JPH1112092A - Production of silicon single crystal and production device - Google Patents

Abstract

(57) [Summary] (with correction) [Problem] To reduce a difference in thermal history in the longitudinal direction of a silicon single crystal ingot during growing, and to produce a silicon single crystal having a small variation in quality in the longitudinal direction of the ingot and a high product yield. A method and a manufacturing apparatus are provided. SOLUTION: Over a period from the start of the pulling operation to the time when the grown silicon single crystal ingot 9 enters into the pull chamber section 12, the main chamber section 1 and the pull chamber section 12 are roughly divided into positions. A heat insulator 16a having a cross-sectional shape capable of closing at least a part of the internal space cross-section of the pull chamber portion 12 is provided, having an insertion portion for the seed crystal pulling wire 11a that suspends the seed crystal 11c, and pulling up. A method for producing a silicon single crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing a silicon single crystal. More specifically, the present invention reduces the thermal history difference in the longitudinal direction of a silicon single crystal ingot in a single crystal manufacturing apparatus,
The present invention relates to a manufacturing method and a manufacturing apparatus capable of suppressing a variation in quality in a longitudinal direction of an ingot and improving a product yield.

[0002]

2. Description of the Related Art As a method for producing a single crystal such as silicon,
Czochralski method (abbreviated as Czochralski method or CZ method) in which a crystal is pulled from a melt in a crucible while growing the crystal.
Is widely used.

In this CZ method, a large amount of oxygen is mixed into a melt from a quartz crucible and is taken into a silicon single crystal ingot to be grown at a high concentration. As described above, since the above-described oxygen or other impurities that are taken in during the growth of the silicon single crystal ingot are present, the thermal history of the ingot during the crystal growth in the CZ method depends on the obtained silicon single crystal. It greatly affects the quality of the crystal.

[0004] That is, the thermal history at the time of growing a single crystal affects the rate of generation of OSF generated by high-temperature oxidation in a device process. As described above, a large amount of impurities such as oxygen taken in during the growth of a single crystal are mixed into the melt, and the grown silicon single crystal ingot is taken in by the impurities to generate a point defect. This is because the nuclei grow by agglomeration due to the subsequent heat history, and stacking faults are precipitated from the nuclei in the high-temperature oxidation treatment of the device process.

[0005] The heat history changes the oxygen precipitation concentration in the silicon single crystal. The amount of deposition determines the magnitude of the warpage of the silicon wafer and also determines the intrinsic gettering (IG) effect.

Conventionally, in pulling a silicon single crystal by the CZ method, the upper and lower sides of a silicon single crystal ingot to be grown are grown at the melt interface and then moved upward in a silicon single crystal manufacturing apparatus. Cooling conditions, that is, the heat history is greatly different.
In the obtained silicon single crystal ingot, the crystal quality is greatly different between the upper side and the lower side based on the above-described action, and the desired crystal quality is obtained from a part of the silicon single crystal ingot. There was a problem that the product yield was poor.

Conventionally, in order to reduce the difference in thermal history in the longitudinal direction of a silicon single crystal ingot in such a single crystal manufacturing apparatus and to eliminate the variation in quality in the longitudinal direction of a silicon single crystal ingot to be grown, a conventional single crystal ingot has been used. Various adiabatic or cooling techniques in manufacturing equipment have been proposed.

For example, (1) a method of arranging a heat insulating board having a V-shaped cross section so as to surround a grown single crystal above a silicon melt interface or a method of improving the same (for example, US Pat. No. 4,330,362; -27920),
(2) A method of disposing a water-cooled Ag-plated reflector on the inner surface of a main chamber in which a crucible containing a silicon melt is arranged (Japanese Patent Laid-Open No. 59-199598) is known.

[0009]

By disposing the heat insulating member or the reflecting member as described above in the main chamber, the difference in the thermal history received by each part of the grown single crystal ingot during the pulling operation can be reduced to some extent. It can be alleviated.

