JP5447946B2 - Silica glass crucible for pulling silicon single crystal and manufacturing method thereof - Google Patents

Description

  The present invention relates to a quartz glass crucible and a method for producing the same, and more particularly to a quartz glass crucible for pulling a silicon single crystal and a method for producing the same.

  In general, the Czochralski method (CZ method) is widely used as a method for producing a silicon single crystal for semiconductor production. In this CZ method, as shown in FIGS. 1 and 2, first, a single crystal seed crystal 102 is immersed in a polycrystalline silicon 101 melted in a crucible 100 made of quartz glass. At this time, since the seed crystal 102 is subjected to a rapid thermal shock, dislocation occurs at the tip of the seed crystal. In order to remove the dislocations, the neck portion 103 is formed by a predetermined method so that the dislocations are not taken over by the subsequently grown silicon. Thereafter, while controlling the pulling speed and the melt temperature, the seed crystal 102 is rotated and gradually pulled, thereby gradually increasing the diameter and forming the shoulder 104. When the desired diameter is reached, the pulling is continued while controlling to a constant diameter, and the straight body portion 105 is formed. Finally, a tail portion 106 is formed while gradually reducing the diameter, and a silicon single crystal ingot 107 is manufactured.

As shown in FIG. 1, the quartz glass crucible used for pulling up the silicon single crystal uses natural quartz glass 108 in the outer portion to increase the mechanical strength of the crucible, and impurities are mixed in the inner portion. In general, synthetic quartz glass 109 is used to avoid this. Here, “natural quartz glass” refers to quartz glass formed using natural quartz powder as a raw material, and “synthetic quartz glass” refers to quartz glass formed using synthetic quartz powder as a raw material. . In general, a reaction of SiO ₂ (solid) → Si (liquid) + 2O occurs at the interface between the synthetic quartz glass 109 and the silicon melt 101, and the synthetic quartz glass 109 is dissolved. When a silicon single crystal is pulled, depending on an increase in pulling temperature or a decrease in atmospheric pressure, a reaction of Si (liquid) + O → SiO (gas) occurs to generate SiO gas, and FIGS. As shown in b), the silicon melt 101 may be repelled from the surface of the synthetic quartz glass 109 to cause molten metal surface vibration. 3 (a) and 3 (b) are drawn with exaggeration of the hot water surface vibration for easy understanding of the state of the hot water surface vibration.

  When such molten metal surface vibration occurs, the seed crystal 102 cannot be joined to a flat molten metal surface, and problems such as silicon becoming polycrystalline during pulling occur. In particular, the seeding and shoulder formation process, which is the initial stage of the pulling process of the silicon single crystal, is easily affected by the molten metal vibration, and this influence greatly affects the quality of the pulled silicon single crystal ingot. For this reason, the technique which suppresses the molten metal surface vibration of a silicon melt in these processes was desired.

  Patent Document 1 is based on the present applicant, and in order to suppress the melt surface vibration of the silicon melt filled in the quartz glass crucible, the bubble content of the inner peripheral surface layer of the crucible in the vicinity of the start surface of the pull-up is set. A technique for adjusting to a certain range has been disclosed. This is because the melt surface vibration of the silicon melt at the start of silicon pulling was found to be affected by the bubble content of the inner surface layer of the crucible near the melt surface.

As an example, when a large amount of bubbles are contained in a quartz glass crucible, as the reaction of SiO ₂ (solid) → Si (liquid) + 2O proceeds, the quartz glass dissolves, and an open cell 201 as shown in FIG. Will appear. This open bubble 201 can suppress the molten metal surface vibration based on the same principle as the boiling stone prevents bumping. However, the inclusion of a large amount of bubbles 202 in quartz glass substantially reduces the proportion of the crucible itself in the volume of the quartz glass crucible, and the dissolution rate is lower than when no bubbles are provided. There was a problem that it became large, which led to the shortening of life of the quartz glass crucible. In recent years, a large-diameter crucible is required for pulling up a large-diameter silicon single crystal, and accordingly, a quartz glass crucible is expensive. A quartz glass crucible is also desired. In addition, unopened bubbles immediately below the inner surface of the peripheral wall of the crucible expand and rupture during pulling, and there is a problem that the quartz piece is mixed into the silicon melt, and an improvement in the yield of the silicon single crystal is also desired. .

