KR101331753B1 - Single crystal growing apparatus' eccentric control apparatus and method for it - Google Patents

Abstract

The present invention relates to a device for controlling the eccentricity of a device for single crystal growth and a method thereof capable of preventing a support for a crucible from becoming eccentric when rotating. The present invention provides the device for controlling the eccentricity of a device for single crystal growth comprising a crucible containing silicon solution; a support for supporting the bottom of the crucible; a driving part for transferring a rotational force by gearing with the bottom of the support; a plurality of distance-measuring sensors placed along the circumference of the support so as to measure the eccentricity of the support; and a shifting unit for the driving part which shifts the driving part as far as the eccentricity of the support in a direction to remove the eccentricity of the support. Also the present invention provides the method for controlling the eccentricity of a device for single crystal growth comprising: the first step for rotating the support for a crucible in gear with the driving part; the second step for measuring the eccentricity of the support rotating in the first step; and the third step for shifting the driving part as far as the eccentricity measured in the second step in a direction to remove the eccentricity of the support.

Description

Eccentric Control Device and Method for Single Crystal Growth Device {SINGLE CRYSTAL GROWING APPARATUS 'ECCENTRIC CONTROL APPARATUS AND METHOD FOR IT}

The present invention relates to an eccentric control apparatus and a method of a single crystal growth apparatus capable of preventing the support for supporting the crucible from being eccentric during rotation.

Generally, in a single crystal device for growing a silicon single crystal ingot according to the Czochralski method, polycrystalline silicon is loaded inside the crucible, the polycrystalline silicon is melted by heat radiated from a heater, and then the silicon single crystal ingot is removed from the surface of the silicon melt. To grow.

When growing a silicon single crystal ingot, the crucible is raised while rotating the shaft supporting the crucible so that the solid-liquid interface maintains the same height, and the silicon single crystal ingot is about the same axis as the rotation axis of the crucible in the opposite direction of the crucible rotation. Rotate to and pull up.

As the semiconductor process becomes more sophisticated, more and more high-quality wafers are required, so as to produce high-quality wafers, silicon single crystal ingots must be formed without growth defects.

As an effort to eliminate growth defects, the defect characteristics inside the silicon single crystal ingot are highly sensitive to the growth and cooling conditions of the crystal, so that the type and distribution of growth defects are controlled by controlling the thermal environment near the growth interface.

Therefore, when growing a silicon single crystal ingot, the quality of the silicon single crystal ingot is determined according to the temperature of the silicon melt and the hot zone, and it is necessary to accurately control the temperature of the silicon melt.

In order to accurately measure the temperature of the silicon melt as described above, Korean Laid-Open Patent Publication No. 2003-0040950 discloses a technique provided with a cylindrical water cooling tube located close to the growth interface and a temperature detecting means for detecting the silicon melt temperature. .

However, the prior art as described above affects the diameter or quality of the ingot growing from the melt surface because the melting surface of the crucible is also inclined as the crucible and the support are eccentric during rotation, and the temperature detection is located close to the melt surface. There is a problem that can damage the sensor.

1 is a view showing a part of a single crystal growth apparatus equipped with a temperature sensor according to the prior art.

As shown in FIG. 1, a temperature measuring sensor 4 is provided at a predetermined distance from the outside of the crucible 1, and an elongated shaft support 2 is provided below the crucible 1. (2) The drive part 3 which transmits power to the lower part is provided. Therefore, while the crucible 1 is rotated, while the single crystal ingot is grown, the temperature of the melt can be measured by the temperature measuring sensor 4 and the quality can be controlled based on the measured value.

However, the crucible 1 and the support 2 are eccentric due to structural asymmetry as the load of the crucible 1 increases because the support 2 and the driving part 3 are engaged with a predetermined tolerance. To rotate.

FIG. 2 is a graph illustrating a rotating crucible orbit of the single crystal growth apparatus of FIG. 1, and FIG. 3 is a graph periodically showing a trajectory of a rotating crucible of the single crystal growth apparatus of FIG. 1.

As shown in FIG. 2, the crucible is rotated along an orbit such as an elliptical shape, not an accurate circular motion, and rotates in an eccentric state of about 5.5 mm as shown in FIG. 3.