However, in general, the chamber of the single crystal manufacturing apparatus is provided with a main chamber (heating chamber) in which a crucible for forming a melt is disposed, and is provided above the main chamber and has a diameter larger than that of the pulling chamber. The single crystal pulling operation in a single crystal manufacturing apparatus having a small pull chamber portion (pulling chamber portion) having such a main chamber portion and a pull chamber portion is performed by using the main chamber portion and the pull chamber. Since the heat treatment is performed in a state where the internal space communicates with the portion, even if the above-described heat insulating member or reflecting member is arranged, the heat at the upper portion of the grown single crystal ingot easily escapes to the pull chamber side. The temperature of the upper portion of the single crystal ingot decreases, and the temperature in the longitudinal direction of the single crystal ingot decreases. It was those that can not be sufficiently reduce the difference.

Accordingly, an object of the present invention is to provide an improved method and apparatus for producing a silicon single crystal. The present invention also provides a method and an apparatus for producing a silicon single crystal having a small product variation in the longitudinal direction of the ingot and a high product yield with a reduced thermal history difference in the longitudinal direction of the silicon single crystal ingot during growth. It is an issue.

[0012]

Means for Solving the Problems The present inventor has conducted intensive studies in order to solve the above problems, and as a result, has grown a silicon single crystal ingot in a single crystal manufacturing apparatus having a main chamber portion and a pull chamber portion. In the period from the start of the pulling operation to the time when the silicon single crystal ingot grown in the pull chamber portion enters, the single crystal pulling striatum is located at a roughly partitioned position between the main chamber portion and the pull chamber portion. By arranging a heat insulator having a cross-sectional shape capable of substantially closing the internal space cross-section of the pull chamber while ensuring the insertion of Prevents escape to the chamber side and reduces the difference in thermal history in the longitudinal direction of the resulting single crystal ingot It is intended that led to found the present invention.

That is, the present invention which solves the above-mentioned problems,
(1) A seed crystal is immersed in the melt and pulled up in a chamber including a main chamber section in which a crucible for forming a melt is disposed and a pull chamber section provided above the main chamber section. In the method for producing a silicon single crystal in which a silicon single crystal ingot is grown at the rear end of the seed crystal, the silicon single crystal ingot grown from the start of the pulling operation until the silicon single crystal ingot grows into the pull chamber. An insertion portion of a seed crystal pulling striatum for suspending the seed crystal at a roughly defined position between the main chamber portion and the pull chamber portion, and closes at least a part of an internal space cross section of the pull chamber portion. Silicon single crystal characterized by arranging a heat insulator having a cross-sectional shape capable of being pulled up It is a manufacturing method.

Further, in the method for producing a silicon single crystal according to the present invention, (2) the heat insulator can be moved up and down in a pull chamber, and the grown silicon single crystal ingot is moved into the pull chamber. After entering, the heat insulator can be gradually moved upward while being separated from the upper part of the silicon single crystal ingot by a predetermined distance as the silicon single crystal ingot is pulled up.

Further, in the method for producing a silicon single crystal according to the present invention, (3) the heat insulator has an insertion portion for the seed crystal pulling filament, and substantially has an internal space cross section of the pull chamber portion. It is desirable to have a cross-sectional shape that can cover the entire target.

Another object of the present invention is to provide (4) a chamber having a main chamber section in which a crucible for forming a melt is disposed and a pull chamber section provided above the main chamber section. In a silicon single crystal manufacturing apparatus comprising a mechanism for hanging the body from the upper part of the pull chamber up and down freely in the chamber,
A heat insulator having a cross-sectional shape capable of closing at least a part of the internal space cross-section of the pull chamber portion, having a penetrating portion of the seed crystal pulling striatum suspending the seed crystal, the main chamber portion and The present invention is also attained by a silicon single crystal manufacturing apparatus characterized in that the apparatus is provided so as to be disposed / removable at a roughly partitioned position with respect to the pull chamber.

In the apparatus for manufacturing a silicon single crystal according to the present invention, (5) the heat insulator is located in the chamber radial direction at a position where the main chamber portion and the pull chamber portion are roughly partitioned from each other and at a position where they do not interfere with the chamber interior space. Between the first position and the second position.

