JP3953042B2 - Raw material supply apparatus and raw material supply method by Czochralski method - Google Patents

Description

  The present invention relates to a raw material supply apparatus used for growing a single crystal by the Czochralski method (hereinafter referred to as “CZ method”) and a raw material supply method employed in the apparatus, and more specifically, in growing a silicon single crystal, The present invention relates to a raw material supply apparatus using a raw material container and a raw material supply method employed in the apparatus, which are used when a solid raw material is additionally charged or recharged to a raw material melt in a crucible.

  Usually, in the growth of a silicon single crystal by the CZ method, solid polycrystalline silicon charged as an initial charge in a crucible is heated and melted by a heater surrounding the crucible. When the raw material melt is formed in the crucible, the seed crystal held on the crucible is lowered while rotating the crucible in a certain direction, and immersed in the raw material melt in the crucible. Thereafter, a cylindrical silicon single crystal is grown below the seed crystal by raising the seed crystal while rotating the seed crystal in a predetermined direction.

  The solid raw material charged into the crucible as the initial charge is polycrystalline silicon of various shapes such as rod, lump, or granule, and each is supplied alone or in combination, and is used to grow a silicon single crystal. It becomes the raw material of the liquid.

  In the growth of the silicon single crystal by the CZ method described above, when the solid material initially charged in the crucible is melted, the volume after melting is reduced, so that the amount of the raw material melt obtained is insufficient compared to the volume of the crucible. . If the single crystal is grown in such a state, the productivity is inevitably lowered due to the shortage of the raw material melt.

  In order to avoid a decrease in productivity due to the above-mentioned causes, it is necessary to supplement the shortage of the raw material melt to ensure a desired amount of the melt, and after the initial charge to the crucible, additional solid raw material is supplied. “Additional charge” is performed as a technology.

  In other words, “additional charge” is a technology that increases the amount of the raw material melt in the crucible by melting the solid raw material initially charged in the crucible and then adding additional solid raw material to the formed raw material melt. It is. By applying this “additional charge”, the volume of the crucible to be used can be used effectively, and the productivity in silicon single crystal growth can be improved.

  Furthermore, in the growth of a silicon single crystal by the CZ method, a technique of supplying a solid material called “recharge” is also performed. Specifically, after the first single crystal is grown and pulled, a solid raw material in an amount commensurate with the reduced amount of the raw material melt is added to the residual melt in the crucible.

  In other words, by “recharging”, a predetermined amount of the raw material melt is re-formed in the crucible, and the pulling of the single crystal is repeated to increase the number of crystals pulled per crucible.

  Therefore, by adopting “recharge”, the cost can be reduced by using the crucible efficiently, and productivity can be improved and the growth cost of the silicon single crystal can be reduced as in the “additional charge” described above.

  However, the raw material supply by additional charge or recharge is based on a method of additionally charging agglomerated solid raw material into the raw material melt in the crucible using a raw material supply pipe inserted into the growth furnace. For this reason, as additional raw materials are added, the crucible may be damaged, or the raw material melt may splash, and the raw material splash may adhere to the components in the chamber, reducing the life of the components. The problem of adversely affecting the growth of single crystals has arisen.

For this reason, various proposals have conventionally been made regarding additional charging and recharging.
For example, in Patent Document 1, when recharging, a quartz crucible is easily damaged, and dislocations are likely to occur during the growth of a single crystal. Therefore, on the molten surface of the silicon melt, on the solidified surface. A silicon raw material supply method has been proposed that is suitable for both, and can supply additional silicon raw material quickly and without damaging the quartz crucible during melting.

  By adopting the method proposed in Patent Document 1, it is said that the splash of the raw material melt can be eliminated, and the productivity and production yield in the growth of the silicon single crystal can be improved.

