WO2016021843A1

WO2016021843A1 - Silicon single crystal growing apparatus and silicon single crystal growing method using same

Info

Publication number: WO2016021843A1
Application number: PCT/KR2015/007169
Authority: WO
Inventors: 김도연; 최일수; 안윤하
Original assignee: 주식회사 엘지실트론
Priority date: 2014-08-05
Filing date: 2015-07-10
Publication date: 2016-02-11

Abstract

An exemplary embodiment of the present invention provides a silicon single crystal growing apparatus and method. The apparatus comprises: a chamber; a crucible that is disposed in the chamber and receives melted silicon; a heater disposed outside the crucible to heat the crucible; a heat shield part disposed in the chamber; and an auxiliary heat shield part disposed above the crucible to move upward and downward, wherein the auxiliary heat shield part is disposed to be separated from a body part of a single crystal that has grown from the melted silicon, and a rising speed is controlled such that a defect-free zone in the single crystal body part increases. The auxiliary heat shield part can reduce a deviation of a temperature gradient in the body part, thereby increasing the distribution of a defect-free zone in the body part.

Description

Silicon single crystal growth apparatus and silicon single crystal growth method using the same

Embodiments relate to a silicon single crystal growth apparatus for controlling a crystal defect region in a growing single crystal body portion and a silicon single crystal growth method using the same.

Generally, a floating zone (FZ) method or a CZochralski (CZ: CZochralski) method is widely used as a method for producing a silicon single crystal. In the case of growing a silicon single crystal ingot by applying the FZ method, it is not only difficult to manufacture a large diameter silicon wafer but also has a very expensive process cost. Therefore, it is common to grow a silicon single crystal ingot by the CZ method.

According to the CZ method, polycrystalline silicon is charged into a quartz crucible, the graphite heating element is heated to melt it, and then seed crystal is immersed in the silicon melt formed as a result of melting, and the seed crystal is caused to crystallize at the melt interface. The monocrystalline silicon ingot is grown by pulling while rotating.

Single crystal ingots grown in this way are connected to the seed crystals to form a thin and elongated neck and neck after the necking process, gradually increasing the diameter of the single crystal to grow the shoulders and the shaft while maintaining the increased diameter. A body formed by growing in a direction and a tail formed by separating the molten silicon by gradually decreasing the diameter of the growing crystal.

In the conventional silicon single crystal ingot growth apparatus and single crystal ingot growth method using the same, the upper part of the crucible is open, so that the heat distribution in the single crystal may not be uniform during the growth process, and the cooling rate between the center and the outer edge of the single crystal cross section may be increased. There will be a difference.

Due to the difference in temperature gradient in the radial direction of the single crystal, the distribution of crystal defects formed in the center and the outer region is also different in the cut surface of the single crystal ingot at the same position in the impression axis direction, thereby increasing the defect-free crystal region to grow the single crystal. It is a difficult problem.

The embodiment is to provide a silicon single crystal growth apparatus and a growth method capable of increasing the defect area in the body portion of the single crystal by placing the auxiliary heat shield on the top of the crucible and controlling the pulling speed of the auxiliary heat shield.

An embodiment includes a chamber; A crucible disposed within the chamber and containing a silicon melt; A heater disposed outside the crucible to heat the crucible; A heat shield disposed in the chamber; And an auxiliary heat shield disposed above the crucible and capable of vertical movement. It includes, wherein the auxiliary heat shield is disposed on the body portion of the single crystal grown in the silicon melt spaced apart, to provide a silicon single crystal growth apparatus in which the rising speed is controlled to increase the defect area in the single crystal body portion.

Another embodiment includes a chamber; A crucible disposed within the chamber and containing a silicon melt; A heater disposed outside the crucible to heat the crucible; A heat shield disposed in the chamber; An auxiliary heat shield disposed above the crucible and capable of vertical movement; A main control unit controlling a pulling rate of the single crystal grown in the silicon melt; An auxiliary control unit controlling a rising speed of the auxiliary heat shield; And an pulling device for pulling up the single crystal and the auxiliary auxiliary heat shield respectively according to the control signals input from the main control unit and the auxiliary control unit.

Another embodiment is performed in a silicon single crystal growth apparatus comprising a chamber, a crucible disposed within the chamber and containing a silicon melt, a heat shield disposed in the chamber, and an auxiliary heat shield disposed above the crucible and capable of vertical movement. In the silicon single crystal growth method, the auxiliary heat shielding portion is maintained at a predetermined distance from the single crystal body portion grown in the silicon melt to control the rising speed of the auxiliary heat shield portion to increase the defect area in the single crystal body portion. It provides a silicon single crystal growth method comprising.

Still another embodiment includes a chamber, a crucible disposed within the chamber and containing a silicon melt, a heat shield disposed in the chamber, and an auxiliary heat shield disposed above the crucible and movable up and down; A main control unit controlling a pulling rate of the single crystal grown in the silicon melt; Auxiliary control unit for controlling the rising speed of the auxiliary heat shield; and Raising device for pulling up the single crystal and the auxiliary auxiliary heat shield respectively according to the control signal input from the main control unit and the auxiliary control unit: Silicon single crystal growth apparatus comprising a A method for growing a single crystal of silicon, the method comprising: checking a length of a body portion of the grown single crystal; Determining whether the auxiliary heat shield is operated by the auxiliary controller according to the identified body length; It provides a silicon single crystal growth method comprising a.