In the apparatus for manufacturing a silicon single crystal according to the present invention, (6) the heat insulator can be moved up and down in the pull chamber. , Can be displaced between an upper position in the pull chamber.

In the apparatus for producing a silicon single crystal according to the present invention, (7) the heat insulator has an insertion portion for the seed crystal pulling striatum, and substantially the entire internal space cross section of the pull chamber portion. It is desirable to have a cross-sectional shape capable of closing the space.

[0020]

As described above, according to the present invention, when growing a silicon single crystal ingot using a single crystal manufacturing apparatus having a main chamber portion and a pull chamber portion, the silicon grown in the pull chamber portion after the start of the pulling operation is started. In the period until the single crystal ingot enters, the main chamber part and the pull chamber part have a penetration part of a seed crystal pulling striatum that suspends the seed crystal at a roughly partitioned position and the pull chamber part. A heat insulator having a cross-sectional shape capable of closing at least a part of the internal space cross-section is disposed. In a state where such a heat insulator does not exist, the communication between the space in the main chamber and the space in the pull chamber is performed as described above until the silicon single crystal ingot to be grown enters the pull chamber. Since there is nothing to block heat radiation in the part, heat from the upper surface of the single crystal ingot grown as described above can easily escape to the pull chamber side, but by disposing the heat insulating material as described above, Such heat dissipation is reduced. On the other hand, when the silicon single crystal ingot grows and enters the pull chamber portion, the upper portion of the silicon single crystal ingot itself is present in the communication portion, so that heat from the lower surface of the ingot, Heat is hardly dissipated to the pull chamber side. After all, during the period until the silicon single crystal ingot to be grown enters the pull chamber portion, by disposing a heat insulator to suppress heat from escaping to the pull chamber side, the longitudinal length of the single crystal ingot to be grown is reduced. This makes it possible to reduce the difference in thermal history (temperature difference) in the direction and to produce a single crystal ingot with less variation in quality in the longitudinal direction.

The heat insulator blocks the space in the chamber in the cross-sectional direction, but since the insertion portion of the seed crystal pulling striated body is secured, there is no problem in the pulling operation itself. .

Further, the heat insulator can be moved up and down in the pull chamber. After the grown silicon single crystal ingot enters the pull chamber, the silicon single crystal ingot is pulled up as the silicon single crystal ingot is pulled up. If the operation of moving the heat insulator gradually upward while separating the upper portion of the silicon single crystal ingot from the upper portion of the silicon single crystal ingot is performed, it is possible to further reduce the difference in heat history in the longitudinal direction of the grown single crystal ingot, and the variation in quality. .

Further, in the present invention, since the heat loss in the direction of the pull chamber during the growth of the single crystal can be reduced as described above, the power consumption for the production of the single crystal (maintaining the silicon melt state, etc.) can be reduced. Can be reduced.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on specific embodiments.

The apparatus for producing a single crystal according to the present invention has a chamber comprising a main chamber for disposing a crucible for forming a melt and a pull chamber provided above the main chamber. Note that the pull chamber portion is usually smaller in inner diameter than the main chamber portion, but is not limited to such an embodiment. In addition, in the section between the main chamber and the pull chamber, a melt forming operation in the crucible before the single crystal pulling operation and an operation of taking out the grown single crystal ingot after the single crystal pulling operation are completed. It is desirable to provide a vacuum gate valve capable of completely shutting off the communication between the internal spaces of the two chambers for the sake of simplicity, but a mode without such a vacuum gate valve may be adopted.

Further, in the single crystal manufacturing apparatus according to the present invention, similarly to the conventionally known single crystal manufacturing apparatus, the pull chamber is connected to a driving device such as a filament winding device disposed outside the chamber. The seed crystal pulling striated body, which extends vertically through the upper wall surface of the part, is extended into the chamber, and the seed crystal is attached to the seed crystal holding mechanism attached to the lower end, and the main crystal is attached. The seed crystal is once immersed in a silicon melt formed in a crucible placed in the chamber, and is pulled up to grow a single crystal ingot. In addition, as the seed crystal pulling striatum and its driving mechanism,
There is no particular limitation, for example, wire and wire take-up device, chain and chain drive mechanism, rack
Various configurations such as an AND-pinion mechanism can be adopted.

