JP2017088462A - Method of manufacturing silicon single crystal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a silicon single crystal that can properly control an oxygen concentration of the silicon single crystal.SOLUTION: A method of manufacturing a silicon single crystal comprises: manufacturing a first silicon single crystal using information for concentration estimation representing a relation between a difference in an oxygen concentration at identical growth positions of two silicon single crystals manufactured under the same conditions using the same quartz crucible and support crucible and a total use time of the support crucible, and also using a quartz crucible and a support crucible having the same quartz crucible and support crucible used to generated the information for concentration estimation; estimating an oxygen concentration at the growth position of the first silicon single crystal with manufacture of a second silicon single crystal under the same conditions with the first single crystal manufacturing process on the basis of the oxygen concentration at the growth position of the first silicon single crystal, the information for concentration estimation and the total use time of the support crucible; and manufacturing the second silicon single crystal within a predetermined oxygen concentration range on the basis of the estimation result.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for producing a silicon single crystal.

Conventionally, a CZ method (Czochralski method) is known as a method for producing a silicon single crystal. As a method applying this CZ method, a so-called multiple pulling method is known in which a silicon raw material is charged each time a silicon single crystal is pulled up to pull up a plurality of single crystals.
Such a multiple pulling method has the advantage of improving the productivity of silicon single crystals, but the same growth of multiple silicon single crystals with different operation times (elapsed time immediately after completion of melting of the polycrystalline raw material) When the positions were compared, there was a problem that the oxygen concentration decreased with the passage of operation time. Therefore, studies for solving such problems have been made (see, for example, Patent Document 1).

  In Patent Document 1, the relationship between the operation time when the pulling is performed under the same apparatus and the same operating conditions and the oxygen concentration at the same growth position in the silicon single crystal is obtained by setting the number of revolutions of the crucible as a parameter and set in advance. The rotation speed of the crucible is set from the relationship between the desired oxygen concentration range at the same growth position in the silicon single crystal and the operation time and the oxygen concentration, and the conditions other than the rotation speed are determined when the relationship is obtained. It is disclosed that the above problem can be solved by pulling up as the same apparatus and the same operation condition.

Japanese Patent Laid-Open No. 9-110578

  However, in a crucible including a quartz crucible and a support crucible, if the same support crucible is used for a long time, a silicon single crystal having a desired oxygen concentration may not be produced even if the method of Patent Document 1 is used. I understood. For this reason, a configuration capable of appropriately controlling the oxygen concentration of the silicon single crystal is desired.

  An object of the present invention is to provide a method for producing a silicon single crystal capable of appropriately controlling the oxygen concentration of the silicon single crystal.

  As a result of extensive research, the present inventor has found that a supporting crucible repeatedly used in the production of a silicon single crystal deteriorates with the passage of time of use, and this deterioration affects the oxygen concentration of the silicon single crystal. The headline and the present invention have been completed.

That is, the method for producing a silicon single crystal according to the present invention includes a step of supplying a silicon raw material into a quartz crucible housed in a support crucible, and the silicon raw material is melted from the raw material melt by a Czochralski method. Repeating the growing step, a method for producing a silicon single crystal using a multiple pulling method for producing a plurality of silicon single crystals using one quartz crucible, wherein the oxygen concentration of the first silicon single crystal, A concentration estimation step of estimating an oxygen concentration of a second silicon single crystal manufactured after the first silicon single crystal based on a total usage time of the support crucible is provided.
The method for producing a silicon single crystal according to the present invention includes a step of supplying a silicon raw material into a quartz crucible housed in a supporting crucible, and the silicon raw material is melted and a silicon single crystal is grown from the raw material melt by the Czochralski method. A method for producing a silicon single crystal using a multiple pulling method in which a single quartz crucible is used to produce a plurality of silicon single crystals using the same quartz crucible and a supporting crucible under the same conditions. The quartz crucible used to generate the concentration estimation information using the concentration estimation information indicating the relationship between the difference in oxygen concentration at the same growth position of the two silicon single crystals formed and the total usage time of the support crucible And a first single crystal manufacturing process for manufacturing a first silicon single crystal using a quartz crucible and a support crucible having the same structure as the support crucible, and the first silicon single crystal Based on the oxygen concentration at the crystal growth position, the concentration estimation information, and the total usage time of the support crucible, a second silicon single crystal was manufactured under the same conditions as in the first single crystal manufacturing step. A concentration estimating step for estimating the oxygen concentration at the growth position in the case, and a second single crystal manufacturing for manufacturing the second silicon single crystal in a predetermined oxygen concentration range based on the estimation result in the concentration estimating step And a process.

