KR101293526B1

KR101293526B1 - Vitreous silica crucible for pulling silicon single crystal, and method for manufacturing the same

Info

Publication number: KR101293526B1
Application number: KR1020110008613A
Authority: KR
Inventors: 히로시 키시; 에리코 스즈키
Original assignee: 쟈판 스파 쿼츠 가부시키가이샤
Priority date: 2011-01-28
Filing date: 2011-01-28
Publication date: 2013-08-06
Also published as: KR20120087430A

Abstract

(Problem) The present invention provides a quartz glass crucible for raising a silicon single crystal, which can stably suppress the surface vibration of a silicon melt filled in the inside, and a long life.
(Solution means) A quartz glass crucible for pulling a silicon single crystal having a main wall portion, a curved portion, and a bottom portion, wherein the quartz glass crucible has a plurality of micro recesses in a specific region of the inner wall portion of the main wall portion. And a plurality of bubbles in a position below the micro recessed portion.

Description

Quartz glass crucible for raising silicon single crystal and its manufacturing method {VITREOUS SILICA CRUCIBLE FOR PULLING SILICON SINGLE CRYSTAL, AND METHOD FOR MANUFACTURING THE SAME}

TECHNICAL FIELD This invention relates to a quartz glass crucible and its manufacturing method. Specifically, It is related with the quartz glass crucible for pulling a silicon single crystal, and its manufacturing method.

Generally, the Czochralski method (CZ method) is widely used as a method for producing a silicon single crystal for semiconductor production. 1 and 2, this CZ method first immerses the single crystal seed crystal 102 in the silicon melt 101 melted in the crucible 100 of quartz glass. At this time, since the seed crystal 102 is subjected to a sudden thermal shock, a potential occurs at the tip of the seed crystal. In order to remove this dislocation, the neck portion 103 is formed by a predetermined method so that the dislocation does not take over to the subsequently grown silicon. Thereafter, the seed crystal 102 is rotated and pulled up gradually while controlling the pulling speed and the melt temperature, thereby gradually increasing the diameter to form the shoulder 104. When the desired diameter is reached, pulling is continued while controlling to be a constant diameter, thereby forming the linear motion portion 105. Finally, the tail portion 106 is formed while gradually reducing the diameter to produce an ingot 107 of silicon single crystal.

In the quartz glass crucible used for pulling up such a silicon single crystal, as shown in FIG. 1, the natural quartz glass 108 is used on the outer part to increase the mechanical strength of the crucible, and the synthetic quartz is used on the inner part to avoid the incorporation of impurities. It is common to use glass 109. Here, "natural quartz glass" means the quartz glass formed using the natural quartz powder as a raw material, and "synthetic quartz glass" means the quartz glass formed using the synthetic quartz powder as a raw material. In general, at the interface between the synthetic quartz glass 109 and the silicon melt 101, a reaction of SiO ₂ (solid) → Si (liquid) + 2O occurs to dissolve the synthetic quartz glass 109. When pulling up the silicon single crystal, the reaction of Si (liquid) + O → SiO (gas) occurs due to the increase of the pulling temperature, the decrease in the atmospheric pressure, etc., and SiO gas is generated, and FIGS. 3A and 3B are used. As shown in the drawing, the silicon melt 101 is thrown off from the surface of the synthetic quartz glass 109, and there is a possibility that the surface vibration occurs. 3 (a) and 3 (b) are exaggerated drawings of the water surface vibrations in order to clearly explain the state of the water surface vibrations.

When such a water surface vibration occurs, the seed crystal 102 cannot be joined to the flat water surface, which causes problems such as polycrystallization of silicon during pulling. In particular, the process of seed immersion and shoulder formation, which are the initial stages of the silicon single crystal pulling process, is susceptible to hot water vibration, and this influence greatly influences the quality of the silicon single crystal ingot that has been pulled up. For this reason, in these processes, the technique of suppressing the water surface vibration of a silicon melt was desired.

Patent Document 1 discloses a technique for adjusting the bubble content of the crucible inner circumferential surface layer near the water surface at the start of pulling up in a certain range in order to suppress the water surface vibration of the silicon melt filled in the quartz glass crucible. This is because the surface vibration of the melt of the silicon melt at the start of the pulling of the silicon is affected by the bubble content of the inner surface layer of the crucible near the surface of the melt.

