JP2023067364A - Heat shield member, component set thereof, and apparatus and method for manufacturing single crystal using heat shield member - Google Patents

Abstract

To provide a heat shield member capable of growing single crystals having different crystal diameters using the same CZ pulling furnace, and an apparatus and method for manufacturing a single crystal using the same.SOLUTION: A heat shield member 20 used for pulling a single crystal by the CZ method and surrounding the single crystal pulled from a melt in a crucible includes an approximately cylindrical insulating member 30 and a wall member 40 covering the exposed surface of the insulating member 30. The wall member 40 includes: an outer wall part 41 covering at least the outer peripheral surface of the insulating member 30; an inner wall part 42 covering the inner peripheral surface of the insulating member 30; and a bottom wall part 43 covering the lower end surface of the insulating member 30. The insulating member 30 includes an approximately cylindrical first heat insulation part 31 and an approximately cylindrical second heat insulation part 32 provided in the inside of the first heat insulation part 31, and the second heat insulation part 32 is freely attachably/detachably constituted of the first heat insulation part 31.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a heat shield member and its component set used for pulling a single crystal by the Czochralski method (CZ method). The present invention also relates to a single crystal manufacturing apparatus and a single crystal manufacturing method using such a heat shield member.

Most of the silicon single crystals used as substrate materials for semiconductor devices are manufactured by the CZ method. In the CZ method, a seed crystal is immersed in a silicon melt contained in a quartz crucible, and the seed crystal and the quartz crucible are rotated while the seed crystal is gradually pulled up to grow a large single crystal at the lower end of the seed crystal. According to the CZ method, it is possible to manufacture a high quality silicon single crystal ingot with a high yield.

In order to improve the crystal quality of the silicon single crystal, the CZ method uses a heat shield member that surrounds the silicon single crystal pulled up from the silicon melt and shields the radiant heat from the heater. Regarding heat shield members, for example, Patent Document 1 describes a method of preventing concentration of thermal stress on a notch by dividing a disk-shaped bottom plate portion of a heat shield into two parts. Further, Patent Literature 2 describes a heat shielding member in which only the bottom portion of the bulging portion can be replaced.

In Patent Document 3, in order to pull silicon single crystal rods having different diameters without replacing the heat shield member, a plurality of heat radiators configured to be radially movable are applied to the peripheral surface of the silicon single crystal rod. It mentions changing the distance. When forming the shoulder portion of the silicon single crystal rod, the plurality of heat radiators are moved away from the shoulder portion, and when forming the straight body portion of the silicon single crystal rod, the plurality of heat radiators are moved near the straight body portion. do.

Silicon single crystals are used not only as substrate materials for semiconductor devices, but also as electrode materials for plasma etching apparatuses, for example. Patent Document 4 describes that a silicon single crystal is used as an electrode plate of a plasma etching apparatus.

Japanese Patent Application Laid-Open No. 2004-323322 JP-A-2004-352581 JP-A-2000-7488 JP-A-2003-51491

Silicon single crystals for electrode materials are not standardized in crystal diameter unlike silicon single crystals for semiconductors, and the required crystal diameter varies depending on the device design. Therefore, in the production of silicon single crystals for electrode materials, it is required to efficiently produce silicon single crystals having different straight body diameters (hereinafter simply referred to as crystal diameters) according to the order quantity. In response to such demands, conventionally, a dedicated heat shield member was prepared for each crystal diameter to be pulled. However, if a dedicated heat shield member is prepared for each crystal diameter, there is a problem of an increase in cost due to an increase in the number of types of parts to be possessed, and there is also a problem of securing storage space.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a heat shielding member and a component set thereof, a single crystal manufacturing apparatus using the heat shielding member, and a single crystal, which are capable of efficiently pulling single crystals having different crystal diameters using the same CZ pulling furnace. It is to provide a manufacturing method of

In order to solve the above problems, a heat shield member according to the present invention is a member that is used for pulling a single crystal by the CZ method, surrounds the single crystal pulled from the melt in the crucible, and has a substantially cylindrical shape. a heat insulating member; and a wall member covering an exposed surface of the heat insulating member, wherein the wall member includes an outer wall portion covering at least an outer peripheral surface of the heat insulating member, an inner wall portion covering an inner peripheral surface of the heat insulating member, and the a bottom wall portion covering a lower end surface of a heat insulating member, the heat insulating member including a substantially cylindrical first heat insulating portion and a substantially cylindrical second heat insulating portion provided inside the first heat insulating portion; , wherein the second heat insulating part is detachably attached to the first heat insulating part.

According to the present invention, when pulling a plurality of types of single crystals having different crystal diameters, the first heat insulating portion of the heat insulating member and the outer wall portion of the wall member are used as common parts, and the first heat insulating portion such as the second heat insulating portion and the inner wall portion are used. The opening size can be changed by omitting or replacing the parts inside. Therefore, it is possible to efficiently pull a plurality of types of single crystals having different crystal diameters using the same CZ pulling furnace.

In the present invention, the outer peripheral surface of the first heat insulating portion is covered with the outer wall portion, the inner peripheral surface of the second heat insulating portion is covered with the inner wall portion, and the outer peripheral surface of the second heat insulating portion is It is preferable that it is in close contact with the inner peripheral surface of the first heat insulating portion. As a result, the first and second heat insulating portions can be treated as one heat insulating member, and by combining the first and second heat insulating portions, it is possible to provide a heat shielding member suitable for pulling small-diameter single crystals. can. Also, by removing the second heat insulating portion, it is possible to provide a heat shielding member suitable for pulling a large-diameter single crystal.

In the present invention, the bottom wall portion is configured to be detachable from the outer wall portion, and the inner wall portion is configured to be detachable from the bottom wall portion and the outer wall portion. It is preferably configured to be detachable from the first bottom wall portion. This makes it possible to deal with both small-diameter single crystals and large-diameter single crystals.

In the present invention, the upper surface of the inner peripheral end portion of the bottom wall portion connected to the lower end portion of the inner wall portion is provided with a tapered surface inclined radially outward, and the lower end portion of the inner wall portion is provided with a tapered surface. is preferably in contact with the tapered surface. As a result, it is possible to improve the adhesion between the inner wall portion and the bottom wall portion at the connecting position, and it is possible to maintain the sealed state of the heat insulating member by the wall member. Therefore, even if the heat insulating member deteriorates and becomes powdery, it is possible to prevent deterioration of the single crystal yield due to leakage of fine powder of the heat insulating member to the outside.