In the silicon single crystal growth apparatus and the growth method according to the embodiment, by placing the auxiliary heat shield on the crucible and controlling the rising speed, it is possible to control the defect area in the body part of the single crystal and increase the defect free area.

1 is a view showing an embodiment of a silicon single crystal growth apparatus,

2a to 2b is a view showing an embodiment of the auxiliary heat shield,

3 illustrates a portion of a silicon single crystal growth apparatus of one embodiment,

4A to 4B are diagrams showing the distribution of crystal defects in the single crystal body portion,

5 is a view showing a temperature distribution in a single crystal cut plane,

6 is a view showing a difference in cooling rate in a single crystal cut surface,

7 is a view showing an embodiment of a silicon single crystal growth apparatus,

8 is a block diagram illustrating an embodiment of an auxiliary control unit;

9 is a block diagram illustrating an embodiment of a main controller.

10 is a flow chart illustrating one embodiment of a silicon single crystal growth method.

Hereinafter, the present invention will be described in detail with reference to examples, and detailed description will be made with reference to the accompanying drawings in order to help understanding of the present invention. However, embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

In the description of the embodiment according to the present invention, when described as being formed on "on" or "under" of each element, the above (up) or below (on) or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as “on” or “under”, it may include the meaning of the downward direction as well as the upward direction based on one element.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1 is a view showing an embodiment of a silicon single crystal growth apparatus.

The silicon single crystal growth apparatus of the embodiment shown in FIG. 1 may include a chamber 10, a crucible 30 containing a silicon melt, a heater 20 disposed outside the crucible, and a heat shield 40.

The chamber 10 may have a cylindrical shape having a cavity formed therein, and a pull chamber (not shown) may be connected to an upper portion of the chamber 10.

The crucible 30 containing the silicon melt SM may be disposed in the chamber 10. The crucible 30 may be disposed in a central region within the chamber 10 and may be in the shape of a concave bowl as a whole. In addition, the crucible 30 may be formed of a quartz crucible in direct contact with the silicon melt SM and a graphite crucible supporting the quartz crucible while surrounding the outer surface of the quartz crucible.

The heater 20 for supplying heat toward the crucible 30 may be disposed on the side of the crucible 30. The heater 20 may be disposed outside the crucible 30 spaced apart from the outer circumferential surface of the crucible 30 by a predetermined interval, and may be disposed in a cylindrical shape to surround the side of the crucible 30. In addition, the upper portion of the chamber 10 may further include a water cooling tube 60 for cooling the grown single crystal 50.

In the chamber 10 of the single crystal growth apparatus, the heat shield 40 may be disposed to preserve heat of the crucible 30 heated by the heater 20. The heat shield 40 may be included between the heater 20 and the chamber 10, and the upper heat shield and the side heat shield and the crucible 30 disposed on the side of the crucible 30 and the upper heat shield disposed above the crucible 30. But it may include a lower heat shield disposed on the lower side of the heat shield 40 is not limited to this arrangement.

The heat shield 40 may be designed in a material and a shape to make an optimal thermal distribution in the heater 20 and the crucible 30 and to utilize the energy without loss as much as possible.

The single crystal growth apparatus of the embodiment shown in FIG. 1 may include an auxiliary heat shield 70.

The auxiliary heat shield 70 may be disposed above the crucible, and may be moved up and down.

2A to 2B are diagrams of an embodiment of the auxiliary heat shield.

2A to 2B, the

auxiliary heat shields

70A and 70B may have cylindrical side surfaces of which upper and lower surfaces are open to be disposed to surround the seed chuck, and the inside of the side may have an empty shape. .

The

auxiliary heat shields

70A and 70B may have a disk shape as shown in FIG. 2A or a truncated cone shape as shown in FIG. 2B, but are not limited thereto. The

auxiliary heat shields

70A and 70B may include graphite or carbon composite material.

Lower surfaces of the

auxiliary heat shields

70A and 70B may be formed to be flat to maintain a predetermined distance from the body portion of the single crystal.

The upper portion of the auxiliary heat shields (70A, 70B) is attached to the wire 72 can be adjusted to enable vertical movement. In this case, the wire 72 may be the first wire 72 in the embodiment of the silicon single crystal growth apparatus described later. In addition, only two wires 72 connected to the auxiliary heat shields are illustrated in the drawings, but embodiments are not limited thereto, and three or more wires may be connected to the auxiliary heat shields to control the movement of the auxiliary heat shields.

3 shows a portion of a single crystal growth apparatus of one embodiment.

Referring to FIG. 3, the auxiliary heat shield 70 may be disposed above the accommodated silicon melt SM, and spaced apart from the top of the silicon single crystal 50 grown from the silicon melt SM, for example. Can be.