Here, the above-mentioned “predetermined oxygen concentration range” will be supplemented.
The silicon single crystal is supplied to a device manufacturer as a silicon wafer through processes such as slicing and polishing. The oxygen concentration of the silicon single crystal corresponds to the oxygen concentration of the silicon wafer, and affects the quality characteristics of a device manufactured using the silicon wafer, and thus is an extremely important quality factor. Therefore, each device manufacturer requests a wafer manufacturer for a silicon wafer having an oxygen concentration range suitable for the device. This oxygen concentration range may differ depending on the device manufacturer, or depending on the type of device even if the device manufacturer is the same. The wafer manufacturer sets the oxygen concentration range of the silicon single crystal so as to meet the specifications required by the device manufacturer, and controls the oxygen concentration based on this setting. The oxygen concentration range set at this time corresponds to a “predetermined oxygen concentration range”.

Further, the above “same quartz crucible” and “same support crucible” will be supplemented.
The same quartz crucible means quartz crucibles having the same size, shape and material. The same size and shape are concepts including not only the case where the size and shape are exactly the same but also the case where there is a difference within a predetermined range. Examples of the difference within the predetermined range include a dimensional tolerance of inner and outer diameters, a curvature tolerance of the bottom part, and a curvature tolerance of the R part located between the side wall part and the bottom part, which are generally required for a quartz crucible. The same material means that the concentration of inevitable impurities such as boron and the concentration of impurities added intentionally are within a predetermined range, and the process conditions for manufacturing the quartz crucible are the same. For example, the same type of quartz crucible manufactured by the same manufacturer is the same material, and in this case, the size and shape are also the same.
On the other hand, the same supporting crucible means a supporting crucible having the same size, shape and material, and the same size and shape has the same meaning as the above-described quartz crucible. Further, the same material means that the concentration and bulk density of inevitable impurities such as ash are within a predetermined range, and the process conditions for producing the supporting crucible are the same. For example, the same type of support crucible manufactured by the same manufacturer is the same material, and in this case, the size and shape are also the same.

According to the present invention described above, in order to take into account the total usage time of the support crucible in the estimation of the oxygen concentration of the second silicon single crystal, the second effect is taken into account the influence of the oxygen concentration accompanying the deterioration of the support crucible. The manufacturing conditions for the silicon single crystal can be set. Therefore, it is possible to provide a method for producing a silicon single crystal capable of appropriately controlling the oxygen concentration of the silicon single crystal.
Note that the oxygen concentration of the first silicon single crystal used in the concentration estimation step may be an actual measurement value, the past manufacturing conditions, and the oxygen concentration of the silicon single crystal manufactured under the past conditions. And an estimated value based on the conditions of the first single crystal manufacturing process.
The target oxygen concentration of the second silicon single crystal may be the same as or different from that of the first silicon single crystal. The case where the first silicon single crystal and the second silicon single crystal have the same oxygen concentration is a case where a silicon single crystal having the same target oxygen concentration is manufactured. This is a case where silicon single crystals having different oxygen concentrations are manufactured.

The inventor further found that the influence on the oxygen concentration of the silicon single crystal differs depending on the characteristics of at least one of the size, shape, and material of at least one of the quartz crucible and the support crucible. completed.
That is, in the method for producing a silicon single crystal of the present invention, the concentration estimation information includes a plurality of pieces of quartz crucible correspondence information generated corresponding to at least one characteristic among the size, shape and material of the quartz crucible. The concentration estimation step preferably estimates the oxygen concentration based on the quartz crucible correspondence information corresponding to the at least one characteristic of the quartz crucible used in the first single crystal manufacturing step.
In the method for producing a silicon single crystal of the present invention, the concentration estimation information includes a plurality of support crucible correspondence information generated corresponding to at least one characteristic among the size, shape, and material of the support crucible, In the concentration estimation step, it is preferable to estimate the oxygen concentration based on the support crucible correspondence information corresponding to the at least one characteristic of the support crucible used in the first single crystal manufacturing step.