In the present invention, the lower end portion of the outer wall portion connected to the outer peripheral end portion of the bottom wall portion is provided with a tapered surface inclined radially outward, and the outer peripheral end portion of the bottom wall portion is It is preferable to abut on the tapered surface. As a result, the contact between the bottom wall portion and the outer wall portion can be enhanced at the connecting position, and the sealing state of the heat insulating member by the wall member can be maintained. Therefore, even if the heat insulating member deteriorates and becomes powdery, it is possible to prevent deterioration of the single crystal yield due to leakage of fine powder of the heat insulating member to the outside.

In the present invention, it is preferable that a protrusion is provided at the lower end of the outer wall, and a hook that engages with the protrusion is provided at the outer peripheral end of the bottom wall. Also in this case, it is possible to improve the adhesion between the bottom wall portion and the outer wall portion at the connection position between them, and it is possible to maintain the sealed state of the heat insulating member by the wall member.

In the present invention, the difference between the opening diameter of the heat shielding member when the first heat insulating portion is used alone and the opening diameter of the heat shielding member when the first heat insulating portion and the second heat insulating portion are used in combination. is preferably greater than or equal to 50 mm (about 2 inches). As a result, multiple types of single crystals having different crystal diameters can be efficiently pulled using the same CZ pulling furnace.

In the present invention, the inner wall portion is a substantially cylindrical first inner wall portion that covers the inner peripheral surface of the first heat insulating portion or a substantially cylindrical second inner wall portion that covers the inner peripheral surface of the second heat insulating portion. is preferred. By using the first inner wall portion in combination with the first heat insulating portion, a heat shielding member having a large opening size can be realized. Further, by combining the second inner wall portion with the first and second heat insulating portions, it is possible to realize a heat shielding member with a small opening size.

In the present invention, it is preferable that the difference between the opening diameter of the first inner wall portion and the opening diameter of the second inner wall portion is 50 mm or more. As a result, two types of single crystals having a diameter difference of 50 mm or more can be efficiently pulled.

In the heat shielding member according to the present invention, when the first single crystal is pulled, the second heat insulating portion is omitted and the first heat insulating portion is used alone, and the bottom wall portion is omitted and the first heat insulating portion is used alone. An inner wall portion is used in combination with the outer wall portion, and the second heat insulation portion is used in combination with the first heat insulation portion when pulling a second single crystal having a smaller diameter than the first single crystal. and preferably the second inner wall portion and the bottom wall portion are used in combination with the outer wall portion. Thus, the heat shield member according to the present invention can be applied to both the CZ pulling process of the first and second single crystals having different crystal diameters.

The bottom wall portion is a substantially annular first bottom wall portion that covers the lower end surface of the first heat insulating portion or a substantially annular second bottom wall portion that covers the lower end surfaces of the first and second heat insulating portions. is preferred. By using the first bottom wall portion in combination with the first heat insulation portion and the first inner wall portion, a heat shield member having a large opening size can be constructed. Also, by using the second bottom wall portion in combination with the first and second heat insulating portions and the second inner wall portion, a heat shielding member having a small opening size can be constructed.

In the heat shielding member according to the present invention, when the first single crystal is pulled, the second heat insulating portion is omitted and the first heat insulating portion is used alone, and the first inner wall portion and the first bottom are used. Preferably, a wall portion is used in combination with the outer wall portion, and the second heat insulating portion overlaps with the first heat insulating portion when pulling a second single crystal having a smaller diameter than the first single crystal. Preferably, they are used in combination and the second inner wall and the second bottom wall are used in combination with the outer wall. Thus, the heat shield member according to the present invention can be applied to both the CZ pulling process of the first and second single crystals having different crystal diameters.

The present invention also provides a component set of a heat shield member used for pulling a single crystal by the CZ method and surrounding the single crystal pulled from the melt in the crucible, comprising a substantially cylindrical first heat insulating portion and , a substantially cylindrical second heat insulating portion detachably provided inside the first heat insulating portion; an outer wall portion covering the outer peripheral surface of the first heat insulating portion; and a second inner wall covering the inner peripheral surface of the second heat insulating part, wherein the first heat shielding member is composed of the first heat insulating part, the outer wall and the first inner wall. , wherein the second heat shielding member having an opening diameter smaller than that of the first heat shielding member is composed of the first heat insulating portion, the second heat insulating portion, the outer wall portion, and the second inner wall portion. Characterized by

According to the present invention, the opening diameter of the heat shielding member can be changed by adding or exchanging some of the constituent parts of the heat shielding member, and it is possible to handle the pulling of multiple types of single crystals with different crystal diameters. can be done.

Moreover, it is preferable that the parts set of the heat shielding member according to the present invention further includes a bottom wall portion covering at least the lower end surface of the second heat insulating portion, and the second heat shielding member further includes the bottom wall portion. . Further, the parts set for the heat shield member according to the present invention includes a first bottom wall portion covering the lower end surface of the first heat insulating portion and a second bottom wall portion covering the lower end surfaces of the first and second heat insulating portions. Further, the first heat shield member may further include the first bottom wall portion, and the second heat shield member may further include the second bottom wall portion. In this way, by adding or replacing the bottom wall portion, it is possible to provide a heat shield member that can handle pulling of a plurality of single crystals having different crystal diameters.

In the present invention, it is preferable that the difference between the opening diameter of the first inner wall portion and the opening diameter of the second inner wall portion is 50 mm or more. As a result, multiple types of single crystals having different crystal diameters can be efficiently pulled using the same CZ pulling furnace.

Further, the single crystal manufacturing apparatus according to the present invention includes a chamber, a crucible supporting the melt in the chamber, a heater for heating the melt, a crucible driving mechanism for rotating and raising and lowering the crucible, and the melt. A crystal pulling mechanism for pulling the single crystal from the liquid, and a heat shield according to the present invention, which is installed above the melt and surrounds the single crystal pulled from the melt to shield the radiant heat from the heater. A member is provided. According to the present invention, the opening size can be changed by omitting or changing some parts. Therefore, it is possible to efficiently pull a plurality of types of single crystals having different crystal diameters using the same CZ pulling furnace.

Further, the method for producing a single crystal according to the present invention is a CZ method in which a single crystal is pulled from a melt in a crucible, and the heat shielding member according to the present invention is used to surround the single crystal pulled from the melt. Characterized by According to the present invention, the opening size can be changed by omitting or changing some parts, and multiple types of single crystals having different crystal diameters can be efficiently pulled.