In addition, the auxiliary heat shield 70 may be controlled to increase the speed so that the defect-free area in the body portion (B) of the single crystal growing at a constant interval with the body portion (B) of the single crystal (50).

At this time, the spaced apart interval of the auxiliary heat shield 70 and the single crystal body portion B may be controlled to change in accordance with the growth process conditions in which the single crystal is produced.

That is, in the single crystal growth process, the interval between the auxiliary heat shield 70 and the single crystal body B may be adjusted according to the pulling speed of the single crystal, the temperature of the silicon melt in the crucible, or the temperature condition in the chamber.

The auxiliary heat shield 70 may be disposed while maintaining a predetermined distance d from the boundary between the shoulder portion S and the body portion B of the growing single crystal 50.

For example, the auxiliary heat shield 70 may be disposed above the body portion B, and the distance from the boundary between the shoulder portion S and the body portion B of the ingot which is the starting point of the body portion B is. The speed can be controlled so that (d) is maintained at 150 mm to 300 mm.

The auxiliary heat shield 70 may have a rising speed of 0.5 mm / min to 0.7 mm / min to maintain a predetermined distance from the body portion B. When the auxiliary heat shield 70 is raised at a speed faster than 0.7 mm / min, the distance d between the growing single crystal 50 and the auxiliary heat shield 70 is increased, so that the temperature at the center and the outside of the single crystal 50 is increased. The difference in the gradient cannot be reduced by the target value, and the risk of contact with the growing single crystal 50 may occur if it is moved at a speed slower than 0,5 mm / min.

The rising speed of the auxiliary heat shield 70 may be equal to the pulling speed of the growing single crystal 50.

That is, in the single crystal growth process, at the beginning of the shoulder portion S and the body portion B, the pulling speeds of the auxiliary heat shielding portion 70 and the single crystal 50 are the same, and the auxiliary heat shielding portion 70 is the body portion 50 and the same. It is possible to increase the defect free area in the crystal formed at the beginning of the body portion B by adjusting the cooling rate in the growing single crystal body portion by maintaining a constant interval.

4A to 4B are diagrams schematically showing crystal defect regions in the body portion B depending on whether or not the auxiliary heat shield 70 is applied.

In the drawing, the X axis is the axial length of the single crystal body portion, and the starting point of the body portion B, that is, the boundary point between the shoulder portion S and the body portion B, is 0 mm, and the axis in which the single crystal is grown. Corresponds to the increased length in the direction.

The Y axis of the figure shows the pulling speed of the single crystal, and the solid line in the figure shows the change of the pulling speed according to the length of the single crystal body.

In addition, the Y-axis direction may correspond to a radial direction at one point in the longitudinal direction in which the body portion grows. For example, the center of the Y-axis region shown in the graph may correspond to the center of the single crystal cross section, and the direction in which the Y-axis value decreases and the direction of increase may correspond to the outer region of the single crystal cross section, respectively.

The dotted lines in the figure indicate the distribution of the defect regions of the crystal. 1) The region is an octahedral void region, which is a defect region of vacancy, and 2) the region is an oxygen induced stacking fault (OiSF) region. , 3) represents a defect free area.

4A shows crystal defect distribution in the single crystal body portion when the auxiliary heat shield 70 is not applied.

Referring to FIG. 4A, when the auxiliary heat shield is not disposed, the defect area included in the single crystal is distributed to a point where the length of the body part becomes 350 mm, and the same type of defect shape is disposed in the radial direction of the body part. In addition to the area, it can be seen that the area that includes Octahedral void defects, OiSF defects, and defect-free areas are also displayed.

In comparison, in the defect distribution of the crystal when the auxiliary heat shield 70 of FIG. 4B is applied, only a defect free area is distributed when the body length is longer than 200 mm, and the defect distribution when the body length is 200 mm or less. It can be seen that even in the region, the same crystal defects appear in the radial direction of the body portion.

That is, when the auxiliary heat shield 70 is disposed above the silicon melt SM to maintain a predetermined distance from the single crystal, the single crystal growth process is performed, and the auxiliary heat shield 70 is accommodated in the crucible. By shielding the heat lost to the top of the system, it is possible to prevent rapid cooling at the beginning of the shoulder (S) and body (B) during the growth of single crystals, thereby reducing the area of crystal defects that may occur. Can have

In the single crystal growth apparatus of the embodiment, the ascending speed of the auxiliary heat shield 70 may be controlled to reduce the temperature difference at the center and the outside of the body cut surface perpendicular to the rising direction of the auxiliary heat shield 70.

5 is a graph showing a temperature (K) distribution in the single crystal body part depending on whether the auxiliary heat shield 70 is applied. In the graph of FIG. 5, A and B show results of the outer region of the cross section of the single crystal body part, where A is when the auxiliary heat shield is not disposed and B is when the auxiliary heat shield is disposed. In addition, C and D are for the central region of the cross section of the body, C is the case where the auxiliary heat shield is not arranged, D corresponds to the case where the auxiliary heat shield is arranged.

Referring to FIG. 5, in the case of a single crystal grown by a single crystal growing apparatus that does not include the auxiliary heat shield 70, the temperature difference between the center C and the outer portion A of the body portion increases as the length of the body portion grows. .