According to the apparatus for producing a single crystal of the present invention, there is provided an insertion part for a seed crystal pulling filament that suspends the seed crystal, and at least a part of the internal space cross section of the pull chamber part. Preferably substantially whole (eg, at least 75% of the internal space cross section, more preferably 90%
Above) a heat insulator having a cross-sectional shape that can block
The main chamber and the pull chamber are provided so as to be disposed / removed at roughly divided positions.

As the heat insulator and its displacement mechanism,
There is no particular limitation. For example, as in an embodiment group shown in FIGS. 1 and 2 described below, a displacement is made in the radial direction with respect to the axis of the chamber to block the communication space between the main chamber portion and the pull chamber portion. A slide gate valve type that moves between a first position and a second position located in a storage portion provided on the side of the chamber, and can be moved up and down from above the pull chamber portion as in the embodiment shown in FIG. And a hanging type which is arranged at a predetermined position by lifting and lowering, or a combination of a plurality of leaf-like bodies circumferentially overlapping each other as seen in a diaphragm mechanism of a camera, and the overlapping Various modes, such as a type of opening and closing by changing the degree, can be used.

The location of such a heat insulator does not have to be a strictly defined location between the main chamber and the pull chamber, and depends on the shape of the chamber. If there is a sufficient upper portion of the pull chamber portion and a length capable of storing the ingot (crystal) after the growth is completed in the pull chamber, the disposition position is shifted to the pull chamber portion side from the partition position. Even so, a desired effect due to the arrangement of the heat insulator can be expected, and
Even a position shifted to a certain extent toward the main chamber is acceptable as long as heat radiation to the pull chamber can be sufficiently blocked. In particular, as can be seen in the embodiments shown in FIGS. 1 to 3 described later, the main chamber is located at a lower position (substantially) for the purpose of facilitating connection with the pull chamber at the upper position. In the embodiment having a neck portion smaller in diameter than the main chamber region) and having the same diameter as the pull chamber portion, this neck portion can be regarded as a part of the pull chamber, and It is not a problem to arrange the heat insulator at the site.

Further, the material constituting such a heat insulator is not particularly limited. For example, it is desirable that the heat insulator is made of graphite fiber, porous ceramics or the like.

In the single crystal manufacturing apparatus of the present invention, the configuration other than the above-mentioned members is arbitrary.
Various conventionally known modes can be adopted.

The method for producing a single crystal according to the present invention is carried out using the apparatus for producing a single crystal having the above structure,
First, based on a conventional method, a predetermined amount of a material such as polycrystalline silicon and a dopant added as necessary is loaded into a crucible disposed in a main chamber, and the material is melted by heating with a heater or the like. Form a liquid. In the aspect in which the vacuum gate valve as described above is present in the single crystal manufacturing apparatus, until the melt is formed, the vacuum gate valve and the heat insulator are closed, and the communication between the main chamber and the pull chamber is released, The power consumption required for melt formation is reduced.

Next, the vacuum gate valve is opened, the heat insulator is once removed, and the seed crystal held by the seed crystal holding means is once immersed in the melt. Thereafter, the heat insulator is returned to the approximate separation position between the pull chamber and the main chamber, and the seed crystal is pulled up while rotating around the axis by the elevating means connected to the seed crystal gripping means, thereby growing a single crystal at the lower end of the seed crystal. Let me do it. If necessary, to reduce the diameter once to form a dash neck portion to eliminate dislocations, gradually expand the diameter to form a cone portion, and after reaching the desired diameter, maintain the diameter. The straight body is formed by controlling the pulling speed, the melt temperature, and the like.

When the growth of the single crystal ingot proceeds and the upper portion of the grown ingot enters the pull chamber, that is, a position immediately below the heat insulator, the heat insulator is released from the closed position. Move to position. In the embodiment shown in FIG. 1 or FIG. 2, the unblocking position is a storage position provided on the side of the chamber, and in the embodiment shown in FIG. It is a spatial position.