JP 2004-250304 A

  An object of the present invention is to provide a quartz glass crucible for pulling a silicon single crystal having a long life and a method for producing the same, which can stably suppress the molten metal surface vibration of the silicon melt filled therein. .

In order to achieve the above object, the gist of the present invention is as follows.
(1) A quartz glass crucible for pulling a silicon single crystal having a peripheral wall portion, a curved portion, and a bottom portion, wherein the silica glass crucible has a plurality of minute recesses in a specific region on the inner surface of the peripheral wall portion. A quartz glass crucible for pulling up a silicon single crystal, comprising a plurality of bubbles at a position below a recess.

  (2) The quartz glass crucible for pulling up a silicon single crystal according to (1), wherein the specific region is in the region of 0.50H to 0.99H as measured from the bottom when the crucible height is H.

  (3) The specific region may include at least one minute concave portion for each annular inner surface portion divided in a range of 0.1 to 5.0 mm in the crucible height direction. A quartz glass crucible for pulling up a silicon single crystal according to (1).

  (4) The quartz glass crucible for pulling up a silicon single crystal according to the above (1), (2) or (3), wherein the average diameter of the minute recesses is in the range of 1 to 500 μm.

  (5) The quartz glass for pulling up a silicon single crystal according to any one of (1) to (4), wherein the average depth of the minute recesses is in the range of 0.05 to 50% of the crucible thickness in the peripheral wall portion. Crucible.

(6) The silicon single crystal according to any one of (1) to (5), wherein the average diameter of the bubbles is in the range of 10 to 100 μm and the density is in the range of ^{30 to} 300 / mm ^3. A quartz glass crucible for lifting.

  (7) The region including a plurality of bubbles in the synthetic quartz glass layer is the region of 0.5 to 30% of the crucible thickness in the peripheral wall portion, as described in any one of (1) to (6) above. Quartz glass crucible for pulling silicon single crystals.

  (8) A method for producing a quartz glass crucible for pulling a silicon single crystal, which has a peripheral wall portion, a curved portion, and a bottom portion, and is formed of two layers, an outer layer of a natural quartz glass layer and an inner layer of a synthetic quartz glass layer, The method includes a step of forming an outer layer made of natural quartz powder, a step of forming an inner layer made of synthetic quartz powder on the inner surface of the outer layer, an arc discharge from the inner surface side of the inner layer, and melting. Forming a quartz glass crucible having a peripheral wall portion, a curved portion and a bottom portion, wherein the inner layer forming step is positioned below a plurality of minute recesses to be subsequently formed in a specific region of the inner surface of the peripheral wall portion. Using an expandable synthetic quartz powder for the inner layer portion, and further comprising a minute recess processing step for forming a plurality of minute recesses in the specific region after the quartz glass crucible forming step. Method for manufacturing a silicon single crystal for pulling up the quartz glass crucible.

  (9) The method for producing a quartz glass crucible for pulling a silicon single crystal according to (8), wherein the minute recesses are formed by physical grinding using a carbon dioxide laser or a diamond tool.

  According to the present invention, the specific region of the inner surface of the peripheral wall portion is provided with a plurality of minute recesses, and the plurality of bubbles are provided at positions below these minute recesses so that the silicon melt filled therein can be It is possible to provide a quartz glass crucible for pulling a silicon single crystal having a long life and a method for producing the same, which can stably suppress the vibration of the molten metal surface.

FIG. 1 is a schematic cross-sectional view for explaining a method for producing a silicon single crystal. FIG. 2 is a plan view of a general silicon ingot manufactured by a pulling method. FIG. 3A is a schematic cross-sectional view for explaining the melt level vibration of the silicon melt, and FIG. 3B is a schematic plan view showing the melt level vibration of the silicon melt. FIG. 4 is a schematic cross-sectional view of a peripheral wall portion of the crucible showing bubbles contained in a conventional quartz glass crucible. FIG. 5 is a cross-sectional perspective view showing a quartz glass crucible for pulling a silicon single crystal according to the present invention. FIG. 6 is a schematic cross-sectional view showing a method for producing a quartz glass crucible. FIG. 7 is a schematic cross-sectional view in which the interface between the quartz glass crucible and the silicon melt is partially enlarged. FIG. 8 is a cross-sectional perspective view showing a formation pattern of minute recesses.