  Furthermore, since the splash of the melt jumps by directly feeding the solid raw material to the raw material in the crucible, after the initial single crystal is pulled up, the surface of the raw material remaining in the crucible is solidified to a certain extent, A technology is adopted in which a solid raw material is supplied and then melted. In this case, it is necessary for the operator to visually monitor the solidified state of the surface of the melt. However, the operator cannot perform other operations, which hinders productivity improvement.

  For this reason, Patent Document 2 discloses a single crystal pulling apparatus that detects the solidified state of the surface of the melt with a visual sensor so as to reduce the restrictions on the actions of the operator and improve the productivity. A material addition system is proposed. According to this raw material addition system, the operator's work can be reduced, and other work can be performed during this time, so that productivity can be improved.

JP 09-208368 A

JP 11-236290 A

  According to the silicon raw material supply method and the raw material addition system that have been proposed in the past, it is possible to achieve a predetermined target with respect to productivity in the growth of a silicon single crystal, but it is possible to splash the raw material melt in the crucible. There is no disclosure about the specific configuration of the raw material supply device that can be prevented and added statically. For this reason, it is necessary to newly examine a specific configuration that can be adopted as a raw material supply by the CZ method.

  Furthermore, when a polycrystalline silicon rod is used as a solid material for additional charge or recharge, it is more expensive than agglomerated polycrystalline silicon, and at the same time, cracks may occur due to rapid heating in the crucible. In addition, it takes a long time to form the raw material solution. Therefore, it is effective to use agglomerated polycrystalline silicon instead of the polycrystalline silicon rod as a solid material for additional charge or recharge.

  The present invention has been made in view of the above situation, and the raw material cost is low, and when using a solid material in the form of an agglomerate that does not cause cracking due to rapid heating, additional charging or recharging is performed. It is an object of the present invention to provide a raw material supply apparatus using the CZ method and a raw material supply method employed in the apparatus, which can prevent the raw material melt from splashing and can be added statically.

The present invention has been made to achieve the above object, and is a raw material supply apparatus used in the CZ method of (1) to (3) below, and a raw material supply by the CZ method of (4) to (7) The method is summarized.
(1) A raw material supply apparatus that is used for growing a single crystal by the CZ method, and that additionally charges or recharges the raw material melt in the crucible, is filled with agglomerated solid raw material, and has an opening at the bottom or bottom. an inner container, the inner container slidably is inserted and an outer container for closing the opening, comprising a pulling means for suspending the inner container and outer container can be raised and lowered, the lift on the inner container The raw material supply apparatus is characterized in that a latch member for stopping is provided, the opening is opened by sliding the outer container, and the solid raw material is charged into the raw material melt in the crucible.
(2) the raw material supply apparatus of the present invention, the hooking member is provided to stop the elevator before Kisotogawa container, by the sliding of the inner container but it may also have a structure for opening the opening portion.
(3) In the raw material supply apparatus of the present invention, it is preferable that the material constituting the inner container and the outer container is composed of quartz, silicon carbide (SiC), or carbon whose surface is coated with SiC. By comprising with these materials, the risk of contaminating the raw material melt can be eliminated.
(4) A raw material supply method for charging or recharging a raw material melt in a crucible when a single crystal is grown by the CZ method, and an inner container having an opening at the bottom or bottom can be slid to an outer container After inserting and filling the inner container with agglomerated solid raw material with the opening closed, the inner container and the outer container are then suspended and lowered on the crucible located at the center of the growth furnace. , The descent of either the inner container or the outer container is stopped, and accordingly, either the inner container or the outer container is slid to open the opening, and the raw material melt in the crucible is A raw material supply method characterized by charging a solid raw material.
(5) In the raw material supply method of the present invention, the inner container is provided with a latching member for stopping the descent, the opening of the inner container is opened by sliding the outer container, and the raw material melt in the crucible is Even in the method of additionally charging or recharging the solid raw material, the outer container is provided with a retaining member for stopping the descent, the opening is opened by sliding the inner container, and the raw material melt in the crucible is Even if it is the method of carrying out additional charge or recharge of a solid raw material, any may be employ | adopted.
(6) In the raw material supply method of the present invention, it is desirable to fill the lower layer portion close to the opening with a fine raw material having a particle size of 25 mm or less as the agglomerated solid raw material to be filled in the inner container. The reason for this is that Ru Oh as follows.