On the other hand, in the case of the single crystal grown in the single crystal growth apparatus of the embodiment including the auxiliary heat shield 70 and the moving speed of the auxiliary heat shield is controlled to maintain a constant distance from the body portion when the length of the body is grown to 400mm It can be seen that the temperature difference in the center (D) and the outer (B) of the body portion is hardly seen.

Therefore, by arranging the auxiliary heat shield 70 and controlling the rising speed in the single crystal growth apparatus of the embodiment, it is possible to reduce the temperature difference in the cross section of the body part during single crystal growth, thereby making it possible to uniformly distribute the crystal defects.

In the single crystal growth apparatus of the embodiment, the ascending speed of the auxiliary heat shield 70 may be controlled to reduce the difference in the cooling speed at the center and the outside of the cut surface of the body portion perpendicular to the rising direction of the auxiliary heat shield. .

6 is a graph showing a temperature gradient (K / cm) in the single crystal body part according to whether the auxiliary heat shield 70 is applied.

In FIG. 6, the temperature gradient may be a cooling speed. In addition, as shown in Fig. 5, A and C represent the outer region and the center of the single crystal cross section, respectively, when the auxiliary heat shield is not disposed, B and D are the single crystal growth apparatus of the embodiment in which the speed is controlled by the auxiliary heat shield is disposed. The outer region and the center of the single crystal cross section in the case of using are shown, respectively.

Referring to FIG. 6, when the auxiliary heat shield 70 is not applied, it can be seen that there is a difference in cooling rate in the center portion C of the single crystal and the outer region A, and the length of the body portion is 100 mm to 200 mm. In the region, it can be seen that the difference in cooling rate, that is, the temperature gradient, is 5 K / cm or more.

In comparison with this, when the single crystal growth apparatus of the embodiment including the auxiliary heat shield 70 is used, it can be confirmed that the difference in the cooling speeds in the center portion D and the outer portion B of the body portion hardly occurs.

Therefore, the single crystal growth apparatus of the embodiment controls the rising speed so that the auxiliary heat shield has a predetermined interval with the growing single crystal body part, so that the cooling speed at the center and the outer side of the cut surface of the body part perpendicular to the rising direction of the auxiliary heat shield is different. It is possible to adjust the crystal defect region and increase the distribution of the defect region in the body portion by reducing the.

For example, in the case of the embodiment, the difference between the cooling rates at the center (D) and the outer surface (B) of the body portion cut surface may be less than 1K / cm.

7 is a view showing an embodiment of a silicon single crystal growth apparatus.

Embodiments of the single crystal growth apparatus described below with reference to the drawings will not be described again with reference to the above-described embodiments of the single crystal growth apparatus, and the following description will focus on differences.

In the silicon single crystal growth apparatus of the embodiment shown in FIG. 7, the pulling speed of the chamber 10, the crucible 30 containing the silicon melt, the heater 20 disposed outside the crucible, the heat shield 40, and the single crystal are shown. It may include a main control unit 140 for controlling and an auxiliary control unit 130 for controlling the rising speed of the auxiliary heat shield.

In addition, the silicon single crystal growth apparatus of the embodiment is an impression apparatus connected to the water cooling tube 60 and the single crystal and auxiliary heat shields and

wires

72 and 52 which extend in the pulling direction of the single crystal from the upper side of the crucible 30 ( 110).

The pulling device 110 includes a first pulling unit 114 connected to the upper surface of the auxiliary heat shield 70 and the first wire 72, and a second pulling unit connected to the growing silicon single crystal and the second wire 52 ( 112).

The first pulling unit 114 may be a pulling unit connected to the auxiliary heat shield 70 to cause the auxiliary heat shield to rise upward in the crucible. The first pulling unit 114 may be at least one, it may be made of a plurality of auxiliary heat shields 70 to be raised in a balanced manner, and also to connect the auxiliary heat shields 70 and the first pulling unit 114. A plurality of first wires 72 may also be disposed.

The second pulling unit 112 may be a pulling unit for moving the growing single crystal to the upper direction of the crucible, and the second pulling unit may be connected to the single crystal seed portion and the second wire 52 at which the single crystal grows. In addition, the second pulling unit 112 may be connected to the seed chuck and the wire 52 connected to the upper end of the single crystal.

The auxiliary control unit 130 may receive the position information of the grown single crystal body part and the auxiliary heat shielding part output from the pulling device 110, and the correction value calculated by the auxiliary control unit 130 to the pulling device 110. You can give feedback again. In this case, the feedback value may be transmitted to the second pulling unit 114 that is the auxiliary heat shield lifting device of the pulling device 110.

8 is a block diagram briefly illustrating a configuration of the auxiliary control unit 130.

Referring to FIG. 8, the auxiliary controller 130 may include a position value sensing unit 132, a gap calculator 134, a correction value generator 136, and a first driver 138.

The position value sensing unit 132 may be to acquire the position of the single crystal body portion and the position of the auxiliary heat shield that are identified by the pulling device.