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 described above proceeds, the quartz glass is dissolved to form an open bubble as shown in FIG. 4. 201 appears. This opening bubble 201 can suppress the surface vibration by the same principle as that boiling stone prevents the stone. However, incorporating a large amount of bubbles 202 in the quartz glass substantially reduces the proportion of the crucible itself in the volume of the quartz glass crucible, and the dissolution rate increases as compared with the case where no bubbles are formed. There was a problem, leading to shortening of the quartz glass crucible. In recent years, large diameter crucibles are required to raise large diameter silicon single crystals, and quartz glass crucibles have become expensive, and in addition to the effect of suppressing the water surface vibration, a long service life with a small melting speed is required. Quartz glass crucibles are also desired. Moreover, the bubble of the unopened opening just under the inner surface of the crucible circumferential part expands and ruptures during pulling, and there exists a problem that quartz fragments will mix in a silicon melt, and the yield improvement of a silicon single crystal was also desired.

Japanese Laid-Open Patent Publication No. 2004-250304

An object of the present invention is to provide a quartz glass crucible capable of stably suppressing the surface vibration of the silicon melt filled in the inside thereof, and to provide a long-life silicon single crystal impression and a method of manufacturing the same.

In order to achieve the above object, the present invention has the following structure.

(1) A quartz glass crucible for pulling a silicon single crystal having a circumferential wall portion, a curved portion and a bottom portion, and formed of two layers, an outer layer of a natural quartz glass layer and an inner layer of a synthetic quartz glass layer. A plurality of micro recesses are provided in a specific region of the inner wall of the circumferential wall, and a plurality of bubbles are provided below the micro recesses.

(2) The said specific area | region is a quartz glass crucible for silicon single crystal impressions as described in said (1) which is measured from the said bottom part, when crucible height is set to H, and is in the range of 0.50H-0.99H.

(3) Said specific area | region is said (1) or (2) provided with at least 1 said micro recessed part for every annular inner surface part partitioned by the space | interval of the range of 0.1-5.0 mm in the crucible height direction. Quartz glass crucible for silicon single crystal impression described in

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

(5) The quartz glass crucible for pulling a silicon single crystal according to any one of the above (1) to (4), wherein an average depth of the micro recess is 0.05 to 50% of the crucible thickness in the main wall portion.

(6) The quartz glass crucible for pulling a silicon single crystal according to any one of (1) to (5) above, 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 pieces / cc.

(7) The area | region provided with the some bubble in the said synthetic quartz glass layer is the silicon single crystal pulling of any one of said (1)-(6) which is an area | region of 0.5-30% of the crucible thickness in the said main wall part. Quartz glass crucible for

(8) A method for producing a silicon single crystal pulling quartz glass crucible having a main wall portion, a curved portion and a bottom portion and formed of two layers of an outer layer of a natural quartz glass layer and an inner layer of a synthetic quartz glass layer, wherein the method is a natural quartz powder. (I) forming an outer layer, forming an inner layer made of synthetic quartz powder on the inner surface of the outer layer, and causing arc discharge to melt from the inner surface side of the inner layer to form a main wall portion, a curved portion and a bottom portion. And a step of forming a quartz glass crucible having the inner layer forming step, wherein a foamed synthetic quartz powder is placed in an inner layer portion located below a plurality of micro recesses to be formed in a specific region of the inner surface of the main wall portion. It includes using, and after the said quartz glass crucible formation process, the micro recessed part which forms a some micro recessed part in the said specific area | region Method for producing a quartz glass crucible for silicon single crystal pulling, characterized in that it comprises an additional step.

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

According to the present invention, by providing a plurality of micro recesses in a specific region of the inner wall of the circumferential wall portion, and by providing a plurality of bubbles below the micro recesses, the surface of the melt of the silicon melt filled therein can be stably suppressed. In addition, it is possible to provide a quartz glass crucible for raising a silicon single crystal of a long life and a manufacturing method thereof.