  According to the present invention, the oxygen concentration of the silicon single crystal according to the characteristics of the quartz crucible is used to estimate the oxygen concentration of the second silicon single crystal because the quartz crucible correspondence information that further considers the characteristics of the quartz crucible is used. Can be controlled appropriately. Moreover, if the support crucible correspondence information that further considers the characteristics of the support crucible is used, the oxygen concentration of the silicon single crystal can be appropriately controlled according to the characteristics of the support crucible.

  In the method for producing a silicon single crystal of the present invention, the first silicon single crystal is a first silicon single crystal produced using the first quartz crucible, and the second silicon single crystal is 2 A silicon single crystal manufactured after this time is preferable.

  According to the present invention, the oxygen concentration of a plurality of silicon single crystals manufactured by the multiple pulling method can be appropriately controlled, and a high product yield can be realized even when the specification range of the oxygen concentration is narrow. However, it is possible to enjoy the high productivity that is the merit of the multiple pulling method.

  In the method for producing a silicon single crystal of the present invention, the support crucible can be formed of a graphite material or a C / C composite material.

The schematic diagram which shows the structure of the single crystal pulling apparatus which concerns on one Embodiment of this invention. The graph showing the result of the experiment conducted in order to obtain | require the 1st relational expression of the said one Embodiment. The graph showing the result of the experiment conducted in order to obtain | require the 2nd relational expression of the said one Embodiment. The flowchart which shows the manufacturing method of the silicon single crystal of the one embodiment.

[Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Configuration of single crystal pulling device]
As shown in FIG. 1, the single crystal pulling apparatus 1 is an apparatus used for the CZ method, and includes a pulling apparatus main body 2 and a control unit 3.
The lifting device main body 2 includes a chamber 21, a crucible 22 disposed at the center of the chamber 21, a heater 23 that radiates heat to the crucible 22, a heat insulating cylinder 24, a lifting cable 25, And a heat shield 26.

A gas inlet 21 </ b> A for introducing an inert gas such as Ar gas into the chamber 21 is provided at the upper portion of the chamber 21. A gas exhaust port 21 </ b> B that exhausts gas in the chamber 21 by driving a vacuum pump (not shown) is provided at the lower portion of the chamber 21.
An inert gas is introduced into the chamber 21 at a predetermined gas flow rate from the gas inlet 21 </ b> A above the chamber 21 under the control of the control unit 3. The introduced gas is discharged from the gas exhaust port 21 </ b> B at the lower part of the chamber 21, so that the inert gas flows from the upper side to the lower side in the chamber 21.
The pressure in the chamber 21 (furnace pressure) can be controlled by the control unit 3.

The crucible 22 melts polycrystalline silicon, which is a raw material for a silicon wafer, to form a silicon melt M. The crucible 22 is supported by a support shaft 27 that can rotate and move up and down at a predetermined speed.
Here, in the single crystal pulling apparatus 1 of the present embodiment, the first crucible 22A or the second crucible 22B is provided as the crucible 22.
The first crucible 22A includes a bottomed cylindrical first quartz crucible 221A having an aluminum addition layer that is easily crystallized, and a CCM (C / C composite) support crucible 222 that houses the first quartz crucible 221A. And. CCM is a high-strength, high-elasticity carbon material reinforced with carbon fibers. The aluminum addition layer of the first quartz crucible 221A is provided in a range of 0.2 mm to 0.6 mm from the outermost periphery of the first quartz crucible 221A, and 10 ppm to 50 ppm of aluminum is added to the glass in which the quartz powder is melted. It is constituted by.
The second crucible 22B includes a second quartz crucible 221B having the same shape as the first quartz crucible 221A having a semi-molten layer that is easily crystallized, and a support crucible 222. The semi-molten layer of the second quartz crucible 221B is provided in substantially the same range as the aluminum-added layer of the first quartz crucible 221A, and is composed of a mixed layer of quartz powder and glass obtained by melting the quartz powder.