For example, the position value of the single crystal body portion may be a position value of a point where the body portion starts in the grown single crystal, and the position value of the auxiliary heat shield may be a position value of the lower surface of the auxiliary heat shield portion.

The gap calculator 134 may extract the spaced distance between the two from the position values of the body portion and the auxiliary heat shield obtained by the position value sensing unit 132.

For example, referring back to FIG. 3, the spaced distance between the body portion and the auxiliary heat shield may be d, which is a distance between the start of the body portion and the bottom surface of the auxiliary heat shield.

At this time, the start portion of the body portion may correspond to the boundary between the shoulder portion (S) and the body portion (B).

The correction value generator 136 may extract a correction value of the rising speed of the auxiliary heat shield corresponding to the gap between the body portion and the auxiliary heat shield calculated by the gap calculator 134.

In this case, a target value of a gap value of a body part and an auxiliary heat shield may be set, and a correction value of a rising speed may be extracted by comparing the set target distance value with a calculated separation interval value.

For example, when the separation distance value of the body portion and the auxiliary heat shield is within a target value, the rising speed value of the auxiliary heat shield in which the correction value is reflected may be equal to the current rising speed value. In addition, when the calculated separation interval value is larger than the target value, the corrected ascending speed may be smaller than the current climbing speed, and when the calculated separation interval value is smaller than the target value, the corrected climbing speed is greater than the current climbing speed. Can be large.

That is, the ascending speed auxiliary value may be adjusted such that a distance value between the body part and the auxiliary heat shield is consistent with the target value.

At this time, the target value may be 150mm to 300mm.

The auxiliary controller 130 may include a first driver 138.

The first driver 138 may output a signal for causing the auxiliary heat shield to be pulled through the pulling device 110. The first driver 138 may transfer the data of the correction rising speed value generated by the correction value generator 136 to the pulling device 110.

The first driver 138 may be a servo motor for controlling and operating a rising speed of the auxiliary heat shield.

That is, the auxiliary heat shield 70 which is controlled and lifted by the auxiliary controller 130 is controlled to maintain a predetermined distance d from the boundary between the shoulder portion S and the body portion B of the growing single crystal 50. Can be.

For example, the auxiliary heat shield 70 may be disposed on the upper portion of the body portion B, and is formed from a boundary between the shoulder portion S and the body portion B of the silicon single crystal ingot which is the starting point of the body portion B. The speed can be controlled so that the interval d of is maintained at 150 mm to 300 mm.

Referring back to FIG. 7, the main controller 140 receives a signal obtained from the sensor 141 disposed on the upper side of the chamber and transmits a signal to the pulling device 110 to adjust the pulling speed of the single crystal. Can be.

In FIG. 7, the sensor 141 may detect the growth degree of the single crystal through a view port disposed at one upper side of the chamber.

The sensor 141 measures the diameter of the growing single crystal, and various sensors such as an IR sensor, a CCD camera, or a pyrometer may be used. For example, the sensor 141 may be an Automatic Diameter Control (ADC) sensor.

The information sensed by the sensor 210 may be optical information or image information that may infer a change in diameter of the silicon single crystal.

Information about the diameter change value of the growing single crystal detected by the sensor may be transmitted to the main controller 140.

9 is a block diagram briefly illustrating a configuration of the main controller 140.

9, the main controller 140 may include a diameter sensing unit 142, a pulling speed determining unit 144, and a second driving unit 146.

The diameter sensing unit 142 may extract a diameter value of the silicon single crystal from information sensed and transmitted by the sensor 141 described above.

In the diameter sensing unit 142, a change value of the diameter of the silicon single crystal according to the process may be continuously obtained.

The diameter value of the silicon single crystal obtained in the diameter sensing unit 142 may be transmitted to the pulling speed determination unit 144.

In the pulling speed determining unit 144, a pulling speed of the single crystal may be determined from the diameter value of the single crystal input from the diameter sensing unit 142.

For example, it is possible to determine whether to adjust the pulling speed of the single crystal from the data on the diameter of the growing silicon single crystal input from the diameter sensing unit 142, and change the pulling speed by using PID control.

That is, a single crystal pulling speed value may be adjusted when there is a difference between the target value and the measured value by comparing the target diameter value and the measured diameter value detected by the diameter sensing unit 142.

For example, if the measured diameter value is larger than the target diameter value, the pulling speed may be adjusted faster than the current pulling speed, and if the measured diameter value is smaller than the target diameter value, the pulling speed is slower than the current pulling speed. Can be adjusted.

The main controller 140 may include a second driver 146.

The second driver 146 may output a signal for pulling the silicon single crystal through the pulling device 110. The second driver 146 may transfer the data of the corrected pulling speed value generated by the pulling speed determiner 144 to the pulling device 110.

The second driver 146 may be a servo motor for controlling the pulling speed of the growing single crystal to operate the second pulling unit 112.

Therefore, the single crystal growth apparatus of the embodiment illustrated in FIGS. 7 to 9 has a predetermined distance from the single crystal body portion in which the auxiliary heat shield is grown, including an auxiliary control unit for controlling the auxiliary heat shield and a main control unit for controlling silicon single crystal pulling. Ascending speed can be controlled.