That is, by filling the lower part with a fine-grain raw material, the raw material melt is charged in a state where the surface of the raw material melt at the initial stage is not solidified. Melt splash does not occur. Furthermore, since the surface temperature of the raw material melt is lowered and solidified as the solid raw material is continuously charged, the solid raw material is then charged onto the solidified melt surface. Liquid splash does not occur.
(7) Furthermore, in the raw material supply method of the present invention, it is desirable to charge or recharge the solid raw material to the raw material melt in the crucible while rotating the crucible. Thereby, the additionally charged or recharged solid material can be uniformly distributed in the crucible, and the solid material that can be supplied at a time can be increased.

  The “agglomerated solid raw material” defined in the present invention refers to a polycrystalline silicon raw material having a particle diameter in the range of 5 mm to 45 mm. As described above, as defined in (6) above, in the raw material supply method of the present invention, the “flocculated solid raw material” having a particle size of 25 mm or less is filled in the lower layer part in the initial stage of additional charge or recharge. This is because the splash of the raw material melt in the crucible can be reliably prevented.

  According to the raw material supply apparatus according to the CZ method of the present invention, an agglomerated solid raw material is filled, an inner container having an opening at the bottom or bottom, and the inner container are slidably inserted, and the opening is closed. And a lifting means for suspending the inner container and the outer container so that the inner container and the outer container can be lifted and lowered, and the opening is opened by sliding of the inner container or the outer container, and the solid melt in the raw material melt in the crucible By additionally charging or recharging the raw material, splashing of the raw material melt in the crucible can be prevented, the additional charging can be performed statically, the raw material cost is low, and there is no possibility of cracking due to rapid heating.

  Therefore, according to the supply method using this raw material supply apparatus, the productivity in growing silicon single crystals can be improved, the crucible can be used efficiently, and the life of the furnace parts can be extended. Thereby, the growth cost of the silicon single crystal can be significantly reduced.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing the overall configuration of a single crystal growth furnace in which the raw material supply apparatus of the present invention is arranged. FIG. 1 (a) shows a state where a raw material container is filled with agglomerated solid raw material. Indicates a state in which a solid raw material is charged into the raw material solution in the crucible.

  As shown in FIG. 1A, the growth furnace based on the CZ method includes a main chamber 1 and a pull chamber 2 as a furnace body, and further includes a gate valve 13. The pull chamber 2 has a cylindrical shape smaller in diameter than the main chamber 1, and is disposed on the same central axis as the main chamber 1 via a gate valve 13.

  The gate valve 13 is provided to operate the inside of the main chamber 1 and the inside of the pull chamber 2 so that they can communicate with each other or be shut off, and the communication diameter provided in the gate valve 13 is smaller than that of the pull chamber 2.

  A crucible 3 is disposed at the center of the main chamber 1. The crucible 3 has a double structure in which an inner quartz crucible 3a and an outer graphite crucible 3b are combined, and is supported on a support shaft 4 called a pedestal via a crucible receiver (not shown). The support shaft 4 drives the crucible 3 to move up and down in the axial direction or to rotate in the circumferential direction.

  The heater 5 is disposed so as to surround the crucible 3. On the further outer side of the heater 5, a heat insulating material 6 is disposed along the inner surface of the main chamber 1.

  The solid raw material charged as the initial charge into the crucible 3 is made of polycrystalline silicon having a rod shape, a lump shape, or a granular shape, and is melted by heating of the heater 5 to form a raw material melt 12. After the initially charged solid material is melted, additional charging is performed to replenish the shortage of the raw material melt 12 in the crucible 3 and secure a desired amount of melt.