The heater 23 is disposed outside the crucible 22 and heats the crucible 22 to melt silicon in the crucible 22.
The heat insulation cylinder 24 is disposed so as to surround the crucible 22 and the heater 23.
One end of the pulling cable 25 is connected to a pulling drive unit (not shown) disposed above the crucible 22, and the seed crystal SC is attached to the other end. The pulling cable 25 moves up and down at a predetermined speed and rotates around the axis of the pulling cable 25 under the control of the pulling drive unit by the control unit 3.
The heat shield 26 blocks radiant heat radiated upward from the heater 23.

  Based on the concentration estimation information stored in the memory 31 and the operator's setting input, the controller 3 controls the gas flow rate and furnace pressure in the chamber 21, the heating temperature in the chamber 21 by the heater 23, the crucible 22. The silicon single crystal SM is manufactured by controlling the rotational speed of the silicon single crystal SM.

Here, the density estimation information will be described.
The concentration estimation information can be configured to include the following first relational expression (1) and second relational expression (2), and can further include a relational expression that is not explicitly shown. The first and second relational expressions are merely examples of quartz crucible correspondence information in the present embodiment, and may differ from the following expressions depending on the structure of the single crystal pulling apparatus 1 and the like.
In the first and second relational expressions, the growth position for comparing the oxygen concentration in the silicon single crystal SM is within a range from a position of 800 mm to a position of 1000 mm toward the lower end when the upper end of the straight body portion is 0 mm. is there.

D1 = −0.51 + 1.318 × 10 ⁻⁴ × T1 (1)
D1: Oxygen change
(Oxygen concentration of the second silicon single crystal (second silicon single crystal)
-1 oxygen concentration of the first silicon single crystal (first silicon single crystal)
T1: Total usage time (hr) of the supporting crucible 222 of the first crucible 22A

D2 = −0.161 + 2.45 × 10 ⁻⁵ × T2
−4.41 × 10 ⁻⁸ × (T2-4229.52) ² (2)
D2: oxygen change amount
(Oxygen concentration of the second silicon single crystal (second silicon single crystal)
-1 oxygen concentration of the first silicon single crystal (first silicon single crystal)
T2: Total use time (hr) of the support crucible 222 of the second crucible 22B

The above first and second relational expressions were obtained by the following experiment.
First, a first crucible 22A having the following configuration was attached to a single crystal pulling apparatus 1 as shown in FIG.
First quartz crucible 221A (manufactured by company A, model A1)
Inner diameter: 780 mm
Height: 530mm
Support crucible 222 (CCM (B company, model B1))
Inner diameter: 812mm
Height: 500mm

Then, two silicon single crystals SM having a diameter of 300 mm and a straight body length of 2600 mm were continuously manufactured under the following manufacturing conditions. In this production, the first and second production conditions were made the same by using a multiple pulling method.
Ar flow rate: 100 L / min to 200 L / min
-Furnace pressure: 20 Torr (2666 Pa) to 60 Torr (7999 Pa)
-Number of revolutions of crucible: 0.2 rpm to 3.0 rpm
・ Rotation speed of silicon single crystal: 5-12 rpm

Next, a sample of the above-mentioned growth position (range of 800 mm to 1000 mm) is cut out from two silicon single crystals SM, the oxygen concentration is measured, and oxygen obtained by subtracting the first oxygen concentration from the second oxygen concentration The amount of change and the total usage time of the supporting crucible 222 of the first crucible 22A at the time when the production of the first silicon single crystal SM was started were obtained. The total use time is the total time during which the heater 23 is turned on, and does not include the cleaning time of each part of the lifting device body 2 and the idling state time for production adjustment.
The growth position for measuring the oxygen concentration may be in a range other than the above range.

And the above-mentioned experiment was implemented in multiple times, and the relationship between oxygen variation and the total usage time of the support crucible 222 of the 1st crucible 22A was investigated. The result is shown in FIG. As shown in FIG. 2, there is a linear relationship between the amount of oxygen change and the total usage time of the supporting crucible 222 of the first crucible 22A, and the above first relational expression is obtained from this relationship.
In this experiment, the manufacturing conditions such as the Ar flow rate and the furnace pressure may be different from the above-described manufacturing conditions, but there was no problem in obtaining the relational expression.