1 is a schematic cross-sectional view for explaining a method for producing a silicon single crystal.
2 is a plan view of a typical silicon ingot produced by the pulling method.
Fig. 3 (a) is a schematic cross-sectional view for explaining the melt surface vibration of the silicon melt, and Fig. 3 (b) is a schematic plan view showing the melt surface vibration of the silicon melt.
It is typical sectional drawing of the crucible main wall part which shows the bubble contained in the conventional quartz glass crucible.
It is a perspective view of the cross section which shows the quartz glass crucible for pulling a silicon single crystal which concerns on this invention.
It is typical sectional drawing which shows the manufacturing method of a quartz glass crucible.
7 is a schematic cross-sectional view partially enlarged of an interface between a quartz glass crucible and a silicon melt.
It is a perspective view of the cross section which shows the formation pattern of a micro recess.

(Mode for carrying out the invention)

Next, embodiment of the quartz glass crucible for pulling a silicon single crystal of this invention, and its manufacturing method is demonstrated, referring drawings. As shown in FIG. 5 as an example, the quartz glass crucible 1 for pulling a silicon single crystal according to the present invention has a circumferential wall portion 2, a curved portion 3 and a bottom portion 4, and has a natural quartz glass layer 8 Formed of two layers of an outer layer of the inner layer and the inner layer of the synthetic quartz glass layer 9, and provided with a plurality of minute recesses 5 in the specific region 6 on the inner surface of the main wall part 2, and these minute recesses ( In the synthetic quartz glass layer 9 positioned below 5), the plurality of bubbles 7 are provided, and having such a configuration, the micro recesses 5 in the initial use of the crucible are crucibles in the middle of the crucible use. The bubble 7 opened in the inner surface can suppress the surface vibration of the silicon melt filled in the inside thereof, and further optimize the formation position of the bubble 7 to suppress the increase in the dissolution rate, thereby making the crucible longer. It is.

Since the bubble 7 is exposed under a high temperature temperature condition for a long time until it opens, the bubble is saturated and there is no fear of bursting immediately below the inner wall portion of the circumferential wall just before the bubble is opened. Since there is no possibility that the quartz pieces may be mixed in the silicon melt, the yield of the silicon single crystal can be improved.

In general, the quartz glass crucible 1 for pulling up the silicon single crystal is, for example, as shown in FIG. 6 by using a centrifugal force so that the outer part is a natural quartz powder 8a and the inner part is a synthetic quartz powder 9a. These powders are solidified in the shape of a crucible, arc discharge is carried out therein, the natural quartz powder 8a and the synthetic quartz powder 9a are melted and then cooled, thereby cooling the natural quartz glass 8 and the synthetic quartz glass 9. It is formed to have a two-layer structure of).

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

On the other hand, the natural quartz powder 8a means that it is made of natural quartz, and the natural quartz is a raw material obtained by digging out quartz ore present in the natural world, through a process such as crushing and refining, and the natural quartz powder is α-quartz The decision is made. In natural quartz powder, Al and Ti contain 1 ppm or more. Also, other metal impurities are at a higher level than synthetic quartz powder. Natural quartz powder contains little silanol. The silanol amount of the glass obtained by melting a natural quartz powder is less than 50 ppm.

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

In addition, in this invention, although quartz powder is used as a raw material of the natural quartz glass 8 and the synthetic quartz glass 9, the "quartz powder" here is not limited to quartz as long as the said conditions are satisfied. The powder of a well-known material can also be included as a raw material of a quartz glass crucible, such as quartz and silica sand containing silicon dioxide (silica).

The manufacturing method of the quartz glass crucible for pulling a silicon single crystal according to the present invention has a circumferential wall portion 2, a curved portion 3 and a bottom portion 4 as shown in Figs. A method for producing a silicon single crystal pulling quartz glass crucible 1 formed of two layers of an outer layer of the layer 8 and an inner layer of the synthetic quartz glass layer 9, the step of forming an outer layer made of natural quartz powder 8a. And a step of forming an inner layer made of synthetic quartz powder 9a on the inner surface of the outer layer, and arc melting from the inner surface side of the inner layer to melt the main wall portion 2, the curved portion 3, and the bottom portion 4. And a step of forming a quartz glass crucible 1 having a), and the inner layer forming step is performed below a plurality of minute recesses 5 to be formed in a specific region 6 on the inner surface of the main wall part 2. Using expandable synthetic quartz powder in the inner layer part located In addition, after the quartz glass crucible forming step, further comprising a micro-concave processing step of forming a plurality of micro-concave portion 5 in the specific region 6, and having such a configuration, in the initial stage of the crucible use In the middle of crucible use, the concave portion 5 dissolves the bubbles 7 opened on the inner surface of the crucible by suppressing the water surface vibration of the silicon melt filled therein and by optimizing the excretion position of the bubbles 7. It is possible to provide a quartz glass crucible for pulling a silicon single crystal capable of suppressing an increase in speed and making the crucible long.