In the method for producing a single crystal according to the present invention, a first single crystal having a first crystal diameter is pulled using the heat shield member configured by using the first heat insulating portion alone, and the first heat insulating portion is pulled up. It is preferable to pull a second single crystal having a second crystal diameter smaller than the first crystal diameter using the heat shield member configured by combining a portion and the second heat insulating portion. As a result, the opening size can be changed by omitting or changing some parts, and two types of single crystals having different crystal diameters can be efficiently pulled.

In the present invention, the difference between the first crystal diameter and the second crystal diameter is preferably 50 mm (about 2 inches) or more. As a result, two types of single crystals having different crystal diameters can be efficiently pulled using the same CZ pulling furnace.

INDUSTRIAL APPLICABILITY According to the present invention, a heat shielding member and a set of components therefor, and a single crystal manufacturing apparatus and a single crystal manufacturing apparatus using the heat shielding member, are capable of efficiently pulling single crystals having different crystal diameters using the same CZ pulling furnace. can provide a method.

FIG. 1 is a schematic side cross-sectional view showing the configuration of a single crystal manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the completed configuration of the heat shield member according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing the configuration of the heat shield member in an exploded state according to the first embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing the completed configuration of the heat shield member according to the second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing the disassembled configuration of a heat shield member according to a second embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing the completed configuration of a heat shield member according to a third embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing the completed configuration of a heat shield member according to a fourth embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing the disassembled configuration of a heat shield member according to a fourth embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing the completed configuration of a heat shield member according to a fifth embodiment of the present invention. FIG. 10 is a schematic cross-sectional view showing the disassembled configuration of a heat shield member according to a fifth embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing the completed configuration of a heat shield member according to a sixth embodiment of the present invention. FIG. 12 is a schematic cross-sectional view showing the configuration of the heat shield member in an exploded state according to the sixth embodiment of the present invention. FIG. 13 is a schematic cross-sectional view showing the configuration of the completed heat shield member according to the seventh embodiment of the present invention. FIG. 14 is a schematic cross-sectional view showing the configuration of the heat shield member in an exploded state according to the seventh embodiment of the invention.

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic side cross-sectional view showing the configuration of a single crystal manufacturing apparatus according to an embodiment of the present invention.

As shown in FIG. 1, a single crystal manufacturing apparatus 1 includes a water-cooled chamber 10, a quartz crucible 11 holding a silicon melt 2 in the chamber 10, a graphite crucible 12 holding the quartz crucible 11, and a graphite crucible. a shaft driving mechanism 14 for rotating and vertically driving the quartz crucible 11 via the rotating shaft 13 and the graphite crucible 12; a heater 15 arranged around the graphite crucible 12; A heat insulating material 16 arranged outside and along the inner surface of the chamber 10, a wire 17 for pulling a single crystal arranged above the quartz crucible 11 and coaxially with the rotating shaft 13, and above the chamber 10. and a heat shielding member 20 arranged above the quartz crucible 11 .

The chamber 10 is composed of a main chamber 10a and an elongated cylindrical pull chamber 10b connected to an upper opening of the main chamber 10a. It is provided in the chamber 10a. The pull chamber 10b is provided with a gas introduction port 10c for introducing an inert gas (purge gas) such as argon gas or a dopant gas into the chamber 10. At the bottom of the main chamber 10a, the atmospheric gas in the chamber 10 is provided. A gas outlet 10d for discharging is provided. A viewing window (not shown) is provided in the upper portion of the main chamber 10a, and the growing state of the silicon single crystal 3 can be observed through the viewing window.

The quartz crucible 11 is a silica glass container having a substantially cylindrical side wall and a curved bottom. The graphite crucible 12 supports the quartz crucible 11 in close contact with the outer surface of the quartz crucible 11 in order to maintain the shape of the quartz crucible 11 softened by heating. The quartz crucible 11 and the graphite crucible 12 form a double structure crucible that supports the silicon melt in the chamber 10 .

Graphite crucible 12 is fixed to the upper end of rotary shaft 13 , and the lower end of rotary shaft 13 penetrates the bottom of chamber 10 and is connected to shaft drive mechanism 14 provided outside chamber 10 . The rotating shaft 13 and the shaft driving mechanism 14 constitute a crucible driving mechanism that drives the quartz crucible 11 to rotate and move up and down.

The heater 15 is used to heat the silicon raw material filled in the quartz crucible 11 to generate the silicon melt 2 and to keep the silicon melt 2 in a molten state. The heater 15 is a resistance heating heater made of carbon, and is provided so as to surround the quartz crucible 11 inside the graphite crucible 12 . A heat insulating material 16 is provided on the outside of the heater 15 so as to surround the heater 15 , thereby increasing heat retention in the chamber 10 .

Above the quartz crucible 11, a wire 17 as a pulling shaft for the silicon single crystal 3 and a wire winding mechanism 18 for winding the wire 17 are provided. The wire winding mechanism 18 constitutes a crystal pulling mechanism that pulls the silicon single crystal 3 while rotating it together with the wire 17 . The wire winding mechanism 18 is arranged above the pull chamber 10b, the wire 17 extends downward through the inside of the pull chamber 10b from the wire winding mechanism 18, and the tip of the wire 17 extends inside the main chamber 10a. reaching the space. FIG. 1 shows a state in which a silicon single crystal 3 in the process of growing is suspended from a wire 17 . When the silicon single crystal 3 is pulled up, the silicon single crystal 3 is grown by gradually pulling up the wire 17 while rotating the quartz crucible 11 and the silicon single crystal 3 .

The heat shield member 20 suppresses temperature fluctuations in the silicon melt 2 to form an appropriate hot zone in the vicinity of the crystal growth interface, and prevents heating of the silicon single crystal 3 by radiant heat from the heater 15 and the quartz crucible 11. is established for The heat shield member 20 is a substantially cylindrical member made of graphite, and is provided so as to cover the area above the silicon melt 2 excluding the pulling path of the silicon single crystal 3 .

The diameter of the opening 20a at the lower end of the heat shield member 20 is larger than the diameter of the silicon single crystal 3, thereby securing a pulling path for the silicon single crystal 3. As shown in FIG. The outer diameter of the lower end of the heat shielding member 20 is smaller than the diameter of the quartz crucible 11, and the lower end of the heat shielding member 20 is located inside the quartz crucible 11. The heat shield member 20 does not interfere with the quartz crucible 11 even if the heat shield member 20 is raised above the lower end of the quartz crucible 11 .