Further, an experiment similar to that in the case of obtaining the first relational expression was performed except that a second crucible 22B having the following configuration was attached instead of the first crucible 22A. FIG. 3 shows the relationship between the oxygen change amount and the total usage time of the support crucible 222 of the second crucible 22B. As shown in FIG. 3, there is a curve relationship between the oxygen change amount and the total usage time of the support crucible 222 of the second crucible 22B, and the above-described second relational expression is obtained from this relationship.
Second quartz crucible 221B (A company, model A2)
Inner diameter: 780 mm
Height: 530mm
Support crucible 222 (CCM (B company, model B1))
Inner diameter: 812mm
Height: 500mm

[Method for producing silicon single crystal]
Next, a method for manufacturing the silicon single crystal SM will be described.
In the present embodiment, a case where a single crystal pulling apparatus 1 to which the first crucible 22A is attached is used to produce a silicon single crystal SM having a diameter of 300 mm and a total length of 1500 mm to 2500 mm by a multi-pulling method. explain.

First, as shown in FIG. 4, the control unit 3 of the single crystal pulling apparatus 1 sets 1 to the variable N (step S1), the manufacturing conditions of the first silicon single crystal SM, for example, the type of the crucible 22, Ar The flow rate, furnace pressure, the number of revolutions of the crucible 22 and the silicon single crystal SM, etc. are set (step S2).
Note that the manufacturing conditions may be the same as or different from the experiment for obtaining the first relational expression. Further, the manufacturing conditions may be input by the operator, or may be calculated by the control unit 3 based on the target oxygen concentration input by the operator.

Next, the control unit 3 manufactures the first silicon single crystal SM (first silicon single crystal) (step S3: first single crystal manufacturing process).
Specifically, the control unit 3 heats the first crucible 22A with the heater 23 to melt the polysilicon material (silicon raw material) and the dopant in the first crucible 22A, and the dopant-added melt MD. Is generated. Thereafter, the control unit 3 introduces Ar gas into the chamber 21 from the gas introduction port 21A at a predetermined flow rate, reduces the pressure in the chamber 21, and maintains the chamber 21 in an inert atmosphere under reduced pressure. .
Thereafter, the control unit 3 lowers the pulling cable 25 to immerse the seed crystal SC in the dopant-added melt MD.
And the control part 3 manufactures the Nth silicon single crystal SM by pulling up the pulling cable 25 while rotating the first crucible 22A and the pulling cable 25 in a predetermined direction.

Next, the oxygen concentration of the Nth silicon single crystal SM is measured (step S4). At this time, the oxygen concentration at the same growth position as in the experiment for obtaining the first relational expression is measured.
When the operator sets the oxygen concentration measured in step S4 to the control unit 3, the control unit 3 performs the (N + 1) th silicon single unit under the same conditions as the Nth based on the concentration estimation information in the memory 31. The oxygen concentration when the crystal SM (second silicon single crystal) is manufactured is estimated (step S5: concentration estimation step).
Specifically, first, the control unit 3 reads out the first relational expression corresponding to the first crucible 22A from the memory 31, and uses the support crucible 222 of the first crucible 22A as the total relation of the first relational expression. The oxygen change amount D1 is obtained by substituting the time T1. The total usage time T1 substituted at this time is the total usage time at the start of manufacture of the Nth silicon single crystal SM. The total use time T1 may be input by an operator, or may be obtained based on a timer (not shown) provided in the single crystal pulling apparatus 1. Then, the controller 3 estimates the value obtained by adding the first oxygen concentration to the oxygen change amount D1 as the oxygen concentration of the (N + 1) th silicon single crystal SM.

Thereafter, the control unit 3 sets the manufacturing conditions for the (N + 1) th silicon single crystal SM (step S6). This manufacturing condition is set so that the Nth and (N + 1) th oxygen concentrations are the same. In this case, the manufacturing condition is set to a condition for decreasing the oxygen concentration when the oxygen change amount D1 is a positive value, and is set to a condition for increasing the oxygen concentration when the oxygen change amount D1 is a negative value. Is set to the same condition.
Note that the manufacturing conditions may be those input by the operator as in the case of the Nth setting, or are calculated by the control unit 3 based on the target oxygen concentration input by the operator. There may be. When the Nth oxygen concentration is different from the target value, the manufacturing conditions may be set so that the (N + 1) th oxygen concentration becomes the target value. Further, even when the N-th oxygen concentration is the same as the target value, when the silicon single crystal SM having a specification different from that of the N-th crystal is manufactured, the (N + 1) th oxygen concentration is different from the N-th target value. Manufacturing conditions may be set.