  Next, an embodiment of a quartz glass crucible for pulling a silicon single crystal and a method for producing the same according to the present invention will be described with reference to the drawings. As shown in FIG. 5 as an example, a quartz glass crucible 1 for pulling a silicon single crystal according to the present invention has a peripheral wall portion 2, a curved portion 3 and a bottom portion 4, and an outer layer of a natural quartz glass layer 8 and a synthetic quartz glass layer. 9 is formed of two inner layers, and a plurality of minute recesses 5 are provided in a specific region 6 on the inner surface of the peripheral wall portion 2, and a plurality of synthetic quartz glass layers 9 positioned below these minute recesses 5 By providing the bubbles 7 and having such a configuration, the micro concave portion 5 in the initial stage of using the crucible, and the bubbles 7 opening in the inner surface of the crucible in the middle stage of using the crucible cause vibration of the melt surface of the silicon melt filled therein. In addition, by suppressing the arrangement position of the bubbles 7, the increase in dissolution rate can be suppressed and the life of the crucible can be extended.

  Such a bubble 7 is exposed to a high temperature condition for a long time until opening, so that the expansion of the bubble is saturated, and there is no possibility of bursting immediately below the inner surface of the peripheral wall portion immediately before the opening of the bubble. Further, since there is no possibility that the quartz piece is mixed into the silicon melt, the yield of the silicon single crystal can be improved.

  In general, a quartz glass crucible 1 for pulling up a silicon single crystal is formed, for example, as shown in FIG. 6, by using centrifugal force so that the outer portion becomes natural quartz powder 8a and the inner portion becomes synthetic quartz powder 9a. Then, arc discharge is performed in this, and natural quartz powder 8a and synthetic quartz powder 9a are melted and then cooled to form a two-layer structure of natural quartz glass 8 and synthetic quartz glass 9. The

  Here, the synthetic quartz powder 9a means what consists of synthetic quartz, and synthetic quartz is a raw material chemically synthesized and manufactured, and the synthetic quartz glass powder is amorphous. Since the raw material of synthetic quartz is gas or liquid, it can be easily purified, and synthetic quartz powder can have a higher purity than natural quartz powder. Synthetic quartz glass raw materials are derived from gaseous raw materials such as silicon tetrachloride and liquid raw materials such as silicon alkoxide. In the present invention, in the synthetic quartz powder glass, all impurities can be 0.1 ppm or less.

  On the other hand, the natural quartz powder 8a means a material made of natural quartz, and natural quartz is a raw material obtained by digging raw quartz existing in nature, crushing and refining, etc. Consists of α-quartz crystals. Natural quartz powder contains 1 ppm or more of Al and Ti. Other metal impurities are also at a higher level than synthetic quartz powder. Natural quartz powder contains almost no silanol. Silanol content of glass obtained by melting natural quartz powder is less than 50 ppm.

  These natural quartz glass 8 and synthetic quartz glass 9 can be discriminated by measuring a fluorescence spectrum obtained by excitation with ultraviolet light having a wavelength of 245 nm and observing the fluorescence peak, for example.

  In the present invention, quartz powder is used as a raw material for the natural quartz glass 8 and the synthetic quartz glass 9, but the “quartz powder” here is not limited to quartz as long as the above conditions are satisfied. Further, powders of materials known as raw materials for quartz glass crucibles such as quartz, silica sand, etc., including silicon dioxide (silica) can also be included.