  For this reason, the pulling shaft 7 is suspended in the pull chamber 2, and the raw material container 10 used in the raw material supply apparatus of the present invention is suspended. At this time, the raw material container 10 filled with the solid raw material 11 is positioned above the crucible 3 in which the raw material melt 12 is formed via the wire 9 on the hanger 8 connected to the lower end of the pulling shaft. The pull-up shaft 7 is driven to rotate and move up and down by a drive mechanism (not shown) provided at the top of the pull chamber 2.

  FIG. 2 is a diagram showing a first configuration example of a raw material container used in the raw material supply apparatus of the present invention. The raw material container 10 is formed of a double-structured cylindrical body composed of an inner container 10a and an outer container 10b, and the container material is quartz. The outer diameter of the inner container 10a is smaller than the inner diameter of the outer container 10b, the inner container 10a is inserted into the outer container 10b, and both are configured to be slidable.

  In the first configuration example shown in FIG. 2, the inner container 10a is provided with a latching member 30, and the latching member 30 is inserted into the outer container 10b so as to be positioned at the upper end of the outer container 10b. . The outer container 10b is supported by a wire (not shown), so that the raw material container 10 is suspended from the pulling shaft.

  FIG. 3 is a partial detailed view showing a first configuration example of a raw material container used in the raw material supply apparatus of the present invention, in which (a) is a longitudinal sectional view showing a lower layer structure having an opening of the raw material container. (B) is sectional drawing which shows the bottom face structure by 3B-3B arrow of a raw material container.

  As shown in FIG. 3, an opening 18 for introducing the solid raw material 11 into the crucible is provided at the bottom of the inner container 10a. When the solid raw material 11 is not charged, the opening 18 is closed by the closing member 10c of the outer container 10b and the closing member 10d of the inner container 10a. With the opening 18 closed in this manner, the inner raw material 11 made of granular silicon in the inner container 10a is filled into the inner container 10a from the upper opening of the inner container 10a.

  When the solid raw material 11 is charged into the raw material melt in the crucible, if it is charged in the circumferential direction of the crucible, as shown in FIG. 3A, a cover is provided at the lower end of the outer container 10b. 17 can be provided. As a result, the uneven charging of the solid raw material 11 can be eliminated, and as a result, liquid splashing on components such as the heater 5 can be prevented.

  Based on FIGS. 1-3, the work procedure of the additional charge using the 1st structural example of a raw material container is demonstrated. After the solid raw material 11 initially charged in the crucible 3 is melted, the raw material container 10 filled with the solid raw material 11 is connected to the hanger 8 connected to the lower end of the pulling shaft 7 through the wire 9. It is located above the crucible 3 on which the melt 12 is formed. The raw material melt 12 in the crucible 3 is insufficient with respect to the crucible volume.

  As shown in FIG. 2, when the raw material container 10 is lowered, the retaining member 30 of the inner container 10a comes into contact with a predetermined height position, for example, a small diameter portion provided in the gate valve 13, and only the inner container 10a is brought into contact. Descent stops. On the other hand, there is no hindrance to the lowering of the outer container 10b supported by the wire 9, and only the outer container 10b descends while sliding on the outer peripheral surface of the inner container 10a.

  As shown in FIG. 3 (a), when the opening 18 of the inner container 10a is opened along with the sliding of the outer container 10b, the agglomerated solid raw material 11 filled in the inner container 10a is It falls by its own weight and is put into the raw material melt 12.

  At this time, it is desirable that the solid material 11 filled in the inner container 10a is filled with a fine material having a particle diameter of 25 mm or less in a lower layer portion close to the opening 18. First, in the state where the surface of the raw material melt 12 at the initial stage of the additional charge is not solidified, an agglomerated raw material having a small particle diameter is charged from the raw material container 10. At this time, since the particle size of the agglomerated raw material is small, if the feed distance from the liquid surface is adjusted, for example, if it is controlled to 100 mm or less from the liquid surface, the material melt 12 does not splash.