As described above, the crucible and the support are eccentric during rotation, and since the temperature sensor at the fixed position measures the temperature at the crucible side, it is difficult to accurately measure the temperature as the relative position of the crucible and the temperature sensor is changed. Therefore, there is a problem that it is difficult to accurately control the growth defect of the single crystal ingot.

In addition, controlling the diameter of the single crystal ingot in the production of the single crystal ingot is of the highest priority and belongs to the most basic quality items. However, in the single crystal production method using the Czochralski method, it has a mechanically unstable condition because it solidifies at a constant rate in the liquid silicon melt.

Therefore, in order to control the diameter of the single crystal ingot, it monitors the chord diameter of the single crystal ingot and adjusts the diameter of the single crystal ingot when the deviation is from the target value.In general, the temperature of the silicon melt is changed to adjust the diameter of the single crystal ingot. The horizontal growth rate of the single crystal ingot is changing.

As such, in order to quickly monitor the diameter of the single crystal ingot and to eliminate the deviation, Korean Laid-Open Patent Publication No. 2010-0016851 repeatedly measures the diameter of the single crystal ingot during rotation of the single crystal ingot, and measures the diameter data according to the average. The technology to remove the noise is described. At this time, since the apparatus for measuring the diameter data of the single crystal ingot uses at least one of an infrared sensor, a CCD camera or a pyrometer, it is also possible to measure the temperature of the melt.

The prior art likewise removes the noise of the diameter of the single crystal ingot or the melt temperature by averaging the repeated measurement data, but it also makes it difficult to accurately control the actual measurement data change because it removes the change of the measurement data in the actual direction in addition to the noise. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and provides an eccentric control apparatus and method for a single crystal growth apparatus that can structurally remove an eccentricity of a support for supporting a crucible during rotation. have.

The present invention is a crucible containing a silicon melt; A support for supporting a lower portion of the crucible; A driving unit engaged with a lower portion of the support to transmit a rotational force; A plurality of distance measuring sensors provided around the support and measuring an amount of eccentricity of the support; And driving unit moving means for moving the driving unit by the amount of eccentricity of the support in a direction of eliminating the eccentricity of the support.

In addition, the present invention comprises a first step of the support for supporting the crucible is rotated by the drive unit engaged with it; A second step of measuring an eccentric amount of the support rotated in the first step; And a third step of moving the driving unit in a direction to remove the eccentricity of the support by the amount of eccentricity measured in the second step.

The present invention has the advantage that the eccentricity of the support can be safely removed by measuring the eccentricity of the support for supporting the crucible, and by moving the drive unit for driving the support in the opposite direction of the eccentricity by the eccentric amount.

In addition, the crucible is positioned in place by eliminating the eccentricity of the support during rotation, so that the temperature sensor located around the crucible can accurately measure the temperature of the silicon melt and accurately control the growth defect of the ingot according to the measured temperature value. There is an advantage to this.

In addition, by removing the eccentricity of the support during rotation, the silicon melt surface contained in the crucible is kept horizontal, so that the diameter of the ingot growing from the melt surface can be maintained uniformly, and the diameter measuring sensor located above the crucible is located close to the melt surface. In the diameter of the ingot can be measured accurately, there is an advantage that can accurately control the diameter of the ingot by controlling the growth rate of the ingot or the temperature of the hot zone according to the measured ingot diameter value.

1 is a view showing a portion of a single crystal growth apparatus equipped with a temperature sensor according to the prior art.
FIG. 2 is a graph illustrating a rotating crucible trajectory of the single crystal growth apparatus of FIG. 1. FIG.
3 is a graph showing periodically the trajectory of the rotating crucible of the single crystal growth apparatus of FIG.
4 is a view of a portion of a single crystal growth apparatus according to the present invention.
5 is a view showing the installation position of the distance measuring sensor applied to FIG.
6 shows a first embodiment of the eccentricity removal applied to FIG.
7 shows a second embodiment of the eccentricity removal applied to FIG.
8 shows a third embodiment of the eccentricity removal applied to FIG.
9 is a flow chart illustrating an eccentric control method of a single crystal growth apparatus according to the present invention.

Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. It should be understood, however, that the scope of the inventive concept of the present embodiment can be determined from the matters disclosed in the present embodiment, and the spirit of the present invention possessed by the present embodiment is not limited to the embodiments in which addition, Variations.

4 is a view showing a part of the single crystal growth apparatus according to the present invention, Figure 5 is a view showing the installation position of the distance measuring sensor applied to FIG.