  As shown in FIG. 5 and FIG. 6 as an example, the method for producing a silica glass crucible for pulling a silicon single crystal according to the present invention has a peripheral wall portion 2, a curved portion 3 and a bottom portion 4, and is an outer layer of a natural quartz glass layer 8. And a method for producing a quartz glass crucible 1 for pulling a silicon single crystal formed of two inner layers of a synthetic quartz glass layer 9, a step of forming an outer layer made of natural quartz powder 8a, and an inner surface of the outer layer The step of forming the inner layer made of the synthetic quartz powder 9a and the step of forming the quartz glass crucible 1 having the peripheral wall portion 2, the curved portion 3 and the bottom portion 4 by generating arc discharge from the inner surface side of the inner layer and melting it. The inner layer forming step includes using foaming synthetic quartz powder in the inner layer portion located below the plurality of minute recesses 5 to be formed in the specific region 6 on the inner surface of the peripheral wall portion 2 thereafter. After the quartz glass crucible formation step, the micro recess portion processing step for forming a plurality of minute recess portions 5 in the specific region 6 is further provided. By having such a configuration, the micro recess portion 5 is in the middle stage of crucible use at the initial stage of using the crucible. In this case, the bubbles 7 opened on the inner surface of the crucible suppress the molten metal surface vibration of the silicon melt filled therein, and the increase in the dissolution rate is suppressed by optimizing the arrangement position of the bubbles 7. It is possible to provide a quartz glass crucible for pulling a silicon single crystal that can extend the life of a crucible.

  Here, the foamable synthetic quartz powder refers to, for example, quartz powder containing water or air. By containing these water or air at the raw material stage, after the quartz glass crucible forming step, below the plurality of minute recesses 5 to be subsequently formed in the specific region 6 on the inner surface of the peripheral wall portion 2, and The synthetic quartz glass layer 9 can have a plurality of bubbles 7.

The amount of silicon melt in the quartz glass crucible changes as the silicon single crystal is pulled. Therefore, the specific area 6, the user may be appropriately selected depending on the amount of the silicon melt in the crucible when used by at least a shoulder portion formed melt surface is located regions (Fig. 5, h ₁ height position when the h < _b > ₂ region). In particular, this region is preferably in the region of 0.50H to 0.99H as measured from the bottom when the crucible height is H.

The reason why the molten metal surface vibration is likely to occur in the region where the molten metal surface is located will be described below. FIG. 7 is a schematic cross-sectional view in which a part of the molten metal surface position of a quartz glass crucible having a silicon melt therein is enlarged. Thus, the liquid silicon melt is solid due to the wettability of the crucible. At the interface with the quartz glass crucible, it exhibits a cross-sectional shape as shown in region I of FIG. In this region I, since the distance from the liquid surface having a low oxygen concentration in the silicon melt is shorter than that outside this region I, the concentration gradient of oxygen becomes large, and the above-mentioned SiO ₂ (solid ) → Si (liquid) + 2O generated by the reaction of O diffuses quickly. Therefore, this reaction easily proceeds and the melting of the crucible is promoted. Generally, since this region I occurs in the range of 0.1 to 5.0 mm in the crucible height direction, the specific region 6 is partitioned at intervals of 0.1 to 5.0 mm in the crucible height direction (in FIG. 8, h ₃ It is preferable to provide at least one minute concave portion 5 for each annular inner surface portion partitioned at intervals.

  The average diameter of the minute recesses 5 is preferably in the range of 1 to 500 μm. If the average diameter of the minute recesses 5 is less than 1 μm, the same effect as the above-described boiling stone cannot be obtained sufficiently. On the other hand, if the average diameter of the minute recesses 5 exceeds 500 μm, This is because not only the effect cannot be obtained sufficiently, but also the minute recesses 5 are easily lost due to melting of the crucible.

  The average depth of the minute recesses 5 is preferably in the range of 0.05 to 50% of the crucible thickness in the peripheral wall portion. If the average depth of the micro-recesses 5 is less than 0.05% of the crucible thickness in the peripheral wall part, the micro-recesses 5 are likely to disappear due to melting of the crucible, and the expansion of the unopened bubbles may not be saturated. If the average depth of the minute recesses 5 exceeds 50% of the thickness of the crucible in the peripheral wall 2, the wall strength of the crucible may be affected. In addition, it is preferable that the thickness of the surrounding wall part 2 shall be the range of 100-1000 micrometers as an example.

The ratio of the average diameter of the minute recesses 5 to the average depth is preferably more than 0 and less than 0.8. In order to prevent the recess from disappearing due to melting of the crucible, it is necessary to suppress the reaction of SiO ₂ (solid) → Si (liquid) + 2O. For this purpose, if the oxygen concentration in the silicon melt at the interface between the crucible and the melt is increased, the above reaction becomes difficult to proceed. For this purpose, once the oxygen generated by the reaction is prevented from diffusing from the recess, the diameter and the depth are regulated so that the ratio is within the above range so as not to be affected by the thermal convection of the silicon melt. Is preferred.