  Further, when the solid raw material 11 is continuously charged, the surface temperature of the raw material melt 12 is lowered and the melt surface is solidified. After that, since the solid raw material 11 is put on the solidified melt surface, regardless of the particle diameter, the raw material melt in the crucible 3 accompanying the charging of the solid raw material 11 does not splash on the components such as the heater 5. .

  At the same time, since agglomerated polycrystalline silicon is used as the solid raw material 11 to be charged, the raw material cost required for the additional charging is low, and there is no risk of cracking due to rapid heating, so that the additional charging can be performed efficiently.

  When the charging of the solid raw material 11 is finished, the raw material container 10 is pulled upward and taken out of the pull chamber 2. When the amount of the raw material melt in the crucible 3 does not reach the target value, the charging of the solid raw material 11 is repeated using another raw material container 10.

  When the additional charge is completed and the raw material melt 12 in the crucible 3 reaches the target amount, the hanger 7 connected to the lower end of the pull-up shaft 7 is replaced with a seed crystal, and the process proceeds to a single crystal growth process.

  As described above, the additional charge work procedure has been described, but also in the recharge, after growing the first single crystal by the same work procedure, an agglomerated solid raw material 11 in an amount commensurate with the reduced amount of the raw material melt is obtained. The raw material melt 12 remaining in the crucible 3 is additionally charged.

  FIG. 4 is a partial detailed view showing a second configuration example of a raw material container used in the raw material supply apparatus of the present invention, in which (a) is a longitudinal sectional view showing a lower layer structure having an opening of the raw material container. (B) is sectional drawing which shows the bottom face structure by 4A-4A arrow of a raw material container.

  In the second configuration example shown in FIG. 4, the raw material container 10 is formed of a double rectangular tube, and the inner container 10 a is inserted into the outer container 10 b so that both can slide (slide). .

  The opening 18 provided at the bottom of the inner container 10a is closed by the closing member 10c of the outer container 10b and the closing member 10d of the inner container 10a. And the solid raw material 11 which consists of a granular lump-like polycrystalline silicon is filled from the upper opening part of the inner side container 10a in the state by which the opening part 18 was obstruct | occluded.

  FIG. 5 is a diagram showing a third configuration example of the raw material container used in the raw material supply apparatus of the present invention. The raw material container 10 is formed of a double-structured cylindrical body including an inner container 10a and an outer container 10b. The inner container 10a is inserted into the outer container 10b, and both are configured to be slidable (slidable).

  In the third configuration example shown in FIG. 5, the outer container 10 b is configured by a simple cylindrical body, and a retaining member 30 is provided on the upper portion thereof. On the other hand, an inverted U-shaped opening 18 for introducing a solid material into the crucible is provided at the bottom of the lower end of the inner container 10a, and a flange for supporting the lower end of the outer container 10b is provided on the outer peripheral surface of the lower end. A portion 10e is provided. For this reason, the inner container 10a is supported by a wire (not shown), so that the raw material container 10 is suspended from the pulling shaft 7.

  FIG. 6 is a perspective view showing the configuration of the lower end portion in the third configuration example of the raw material container used in the raw material supply apparatus of the present invention.

  As shown in FIG. 6, an inverted U-shaped opening 18 is provided on the lower side surface of the inner charge container 10a, and a charging guide 10f can be provided on the bottom surface of the inner container 10a. For example, by providing the charging guide 10f with an inverted V-shaped shape, it is possible to prevent the residue at the bottom of the inner charge container 10a when charging the solid raw material.

  When the solid raw material is not charged, the opening 18 is covered and closed by the outer container 10b. In the state where the opening 18 is closed in this way, the inner container 10a is filled with a solid raw material made of granular silicon in the shape of a lump from the upper opening 28 of the inner container 10a.

  In the additional charge using the raw material container 10 according to the third configuration example shown in FIGS. 5 and 6, when the raw material container 10 is lowered, the latch member 30 of the outer container 10b is provided in the gate valve 13, for example. Only the outer container 10b stops descending in contact with the small diameter portion. On the other hand, there is no hindrance to the lowering of the inner container 10a supported by the wire 9, and only the inner container 10a descends while sliding on the inner peripheral surface of the outer container 10b.