In addition, the auxiliary heat shield and the silicon single crystal body part controlled to maintain a constant distance control the crystal defect area by reducing the difference in the cooling rate at the center and the outer edge of the cut surface of the body perpendicular to the upward direction of the auxiliary heat shield. Can increase the distribution of defect free areas.

Hereinafter, an embodiment of a silicon single crystal growth method using the silicon single crystal growth apparatus of the above-described embodiments will be described.

In the following description of the embodiment, the content overlapping with the above-described embodiment of the single crystal growth apparatus will not be described again, and the description will be mainly focused on differences.

One embodiment of the silicon single crystal growth method in a silicon single crystal growth apparatus comprising a chamber, a crucible disposed in the chamber to receive the silicon melt, a heat shield disposed in the chamber and an auxiliary heat shield disposed above the crucible and movable up and down A method of growing a silicon single crystal, the step of controlling the rising speed of the auxiliary heat shield so that the auxiliary heat shield maintains a constant distance from the body portion of the single crystal growing in the silicon melt to increase the defect free area in the single crystal body portion. It may be a single crystal production method.

In the single crystal growth process of the embodiment, the rising speed of the auxiliary heat shield may be controlled so as to reduce the temperature difference between the center of the cut surface and the outside of the body portion perpendicular to the rising direction of the auxiliary heat shield.

In addition, the ascending speed of the auxiliary heat shield may be controlled to reduce the difference between the cooling rate at the center and the outside of the cut surface of the body portion, for example, may be controlled such that the difference in the cooling rate is less than 1K / cm. .

That is, in the case of the embodiment, the rising speed of the auxiliary heat shield disposed on the top of the crucible is controlled to block the heat lost from the melt when the body of the single crystal grows, and to prevent rapid cooling of the single crystal, thereby preventing the rapid cooling of the single crystal between the center and the outer region of the cross section. It is possible to reduce the temperature difference and the temperature gradient difference in the axial direction.

Therefore, since the difference in the temperature gradient is reduced, the distribution of defect regions in the radial direction of the single crystal can be made uniform, and a defect free region can be formed from the beginning of the body portion by adjusting the temperature gradient. There is an effect that can increase the proportion of the defect free area in.

The auxiliary heat shield may be controlled to have a rising speed so as to have a gap disposed 150 mm to 300 mm above the boundary of the shoulder portion and the body portion of the single crystal ingot.

In addition, the ascending speed of the auxiliary heat shield can be controlled when the length of the body portion is 400 mm or less.

When the length of the body portion is larger than 400mm, the crystal growth in the body portion is more affected by the water cooling pipe disposed in the upper region of the chamber than the heat insulation effect by the auxiliary heat shield, so that the single crystal using the auxiliary heat shield is determined. Control of the defect area can be more effective when the auxiliary heat shield is located between the surface of the silicon melt and the water cooling tube.

That is, since the auxiliary heat shield passes through the water cooling tube, the effect of controlling the rising speed of the auxiliary heat shield to adjust the crystal defect region in the single crystal can be reduced.

Another embodiment of the silicon single crystal growth method includes a chamber, a crucible disposed within the chamber to receive the silicon melt, a heat shield disposed within the chamber, and an auxiliary heat shield disposed on the top of the crucible and capable of vertically moving up, a single crystal grown from the silicon melt. Checking the body length of the single crystal grown by the silicon single crystal growth method performed in the silicon single crystal growth apparatus including the main control unit controlling the speed and the auxiliary control unit controlling the rising speed of the auxiliary heat shield. The method may include determining whether the auxiliary heat shield is operated by the auxiliary controller.

10 is a flowchart illustrating a silicon single crystal growth method according to an embodiment.

For example, the flowchart of the silicon single crystal growth method illustrated in FIG. 10 may be a diagram illustrating a step in which the single crystal pulling speed and the rising speed of the auxiliary heat shield are controlled by the main controller and the auxiliary controller.

Referring to FIG. 10, an embodiment of the silicon single crystal growth method may include checking the length of the grown single crystal body portion and determining whether the checked body portion length is 400 mm or less (S1000).

When the length of the body portion is 400 mm or less, in the silicon single crystal growth method, the pulling of the single crystal ingot may be controlled by the main controller, and the operation of the auxiliary heat shield may be controlled by the auxiliary controller.

At this time, the step of controlling the operation of the auxiliary heat shield by the auxiliary control, the step of checking the position of the body portion and the location of the auxiliary heat shield and calculates the gap value (Gap) of the body portion and the auxiliary heat shield according to the identified position. Step S1310, determining whether the calculated separation interval value is within a target interval value (S1330), and generating a rising speed correction value when the auxiliary heat shield is out of the range of the separation interval target interval value (S1350). And raising the auxiliary heat shield according to the generated rising speed correction value (S1370).

At this time, the target spacing value of the body portion and the auxiliary heat shield may be 150mm to 300mm. That is, the distance from the boundary of the shoulder portion and the body portion of the growing single crystal to the lower surface of the auxiliary heat shield may be maintained at a target value of 150 mm to 300 mm.