Thereafter, the control unit 3 manufactures the (N + 1) th silicon single crystal SM (step S7: second single crystal manufacturing step).
Specifically, the control unit 3 adds a polysilicon material (silicon raw material) into the first crucible 22A, and adjusts various conditions to the conditions set in step S6, thereby (N + 1) -th silicon. Single crystal SM is manufactured. The addition of the polysilicon material may be performed during the measurement of the oxygen concentration of the Nth silicon single crystal SM.
Thereafter, the control unit 3 determines whether or not the production of the silicon single crystal SM is finished (step S8). When it is judged that the control unit 3 is finished, the single crystal pulling apparatus 1 is subjected to the falling process and is judged not to be finished. , 1 is added to the variable N (step S9), and the process returns to step S4.
When the second crucible 22B is used, in step S5, the total use time T2 of the support crucible 222 of the second crucible 22B is substituted into the second relational expression to obtain the oxygen change amount D2, and this oxygen change The oxygen concentration of the (N + 1) th silicon single crystal SM may be estimated based on the amount D2.

[Effects of Embodiment]
In the above embodiment, since the concentration estimation information that takes into account the total usage time of the support crucible 222 is used for the estimation of the oxygen concentration of the (N + 1) -th silicon single crystal SM, the oxygen concentration accompanying the deterioration of the support crucible 222 is used. In consideration of the above, the manufacturing conditions of the (N + 1) -th silicon single crystal SM can be set. Therefore, it is possible to provide a method for manufacturing a silicon single crystal SM that can appropriately control the oxygen concentration of the silicon single crystal SM.

  Further, the concentration estimation information includes a first relational expression generated corresponding to the first quartz crucible 221A and a second relational expression generated corresponding to the second quartz crucible 221B. Therefore, the oxygen concentration of the silicon single crystal SM can be appropriately controlled according to the material of the quartz crucible.

[Other Embodiments]
It should be noted that the present invention is not limited to the above-described embodiment, and various improvements and design changes can be made without departing from the scope of the present invention. The general procedure and structure may be other structures as long as the object of the present invention can be achieved.

For example, when the production is performed using only the first crucible 22A or the second crucible 22B, the concentration estimation information may be configured only by the relational expression corresponding to the crucible 22 used.
When using a quartz crucible made of a material different from the first and second quartz crucibles 221A and 221B, or a quartz crucible having the same material as the first and second quartz crucibles 221A and 221B but having a different size and shape, A relational expression (quartz crucible correspondence information) corresponding to the quartz crucible used may be obtained, and the oxygen concentration may be controlled based on this relational expression. Similarly, when a support crucible having at least one of the size, shape, and material characteristics different from that of the above-described support crucible 222 is used, a relational expression (support crucible correspondence information) corresponding to the support crucible to be used is obtained. The oxygen concentration may be controlled based on this. For example, the support crucible may be formed of a graphite material, and the oxygen concentration may be controlled based on a relational expression corresponding to the support crucible of the graphite material.
In order to obtain two oxygen changes that are not continuously produced, the information for concentration estimation for obtaining the first and second, ie, two continuously produced oxygen changes in the multiple method is used. The concentration estimation information may be used. For example, the third oxygen concentration may be estimated based on the first oxygen concentration using the concentration estimation information for obtaining the first and third oxygen variation amounts.