  When the opening 18 of the inner container 10a is opened along with the sliding of the inner container 10a, the agglomerated solid raw material 11 filled in the inner container 10a falls due to its own weight and enters the raw material melt 12. It is thrown. At this time, the bottom of the inner container 14a is provided with the charging guide 10f having an inverted V-shaped shape, so that the solid material can be prevented from remaining.

  FIG. 7 is a cross-sectional view showing a fourth configuration example of the raw material container used in the raw material supply apparatus of the present invention. In the fourth configuration example, the raw material container 10 is formed of a double-structured rectangular tube, and the inner container 10a is inserted into the outer container 10b so that both can slide.

  The opening 18a on the bottom surface of the inner container 10a is closed by the closing member 10c of the outer container 10b. Similarly, the opening 18b on the bottom surface of the outer raw material container 10b is closed by the closing member 10d of the inner container 10a. It is desirable that the closing member 10d of the inner container 10a has an inverted V-shaped shape in order to prevent residue when the solid raw material is charged.

  In the additional charge using the raw material container according to the fourth configuration example shown in FIG. 7, a latch member 30 is provided in the inner container 10a as shown in FIG. The openings 18a and 18b are opened by sliding only the container 10b. As a result, the agglomerated solid raw material 11 filled in the inner container 10 a falls due to its own weight and is charged into the raw material melt 12.

  FIG. 8 is a cross-sectional view showing a fifth configuration example of the raw material container used in the raw material supply apparatus of the present invention. In the fifth configuration example, the raw material container 10 is composed of a double-structured square cylinder, and the inner container 10a is inserted into the outer container 10b so that both can slide.

  The opening 18a on the bottom surface of the inner container 10a is closed by the closing member 10c of the outer container 10b. Similarly, the opening 18b on the bottom surface of the outer container 10b is closed by the closing member 10d of the inner container 10a. It is desirable that the closing member 10c of the outer container 10b has an inverted V-shaped shape in order to prevent residual when the solid raw material is charged.

  In the additional charge using the raw material container according to the fifth configuration example shown in FIG. 8, as in the case of the fourth configuration example, the latching member 30 is provided in the inner container 10 a and a predetermined height position is provided. Thereafter, the openings 18a and 18b are opened by sliding only the outer container 10b, and the raw material melt 12 is charged with its own weight of the granular solid material.

  Below, the specific structure of the raw material container used for the raw material supply apparatus of this invention and the raw material supply method using the same are demonstrated based on FIGS. 1-3.

  In the growth furnace shown in FIG. 1, a crucible 3 having a diameter of 22 inches was used to grow a silicon single crystal having a diameter of 8 inches. During the growth, as an initial charge, 100 kg of polycrystalline silicon was added to the crucible 3 in the form of rods, lumps and grains, and an additional charge was performed after the raw material solution 12 was formed.

  As shown in FIG. 2, the raw material container 10 has a double structure composed of an inner container 10a and an outer container 10b, and the bottom portion is formed by both of the closing members 10c and 10d and has a substantially V-shape. Yes. The inner container 10a is composed of a quartz cylinder, and has an inner diameter of 160 mm and a length of 1000 mm. As shown in FIG. 3B, the area ratio of the opening 18 on the bottom surface of the inner container 10a is about 63%, the remainder is the closing member 10d, and the area ratio is about 37%.

  As shown in FIG. 3A, the bottom shape of the inner container 10a is such that the angle θ of the closing member 10d is about 45 degrees, and the distance L between the apex of the opening 18 and the apex of the closing member 10d is about 10 mm. did. Further, since a step is generated between the lower end of the closing member 10d and the lower end of the opening 18, a vertical wall (fixed lid) is provided at that portion. Moreover, the latching member 30 is provided in the outer peripheral surface of the upper part of the inner side container 10a.