As the silicon single crystal 3 grows, the amount of melt in the quartz crucible 11 decreases. The temperature fluctuation of the liquid 2 can be suppressed, and the amount of evaporation of the dopant from the silicon melt 2 can be controlled by keeping the flow velocity of the gas flowing near the melt surface constant. Therefore, it is possible to improve the stability of crystal defect distribution, oxygen concentration distribution, resistivity distribution, etc. in the direction of pulling axis of the silicon single crystal 3 .

In manufacturing the silicon single crystal 3 , first, polycrystalline silicon raw material is put into the quartz crucible 11 , and the raw material in the quartz crucible 11 is heated and melted by the heater 15 to form the silicon melt 2 . Next, the seed crystal attached to the lower end of the wire 17 is lowered and brought into contact with the silicon melt 2 . After that, while maintaining contact with the silicon melt 2 , the seed crystal is gradually pulled up to grow a silicon single crystal 3 . In the crystal pulling step, the diameter is gradually increased to form the shoulder portion, and then the diameter is kept constant to form the straight body portion. After forming a straight body of a desired length, the diameter is gradually reduced and separated from the silicon melt 2 . As described above, a silicon single crystal ingot is completed.

2 and 3 are schematic sectional views showing the configuration of the heat shield member according to the first embodiment of the present invention, wherein FIG. 2 is a completed drawing and FIG. 3 is an exploded view.

As shown in FIGS. 2 and 3 , the heat shield member 20 according to this embodiment includes a substantially cylindrical heat insulating member 30 and a wall member 40 covering the exposed surface of the heat insulating member 30 . A felt material made of carbon fiber can be used as the heat insulating member 30 . Alternatively, alumina or the like may be used as a heat insulating member. As the material of the wall member 40, thermally stable and high-purity graphite or graphite whose surface is coated with SiC can be used. Alternatively, thermally stable Mo (molybdenum) or W (tungsten) may be used as the wall member.

The heat insulating member 30 is composed of a substantially cylindrical first heat insulating portion 31 . An outer peripheral surface 31 a of the first heat insulating portion 31 is a vertical surface and constitutes an outer peripheral surface 30 a of the heat insulating member 30 . An inner peripheral surface 31b of the first heat insulating portion 31 forms a downwardly tapered surface. A lower end surface 31c of the first heat insulating portion 31 is a horizontal surface, and a chamfered tapered surface is provided at a corner portion on the outer peripheral side. The outer peripheral surface 31a of the first heat insulating portion 31 may form a downward tapered surface.

The wall member 40 includes an outer wall portion 41 that covers the outer peripheral side region of the outer peripheral surface 30a and the lower end surface 30c of the heat insulating member 30, an inner wall portion 42 that covers the inner peripheral surface 30b of the heat insulating member 30, and a lower end surface 30c of the heat insulating member 30. and a bottom wall portion 43 covering the inner peripheral region.

The outer wall portion 41 is a substantially cylindrical member, and covers the outer peripheral side regions of the outer peripheral surface 31 a and the lower end surface 31 c of the first heat insulating portion 31 . The inner peripheral surface of the outer wall portion 41 is in close contact with the outer peripheral surface 31 a of the first heat insulating portion 31 . By inserting the first heat insulating portion 31 inside through the upper opening of the outer wall portion 41 , the first heat insulating portion 31 is housed inside the outer wall portion 41 . The first heat insulating portion 21 can be easily removed from the outer wall portion 41 by lifting it upward. In this embodiment, the cylindrical shape of the outer wall portion 41 has a constant diameter from the upper end portion to the position of the tapered portion below, but may be a substantially inverted truncated cone shape in which the diameter gradually decreases.

The inner wall portion 42 is a substantially cylindrical member, is installed inside the substantially cylindrical outer wall portion 41 , and covers the inner peripheral surface 31 b of the first heat insulating portion 31 . As the inner wall portion 42, a first inner wall portion 42X having a shape that fits the inner peripheral surface 31b of the first heat insulating portion 31 is used. is closely related to The upper end portion of the first inner wall portion 42X contacts the inner peripheral surface of the outer wall portion 41 near the upper end portion, and covers the upper end surface 31d of the first heat insulating portion 31 forming the upper end surface 30d of the heat insulating member 30. A lower end portion of the first inner wall portion 42X is in contact with the upper surface of the bottom wall portion 43 near the inner peripheral end portion. The first inner wall portion 42X has a flat shape that slopes obliquely straight from the upper end to the lower end, but may have a step in the middle.

Normally, the opening diameter of the heat shield member 20 becomes smaller as it goes downward, and is the smallest near the lower end. The opening shape of the heat shielding member, which has a large effect on the pulling of the single crystal, is the opening diameter near the lower end near the solid-liquid interface. say about The same applies to the opening diameters of the heat shield member 20 and other parts.

The bottom wall portion 43 is a substantially annular member, is installed inside the substantially cylindrical outer wall portion 41 , and covers the inner peripheral region of the lower end surface 31 c of the first heat insulating portion 31 . As the bottom wall portion 43, a large-diameter first bottom wall portion 43X matching the size of the first heat insulating portion 32X is used. It is preferable that the upper surface of the first bottom wall portion 43X is in close contact with the lower end surface 31c of the first heat insulating portion 31 . The first bottom wall portion 43X is placed on the upper surface of the inner peripheral end portion (lower end portion) of the outer wall portion 41, and constitutes an annular bottom plate. A step is provided on the first bottom wall portion 43X, and this step is fitted to the inner peripheral end portion of the outer wall portion 41, thereby positioning and fixing the first bottom wall portion 43X at the center of the heat shield member 20. be.

In the installed state of the first inner wall portion 42X, the lower end portion of the first inner wall portion 42X is preferably in close contact with the inner peripheral end portion of the first bottom wall portion 43X. In order to ensure such a close contact state, it is preferable that the lower end surface of the first inner wall portion 42X is formed with a tapered surface 42t that is inclined upward toward the center in the radial direction in the installed state. Similarly, the upper surface of the inner peripheral edge of the first bottom wall portion 43X is preferably formed with a tapered surface 43t having substantially the same inclination angle as the lower end surface of the first inner wall portion 42X. In this manner, the tapered surface 42t at the lower end of the first inner wall portion 42X is in surface contact with and engages with the tapered surface 43t at the inner peripheral end portion of the first bottom wall portion 43X, so that the housing space for the heat insulating member 30 is reduced. Can be sealed.