The average diameter of the bubbles 7 is preferably in the range of 10 to 100 μm, and the density is preferably in the range of ^{30 to} 300 / mm ³ . If the average diameter of the bubbles 7 is less than 10 μm, the effect of suppressing the hot water surface vibration cannot be sufficiently obtained. On the other hand, if the average diameter of the bubbles 7 exceeds 100 μm, the inner surface of the crucible is deformed by the expansion of the bubbles 7, This is because quartz pieces or the like may be mixed into the silicon melt. Further, if the density is less than 30 / mm ³ , the effect of suppressing the molten metal surface vibration cannot be sufficiently obtained. On the other hand, if the density of the bubbles 7 exceeds 300 / mm ³ , the expansion of the bubbles 7 causes the inside of the crucible. This is because the surface may be deformed and quartz pieces or the like may be mixed into the silicon melt.

  The region including the plurality of bubbles 7 in the synthetic quartz glass layer 9 is preferably a region of 0.5 to 30% of the crucible thickness in the peripheral wall portion. By providing the bubble 7 in the synthetic quartz glass layer 9 below the minute recess 5, the air in the bubble 7 expands and bursts due to heat, and the quartz piece or the like is mixed into the silicon melt. In addition, by making the region including the plurality of bubbles 7 in the synthetic quartz glass layer 9 in the above range, even if the synthetic quartz glass of the crucible is dissolved and the minute recesses 5 are eliminated. Since the bubbles 7 appearing in the opening can suppress the molten metal surface vibration of the silicon melt, the life of the quartz glass crucible can be extended.

  The minute recess 5 is preferably formed using a carbon dioxide laser or a diamond tool. For example, the irradiation surface of the carbon dioxide laser is opposed to the inner surface of the crucible, and irradiation with 10.6 μm infrared light forms the minute recesses. Alternatively, a minute recess is formed by applying water to a diamond-coated brittle material drill made by Mitsubishi Materials and applying it to the inner surface of the crucible. Repeated “grinding / crucible rotation or elevation” to form a recess on the entire inner surface of a specific area.

  The above description is given as an example, and the present invention is not limited to this embodiment.

Example 1
In Example 1, as shown in FIG. 6, natural quartz powder 8a is formed in the outer portion and synthetic quartz powder 9a is formed in the inner portion by centrifugal force so that these powders are hardened in the shape of a crucible. As a result, a quartz glass crucible for pulling a silicon single crystal having a peripheral wall portion, a curved portion and a bottom portion having a two-layer structure of natural quartz glass 8 and synthetic quartz glass 9 was formed. In addition, foaming synthetic quartz powder was used for the inner layer part located under the several micro recessed part which should be formed after that in the specific area | region of the inner surface of a surrounding wall part. Thereafter, as shown in FIG. 5, when the height of the crucible is set to H (600 mm), a plurality of carbon dioxide lasers are used in the region of 0.50H to 0.99H as measured from the bottom of the inner surface of the peripheral wall. Were formed, and a quartz glass crucible for pulling a silicon single crystal according to the present invention was manufactured. At this time, a plurality of bubbles (average diameter: 40 μm, density: 30 / mm ³ ) are formed in the inner layer portion (region of 5 to 25% of the crucible thickness) located below the formed minute recess. Has been. Further, specific area, for each inner surface portion of the annular partitioned at intervals of 1mm in the crucible height direction (defined by distance in FIG. 8 h _3), and to have at least one micro recesses. The crucible thickness in the peripheral wall portion was 12 mm.

(Example 2)
Quartz for pulling a silicon single crystal according to the present invention by the same method as in Example 1 except that a plurality of minute recesses are formed in the region of 0.3H to 0.4H as measured from the bottom of the inner surface of the peripheral wall. A glass crucible was produced.

(Example 3)
Silicon according to the present invention is produced in the same manner as in Example 1 except that at least one of the annular inner surface portions divided at intervals of 6 mm in the crucible height direction does not have any minute recesses. A quartz glass crucible for pulling a single crystal was manufactured.

Example 4
A quartz glass crucible for pulling a silicon single crystal according to the present invention was manufactured by the same method as in Example 1 except that the average diameter of the minute recesses was 550 μm.