Here, a foamable synthetic quartz powder means quartz powder containing water, air, etc., for example. By containing these water, air, etc. in the step of raw material, after the said quartz glass crucible formation process, below the several micro recesses 5 which should be formed in the specific area | region 6 of the inner surface of the main wall part 2 after that It may also have a plurality of bubbles (7) of the synthetic quartz glass layer (9).

The amount of the silicon melt in the quartz glass crucible changes with the pulling up of the silicon single crystal. Therefore, the specific region 6 may be appropriately selected depending on the amount of silicon melt in the crucible when the user uses it, and at least the region where the hot water surface at the time of shoulder formation is located (h _{1 in} FIG. 5). H ₂ in height position Area to the height position). In particular, when the crucible height is set to H, the area is preferably measured from the bottom to be in the range of 0.50H to 0.99H.

Thus, the reason why the vibration of the water surface is likely to occur in the area where the water surface is located will be described below. FIG. 7 is a schematic cross-sectional view of an enlarged part of the hot water surface position of a quartz glass crucible having a silicon melt therein. As described above, the wet liquid of the crucible causes the silicon melt of the liquid to interface with a solid quartz glass crucible. The cross-sectional shape as shown to area | region I of 7 is shown. In this region I, since the distance from the liquid surface in which the oxygen concentration is lower in the silicon melt is closer than that in the range outside the region I, the concentration gradient of oxygen is increased, so that SiO ₂ (solid) → Si (liquid) described above is increased. The diffusion of O generated by the reaction of + 2O is fast. Therefore, this reaction tends to proceed and the melting of the crucible is promoted. In general, in the zone (I), the crucible in that it occurs in the range of 0.1~5.0㎜ in the height direction, in the specified area (6) is divided into intervals of the crucible 0.1~5.0㎜ range (Fig. 8 in the direction of height h ₃ It is preferable to provide at least 1 micro recessed part 5 for every annular inner surface part partitioned by space | interval.

It is preferable that the average diameter of the micro recesses 5 is 1-500 micrometers. If the average diameter of the micro recesses 5 is less than 1 µm, the same effect as the above-described boiling stone cannot be sufficiently obtained. On the other hand, if the average diameter of the micro recesses 5 exceeds 500 µm, the above-described ratio This is because not only the same effect as that of the class can be obtained sufficiently, but also the micro recesses 5 tend to disappear due to melting of the crucible.

It is preferable that the average depth of the micro recessed part 5 is 0.05 to 50% of range of the crucible thickness in a circumferential wall part. If the average depth of the micro recesses 5 is less than 0.05% of the crucible thickness in the circumferential wall portion, the micro recesses 5 are likely to disappear due to melting of the crucible, and the expansion of unopened bubbles is not saturated. On the other hand, when the average depth of the micro recesses 5 exceeds 50% of the crucible thickness in the main wall part 2, there exists a possibility that it may affect the wall part strength of the crucible. In addition, it is preferable to make the thickness of the circumferential wall part 2 into the range of 100-1000 micrometers as an example.

Moreover, it is preferable to make ratio with respect to the average depth of the average diameter of the micro recessed part 5 more than 0 and less than 0.8. In order to suppress that the recess is lost due to melting of the crucible, it is necessary to suppress the reaction of SiO ₂ (solid) → Si (liquid) + 2O. For this purpose, when the oxygen concentration in the silicon melt at the interface between the crucible and the melt is increased, the reaction becomes difficult to proceed. It is preferable to define the diameter and depth so that the oxygen generated by the reaction may not be diffused from the concave portion once, and the range of the ratio is so as not to be affected by the tropical flow of the silicon melt.