As shown in FIG. 4, the single crystal growth apparatus according to the present invention has a crucible 101, a support table 102, a driving unit 103, a temperature measuring sensor 104, a distance measuring sensor 105, and a driving unit. It is configured to include a vehicle (not shown).

The crucible 101 may be composed of a quartz crucible and a graphite crucible surrounding the crucible, and a silicon polycrystalline raw material is added thereto and then melted as it is heated by a heater. Of course, when the crystal seed is pulled up in the melt, the ingot suspended in the crystal seed grows from the melt surface.

The support 102 is installed to support a lower portion of the crucible 101 and is made of graphite material. At this time, the support 102 is provided long in the vertical direction to match the central axis of the crucible 101, it is installed so as to rotate or move vertically as the crucible (101).

The driving unit 103 is connected to the lower portion of the support 102, and transmits a driving force for rotating or vertically moving the support (102). In this case, the driving unit 103 includes a power transmission structure including several motors, and may be configured in various forms, and thus detailed description thereof will be omitted.

However, the upper end of the driving unit 103 is formed in a kind of axial shape, is configured in the form that can transmit power by engaging the lower end of the support (102). At this time, the assembling projection 102a is provided at the lower end of the support 102, the assembling groove 103a is provided at the upper end of the driving unit 103, and is installed to engage with each other with a predetermined safety tolerance. Of course, although the assembling protrusion 102a and the assembling groove 103a may be assembled and configured in various forms, the assembling protrusion 102a and the assembling groove 103a must be configured to transmit a rotational force or a linear driving force from the driving unit 103 to the support 102. .

The temperature measuring sensor 104 is provided at a position spaced apart from the crucible 101 at a predetermined distance, and outside the chamber (not shown) in which the support 102 and the driving unit 103 are installed, including the crucible 101. It may be provided. For example, the temperature measuring sensor 104 may be configured to sense the temperature with the brightness of the light. However, as the crucible 101 is eccentrically rotated, the distance from the crucible 101 to the temperature measuring sensor 104 changes, and in this case, the temperature value measured by the temperature measuring sensor 104 may change. It is difficult to measure accurately. However, the distance between the crucible 101 and the temperature measuring sensor 104 because it is operated to remove the eccentricity of the crucible 101 and the support 102 by the distance measuring sensor 105 and the drive unit moving means to be described below The interval is kept constant, thereby allowing the temperature measuring sensor 104 to accurately measure the melt temperature on the crucible 101 side.

The distance measuring sensor 105 is provided with a plurality of spaced intervals around the support 102, it is configured to detect the eccentric direction of the support as well as measuring the distance to the support (102). For example, four distance measuring sensors 105a, 105b, 105c, and 105d may be installed at intervals of 90 ° in the circumferential direction of the support 102, and the distance measuring sensors 105a, 105b, 105c, and 105d may be installed. Measures the distance to the support 102 and at the same time to calculate the eccentric distance (h) or the eccentric angle (α), including the eccentric direction by comparing with a preset value.

The driving unit moving means may be configured to move the driving unit 103 according to the eccentric direction, the eccentric distance, and the eccentric angle measured by the distance measuring sensor 105, and the eccentric distance of the driving unit 103 in the opposite direction of the eccentric ( h) or by an eccentric angle α. In this case, the driving unit moving means may be configured to horizontally move the driving unit 103, or may be configured to tilt the driving unit 103 about a reference rotation axis, and may be configured in various ways, so that description of the detailed configuration It will be omitted.

FIG. 6 is a diagram illustrating a first embodiment of the eccentricity removal applied to FIG. 4.

The first embodiment of the drive unit moving means shown in Figs. 4 and 6 is configured to move the drive unit 103 by the eccentric distance h 'in the direction opposite to the eccentricity.

The crucible 101 and the support 102 are located on the reference axis of rotation A, but when structural asymmetry occurs due to the weight of the crucible 101 when the crucible 101 is rotated, the support 102 Since the assembling protrusion 102a is engaged with a predetermined tolerance with respect to the assembling groove 103a of the driving unit 103, the support shaft 102 may be eccentric from the reference rotation axis A even when the supporting unit 102 is connected to the driving unit 103. Will be tilted to B).