Here, as in the embodiment shown in FIG. 3, when the heat insulator is constructed so as to be able to move up and down in the pull chamber portion, the heat insulator is immediately moved to the end of the chamber at the time of the closing operation. Although it is possible to pull up to the upper position, even during the subsequent single crystal pulling operation period, it is possible to further reduce the heat radiation to the upper space as much as possible, thereby reducing the difference in the heat history in the longitudinal direction of the obtained single crystal ingot. Therefore, in the case of such a configuration, after the silicon single crystal ingot has entered the pull chamber portion, the heat insulator is moved to the silicon single crystal ingot as the silicon single crystal ingot is pulled up. It is desirable to move the crystal ingot gradually upward while keeping a predetermined distance from the top of the crystal ingot. .

Thereafter, single crystal growth is continued according to a conventional method until the straight body of the ingot reaches a desired length, and when a straight body of a desired length is obtained, the pulling speed is gradually increased to increase the ingot. And finally the lower end of the ingot (rear end of the lower cone) is dissociated from the melt interface, and the obtained single crystal ingot is pulled as it is until it is completely contained in the pull chamber. The crystal growing operation ends. In the embodiment having the vacuum gate valve as described above, the vacuum gate valve is closed when the single crystal ingot is completely housed in the pull chamber.

In the method for producing a single crystal according to the present invention, the above operation suppresses heat radiation to the pull chamber side during the single crystal pulling operation.
The change of the single crystal temperature (temperature drop) with respect to the displacement of the position of the grown single crystal ingot in the chamber axis direction becomes gentle, whereby the difference in thermal history in the longitudinal direction of the single crystal ingot becomes small, Variations in quality are improved. In addition,
FIG. 8 shows the relationship between the distance from the melt interface and the temperature of the crystal center of the single crystal ingot when a single crystal ingot was actually grown according to the present invention. However, as shown in this figure, according to the production method of the present invention, an excellent crystal heat retaining effect can be obtained.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below more specifically based on embodiments.

FIG. 1 schematically shows a configuration of an embodiment of a silicon single crystal manufacturing apparatus according to the present invention in a use state.

In the manufacturing apparatus of this embodiment, the chamber comprises a main chamber 1 having a relatively large diameter,
A pull chamber portion 12 having a relatively small diameter is coaxially arranged with the main chamber portion above the main chamber portion, and both are fastened at a position indicated by reference numeral 20 in the figure. The upper region of the main chamber 1 is reduced in diameter to have substantially the same diameter as the pull chamber 12.

Then, similarly to the conventional single crystal manufacturing apparatus,
In the main chamber portion 1, a quartz crucible 3b and a graphite crucible 3a surrounding the
Is supported and arranged by a rotating shaft 6 extending through a bottom wall surface of the main chamber from a driving device (not shown) located outside the chamber. Further, a cylindrical heater 4 surrounding the crucible 3 at a predetermined interval is provided in the main chamber portion 1, and a heater 4 is provided outside the heater 5 at a predetermined interval from the inner wall surface of the main chamber. A partition plate 2 is provided along the shape of the formed chamber, and a gap between the partition plate 2 and the inner wall surface of the main chamber is filled with a heat insulating material to form a cylindrical heat retaining cylinder 6. Similarly, the partition plate 1 integrally formed with the partition plate 2 is formed on the inner side wall or upper wall surface of the main chamber above the portion where the heat retaining cylinder 6 is disposed.
0 indicates that a heat retaining cylinder 18 is provided. In the upper space of the crucible 3, a truncated inverted conical cylindrical heat shield 8 formed integrally with the partition plates 2 and 10 is arranged.

Further, in the chamber, a seed for holding a seed crystal 11c at a tip end hanging down along the chamber axis is provided by a crystal rotating / wire winding mechanism 13 disposed at an upper end of the pull chamber portion 12. Crystal holding jig 1
A single crystal pulling wire 11a having 1b is provided.