It is preferable to make the average diameter of the bubble 7 into the range of 10-100 micrometers, and to make a density into the range of 30-300 piece / cc. If the average diameter of the bubble 7 is less than 10 μm, the effect of suppressing the surface vibration is not sufficiently obtained. If the average diameter of the bubble 7 exceeds 100 μm, the inside of the crucible is expanded by the expansion of the bubble 7. This is because the surface may be deformed and quartz fragments or the like may be mixed into the silicon melt. If the density is less than 30 / cc, the effect of suppressing the surface vibration is not sufficiently obtained. On the other hand, if the density of the foam 7 exceeds 300 / cc, the inner surface of the crucible is caused by expansion of the foam 7. This is because there is a risk of deforming and incorporating quartz fragments or the like into the silicon melt.

It is preferable that the area | region provided with the some bubble 7 in the synthetic quartz glass layer 9 is 0.5-30% of the crucible thickness in the said main wall part. By providing the bubble 7 in the synthetic quartz glass layer 9 which is a position below the micro recesses 5, the air in the bubble 7 expands and ruptures by heat, and the quartz pieces or the like are mixed into the silicon melt. It is possible to prevent the discard and further to open 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 dissolves and the micro recesses 5 disappear. The lifespan of the quartz glass crucible can be achieved in that the bubble 7 shown can suppress the surface vibration of the silicon melt.

The minute concave portion 5 is preferably formed using a carbon dioxide gas laser or a diamond tool. For example, a minute recess is formed by replacing the irradiation surface of the carbon dioxide laser with the inner surface of the crucible and irradiating infrared light of 10.6 µm. Alternatively, a micro depression is formed by touching the inner surface of the crucible while immersing water in a diamond coating brittle material drill manufactured by Mitsubishi Materials Corporation. "Rotation or lift of grinding and crucible" is repeated, and a recess is formed in the whole inner surface of a specific area | region.

The above-mentioned part is shown as an example and the present invention is not limited to this embodiment.

(Example)

(Example 1)

As shown in FIG. 6, these powders were hardened into a crucible shape using centrifugal force so that the natural quartz powder 8a was made into the outer part and the synthetic quartz powder 9a was made into the inner part, as shown in FIG. By discharging, a quartz glass crucible for pulling up a silicon single crystal having a main wall portion, a curved portion and a bottom portion having a two-layer structure between the natural quartz glass 8 and the synthetic quartz glass 9 was formed. In addition, foamable synthetic quartz powder was used for the inner layer part located below the some micro recessed part which should be formed in the specific area | region of the inner surface of a circumferential wall part. Then, as shown in FIG. 5, when making crucible height H (600 mm), it measures from the bottom part of the inner surface of the circumferential wall part, and uses a carbon dioxide gas laser in the area of 0.50H-0.99H, and it is a some micro recess. The part (average diameter: 300 micrometers, average depth: 500 micrometers) was formed and the quartz glass crucible for pulling up the silicon single crystal which concerns on this invention was manufactured. At this time, several bubbles (average diameter: 40 micrometers, density: 30 pieces / kPa) are formed in the inner-layer part (5-25% of the thickness of a crucible) located under the formed micro recess. In addition, a specific area, has to have each inner portion of the crucible height direction by a distance of 1㎜ compartment (Fig. 8, the blocks at intervals of ₃ h) annular shape, parts of at least one minute recess. In addition, the crucible thickness in the circumferential wall part was 12 mm.

(Example 2)

A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced in the same manner as in Example 1 except that a plurality of minute recesses were measured from the bottom of the inner surface of the circumferential wall and formed in a region of 0.3H to 0.4H. did.

(Example 3)

The quartz glass crucible for pulling the silicon single crystal according to the present invention by the same method as in Example 1, except that at least one of the annular inner surface portions partitioned at intervals of 6 mm in the crucible height direction does not have any one micro recess. Prepared.

(Example 4)

A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced in the same manner as in Example 1 except that the average diameter of the micro recesses was 550 µm.

(Example 5)

A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced in the same manner as in Example 1 except that the average depth of the micro recesses was 0.004 mm.

(Example 6)

A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced in the same manner 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 in the same manner as in Example 1 except that the bubble had a density of 25 particles / cc.