(Example 5)
A quartz glass crucible for pulling a silicon single crystal according to the present invention was manufactured by the same method as in Example 1 except that the average depth of the minute recesses was 0.004 mm.

(Example 6)
A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced by the same method as in Example 1 except that the average diameter of the bubbles was 120 μm.

(Example 7)
A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced by the same method as in Example 1 except that the density of the bubbles was 25 / mm ³ .

(Example 8)
A quartz glass crucible for pulling a silicon single crystal according to the present invention is manufactured in the same manner as in Example 1 except that the region having a plurality of bubbles is a region of 32 to 50% of the crucible thickness in the peripheral wall portion. did.

Example 9
A quartz glass crucible for pulling a silicon single crystal according to the present invention was manufactured by the same method as in Example 1 except that a diamond tool was used for forming the minute recesses.

(Comparative Example 1)
A quartz glass crucible for pulling up a silicon single crystal was manufactured in the same manner as in Example 1 except that no minute recess was provided.

(Comparative Example 2)
A quartz glass crucible for pulling up a silicon single crystal was manufactured by the same method as in Example 1 except that the inner layer portion located below the formed minute recess did not have bubbles.

(Comparative Example 3)
A quartz glass crucible for pulling up a silicon single crystal was manufactured in the same manner as in Example 1 except that it did not have microscopic recesses and bubbles in the inner layer portion.

(Evaluation 1)
With respect to the quartz glass crucible for pulling up the silicon single crystal thus produced, the molten metal surface vibration was evaluated. Sample pieces (30 mm × 30 mm) were cut out from specific regions of the crucibles of Examples 1 to 9 and Comparative Examples 1 to 3, these sample pieces were placed in a vacuum furnace, 10 g of high-purity silicon was placed on these sample pieces, argon High-purity silicon was melted by adjusting the pressure to 20 Torr and the temperature to 1560 ° C. Using a device equipped with a high-power lens and a high-speed camera that can photograph 500 or more silicon surfaces melted in a drop shape by surface tension per second, the elevation of the surface was measured, and the vibration cycle of the silicon melt was measured. .

(Evaluation 2)
Furthermore, using the crucibles of Examples 1 to 9 and Comparative Examples 1 to 3, a plurality of silicon single crystal ingots were produced by the CZ method, respectively, and silicon melts for producing the first and third silicon single crystal ingots were produced. The hot water surface vibration was observed. This observation is a high-speed lens that can capture more than 500 shots per second with a high-power lens when the quartz glass and silicon melt are wetted by the surface tension (the contact area between the outermost surface of the silicon melt and the quartz glass). Observation was made with an apparatus equipped with a camera, and the vibration period of the silicon melt was measured. Evaluation was made with ◎ as the vibration cycle of 1 second or more, ○ as 1/6 seconds or more and less than 1 second, and × as less than 1/6 second.

  Table 1 shows the results of Evaluation 1 and Evaluation 2, and the number of silicon single crystal ingots that were able to be pulled up until the thickness of the peripheral wall of the crucible reached 9 mm.

In addition, the raising time in the table indicates an elapsed time after the crucible reaches 1400 ° C. or more once.
In addition, the quartz glass crucible has a maximum usable time of 300 hours. The inner surface of the crucible is covered with a circular crystal formed by the reaction of silicon melt and quartz glass (the inner surface is cristobalite, the appearance is brown in the edge and the inner surface is milky white), but the crystal is 300 hours If it exceeds the upper limit, it peels off and mixes into the silicon melt to polycrystallize the silicon single crystal, making it difficult to use beyond that time. In Comparative Example 1, since there are no minute recesses on the inner surface, the molten metal surface vibration is large until bubbles are exposed on the surface. After exposure (after about 180 hours), the molten metal surface vibration is suppressed, so that the silicon single crystal can be pulled up, but the number that can be pulled up in the remaining 120 hours is limited.
In Comparative Example 2, the molten metal surface vibration is suppressed until the minute concave portion disappears (about 180 hours), but thereafter, the molten metal surface vibration is not suppressed, so that the silicon single crystal can be pulled up within the remaining time.
In Comparative Example 3, since the molten metal surface vibration is generated from beginning to end, the silicon single crystal cannot be pulled up.