Further, in the single crystal manufacturing apparatus of this embodiment, the wall of the main chamber portion is extended radially laterally immediately below the fastening position 20 between the main chamber portion and the pull chamber portion so as to have a short rectangular cross section. A vacuum gate valve housing 15a is formed, and a vacuum gate valve 15b disposed here is movable in a radial direction of the chamber.
Between the open position in the inside and the closed position in the main chamber portion 1.

In this embodiment, as a heat insulator mechanism according to the present invention, the wall of the main chamber portion is similarly extended to the side in the radial direction near the lower part of the gate valve housing 15a, and has a rectangular shape with a short cross section. An insulated gate valve housing 16a is formed, and the insulated gate valve 16b disposed therein is movable in the radial direction of the chamber.
a between the open position in a and the heat blocking position in the main chamber portion 1.

FIG. 4 is a view showing a detailed structure of the single crystal manufacturing apparatus of the embodiment shown in FIG. 1 in the vicinity of the heat insulating gate valve. As shown in FIG. 4 (a), the heat insulating gate valve 16a Has a slit-shaped notch 16e extending from the center of one side to the approximate center in the movement direction (radial direction of the chamber). Insulated gate valve 16
When b is located at the heat blocking position in the main chamber portion 1 or moves from this position to the open position in the heat-insulating gate valve housing 16a, as described above, the presence of the notch 16e causes The real part of the heat-insulating gate valve 16b is prevented from interfering with the pulling wire 11a hanging down in the chamber along the axis of the chamber.
During the single crystal pulling operation by 1a, the opening and closing of the heat insulating gate valve 16b is enabled. Further, as shown in FIG. 4 (b), the heat insulating gate valve 16b is composed of a heat insulating material holding material 16c which is a frame-shaped main body for shape retention and a heat insulating material 16d housed therein.

In the single crystal manufacturing apparatus of this embodiment, reference numeral 7 in FIG. 1 designates a vacuum exhaust port provided below the main chamber to keep the inside of the chamber at reduced pressure.
Reference numerals 14a, 14b and 14c denote inert gas inlets for introducing an inert gas such as Ar into the chamber, respectively.

FIG. 2 schematically shows a configuration of another embodiment of the single crystal manufacturing apparatus according to the present invention in a use state.

The embodiment shown in FIG. 2 has substantially the same configuration as that of the embodiment shown in FIG. 1 except that the shape of the main chamber portion 1 is different. The reference numerals indicate the same members as those having the same reference numerals shown in FIG.

In this embodiment, the length of the portion of the upper region of the main chamber portion 1 reduced in diameter substantially to the same diameter as the pull chamber 12 is shorter than that in the first embodiment. It has been.

FIG. 3 schematically shows the configuration of still another embodiment of the single crystal manufacturing apparatus according to the present invention in use.

The embodiment shown in FIG. 3 has substantially the same configuration as the embodiment shown in FIG. 2 except that the structure of the heat insulator according to the present invention is different.
The reference numerals shown in the drawing indicate the same members as the members having the same reference numerals shown in FIG. In this embodiment, the insulated gate valve 16b (and the insulated gate valve housing 16) in the embodiment group shown in FIGS.
Instead of a), the heat insulating valve 19 (and the heat insulating valve support wire 21) is provided as a heat insulator according to the present invention. That is, in the present embodiment, in the crystal rotation / wire hoisting mechanism 13 arranged at the upper end of the pull chamber section 12, separately from the wire hoisting device (not shown) of the single crystal pulling wire 11a, A wire hoisting device (not shown) for the insulating valve support wire 21 is provided, and is disposed equidistantly (equally angled) around the chamber axis in the radial section of the chamber and in the circumferential direction of the chamber. A plurality of insulation valve support wires 21 suspended along the shaft are connected to a drive shaft of the insulation valve support wire winding device, and an insulation valve 19 is connected at the other end of the insulation valve support wires 21. Thus, the heat insulating valve 19 is suspended and supported in the pull chamber portion so as to be able to move up and down. The single crystal pulling wire 11a and the insulating valve support wire 21 are connected to independent winding devices, respectively.
It can be lifted and lowered independently of each other. In addition, the insulation valve 19
Is a disc-shaped body that is slightly smaller than the internal space cross section of the pull chamber portion 12, and a through hole 22 through which the single crystal pulling wire 11a can freely pass is provided at the center, that is, at a portion where the chamber axis passes. Since the heat insulating valve 19 is provided, the real part of the heat insulating valve 19 is connected to the single crystal pulling wire 11.
It does not interfere with the movement of a. Accordingly, during the single crystal pulling operation by the pulling wire 11a, the heat insulating valve 19 can be arbitrarily displaced in the vertical direction with respect to the single crystal ingot 9 to be grown. In this embodiment, the heat-insulating valve 19 is a disk-shaped body. However, the heat-insulating valve 19 may be any one that can substantially close the internal space of the pull chamber portion in one cross section or a certain region width. There is no particular limitation, and various modifications such as an umbrella shape, a short conical shape, or a combination of a plurality of members may be used.