(Example 8)

A quartz glass crucible for pulling the silicon single crystal according to the present invention was produced in the same manner as in Example 1 except that the region having a plurality of bubbles was a region of 32 to 50% of the crucible thickness in the main wall portion.

(Example 9)

A quartz glass crucible for pulling a silicon single crystal according to the present invention was produced in the same manner as in Example 1 except that a diamond tool was used for the formation of the micro recesses.

(Comparative Example 1)

A quartz glass crucible for pulling up a silicon single crystal was produced in the same manner as in Example 1 except that the micro recesses were not provided.

(Comparative Example 2)

A quartz glass crucible for pulling up a silicon single crystal was produced in the same manner as in Example 1 except that no bubbles were provided in the inner layer portion located below the formed micro-concave portion.

(Comparative Example 3)

A quartz glass crucible for pulling up a silicon single crystal was produced in the same manner as in Example 1, except that the micro recesses and the bubbles of the inner layer portions were not provided.

(Evaluation 1)

Thus, the surface vibration was evaluated about the quartz glass crucible for silicon single crystal pulling. Sample pieces (30 mm x 30 mm) are cut out from the specific area | region of the crucible of these Examples 1-9 and Comparative Examples 1-3, these sample pieces are installed in a vacuum furnace, and high purity silicon | silicone is placed on these sample pieces. 10g was put up, the argon pressure was adjusted to 20 Torr, and the temperature was 1560 degreeC, and high purity silicon was melted. The surface tension is measured by a device equipped with a high-speed camera capable of capturing 500 or more sheets of silicon melted in a drop shape by a surface tension between a high-magnification lens and one second, thereby measuring the oscillation period of the silicon melt. Measured.

(Evaluation 2)

Further, 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 the melt surface of the silicon melt at the time of producing the first and third silicon single crystal ingots. The state of vibration was observed. This observation is based on a high-speed camera that can shoot more than 500 sheets of quartz glass and the silicon melt wetted by the surface tension (the outermost surface of the silicon melt and the contact portion of the quartz glass) between the high magnification lens and one second. It observed by the equipped apparatus and measured the vibration period of a silicon melt. (Circle) and the thing of 1/6 second or more and less than 1 second (circle) and the thing of less than 1/6 second were evaluated as what made the vibration period into x.

In Table 1, as a result of the evaluation 1 and the evaluation 2, the number of the silicon single crystal ingots which could be pulled up until the thickness of the crucible main wall part became 9 mm is further shown.

Of oscillation
Vibration cycle
(second) Impression
Bath surface vibration
Suppression (the first) Impression
Bath surface vibration
Suppression (the third) impression
Possible number
(dog) impression
time
(h) Example 1 3 ◎ ◎ 3 210 Example 2 1/3 ○ ○ 3 259 Example 3 1/4 ○ ○ 3 274 Example 4 1/5 ○ ○ 3 260 Example 5 1/6 ○ ○ 3 277 Example 6 1/6 ○ ○ 3 268 Example 7 1/6 ○ ○ 3 278 Example 8 1/6 ◎ ○ 3 230 Example 9 1/6 ◎ ○ 3 234 Comparative Example 1 1/14 (to 180 h)
1/4 (~ 300h) × (~ 180h)
○ (-300 h) - One 300 Comparative Example 2 1/4 (~ 180h)
1/15 (to 300 h) ○ (-180 h)
× (-300 h) × One 300 Comparative Example 3 1/14 (to 300 h) × (-300 h) × 0 300

In addition, the pulling time in a table | surface shows the elapsed time after a crucible reaches 1400 degreeC or more once.

In addition, the quartz glass crucible has a longest usable time of 300 hours. It is the inner surface of the crucible is covered with circular crystals (the inside is christobalite) made by the reaction of the silicon melt and the quartz glass, the outer characteristic is brown border, the inside is milky white, but the crystal When it exceeds this 300 hours, it peels and it mixes in a silicon melt and polycrystallizes a silicon single crystal, Therefore, use beyond that time is difficult. In Comparative Example 1, since there are no micro recesses on the inner surface, the surface vibration is large until bubbles are exposed on the surface. After the exposure (after about 180 hours), since the surface vibration is suppressed, 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 surface vibration is suppressed until the micro depressions disappear (about 180 hours), but since the surface vibration is not suppressed, the silicon single crystal can be pulled up within the remaining time.