  On the other hand, the outer container 10b is formed of a quartz cylinder, and the inner diameter thereof is approximately 10 mm larger than the outer diameter of the inner container 10a, and the length thereof is shorter than that of the inner raw material container 10a. When the inner container 10a is inserted, the upper end of the outer container 10b supports the retaining member 30 provided on the inner container 10a in a state where the opening 18 is closed by the closing member 10c.

  The bottom surface of the outer container 10b has a structure that is closed by the opening 18 of the inner container 10a, and the area ratio is approximately 38%. The angle β of the closing member 10c is about 45 degrees. A plurality of horizontal holes (not shown) are provided in the upper part of the outer container 10b through which the wire 9 for suspension is passed.

  Next, with the opening 18 closed by the closing member 10c, the inner container 10a was filled with 20 kg of the solid material 11 in the form of agglomerates having a particle size of 5 mm to 25 mm.

  When the melting of the initially charged solid raw material 11 is completed, as shown in FIG. 1A, the raw material container 10 filled with the solid raw material 11 is pulled up using a dedicated hanger 8 via a plurality of wires 9. 7 and hung on the crucible 3. At this time, the plurality of wires 9 support the outer container 10 b, and the inner container 10 a is supported by the outer container 10 b via the latch member 30.

  As the pull-up shaft 7 is driven, when the raw material container 10 is lowered to a predetermined height position, as shown in FIG. 1B, the latch member 30 comes into contact with the gate valve 13, and the inner container 10a is lowered. Was stopped, the outer container 10b slid by 30 mm to 35 mm, the opening 18 was opened, and the solid raw material 11 was supplied into the crucible 3.

  When the supply of the raw material was continued, the raw material melt 12 initially charged in the crucible 3 was cooled and the surface of the melt was solidified. The outer raw material container 10 b was further lowered by 10 mm to 15 mm, and all the raw materials inside were supplied into the crucible 3. At this time, the crucible 3 was rotated at 10 rpm.

  After the supply is completed, the raw material container 10 is taken out of the chamber, and the solid raw material 11 supplied into the crucible 3 forms a raw material solution by heating the heater 5 to compensate for the shortage of the melt amount. In the raw material supply apparatus of the present invention, the cover 17 can be attached to the lower end portion of the raw material container 10. Thereby, the variation in the charging position can be eliminated, and the liquid splash to the components such as the heater 5 can be prevented.

  As described above, the additional charge using the raw material container used in the raw material supply apparatus of the present invention uses agglomerated polycrystalline silicon as the solid raw material, so the raw material cost is low and there is a risk of cracking due to rapid heating. There is no. Furthermore, the splash of the raw material melt accompanying the additional charge can be prevented.

  According to the raw material supply apparatus and supply method by the CZ method of the present invention, by suspending an inner container filled with agglomerated solid raw material and an outer container into which the inner container is slidably inserted, it can be lifted and lowered. The solid raw material can be additionally charged or recharged to the raw material melt in the crucible by providing an opening by sliding the inner container or the outer container.

Therefore, the raw material cost is low, the raw material melt in the crucible is prevented from splashing, can be added statically, and there is no risk of cracking due to rapid heating. Therefore, productivity in the growth of the silicon single crystal can be improved, the crucible can be used efficiently, and the life of the furnace parts can be extended, so that the cost for growing the silicon single crystal can be greatly reduced.
Thereby, the raw material supply apparatus and the supply method of the present invention can be widely applied in the production of a silicon single crystal for forming a semiconductor substrate.