The production of a silicon single crystal using the apparatus for producing a single crystal in the above-described embodiment is performed during the single crystal pulling operation, as described in detail in the description of the single crystal production method of the present invention. , The heat insulating gate valve 16b or the heat insulating valve 19 as a heat insulator according to the present invention.
At a predetermined position. In addition,
Table 1 shows an example of the movement of the adiabatic gate valve and the vacuum gate valve during the production of a single crystal in the single crystal production apparatus of the group of examples shown in FIGS. 1 and 2, and Table 2 shows FIG. 3 shows an example of the movement of a heat insulating valve and a vacuum gate valve in a single crystal manufacturing apparatus according to an embodiment when the single crystal is manufactured. FIGS. 5 to 7 schematically show the movement of the adiabatic gate valve and the vacuum gate valve during the production of the single crystal of the embodiment shown in FIG. 2 during the production of the single crystal, together with the position of the single crystal to be grown. FIG. 5 shows the dissolution of the raw material and the removal of the crystal, FIG. 6 shows the crystal being pulled from the seed crystal contact, and FIG.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

As described above, according to the present invention, when growing a silicon single crystal ingot using a single crystal manufacturing apparatus having a main chamber portion and a pull chamber portion, the pull chamber portion is started after the pulling operation is started. In the period until the silicon single crystal ingot to be grown into the intruder enters, in the approximate division position of the main chamber part and the pull chamber part, the insertion part of the seed crystal pulling striatum for suspending the seed crystal is provided. In addition, a heat insulator difference (cooling temperature difference) in the longitudinal direction of the single crystal ingot to be grown is reduced by disposing a heat insulator having a cross-sectional shape capable of closing at least a part of the internal space cross section of the pull chamber portion. This makes it possible to manufacture a single crystal ingot with less variation in quality in the longitudinal direction.

The heat insulator can be moved up and down in the pull chamber. After the grown silicon single crystal ingot enters the pull chamber, the silicon single crystal ingot is pulled up as the silicon single crystal ingot is pulled up. If the operation of moving the heat insulator gradually upward while separating the upper portion of the silicon single crystal ingot from the upper portion of the silicon single crystal ingot is performed, it is possible to further reduce the difference in heat history in the longitudinal direction of the grown single crystal ingot, and the variation in quality. .

Further, in the present invention, since the heat loss in the direction of the pull chamber during the growth of the single crystal can be reduced as described above, the power consumption for the production of the single crystal (maintaining the silicon melt state, etc.) can be reduced. Can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing a configuration of an embodiment of a single crystal pulling apparatus according to the present invention in a use state;

FIG. 2 is a schematic view schematically showing a configuration of another embodiment of the single crystal pulling apparatus according to the present invention in a use state;

FIG. 3 is a schematic view schematically showing the configuration of still another embodiment of the single crystal pulling apparatus according to the present invention in a use state;

4A is a cross-sectional view showing a main part configuration of the apparatus in the embodiment shown in FIG. 1, FIG. 4B is a longitudinal sectional view of the main part configuration,

