of oxygen excess defects depending on the position in the depth direction. In Example 1, the amount of oxygen excess defects at a position 1 mm from the inner surface of the crucible, in Example 2 at a position 2 mm from the inner surface of the crucible, and in Example 3 at a position 3 mm from the inner surface of the crucible was measured by the method described in Patent Document 2.

[0036] The results of Experiment 1 are shown in Table 1. Note that the amount of oxygen excess defects in Table 1 is the average value of each part measured at each depth.

Table 1

[0037] From the results of Experiment 1, it was confirmed that when the depth from the inner surface of the crucible was within the range up to 3 mm, the amount of oxygen excess defects was 3×10 11 pieces / g or less.

[0038] [Experiment 2] In Experiment 2, a quartz glass crucible was manufactured by changing the conditions of the holding temperature after forming the crucible-shaped body, setting the introduction rate of the reactive gas at 10 L / second, and varying the introduction time conditions. The amount of oxygen excess defects at a depth of 3 mm from the inner surface of the crucible was measured at three locations indicated by reference numerals 11, 12, and 13 in FIG. 1 of the manufactured quartz glass crucible. Also, the presence or absence of deformation of the quartz glass crucible and its influence on the opaque outer layer at that time were confirmed.

[0039] [Examples 4, 5] In Examples 4 and 5, the conditions of the holding temperature after forming the crucible-shaped body were verified by changing them as shown in Table 2, different from Experiment 1. Other conditions were the same as in Experiment 1.

[0040] [Examples 6, 7] In Examples 6 and 7, the conditions of the introduction time of the reactive gas after forming the crucible-shaped body were verified by changing them as shown in Table 2, different from Experiment 1. Other conditions were the same as in Experiment 1. [Comparative Example 1] In Comparative Example 1, as shown in Table 2, a quartz glass crucible was manufactured without introducing a reactive gas after forming the crucible-shaped body.

[0041] [Comparative Example 2] In Comparative Example 2, as shown in Table 2, the conditions of the holding temperature after forming the crucible-shaped body were verified by changing them from those in Experiment 1. Other conditions were the same as those in Experiment 1. [Example 8] In Example 8, as shown in Table 2, the conditions of the holding temperature after forming the crucible-shaped body were verified by changing them from those in Experiment 1. Other conditions were the same as those in Experiment 1. [Comparative Example 3] In Comparative Example 3, as shown in Table 2, the conditions of the introduction time of the reactive gas after forming the crucible-shaped body were verified by changing them from those in Experiment 1. In Comparative Example 3, the holding temperature of the crucible-shaped body was set at 1100 °C. Other conditions were the same as those in Experiment 1. [Example 9] In Example 9, as shown in Table 2, the conditions of the introduction time of the reactive gas after forming the crucible-shaped body were verified by changing them from those in Experiment 1. Other conditions were the same as those in Experiment 1.

[0042] The results of Experiment 2 are shown in Table 2. Note that the amount of oxygen excess defects in Table 2 is the average value of the amounts of oxygen excess defects at three locations indicated by reference numerals 11, 12, and 13 in FIG. 1. [Table 2]

[0043] [Experiment 3] In Experiment 3, the conditions of the holding temperature after forming the crucible-shaped body were fixed at 1200 °C and the introduction time of the reactive gas was fixed at 120 minutes. The amount of the reactive gas introduced was changed, and the amount of oxygen excess defects at a depth of 3 mm from the inner surface of the crucible was measured. [Example 10] In Example 10, the conditions (introduction time of the reactive gas) of the amount of the reactive gas introduced after forming the crucible-shaped body were verified by changing them from those in Experiment 1. Other conditions were the same as those in Experiment 1. [Comparative Examples 4 and 5] In Comparative Examples 4 and 5, the conditions (introduction time of the reactive gas, flow rate of the reactive gas (L / second) as shown in Table 3) of the amount of the reactive gas introduced after forming the crucible-shaped body were verified by changing them from those in Experiment 1. Other conditions were the same as those in Experiment 1. The results of Experiment 3 are shown in Table 3. [Table 3]

[0044] From the results of Tables 2 and 3, at least at a position 3 mm from the crucible surface, the crucible-shaped body is maintained at a high temperature of 950 to 1200 °C, and hydrogen gas is introduced at 10 L / second for 60 to 180 minutes and exposed to the crucible surface, so that the content of oxygen excess defects can be formed to be 3×10 11 pieces / g or less. It was confirmed that this was possible.

[0045] [Experiment 4] Using a crucible with an oxygen excess defect content of 3×10 11 pieces / g or less in the region 3 mm deep from the inner surface of the crucible and a crucible with an oxygen excess defect content exceeding 3×10 11 pieces / g in the region 3 mm deep from the inner surface of the crucible, a single crystal silicon was pulled up, and the generation status of bubble swelling on the inner surface of the crucible was verified. As the pulling conditions, the CZ (Czochralski) method was used. Polycrystalline silicon, B (boric acid), and P (phosphorus) were put into a quartz glass crucible, melted at 1400 °C or higher, and a single crystal silicon was pulled up over 70 hours.

[0046] As a result, it was confirmed that in the crucible with an oxygen excess defect content of 3×10 11 pieces / g or less in the region 3 mm deep from the inner surface of the crucible, the generation of bubble swelling on the inner surface of the crucible was suppressed, and the dissolution of bubbles into the silicon melt could be suppressed. [Explanation of Signs]

[0047] 1 Quartz glass crucible 2 Opaque outer layer (opaque layer) 3 Transparent inner layer 11 Straight barrel part 12 Corner part 13 Bottom part 20 Quartz glass crucible manufacturing apparatus

Claims

**Claim 1**: A method for manufacturing a quartz glass crucible for growing a single crystal silicon, wherein the content of oxygen excess defects in the region from the inner surface of the crucible to a depth of 3 mm is 3×10^11 pieces / g or less at least on the inner surface of the crucible, comprising: rotating an inner member of a crucible forming mold around an axis and supplying glass raw material powder into the inner member; pressing the glass raw material powder against the inner surface of the inner member rotating around the axis by suction force and centrifugal force to form a raw material powder laminate composed of at least one layer; heating and melting the inside of the raw material powder laminate to vitrify the entire raw material powder laminate into a crucible-shaped body; maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C; including: In the step of maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C, a reactive gas that reacts with oxygen contained in the crucible-shaped body is exposed at least to the inner surface of the crucible-shaped body. A method for manufacturing a quartz glass crucible characterized by this. **Claim 2** In the step of maintaining the inner surface temperature of the crucible-shaped body between 950°C and 1200°C, a reactive gas that reacts with oxygen contained in the crucible-shaped body is sprayed onto the inner surface of the crucible-shaped body at 10 L / second for 60 minutes or more, and the reactive gas is hydrogen gas. The method for manufacturing a quartz glass crucible according to Claim 1, characterized by this. **Claim 3** The method for manufacturing a quartz glass crucible according to Claim 1, wherein the reactive gas is hydrogen gas.

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