In this case, the distance measuring sensors 105 measure the distance to the support 102, and calculate the eccentric direction and the eccentric distance h based on the distance values measured by the respective distance measuring sensors 105. Done.

Subsequently, the driving unit moving means horizontally moves the driving unit 103 by the eccentric distance h 'in the direction opposite to the eccentric from the reference rotation axis A and positions it on the moving shaft C. At this time, the support 102 connected to the driving unit 103 is also horizontally moved by the eccentric distance (h) in the direction opposite to the eccentricity, and the support 102 can be located on the reference rotation axis A again to remove the eccentricity.

FIG. 7 is a diagram illustrating a second embodiment of the eccentricity removal applied to FIG. 4.

The second embodiment of the drive unit moving means shown in Figs. 4 and 7 is configured to tilt the drive unit 103 by the eccentric angle α 'in the opposite direction of the eccentricity.

Similarly, the crucible 101 and the support 102 are located on the reference rotation axis, but when structural asymmetry occurs, even if the support 102 is connected to the driving unit 103 according to engagement with a predetermined tolerance, the reference rotation axis A ) Is inclined from the eccentric shaft (B).

In this case, the distance measuring sensors 105 measure a distance to the support 102 and calculate an eccentric direction and an eccentric angle α based on the distance values measured by the respective distance measuring sensors 105. Done.

Thereafter, the driving unit moving means is inclined by the eccentric angle α 'in the direction opposite to the eccentric from the reference rotation axis A and positioned on the moving shaft C. In this case, the support 102 connected to the driving unit 103 may also be inclined by the eccentric angle α in the opposite direction of the eccentricity, and the support 102 may be located on the reference rotation axis A to remove the eccentricity.

FIG. 8 is a diagram illustrating a third embodiment of the eccentricity removal applied to FIG. 4.

4 and 8 operate similarly to the first embodiment, but the assembling protrusion 102a of the support 102 and the assembling groove of the driving unit 103 are shown. In addition to 103a, a groove 102b and a protrusion 103b are engaged with each other to a predetermined tolerance, and are configured to move the protrusion 103b of the drive unit 103 by an eccentric distance in the opposite direction of the eccentricity.

Of course, the grooves 102b of the support 102 and the projections 103 of the driving unit 103 are larger than a tolerance between the assembling protrusion 102a of the support 102 and the assembling groove 103a of the driving unit 103. The tolerance between the 103b is configured to be smaller, and in the assembling groove 103a of the driving unit 103 with the groove 102b of the support 102 and the protrusion 103b of the driving unit 103 engaged with each other. In the horizontal direction.

As in the first embodiment, when the support 102 is eccentric, the eccentric direction and the eccentric distance are calculated by the measured values of the distance measuring sensors 105, and are engaged with the groove 102b of the support 102. By moving the protrusion 103b of the drive unit 103 by the eccentric distance in the direction opposite to the eccentricity, the eccentricity can be removed and returned to the original position.

9 is a flowchart illustrating an eccentric control method of the single crystal growth apparatus according to the present invention.

As shown in FIG. 4, an eccentric control method is described with reference to FIG. 9 based on a growth apparatus including a crucible 101, a support 102, a driving unit 103, and a distance measuring sensor 105. You can look.

First, the reference distance to the support 102 is measured, and the crucible 101 is rotated (see S1 and S2).

The reference distance may be measured by the ranging sensors 105, but may be set to a pre-input value. Then, when the crucible 101 is rotated, the crucible 101 and the support 102 are inclined so as to be eccentric from the reference rotation axis due to the asymmetry caused by the weight of the crucible 101 or the melt contained therein.

Next, by measuring the distance to the support 102, and comparing the reference distance and the measurement distance to determine whether the eccentricity (see S3, S4).

The ranging sensors 105 are positioned at least four in the circumferential direction, and measure the distance from the position of the ranging sensors 105 to the support 102 and compare these measuring distances with the reference distance. Done. At this time, if the measured distances are the same as the reference distance, it is determined that they are not eccentric, and the measured distances are repeatedly measured and compared. However, if the measured distances are not the same as the reference distance, it is determined as eccentric.

Next, in the case of eccentricity, an eccentric direction, an eccentric distance or an eccentric angle is calculated, and the driving unit is moved in accordance with this calculated value (see S5 and S6).