FIG. 5 is a schematic diagram showing a state of a valve during melting of raw materials of the apparatus of the embodiment shown in FIG. 2;

FIG. 6 is a schematic diagram showing a state of a valve during a single crystal pulling operation from the start of the single crystal pulling operation of the apparatus of the embodiment shown in FIG. 2;

FIG. 7 is a schematic diagram showing a state of a valve when the single crystal ingot is moved to a pull chamber after completion of a single crystal pulling operation of the apparatus of the embodiment shown in FIG. 2;

FIG. 8 is a graph showing a relationship between a single crystal center temperature and a distance from a melt interface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main chamber part 2 Partition plate 3 Crucible 3a Graphite crucible 3b Quartz crucible 4 Heater 5 Heat retention cylinder 6 Crucible rotation shaft 7 Vacuum exhaust port 8 Heat blocker 9 Silicon single crystal ingot 10 Partition plate 11a Single crystal pulling wire 11b Seed crystal Holding jig 11c Seed crystal 12 Pull chamber 13 Crystal rotation / wire hoisting mechanism 14, 14a, 14b, 14c Inert gas inlet 15a Vacuum gate valve housing 15b Vacuum gate valve 16a Insulated gate valve housing 16b Insulated gate valve 16c Insulated Material holding 16d Heat insulating material 16e Slit-shaped notch 17 Silicon melt 18 Heat insulating cylinder 19 Heat insulating valve 20 Fastening position of pull chamber and main chamber 21 Heat insulating valve support wire 22 Through hole of heat insulating valve

Claims (7)

[Claims] 1. A seed crystal is immersed in a melt in a chamber including a main chamber in which a crucible for forming a melt is disposed and a pull chamber provided above the main chamber. In the method for producing a silicon single crystal in which a silicon single crystal ingot is grown at the rear end of the seed crystal by pulling up, the silicon single crystal ingot grown from the start of the pulling operation until it enters the pull chamber. Over a period, at an approximate division position between the main chamber portion and the pull chamber portion, the insertion portion of the seed crystal pulling filament that suspends the seed crystal, and at least a part of the internal space cross section of the pull chamber portion Silicon, characterized in that a heat insulator having a cross-sectional shape capable of closing the space is arranged and pulled up. Single crystal production method. 2. The heat insulator can be raised and lowered in a pull chamber, and after the grown silicon single crystal ingot enters the pull chamber,
With the progress of pulling up the silicon single crystal ingot,
The method according to claim 1, wherein the heat insulator is gradually moved upward while being separated from the upper part of the silicon single crystal ingot by a predetermined distance. 3. The heat insulator has a section through which the seed crystal pulling filament is inserted and has a cross-sectional shape capable of closing substantially the entire internal space cross section of the pull chamber. Item 3. The method for producing a silicon single crystal according to Item 1 or 2. 4. A chamber having a main chamber portion in which a crucible for forming a melt is disposed and a pull chamber portion provided above the main chamber portion. An apparatus for manufacturing a silicon single crystal, comprising a mechanism for hanging the seed crystal in a chamber so as to be able to move up and down more freely. An apparatus for manufacturing a silicon single crystal, comprising a heat insulator having a cross-sectional shape capable of closing at least a part of the silicon single crystal, which can be disposed and removed at a roughly partitioned position between the main chamber and the pull chamber. 5. The heat insulator is displaceable in a radial direction of the chamber between a general partition position of the main chamber portion and the pull chamber portion and a position that does not interfere with a space in the chamber. The apparatus for producing a silicon single crystal according to claim 4. 6. The heat insulator can be moved up and down in a pull chamber, and can be displaced between a general division position of the main chamber and the pull chamber and an upper position in the pull chamber. The single crystal manufacturing apparatus according to claim 4, wherein 7. The heat insulating body has a cross-sectional shape that has an insertion portion of the seed crystal pulling filament and can close substantially the entire internal space cross section of the pull chamber portion. Item 7. The silicon single crystal manufacturing apparatus according to any one of Items 4 to 6.