A similar tapered surface is preferably provided also at the connecting position between the outer wall portion 41 and the first bottom wall portion 43X. That is, a tapered surface 41u is formed on the upper surface of the inner peripheral end of the outer wall portion 41, and a tapered surface 43u having substantially the same inclination angle as the tapered surface 41u is formed on the bottom surface of the outer peripheral end of the first bottom wall portion 43X. formed. Therefore, the connection between the two can be made strong, and the accommodation space of the heat insulating member 30 can be sealed.

Since the heat insulating member 30 gradually deteriorates and becomes powdery, if the sealing state of the heat insulating member 30 by the wall member 40 is insufficient, the fine powder of the heat insulating member 30 leaks out and adversely affects the yield of the single crystal. However, when the joints between the plurality of parts forming the wall member 40 are in close contact with each other, it is possible to prevent the fine powder from leaking out.

As shown in FIG. 3, the heat shield member 20 according to the present embodiment is completed by installing each part inside the outer wall portion 41 in a predetermined order. Each part simply needs to be accommodated within the outer wall portion 41, and no special fixing means is required. Therefore, it is extremely easy to take out and replace each part.

As described above, the heat insulating member 30 according to the present embodiment is composed only of the first heat insulating portion 31, and the wall member 40 includes the first inner wall portion 42X and the first bottom wall portion 43X corresponding to the first heat insulating portion 31. are used, respectively, thereby constructing the heat shield member 20 having a relatively large opening size. If it is desired to construct the heat shield member 20 with a relatively small opening size, additional or modified parts are required.

4 and 5 are schematic cross-sectional views showing the configuration of a heat shield member according to a second embodiment of the present invention, wherein FIG. 4 is a completed drawing and FIG. 5 is an exploded view.

As shown in FIGS. 4 and 5, the heat shield member 20 according to this embodiment is a modification of the first embodiment shown in FIGS. and the second heat insulating portion 32 . The first heat insulating portion 31 is the same as that used in the first embodiment. The second heat insulating portion 32 is a substantially cylindrical member provided on the inner peripheral side of the first heat insulating portion 31 and configured to be detachable from the first heat insulating portion 31 . That is, the heat insulating member 30 according to the present embodiment is obtained by adding the second heat insulating portion 32 to the first heat insulating portion 31, which is a common component with the first embodiment.

The outer peripheral surface 32a of the second heat insulating portion 32 is a tapered surface that fits the inner peripheral surface 31b of the first heat insulating portion 31, and is in close contact with the inner peripheral surface 31b. The inner peripheral surface 32 b of the second heat insulating portion 32 is a tapered surface having an inclination angle close to that of the outer peripheral surface 32 a and constitutes the inner peripheral surface 30 b of the heat insulating member 30 . When the second heat insulating portion 32 is inserted inside through the upper opening of the first heat insulating portion 31, the outer peripheral surface 32a of the second heat insulating portion 32 is in close contact with the inner peripheral surface 31b of the first heat insulating portion 31, and the two are integrated. The second heat insulating portion 32 can be easily removed from the first heat insulating portion 31 by lifting it upward.

In this embodiment, the second heat insulating portion 32 is a relatively large member that extends over a wide range from the upper end to the lower end of the first heat insulating portion 31, but is provided only at the lower end portion of the first heat insulating portion 31 and is relatively large. It may be a small member.

The wall member 40 includes an outer wall portion 41 that covers the outer peripheral side region of the outer peripheral surface 30a and the lower end surface 30c of the heat insulating member 30, an inner wall portion 42 that covers the inner peripheral surface 30b of the heat insulating member 30, and a lower end surface 30c of the heat insulating member 30. and a bottom wall portion 43 covering the inner peripheral region. Here, the outer wall portion 41 is the same as that used in the first embodiment, and is a component common to the first and second embodiments, like the first heat insulating portion 31 .

As the inner wall portion 42, a second inner wall portion 42Y having a shape that fits the inner peripheral surface 32b of the second heat insulating portion 32 is used. The second bottom wall portion 43Y for is used. Therefore, the shape of the second inner wall portion 42Y is slightly different from that of the first inner wall portion 42X, and the shape of the second bottom wall portion 43Y is slightly different from that of the first bottom wall portion 43X.

The outer peripheral surface of the second inner wall portion 42Y is in close contact with the inner peripheral surface 32b of the second heat insulating portion 32, and the upper surface of the second bottom wall portion 43Y is in close contact with at least the lower end surface 32c of the second heat insulating portion 32. . The upper end portion of the second inner wall portion 42Y is in contact with the inner peripheral surface near the upper end portion of the outer wall portion 41, and the upper end surface 31d and the second heat insulating portion of the first heat insulating portion 31 that constitute the upper end surface 30d of the heat insulating member 30 and the second heat insulating portion. 32 covers the upper end surface 32d. A lower end portion of the second inner wall portion 42Y is in contact with the upper surface of the bottom wall portion 43 near the inner peripheral end portion. The inner wall portion 42 has a flat shape that slopes obliquely straight from the upper end to the lower end, but may have a step in the middle.

As described with reference to FIGS. 2 and 3, when the first heat insulating portion 31 is used alone, the opening size of the heat shielding member 20 can be increased, which is suitable for pulling a silicon single crystal having a large crystal diameter. It can be preferably used. On the other hand, when the first heat insulating portion 31 and the second heat insulating portion 32 are combined as in the present embodiment, the opening size (diameter of the opening 20a) of the heat shield member 20 can be reduced, and the crystal diameter is small. It can be preferably used for pulling a silicon single crystal.

In this way, the inner wall portion 42 of the heat shielding member 20 has a first inner wall portion 42X that matches the shape of the inner peripheral surface 31b of the first heat insulating portion 31 and a shape of the inner peripheral surface 32b of the second heat insulating portion 32. Two types of the combined second inner wall portion 42Y are prepared, and one of them is selectively used according to the use condition of the second heat insulating portion 32 . Similarly, as the bottom wall portion 43 of the heat shielding member 20, a first bottom wall portion 43X matching the shape of the bottom surface when the first heat insulating portion 31 is used alone, the first heat insulating portion 31, and the second heat insulating portion Two types of the second bottom wall portion 43Y are prepared according to the shape of the bottom surface when the second heat insulating portion 32 is used in combination.

