JP2000272993A - Method for measuring quake of ingot and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the quake of an ingot in a CZ type semiconductor single crystal pulling device, wherein the method uses a dummy ingot, enables the accurate measurement of the quake width of the ingot by the use of numerical values, and further enables the separated measurements of the quake characteristics at respective processes with the growth of the ingot, and to provide the device therefor. SOLUTION: This device for measuring the quake of the ingot comprises a dummy ingot 7 hung from the tip of a seed wire 2, a laser type transmission type sensor 12, a sensor attaching jig 13 for adjusting the position of the sensor 12, a data-collecting and analyzing member 14 for collecting the detected dummy ingot quake width data and analyzing the prescribed quake characteristics of the ingot from the collected data, and a display 15 for outputting the obtained ingot quake characteristics by a prescribed method in a prescribed form. The dummy ingot is an assembly type ingot which comprises plural small divided blocks, and the small blocks are assembled in response to the shapes of the portions of the practically produced ingot at respective processes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for measuring the deflection of an ingot for a CZ (Czochralski) type semiconductor single crystal pulling apparatus.

[0002]

2. Description of the Related Art For example, in a CZ type silicon single crystal pulling apparatus, it is necessary to precisely control the crystal orientation and cross-sectional shape of a silicon ingot growing from the tip of a seed crystal to obtain a high quality single crystal. , So that the wire axis of the seed wire and the center of rotation of the crucible are exactly aligned,
It is necessary to prevent the silicon ingot suspended at the tip of the seed wire from swinging around the center of rotation of the crucible.

Conventionally, in order to align the center of the seed wire, a pointed conical weight having an appropriate size is hung at the tip of the seed wire, and a diameter corresponding to a permissible error range of the swing width of the seed wire is set. Circle, for example, diameter 2
A paper drawing a circle of about 3 mm is placed on the rotating shaft of the crucible or on the upper surface of the crucible so as to be concentric with the axis of the rotating shaft, and the wire rotating mechanism of the pull head of the CZ type silicon single crystal pulling apparatus is used. The seed wire is rotated at a predetermined speed (5 to 25 rpm), and it is visually checked whether or not the deflection of the tip of the conical weight suspended from the tip of the seed wire is within a circle indicating an allowable error range. It was judged by doing.

[0004]

However, in the case of the above-described conventional method, it is difficult to make an accurate and objective judgment because the judgment of good or bad depends on the visual observation of an operator.
In addition, there has been a problem that the fluctuation width cannot be represented by a numerical value or left as data. There is also a problem that it is not possible to individually measure ingot runout in each process (neck process, crown process, body process, and tail process) accompanying the growth of the ingot.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. In a CZ type semiconductor single crystal pulling apparatus, the swing width of an ingot can be accurately measured by a numerical value, and the growth width of the ingot can be increased. It is an object of the present invention to provide a method and an apparatus for measuring ingot runout using a dummy ingot, which can individually measure runout characteristics in each of the steps (a neck step, a crown step, a body step, and a tail step).

[0006]

In order to achieve the above object, a method of the present invention comprises a CZ type in which a seed wire connected to a pull head is pulled up at a predetermined speed while rotating at a predetermined rotation speed. A method for measuring runout of an ingot for a semiconductor single crystal pulling apparatus, comprising: suspending a dummy ingot having substantially the same shape and weight as an actually manufactured ingot at the tip of said seed wire; While rotating the seed wire at a predetermined speed by the wire rotating mechanism of the pulling head unit of the crystal pulling apparatus, the horizontal swing width of the rotating dummy ingot is detected, and the swing width of the obtained dummy ingot is used as the ingot. Is determined.