In addition, in the step of the operation of the auxiliary heat shield is controlled by the auxiliary control unit, when the separation interval between the body portion and the auxiliary heat shield is included in the range of the target interval value, the auxiliary heat shield is raised without changing the current rising speed It may proceed to S1360.

On the other hand, if the length of the body portion measured in step S1000 of checking the length of the grown single crystal body portion and determining whether the checked body portion length is 400 mm or less is greater than 400 mm, the rising speed of the auxiliary heat shield is greater than the pulling speed of the single crystal. Can be maintained.

That is, the operation of the auxiliary heat shield may include maintaining the pulling speed of the auxiliary heat shield to be higher than the pulling speed of the silicon single crystal (S1210).

For example, in the process after the silicon single crystal is grown to have a body length of 400 mm or more, the rising speed of the auxiliary heat shield can be maintained above the pulling speed of the silicon single crystal to be pulled up regardless of the distance from the body. .

In the embodiment of the silicon single crystal growth method shown in FIG. 10, the pulling speed of the single crystal may be controlled by the main controller.

In the controlling of the pulling speed of the single crystal by the main controller, the sensing of the single crystal diameter in the diameter sensing unit (S1100), calculating an error between the diameter value sensed in the pulling speed determination unit and the target diameter value (S1120), Generating a correction value of the pulling speed from the calculated error (S1140) and pulling the single crystal at the pulling speed converted according to the correction value (S1160).

Therefore, the silicon single crystal growth method of the embodiment shown in FIG. 10 may extract the separation distance value of the body portion and the auxiliary heat shield of the single crystal to control the pulling speed of the auxiliary heat shield and the silicon single crystal therefrom.

In addition, the auxiliary heat shield and the single crystal controlled to maintain a constant interval by the auxiliary control unit controls the crystal defect region by reducing the difference in the cooling rate at the center and the outer edge of the cut surface of the body perpendicular to the upward direction of the auxiliary heat shield. It is possible to increase the distribution of the defect free areas in the body part.

In the single crystal growth apparatus and the growth method of the above-described embodiments, it is possible to expect a heat insulation effect in the initial growth of the single crystal body portion by arranging the auxiliary heat shield. In addition, by minimizing heat dissipation to the top of the crucible at the beginning of growth of the body, reducing the difference in temperature gradients in the axial and radial directions in the center and the outer part of the body, thereby uniformly controlling defect areas of growing crystals and defect areas. Can increase the ratio.

Although the above description has been made based on the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains may not have been exemplified above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

The silicon single crystal growth apparatus and growth method according to the embodiment can be used industrially because it can control the defect area in the body portion of the single crystal and increase the defect area by arranging the auxiliary heat shield at the top of the crucible and controlling the rising speed. There is a possibility.

Claims

chamber;

A crucible disposed within the chamber and containing a silicon melt;

A heater disposed outside the crucible to heat the crucible;

A heat shield disposed in the chamber; And

An auxiliary heat shield disposed above the crucible and capable of vertical movement; Including,

The auxiliary heat shield is disposed on the body portion of the single crystal grown in the silicon melt spaced apart, the rising speed is controlled so that the defect area in the single crystal body portion is increased.
The silicon single crystal growth apparatus of claim 1, wherein the auxiliary heat shield is disposed at a predetermined interval on the body portion, and the predetermined interval is controlled according to growth conditions of the single crystal body portion.
The silicon single crystal growth apparatus according to claim 1, wherein a rising speed of the auxiliary heat shield is equal to a pulling speed of the single crystal.
The silicon single crystal growth apparatus of claim 1, wherein a rising speed of the auxiliary heat shield is controlled to reduce a temperature difference at the center and the outer edge of the body cut surface perpendicular to the rising direction of the auxiliary heat shield.
The silicon single crystal growth apparatus according to claim 1, wherein the ascending speed of the auxiliary heat shield is controlled to reduce a difference in cooling speed at the center and the outer edge of the cut surface of the body portion perpendicular to the rising direction of the auxiliary heat shield.
6. The silicon single crystal growth apparatus of claim 5 wherein the difference in cooling rate is less than 1K / cm.
chamber;

A crucible disposed within the chamber and containing a silicon melt;

A heater disposed outside the crucible to heat the crucible;

A heat shield disposed in the chamber;

An auxiliary heat shield disposed above the crucible and capable of vertical movement;

A main control unit controlling a pulling rate of the single crystal grown in the silicon melt;

An auxiliary control unit controlling a rising speed of the auxiliary heat shield; And

A pulling device for pulling up the single crystal and the auxiliary heat shield respectively according to the control signals input from the main control unit and the auxiliary control unit; Silicon single crystal growth apparatus comprising a.
The method of claim 7, wherein the auxiliary control unit

A position value sensing unit for detecting a position of the body portion of the single crystal and a position of the auxiliary heat shield portion;

A gap calculator configured to calculate a separation distance between the body part and the auxiliary heat shield detected by the position value sensing part;

A correction value generator for generating a correction value of a rising speed of the auxiliary heat shield according to the value output from the gap calculator; And