The difference between the opening diameter _R1 when the opening size of the heat shield member 20 is increased and the opening diameter _R2 when the opening size is decreased is preferably 50 mm (about 2 inches) or more. If the diameter difference between two types of silicon single crystals having different crystal diameters is less than 50 mm, fine adjustment of other crystal pulling conditions without changing the opening size of the heat shield member 20 can substantially This is because it is possible to pull silicon single crystals of the same quality in In this way, when the opening size of the heat shield member 20 must be changed, the two types of silicon single crystals have substantially the same quality because the difference in diameter between the two types of silicon single crystals is large to some extent. This is the case in which the difference in diameter between the straight bodies of the two types of silicon single crystals is 50 mm or more.

The upper limit of the difference in opening diameter is not particularly limited. Therefore, for example, since a silicon single crystal with a diameter of about 200 mm and a silicon single crystal with a diameter of about 400 mm are pulled in the same CZ pulling furnace, the difference between the large opening diameter and the small opening diameter of the heat shield member 20 may be 200 mm or more. It is possible.

A first heat insulating portion 31 and a second heat insulating portion 32 forming the heat insulating member 30, an outer wall portion 41 forming the wall member 40, a first inner wall portion 42X, a second inner wall portion 42Y, a first bottom wall portion 43X, and a second heat insulating portion 43X. The bottom wall portion 43Y constitutes a part set of heat shield members corresponding to two types of opening sizes. The first heat insulating part 31 and the outer wall part 41 are basic parts common to both large and small diameters, and the second heat insulating part 32 is an additional part used only for small diameters. The first inner wall portion 42X and the first bottom wall portion 43X are optional parts used only for large diameters, and the second inner wall portion 42Y and the second bottom wall portion 43Y are optional parts used only for small diameters.

As described above, when pulling a silicon single crystal with a large diameter (for example, 395 mm), the first heat insulating portion 31 is used alone as the heat insulating member 30, and the first inner wall that fits the first heat insulating portion 31 as the inner wall portion 42. A first bottom wall portion 43X that covers the lower end surface of the first heat insulating portion 31 is used as the bottom wall portion 43 .

On the other hand, when pulling a silicon single crystal with a small diameter (for example, 320 mm), both the first heat insulating portion 31 and the second heat insulating portion 32 are used as the heat insulating member 30, and the inner wall portion 42 is fitted to the second heat insulating portion 32. A second inner wall portion 42</b>Y is employed, and a second bottom wall portion 43</b>Y that covers the lower end surfaces of the first heat insulating portion 31 and the second heat insulating portion 32 is employed as the bottom wall portion 43 .

As described above, the heat shield member 20 according to the present embodiment can change the opening size by replacing, adding, or omitting other parts while using some of the parts in common. Therefore, two types of silicon single crystals with different crystal diameters can be pulled using the same CZ pulling furnace, and the variation in quality of two types of silicon single crystals with different crystal diameters is reduced. be able to.

Further, in the method for manufacturing a single crystal according to the present embodiment, when pulling a silicon single crystal having a large crystal diameter, the heat shielding member 20 (the first heat shielding member ) is used to pull a silicon single crystal with a small crystal diameter, a double-structure heat shielding member 20 (second heat shielding member ), two types of silicon single crystals with different crystal diameters can be pulled using the same CZ pulling furnace, and variations in the quality of two types of silicon single crystals with different crystal diameters can be reduced. can be done.

FIG. 6 is a schematic cross-sectional view showing the configuration of a heat shield member according to a third embodiment of the invention.

As shown in FIG. 6, the heat shield member 20 according to this embodiment is a further modification of the heat shield member according to the second embodiment shown in FIGS. It consists of a combination of the portion 31 , the second heat insulating portion 32 and the third heat insulating portion 33 . The first heat insulating portion 31 and the second heat insulating portion 32 are the same as those used in the second embodiment. The third heat insulating portion 33 is a substantially cylindrical member provided on the inner peripheral side of the second heat insulating portion 32 and configured to be detachable from the second heat insulating portion 32 . That is, the heat insulating member 30 according to the present embodiment is obtained by adding the second heat insulating portion 32 and the third heat insulating portion 33 to the first heat insulating portion 31 which is a common component with the first embodiment.

The difference between the opening diameter R ₂ (see FIG. 4) when the third heat insulating portion 33 is not used and the opening diameter R ₃ when the opening size is reduced using the third heat insulating portion 33 is 50 mm (about 2 inches). It is preferable that it is above. If the diameter difference between two types of silicon single crystals having different crystal diameters is less than 50 mm, fine adjustment of other crystal pulling conditions without changing the opening size of the heat shield member 20 can substantially This is because it is possible to pull silicon single crystals of the same quality in

The outer peripheral surface 33a of the third heat insulating portion 33 is a tapered surface that fits the inner peripheral surface 32b of the second heat insulating portion 32, and is in close contact with the inner peripheral surface 32b. An inner peripheral surface 33 b of the third heat insulating portion 33 is a tapered surface having an inclination angle close to that of the outer peripheral surface 33 a , and constitutes an inner peripheral surface 30 b of the heat insulating member 30 . When the third heat insulating portion 33 is inserted inside from the upper opening of the second heat insulating portion 32, the outer peripheral surface 33a of the third heat insulating portion 33 is brought into close contact with the inner peripheral surface 32b of the second heat insulating portion 32, and the two are integrated. The third heat insulating portion 33 can be easily removed from the second heat insulating portion 32 by lifting it upward.

In the present embodiment, the third heat insulating portion 33 is a relatively large member that extends over a wide range from the upper end to the lower end of the first heat insulating portion 31 and the second heat insulating portion 32. It may be a relatively small member provided only at the lower end of the portion 32 .

The wall member 40 includes an outer wall portion 41 that covers the outer peripheral side region of the outer peripheral surface 30a and the lower end surface 30c of the heat insulating member 30, an inner wall portion 42 that covers the inner peripheral surface 30b of the heat insulating member 30, and a lower end surface 30c of the heat insulating member 30. and a bottom wall portion 43 covering the inner peripheral region. Here, the outer wall portion 41 is the same as that used in the first embodiment, and, like the first heat insulating portion 31, is a component common to the first to third embodiments.

As the inner wall portion 42, a third inner wall portion 42Z having a shape that fits the inner peripheral surface 33b of the third heat insulating portion 33 is used. A third bottom wall portion 43Z having a smaller size is used. Therefore, the shape of the third inner wall portion 42Z is slightly different from that of the second inner wall portion 42Y, and the shape of the third bottom wall portion 43Z is slightly different from that of the second bottom wall portion 43Y.