Without performing the oxygen concentration measurement process of the N-th silicon single crystal SM in step S4, the past manufacturing conditions, the oxygen concentration of the silicon single crystal manufactured under the past conditions, and the N-th silicon single crystal SM The oxygen concentration of the N-th silicon single crystal SM may be estimated based on the manufacturing conditions, and the process of step S5 may be performed based on the estimated oxygen concentration.
In the process of step S5, the control unit 3 may display the oxygen change amount D1 on a display unit (not shown), and the operator may estimate the (N + 1) th oxygen concentration. In this case, the operator does not need to input the Nth oxygen concentration to the control unit 3.
The total usage time T1 and T2 of the support crucible 222 of the first and second crucibles 22A and 22B included in the first and second relational expressions are the total usage time at the start of manufacturing the Nth silicon single crystal SM. Instead, it may be the production end time of the first silicon single crystal SM, the production start scheduled time or the production end scheduled time of the second silicon single crystal SM.

You may apply the manufacturing method of the silicon single crystal of this invention to the MCZ (magnetic field application Czochralski) method of applying a magnetic field. In this case, as shown by a two-dot chain line in FIG. 1, a pair of electromagnetic coils 28 are arranged outside the chamber 21 so as to face each other with the crucible 22 interposed therebetween, and natural convection of the silicon melt M is performed in a horizontal transverse magnetic field. By suppressing the oxygen concentration, the oxygen concentration of the silicon single crystal SM can be controlled.
You may include the experiment for calculating | requiring the 1st, 2nd relational expression in the manufacturing method of the silicon single crystal of this invention as an information generation process for concentration estimation.

  DESCRIPTION OF SYMBOLS 1 ... Single crystal pulling apparatus (pulling apparatus), 221A, 221B ... 1st, 2nd quartz crucible, 222 ... Supporting crucible, SM ... Silicon single crystal.

Claims (5)

Using a single quartz crucible, the steps of supplying a silicon raw material into a quartz crucible housed in a supporting crucible and the step of melting the silicon raw material and growing a silicon single crystal from the raw material melt by the Czochralski method are repeated. A method for producing a silicon single crystal using a multiple pulling method for producing a plurality of silicon single crystals,
A concentration estimation step of estimating the oxygen concentration of the second silicon single crystal manufactured after the first silicon single crystal based on the oxygen concentration of the first silicon single crystal and the total usage time of the support crucible A method for producing a silicon single crystal, comprising: Using a single quartz crucible, the steps of supplying a silicon raw material into a quartz crucible housed in a supporting crucible and the step of melting the silicon raw material and growing a silicon single crystal from the raw material melt by the Czochralski method are repeated. A method for producing a silicon single crystal using a multiple pulling method for producing a plurality of silicon single crystals,
Using concentration estimation information representing the relationship between the difference in oxygen concentration at the same growth position of two silicon single crystals manufactured under the same conditions using the same quartz crucible and the supporting crucible and the total usage time of the supporting crucible ,
A first single crystal manufacturing step of manufacturing a first silicon single crystal using a quartz crucible and a support crucible having the same configuration as the quartz crucible and the support crucible used for generating the concentration estimation information;
Based on the oxygen concentration at the growth position of the first silicon single crystal, the concentration estimation information, and the total usage time of the support crucible, the second condition is the same as in the first single crystal manufacturing step. A concentration estimation step for estimating an oxygen concentration at the growth position when a silicon single crystal is produced;
And a second single crystal manufacturing step of manufacturing the second silicon single crystal in a predetermined oxygen concentration range based on the estimation result in the concentration estimation step. Method. In the manufacturing method of the silicon single crystal of Claim 2,
The concentration estimation information includes a plurality of quartz crucible correspondence information generated corresponding to at least one characteristic among the size, shape and material of the quartz crucible,
The concentration estimating step estimates the oxygen concentration based on the quartz crucible correspondence information corresponding to the at least one characteristic of the quartz crucible used in the first single crystal manufacturing step. Crystal production method. In the manufacturing method of the silicon single crystal of Claim 2 or Claim 3,
The concentration estimation information includes a plurality of support crucible correspondence information generated corresponding to at least one characteristic among the size, shape and material of the support crucible,
The concentration estimating step estimates the oxygen concentration based on the support crucible correspondence information corresponding to the at least one characteristic of the support crucible used in the first single crystal manufacturing step. Crystal production method. In the manufacturing method of the silicon single crystal according to any one of claims 1 to 4,
The first silicon single crystal is a first silicon single crystal manufactured using the first quartz crucible,
The method of manufacturing a silicon single crystal, wherein the second silicon single crystal is a silicon single crystal manufactured after the second one.

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