A first driver for outputting a converted rising speed value corresponding to the generated correction value and transmitting the converted rising speed value to the pulling device; Silicon single crystal growth apparatus comprising a.
The silicon single crystal growth apparatus of claim 8, wherein the correction value generator generates a correction value such that the auxiliary heat shield maintains a predetermined distance from the body portion of the single crystal.
The silicon single crystal growth apparatus of claim 9, wherein the predetermined interval is controlled according to growth conditions of the body portion of the single crystal.
The apparatus of claim 8, wherein the main controller comprises: a diameter sensing unit detecting a diameter of the single crystal;

A pulling speed determining unit which determines a pulling speed of the single crystal corresponding to the diameter value detected by the diameter sensing unit; And

A second driver for outputting the determined pulling speed value and transmitting the same to the pulling device; Silicon single crystal growth apparatus comprising a.
8. The device of claim 7, wherein the pulling device is

A first impression portion connected to an upper surface of the auxiliary heat shield by a first wire; and

A second pulling unit connected to the single crystal by a second wire; Silicon single crystal growth apparatus comprising a.
The silicon single crystal growth apparatus according to claim 2 or 10, wherein the predetermined interval is an interval in which the auxiliary heat shield is disposed 150 mm to 300 mm above the boundary between the shoulder portion and the body portion of the single crystal.
A silicon single crystal growth method performed in a silicon single crystal growth apparatus including a chamber, a crucible disposed in the chamber and containing a silicon melt, a heat shield disposed in the chamber, and an auxiliary heat shield disposed above the crucible and capable of vertical movement. To

And controlling the ascending speed of the auxiliary heat shield to increase the defect area of the single crystal body by maintaining a predetermined distance from the single crystal body grown in the silicon melt.
15. The method of claim 14, wherein the ascending speed of the auxiliary heat shield is controlled to reduce a temperature difference at the center and the outside of the cut surface of the body portion perpendicular to the rising direction of the auxiliary heat shield.
15. The method of claim 14, wherein the ascending speed of the auxiliary heat shield is controlled to reduce a difference in cooling rate at the center and the periphery of the cut surface of the body portion perpendicular to the rising direction of the auxiliary heat shield.
The method of claim 16, wherein the difference in cooling rate is less than 1 K / cm.
The silicon single crystal growth method of claim 14, wherein the auxiliary heat shield is controlled to have a rising speed such that the auxiliary heat shield is disposed 150 mm to 300 mm above a boundary of the shoulder portion and the body portion of the ingot.
15. The method of claim 14, wherein the ascending speed of the auxiliary heat shield is controlled when the length of the body portion is 400 mm or less.
A chamber, a crucible disposed within the chamber and containing a silicon melt, a heat shield disposed in the chamber, and an auxiliary heat shield disposed above the crucible and movable up and down; A main control unit controlling a pulling rate of the single crystal grown in the silicon melt; An auxiliary controller for controlling a rising speed of the auxiliary heat shield; and an pulling device for pulling up the single crystal and the auxiliary heat shield respectively according to control signals input from the main control unit and the auxiliary control unit; In the silicon single crystal growth method performed in the silicon single crystal growth apparatus comprising:

Checking the length of the body portion of the grown single crystal;

Determining whether the auxiliary heat shield is operated by the auxiliary controller according to the identified body length; Silicon single crystal growth method comprising a.
21. The method of claim 20, wherein the auxiliary heat shield is controlled by the auxiliary controller when the body length is 400 mm or less.
The method of claim 21, wherein the operation of the auxiliary heat shield is controlled by the auxiliary controller

Checking the position of the body portion and the position of the auxiliary heat shield;

Calculating a separation distance between the body portion and the auxiliary heat shield from the identified position;

Determining whether the calculated separation interval is a range of a target interval value;

Generating an ascending speed correction value of the auxiliary heat shield when the separation interval is out of a range of the target interval value; And

Raising the auxiliary heat shield according to the generated rising speed correction value; Silicon single crystal growth method comprising a.
The method of claim 21, wherein the operation of the auxiliary heat shield is controlled by the auxiliary controller

Checking the position of the body portion and the position of the auxiliary heat shield;

Calculating a separation distance between the body part and the auxiliary heat shield according to the identified position;

Determining whether the calculated separation interval is a range of a target interval value; And

When the separation interval is within a range of the target interval value, the auxiliary heat shield is pulled up without a change in the ascending speed; Silicon single crystal growth method comprising a.
21. The method of growing silicon single crystal according to claim 20, wherein the rising speed of the auxiliary heat shield is maintained above the pulling speed of the single crystal when the length of the body portion is larger than 400 mm.
21. The method of claim 20, wherein the pulling rate of the single crystal is controlled by the main controller.
The method of claim 20, wherein the pulling speed of the single crystal is controlled by the main controller.

Sensing the diameter of the single crystal in the diameter sensing unit;

Calculating an error between the sensed diameter value and a target diameter value by the pulling speed determiner;

Generating a correction value of the pulling speed from the calculated error; And

Pulling the single crystal ingot at a pulling speed converted corresponding to the correction value; Silicon single crystal growth method comprising a.