It is sectional drawing which shows the whole structure of the single crystal growth furnace which has arrange | positioned the raw material supply apparatus of this invention, (a) is the state with which the raw material container was filled with the agglomerated solid raw material, (b) is charging a solid raw material. It shows the state. It is a figure which shows the 1st structural example of the raw material container used for the raw material supply apparatus of this invention. It is a partial detailed view which shows the 1st structural example of the raw material container used for the raw material supply apparatus of this invention, (a) is a longitudinal cross-sectional view which shows the lower layer part structure which has the opening part of a raw material container, (b) These are sectional drawings which show the bottom face structure by 3B-3B arrow of a raw material container. It is a partial detail drawing which shows the 2nd structural example of the raw material container used for the raw material supply apparatus of this invention, (a) is a longitudinal cross-sectional view which shows the lower layer part structure which has the opening part of a raw material container, (b) These are sectional drawings which show the bottom face structure by 4A-4A arrow of a raw material container. It is a figure which shows the 3rd structural example of the raw material container used for the raw material supply apparatus of this invention. It is a perspective view which shows the structure of the lower end bottom part in the 3rd structural example of the raw material container used for the raw material supply apparatus of this invention. It is sectional drawing which shows the 4th structural example of the raw material container used for the raw material supply apparatus of this invention. It is sectional drawing which shows the 5th structural example of the raw material container used for the raw material supply apparatus of this invention.

Explanation of symbols

1: main chamber 2: pull chamber 3: crucible 3a: quartz crucible 3b: graphite crucible 4: support shaft 5: heater 6: heat insulating material 7: pulling shaft 8: hanger 9: wire 10: raw material container 10a: inner container, 10b: outer container 10c, 10d: closing member, 11: solid raw material 12: raw material melt, 13: gate valve 17: cover, 18, 18a, 18b: opening 30: latching member

Claims (8)

A raw material supply apparatus that is used for growing a single crystal by the Czochralski method, and that additionally charges or recharges the raw material melt in the crucible,
Filled with agglomerated solid raw material, an inner container having an opening at the bottom or bottom, an outer container for slidably inserting the inner container and closing the opening, and raising and lowering the inner container and the outer container A lifting means to suspend it as possible,
A raw material supply apparatus comprising a hook member for stopping raising and lowering the inner container, opening the opening by sliding the outer container, and charging the solid raw material into the raw material melt in the crucible. A raw material supply apparatus that is used for growing a single crystal by the Czochralski method, and that additionally charges or recharges the raw material melt in the crucible,
Filled with agglomerated solid raw material, an inner container having an opening at the bottom or bottom, an outer container for slidably inserting the inner container and closing the opening, and raising and lowering the inner container and the outer container A lifting means to suspend it as possible,
A raw material supply apparatus comprising: a hook member for stopping raising and lowering of the outer container; opening the opening by sliding of the inner container; and feeding the solid raw material into the raw material melt in the crucible . 3. The raw material according to claim 1, wherein the material constituting the inner container and the outer container is composed of any one of quartz, silicon carbide (SiC), or carbon whose surface is coated with SiC. Feeding device. When a single crystal is grown by the Czochralski method, a raw material supply method for additionally charging or recharging the raw material melt in the crucible,
An inner container having an opening at the bottom or bottom is slidably inserted into the outer container, and the inner container is filled with agglomerated solid raw material in a state where the opening is closed,
Then, after hanging down the inner container and the outer container on a crucible located in the center of the growth furnace, stop the lowering of either the inner container or the outer container,
Accordingly, the raw material supply method is characterized in that either the inner container or the outer container is slid to open the opening, and the solid raw material is charged into the raw material melt in the crucible . A hook member for stopping the descent is provided in the inner container, the opening of the inner container is opened by sliding of the outer container, and the solid raw material is charged into the raw material melt in the crucible. Item 5. The raw material supply method according to Item 4 . Claims wherein the hooking member is provided to stop the descent into the outer container, the opening the pre KiHiraki opening by the sliding of the outer container, characterized by introducing the solid raw materials in the raw material melt in the crucible 4. The raw material supply method according to 4 . The raw material supply method according to claim 4 , wherein as the agglomerated solid raw material to be filled in the inner container, a fine raw material having a particle size of 25 mm or less is filled in a lower layer portion close to the opening . The raw material supply method according to claim 4 , wherein the solid raw material is charged into the raw material melt in the crucible while rotating the crucible .

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