  As shown in Table 1, the quartz glass crucibles of Examples 1 to 9 according to the present invention can stably suppress the molten metal surface vibration of the silicon melt and have a long life as compared with Comparative Examples 1 to 3. It can be seen that it is.

  According to the present invention, a plurality of fine recesses are provided in a specific region of the inner surface of the peripheral wall portion, and a plurality of bubbles are provided in the synthetic quartz glass layer located below these fine recesses, thereby providing an interior thereof. It is possible to provide a quartz glass crucible for pulling up a silicon single crystal having a long life and a method for producing the same, which can stably suppress the molten metal surface vibration of the silicon melt filled in the metal.

DESCRIPTION OF SYMBOLS 1 Quartz glass crucible 2 Circumferential wall part 3 Curved part 4 Bottom part 5 Micro recessed part 6 Specific area | region 7 Air bubble 8 Natural quartz glass 8a Natural quartz powder 9 Synthetic quartz glass 9a Synthetic quartz powder H Crucible height 100 Quartz glass crucible 101 Molten polycrystalline silicon 102 Seed crystal 103 Neck 104 Shoulder 105 Straight body part 106 Tail part 107 Silicon ingot 108 Natural quartz glass 109 Synthetic quartz glass 201 Open cell 202 Closed cell

Claims (8)

A quartz glass crucible for pulling a silicon single crystal having a peripheral wall portion, a curved portion and a bottom portion, the quartz glass crucible is
It has a synthetic quartz glass layer as an inner layer,
In a specific region of the inner surface of the peripheral wall portion, a plurality of minute recesses are provided ,
Comprising a multi-several of the bubble,
The specific region is a region where the hot water surface at the time of shoulder formation is located,
The region having a plurality of bubbles in the synthetic quartz glass layer is a region having a thickness of 0.5 to 30% of the crucible thickness in the peripheral wall portion of the region having the minute recesses. A quartz glass crucible for lifting. The quartz glass crucible for pulling a silicon single crystal according to claim 1, wherein the specific region is in a region of 0.50H to 0.99H as measured from the bottom when the crucible height is H. 3. The silicon single unit according to claim 1, wherein the specific region includes at least one minute concave portion for each annular inner surface portion that is partitioned in a range of 0.1 to 5.0 mm in the crucible height direction. Quartz glass crucible for crystal pulling. 4. The quartz glass crucible for pulling a silicon single crystal according to claim 1, wherein an average diameter of the minute recesses is in a range of 1 to 500 μm. The quartz glass crucible for pulling a silicon single crystal according to any one of claims 1 to 4, wherein an average depth of the minute recesses is in a range of 0.05 to 50% of a crucible thickness in the peripheral wall portion. 6. The quartz glass crucible for pulling a silicon single crystal according to claim 1, wherein an average diameter of the bubbles is in a range of 10 to 100 μm and a density is in a range of ^{30 to} 300 / mm ^3. . A method for producing a quartz glass crucible for pulling a silicon single crystal, which has a peripheral wall portion, a curved portion, and a bottom portion, and is formed of two layers of an outer layer of a natural quartz glass layer and an inner layer of a synthetic quartz glass layer,
Forming an outer layer of natural quartz powder;
Forming an inner layer made of synthetic quartz powder on the inner surface of the outer layer;
Forming and melting an arc discharge from the inner surface side of the inner layer to form a quartz glass crucible having a peripheral wall portion, a curved portion and a bottom portion;
The inner layer forming step includes a plurality of bubbles to be subsequently formed in a specific region of the inner surface of the peripheral wall portion so that a plurality of bubbles are provided in a region of 0.5 to 30% of the crucible thickness in the peripheral wall portion. the inner layer portion located in fine recesses, comprises using a foaming synthetic quartz powder,
After the quartz glass crucible forming step, the specific region further includes a minute recess processing step of forming a plurality of minute recesses,
The method for producing a quartz glass crucible for pulling a silicon single crystal, wherein the specific region is a region where a molten metal surface is located at least when forming a shoulder portion. The method for producing a quartz glass crucible for pulling up a silicon single crystal according to claim 7, wherein the minute recesses are formed by physical grinding using a carbon dioxide laser or a diamond tool.

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