A first heat insulating portion 31, a second heat insulating portion 32, and a third heat insulating portion 33 forming the heat insulating member 30, and an outer wall portion 41, a first inner wall portion 42X, a second inner wall portion 42Y, and a third inner wall forming the wall member 40. The portion 42Z, the first bottom wall portion 43X, the second bottom wall portion 43Y, and the third bottom wall portion 43Z constitute a part set of heat shield members corresponding to three types of opening sizes. The first heat insulating part 31 and the outer wall part 41 are basic parts common to the large, medium and small diameters, the second heat insulating part 32 is an additional part common to the medium and small diameters, and the third heat insulating part 33 is an additional part used only for small diameters. The first inner wall portion 42X and the first bottom wall portion 43X are optional parts used only for large diameters, the second inner wall portion 42Y and the second bottom wall portion 43Y are optional parts used only for medium diameters, The third inner wall portion 42Z and the third bottom wall portion 43Z are optional parts used only for small diameters. Thus, according to this embodiment, the options for the opening size of the heat shield member 20 can be further expanded.

7 and 8 are schematic cross-sectional views showing the configuration of a heat shield member according to a fourth embodiment of the present invention, FIG. 7 being a completed drawing and FIG. 8 being an exploded view.

As shown in FIGS. 7 and 8, the feature of the heat shielding member 20 according to this embodiment is that the bottom wall portion 43 is omitted as a component of the large-diameter heat shielding member. That is, the wall member 40 is composed of an outer wall portion 41 covering the entire outer peripheral surface 30 a and the lower end surface 30 c of the heat insulating member 30 and a first inner wall portion 42 X covering the inner peripheral surface 30 b of the heat insulating member 30 .

9 and 10 are schematic cross-sectional views showing the configuration of a heat shield member according to a fifth embodiment of the present invention, wherein FIG. 9 is a completed drawing and FIG. 10 is an exploded view.

As shown in FIGS. 9 and 10, the heat shield member 20 according to this embodiment is a modification of the heat shield member according to the fourth embodiment shown in FIGS. The wall member 40 is composed of a combination of a first heat insulating portion 31 and a second heat insulating portion 32, and further includes a bottom wall portion 43 in addition to the outer wall portion 41 and the second inner wall portion 42Y.

As described above, the bottom wall portion may be omitted when the opening size of the heat shield member 20 is increased, and the bottom wall portion may be added when the opening size of the heat shield member 20 is decreased. In this case, the first heat insulating portion 31 and the outer wall portion 41 can be used as common parts, and by adding the second heat insulating portion 32 and the bottom wall portion 43 and replacing the inner wall portion 42, it is possible to cope with a small diameter.

11 and 12 are schematic cross-sectional views showing the construction of a heat shield member according to a sixth embodiment of the present invention, wherein FIG. 11 is a completed view and FIG. 12 is an exploded view.

As shown in FIGS. 11 and 12, the heat shield member 20 according to this embodiment is characterized by a key-shaped engaging portion at the connection position of the outer wall portion 41 and the inner wall portion 42 in order to strengthen the connection between the two. is provided. Specifically, the lower end (inner peripheral end) of the outer wall 41 is formed with a protrusion 41v projecting upward, and the lower end of the inner wall 42 is the lower end (inner peripheral end) of the outer wall 41 . ) is engaged with and fixed to the protrusion 41v. When the inner wall portion 42 is installed inside the outer wall portion 41, the lower end portion of the inner wall portion 42 meshes with the projection portion 41v of the outer wall portion 41, and the two are firmly connected.

At the joints of the parts that make up the wall member 40, the key-shaped ends are engaged with each other so that fine powder due to the deterioration of the heat insulating member 30 inside does not fall, thereby maintaining the sealed state inside the wall member 40. It is preferable that Since the heat insulating member 30 gradually deteriorates and becomes powdery, if the sealing state of the heat insulating member 30 by the wall member 40 is insufficient, the fine powder of the heat insulating member 30 leaks out and adversely affects the yield of the single crystal. However, when the joints between the plurality of parts forming the wall member 40 are in close contact with each other, it is possible to prevent the fine powder from leaking out.

13 and 14 are schematic cross-sectional views showing the construction of a heat shield member according to a seventh embodiment of the present invention, wherein FIG. 13 is a completed view and FIG. 14 is an exploded view.

As shown in FIGS. 13 and 14, the heat shield member 20 according to this embodiment is a modification of the heat shield member according to the sixth embodiment shown in FIGS. The wall member 40 is composed of a combination of a first heat insulating portion 31 and a second heat insulating portion 32, and further includes a bottom wall portion 43 in addition to the outer wall portion 41 and the second inner wall portion 42Y. Further, in order to strengthen the connection between the outer wall portion 41 and the bottom wall portion 43, a key-shaped engaging portion is provided at the connection position between the two. Specifically, the lower end (inner peripheral end) of the outer wall 41 is formed with a protrusion 41v that protrudes upward, and the outer peripheral end of the bottom wall 43 is formed with the protrusion 41v of the outer wall 41. An engaging hook portion 43v is formed. When the bottom wall portion 43 is installed inside the outer wall portion 41, the hook portion 43v engages with the projection portion 41v, and the two are firmly connected.

At the joints of the parts that make up the wall member 40, the key-shaped ends are engaged with each other so that fine powder due to the deterioration of the heat insulating member 30 inside does not fall, thereby maintaining the sealed state inside the wall member 40. It is preferable that Since the heat insulating member 30 gradually deteriorates and becomes powdery, if the sealing state of the heat insulating member 30 by the wall member 40 is insufficient, the fine powder of the heat insulating member 30 leaks out and adversely affects the yield of the single crystal. However, when the joints between the plurality of parts forming the wall member 40 are in close contact with each other, it is possible to prevent the fine powder from leaking out.

The heat shield member 20 according to this embodiment can also achieve the same effect as the heat shield members according to the first and second embodiments. That is, the opening size can be changed in three steps by removing or replacing some of the components. Therefore, three types of silicon single crystals with different crystal diameters can be pulled using the same CZ pulling furnace, and variations in the quality of the three types of silicon single crystals with different crystal diameters can be reduced.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. Needless to say, it is included within the scope.

For example, in the above-described embodiment, each of the first heat insulating portion 31, the second heat insulating portion 32, and the third heat insulating portion 33 is configured as a single component. It may consist of

The inner peripheral surface of the inner wall portion 42 constituting the inner peripheral surface of the heat shielding member 20 is a flat surface that is straightly inclined from the upper end to the lower end, but a step may be provided in the middle. . For example, by providing a step functioning as a handle on a part or the entire circumference of the inner peripheral surface of the inner wall portion 42, the workability of attaching and detaching the inner wall portion 42 can be improved. Such a step may be provided in the first to third heat insulating portions 31 to 33 constituting the heat insulating member 30, and may be provided in all the parts accommodated inside the outer wall portion 41 of the wall member 40. .