In Comparative Example 3, since the vibrations of the surface and the water surface are generated at all times, the silicon single crystal cannot be pulled up.

As shown in Table 1, it was found that the quartz glass crucibles of Examples 1 to 9 according to the present invention were able to stably suppress the surface vibration of the silicon melt, and to have a long life as compared with Comparative Examples 1 to 3.

According to the present invention, a plurality of micro recesses are provided in a specific region of the inner wall of the circumferential wall portion, and a plurality of bubbles are provided in the synthetic quartz glass layer located below these micro recesses, whereby The surface vibration can be stably suppressed, and a long life silicon single crystal pulling quartz glass crucible can be provided.

1: quartz glass crucible
2: main wall
3: bend
4: bottom
5: micro recess
6: specific area
7: bubble
8: natural quartz glass (layer)
8a: natural quartz powder
9: synthetic quartz glass (layer)
9a: synthetic quartz powder
H: crucible height
100: quartz glass crucible
101: Silicone Melt
102: seed crystal
103: neck
104: shoulder
105: Straight East
106: tail
107 ingot of silicon single crystal
108: natural quartz glass
109: synthetic quartz glass
201: opening bubble
202: bubble

Claims

A quartz glass crucible for pulling a silicon single crystal having a circumferential wall portion, a curved portion and a bottom portion and formed of two layers, an outer layer that is a natural quartz glass layer and an inner layer that is a synthetic quartz glass layer.
In the specific region of the inner surface of the circumferential wall portion in the inner layer, a plurality of micro recesses are provided,
A quartz glass crucible for pulling a silicon single crystal, comprising a plurality of bubbles formed by using a foamable synthetic quartz powder in an inner layer portion located below the micro concave portion.

The method of claim 1,
The said specific area | region is a quartz glass crucible for pulling a silicon single crystal in the area | region of 0.50H-0.99H measured from the said bottom part, when crucible height is set to H.

The method according to claim 1 or 2,
The said specific area | region is a quartz glass crucible for pulling a silicon single crystal with at least 1 said micro recessed part for every annular inner surface part partitioned at intervals of the range of 0.1-5.0 mm in the crucible height direction.

The method according to claim 1 or 2,
The average diameter of the said micro recess is a quartz glass crucible for pulling a silicon single crystal in the range of 1 to 500 µm.

The method according to claim 1 or 2,
The average depth of the said micro recess is a quartz glass crucible for pulling a silicon single crystal in the range of 0.05-50% of the crucible thickness in the said main wall part.

The method according to claim 1 or 2,
The quartz glass crucible for pulling a silicon single crystal in which the average diameter of the said bubble is the range of 10-100 micrometers, and the density is the range of 30-300 piece / cc.

The method according to claim 1 or 2,
The area | region provided with the some bubble in the said synthetic quartz glass layer is the quartz glass crucible for silicon single crystal pulling which is an area | region of 0.5-30% of the crucible thickness in the said main wall part.

As a manufacturing method of the quartz glass crucible for pulling a silicon single crystal which has a main wall part, a curved part, and a bottom part, and is formed by two layers of the outer layer which is a natural quartz glass layer, and the inner layer which is a synthetic quartz glass layer,
Forming an outer layer made of natural quartz powder,
Forming an inner layer made of synthetic quartz powder on the inner surface of the outer layer;
An arc discharge is generated from the inner surface side of the inner layer and melted to form a quartz glass crucible having a circumferential wall portion, a curved portion and a bottom portion;
After the process of forming the said quartz glass crucible, the micro recessed part process process of providing a some micro recessed part is provided in the specific area | region of the inner surface of the said main wall part in the said inner layer,
The step of forming the inner layer includes a step of forming a plurality of bubbles in the inner layer portion located below the plurality of micro-concave portions by using a foamable synthetic quartz powder. Method of manufacturing crucibles.

9. The method of claim 8,
The said micro recess is a manufacturing method of the quartz glass crucible for silicon single crystal pulling formed by physical grinding using a carbon dioxide laser or a diamond tool.