Since the distance from the distance measuring sensors 105 at different positions in the circumferential direction to the support 102 is measured, an eccentric direction can be calculated according to the position of the distance measuring sensors 105 and the measurement distances. The eccentric distance or the eccentric angle may be calculated by the error of the reference distance and the measurement distances.

The driving unit 103 is moved on the basis of the calculated value. In order to move the support 102 moved in the eccentric direction from the reference rotational axis to the reference rotational axis, the driving unit 102 is moved in the opposite direction from the reference rotational axis. Is moved. That is, when the support 102 moves by the eccentric distance or the eccentric angle from the reference rotation axis in the eccentric direction, the drive unit 103 connected to the support 102 and the shaft by the eccentric distance or the eccentric angle in the opposite direction from the reference rotation axis It works to move.

By repeating the above process, even if the eccentricity of the crucible 101 and the support 102 is generated can be quickly removed. That is, when the crucible 101 is rotated along an eccentric track due to structural asymmetry when the crucible 101 is rotated, an eccentric direction and an eccentric distance with respect to the support 102 supporting the crucible 101. Alternatively, the crucible 101 and the support 102 may be returned to their original positions by immediately detecting the eccentric angle and moving the support 102 by the eccentric distance or the eccentric angle in the opposite direction of the eccentricity in the opposite direction of the eccentricity.

Therefore, even if the crucible 101 is rotated, since it moves in a predetermined position, even if the temperature measuring sensor 105 is installed at a position away from the side of the crucible 101 in order to measure the temperature of the melt, it is possible to accurately measure the temperature value. As a result, the growth defects of the ingot can be controlled to improve quality.

In addition, as the crucible 101 is rotated in an inclined state, the melt surface contained in the crucible 101 is also kept horizontal, so that the diameter of the ingot growing from the melt surface can be uniformly maintained. Furthermore, in order to measure the diameter of the ingot rising from the melt surface, even if the diameter sensor 105 is installed at an oblique position on the upper side of the crucible 101, it can be accurately measured, and the ingot according to the result of comparing the measured diameter value with the target value By controlling the growth rate of the hot zone or the temperature of the hot zone, it can be produced to maintain a uniform diameter even if the ingot grows.

101: crucible 102: support
103: drive unit 104: temperature measuring sensor
105: distance measuring sensor

Claims (9)

Crucibles with silicon melt;
A support for supporting a lower portion of the crucible;
A driving unit engaged with a lower portion of the support to transmit a rotational force;
A plurality of distance measuring sensors provided around the support and measuring an amount of eccentricity of the support; And
Eccentric control device of the single crystal growth apparatus comprising a; drive unit moving means for moving the drive unit by the eccentric amount of the support in a direction to remove the eccentricity of the support. The method of claim 1,
The distance measuring sensor,
At least four or more are installed at predetermined intervals around the support,
Eccentric control device of the single crystal growth apparatus for calculating the eccentric amount of the support in an eccentric distance or an eccentric angle. The method of claim 1,
The driving unit moving means,
Eccentric control device of the single crystal growth apparatus for horizontally moving the drive unit in the opposite direction of the eccentric support. The method of claim 1,
The driving unit moving means,
Eccentric control device of the single crystal growth apparatus for tilting the drive in the opposite direction of the support eccentric. The method of claim 1,
The groove is provided at the bottom of the support,
The upper end of the drive unit is provided with a projection engaging with a predetermined tolerance with the groove of the support,
The drive unit moving means is an eccentric control device of the single crystal growth apparatus for horizontally moving the projections in the drive unit in the direction opposite to the eccentricity of the support. A first step in which a support for supporting the crucible is rotated by a driving unit engaged with the crucible;
A second step of measuring an eccentric amount of the support rotated in the first step; And
And a third step of moving the driving unit in a direction to remove the eccentricity of the support by the amount of the eccentricity measured in the second step. The method according to claim 6,
The second step comprises:
A first process of measuring a distance at least four locations at regular intervals around the support;
And a second step of calculating an eccentric direction and an eccentric distance or an eccentric angle of the support from the distances measured in the first step. The method according to claim 6,
In the third step,
Eccentric control method of a single crystal growth apparatus comprising the step of horizontally moving the drive unit in the opposite direction of the support. The method according to claim 6,
In the third step,
Eccentric control method of a single crystal growth apparatus comprising the step of tilting the drive in the opposite direction of the support.

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