Furthermore, in the above embodiments, the heat shielding member used for the production of silicon single crystals by the CZ method was taken as an example, but the present invention is not limited to silicon single crystals, and can be applied to the production of various single crystals. can do.

1 single crystal manufacturing apparatus 2 silicon melt 3 silicon single crystal 10 chamber 10a main chamber 10b pull chamber 10c gas inlet 10d gas outlet 11 quartz crucible 12 graphite crucible 13 rotating shaft 14 shaft driving mechanism 15 heater 16 heat insulating material 17 wire 18 wire winding mechanism 20 heat shielding member 20a opening 30 heat insulating member 30a outer peripheral surface 30b of heat insulating member inner peripheral surface 30c of heat insulating member lower end surface 30d of heat insulating member upper end surface 31 first heat insulating portion 31a outer peripheral surface 31b inner peripheral surface 31c lower end surface 31d upper end surface 32 second heat insulating portion 32a outer peripheral surface 32b inner peripheral surface 32c lower end surface 32d upper end surface 33 third heat insulating portion 33a outer peripheral surface 33b inner peripheral surface 33c lower end surface 33d upper end surface 40 wall member 41 outer wall portion 41u taper Surface 41v Projection 42 Inner wall 42X First inner wall 42Y Second inner wall 42Z Third inner wall 42t Tapered surface 43 Bottom wall 43X First bottom wall 43Y Second bottom wall 43Z Second bottom wall 43t Tapered surface 43u tapered surface 43v hook portion

Claims (15)

A heat shield member used for pulling a single crystal by the CZ method and surrounding the single crystal pulled from the melt in the crucible,
a substantially cylindrical heat insulating member;
A wall member covering the exposed surface of the heat insulating member,
The wall member
an outer wall portion that covers at least the outer peripheral surface of the heat insulating member;
an inner wall portion covering the inner peripheral surface of the heat insulating member;
A bottom wall portion covering the lower end surface of the heat insulating member,
The heat insulating member is
a substantially cylindrical first heat insulating portion;
including a substantially cylindrical second heat insulating portion provided inside the first heat insulating portion;
A heat shielding member, wherein the second heat insulating portion is detachably attached to the first heat insulating portion. The outer peripheral surface of the first heat insulating portion is covered with the outer wall portion,
The inner peripheral surface of the second heat insulating portion is covered with the inner wall portion,
2. The heat shielding member according to claim 1, wherein the outer peripheral surface of said second heat insulating portion is in close contact with the inner peripheral surface of said first heat insulating portion. The bottom wall portion is configured to be detachable from the outer wall portion,
3. The heat shielding member according to claim 1, wherein said inner wall portion is detachable from said bottom wall portion and said outer wall portion. An upper surface of the inner peripheral end portion of the bottom wall portion connected to the lower end portion of the inner wall portion is provided with a tapered surface inclined radially outward, and the lower end portion of the inner wall portion is the tapered surface. 4. The heat shield member according to any one of claims 1 to 3, which abuts on the A lower end portion of the outer wall portion connected to the outer peripheral end portion of the bottom wall portion is provided with a tapered surface inclined radially outward, and the outer peripheral end portion of the bottom wall portion is formed on the tapered surface. 5. A heat shield according to any one of the preceding claims, abutting. 6. The apparatus according to any one of claims 1 to 5, wherein a protrusion is provided on the lower end of said outer wall, and a hook that engages with said protrusion is provided on an outer peripheral end of said bottom wall. The heat shield member according to the item. the difference between the opening diameter of the heat shielding member when the first heat insulating portion is used alone and the opening diameter of the heat shielding member when the first heat insulating portion and the second heat insulating portion are used in combination is 50 mm or more; 7. A heat shielding member according to any one of claims 1 to 6. A parts set of a heat shield member used for pulling a single crystal by the CZ method and surrounding the single crystal pulled from the melt in the crucible,
a substantially cylindrical first heat insulating portion;
a substantially cylindrical second heat insulating portion detachably provided inside the first heat insulating portion;
an outer wall portion that covers the outer peripheral surface of the first heat insulating portion;
a first inner wall portion covering the inner peripheral surface of the first heat insulating portion;
A second inner wall portion covering the inner peripheral surface of the second heat insulating portion,
The first heat shielding member is composed of the first heat insulating portion, the outer wall portion and the first inner wall portion,
A second heat shielding member having an opening diameter smaller than that of the first heat shielding member is composed of the first heat insulating portion, the second heat insulating portion, the outer wall portion, and the second inner wall portion. A part set of heat shielding members. further comprising a bottom wall portion that covers at least the lower end surface of the second heat insulating portion;
9. The set of parts of a heat shield according to claim 8, wherein said second heat shield further comprises said bottom wall portion. a first bottom wall portion covering the lower end surface of the first heat insulating portion;
A second bottom wall portion covering the lower end surfaces of the first and second heat insulating portions,
The first heat shield member further includes the first bottom wall,
9. The heat shield component set of claim 8, wherein said second heat shield further comprises said second bottom wall portion. 11. The heat shield component set according to claim 8, wherein the difference between the opening diameter of the first inner wall portion and the opening diameter of the second inner wall portion is 50 mm or more. a chamber, a crucible that supports the melt in the chamber, a heater that heats the melt, a crucible driving mechanism that rotates and raises and lowers the crucible, and a crystal pulling mechanism that pulls the single crystal from the melt. 8. The heat shield member according to any one of claims 1 to 7, which is installed above the melt and surrounds the single crystal pulled up from the melt to shield the radiant heat from the heater. A single crystal manufacturing apparatus comprising: A method for producing a single crystal by the CZ method in which a single crystal is pulled from a melt in a crucible, wherein the single crystal pulled from the melt is pulled using the heat shield member according to any one of claims 1 to 7. A method for producing a single crystal, characterized by surrounding. Pulling up a first single crystal having a first crystal diameter using the heat shielding member configured by using the first heat insulating portion alone;
A second single crystal having a second crystal diameter smaller than the first crystal diameter is pulled using the heat shield member configured by combining the first heat insulation portion and the second heat insulation portion. Item 14. A method for producing a single crystal according to Item 13. 15. The method for producing a single crystal according to claim 14, wherein the difference between said first crystal diameter and said second crystal diameter is 50 mm or more.

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