Further, the present invention provides an ingot for a CZ type semiconductor single crystal pulling apparatus in which a seed wire connected to a pull head is pulled up at a predetermined speed while rotating at a predetermined rotation speed. A shake measuring device, a dummy ingot having substantially the same shape and the same weight as an actual ingot for hanging at the tip of the seed wire, and a dummy ingot installed in a crucible portion, and measuring a horizontal shake width of the dummy ingot. A shake detecting means for detecting, a position adjusting means for adjusting a position of the shake detecting means, and a swing width data of the dummy ingot detected by the shake detecting means, and a predetermined ingot of the ingot is collected from the collected swing width data. Data collection / analysis means for generating a vibration characteristic and a predetermined vibration characteristic of an ingot obtained by the data collection / analysis means Those constituted by a display unit for outputting in a manner well format.

The dummy ingot used in the runout measuring method and apparatus of the present invention is of an assembling type in which the whole is divided into a plurality of small blocks, and a neck step, a crown step, a body step, and a step of an actually manufactured ingot are performed. It is desirable to combine the small blocks according to the shape of the ingot in each step of the tail step. In addition, as the shake detecting means used in the shake measuring device of the present invention, it is desirable to use a laser transmission type sensor capable of detecting the shake width of the dummy ingot in a non-contact manner.

[0009] In the case of the above configuration, the horizontal swing width of the ingot is accurately measured and recorded as numerical data using a dummy ingot instead of the actually manufactured ingot, and the ingot of the ingot is measured from the measured data. Necessary shake characteristics can be obtained. Therefore, the centering of the seed wire can be performed easily and accurately, and a high-quality ingot can be manufactured.

In the case where a dummy ingot is of an assembling type divided into a plurality of small blocks, a neck step, a crown step,
By combining the small blocks according to the ingot shape in each of the body process and the tail process, it is possible to obtain the runout characteristics in each process accompanying the growth of the ingot, and to manufacture a higher quality ingot. Becomes possible.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of an ingot shake measuring apparatus according to the present invention. FIG. 1 is a longitudinal sectional view showing a main structure of an embodiment, and FIG.
Is a plan view thereof.

In the drawing, reference numeral 1 denotes a pull head of a silicon CZ type semiconductor single crystal pulling apparatus, and a seed wire 2 is provided.
Is connected to a wire pulling mechanism 1b in the pull head unit 1 through the rotary drive shaft barrel 1a of the pull head unit 1 and is slowly pulled up at a predetermined speed, and the servo driver 3, the servo motor 4, and the rotary By rotating the pull head unit 1 by a wire rotating mechanism unit including the encoder 5, the seed wire 2 is configured to be slowly rotated at a predetermined speed.

At the tip of the seed wire 2, a seed chuck 6 is attached.
Dummy head 7 for measuring runout characteristics of ingot
Is to be suspended.

Reference numeral 8 in the drawing denotes a crucible portion of the CZ type silicon single crystal pulling apparatus, which includes a quartz glass crucible body not shown from the inside, a heater 9 for melting silicon, and a heat insulating material 10. , A crucible frame 11 and the like are arranged. A sensor mounting jig 1 is provided on the top surface of the heat insulating material 10.
The laser transmission of the laser transmission type sensor 12 for detecting the swing width of the dummy ingot 7 suspended and rotated by the seed wire 2 is mounted on the sensor mounting jig 13 so as to be detachable. The element 12a and the laser light receiving element 12b are assembled.

The sensor mounting jig 13 is a rectangular frame member 13a (FIG. 2) surrounding the dummy ingot 7.
The laser light emitting element 12a and the laser light receiving element 12b are attached to the left and right vertical pieces 13b and 13c vertically suspended from the lower surface of the frame member 13a.
It is attached so that the position can be adjusted in the direction of the arrow by d and 13e. The scales 13f and 13g are graduated on the feed screw mechanisms 13d and 13e so that the positions can be adjusted accurately.

Reference numeral 12c in the figure denotes a laser drive control unit which drives the laser light emitting element 12a to emit laser light L and changes the amount of light of the laser light L received by the laser light receiving element 12b. From dummy ingot 7
This is a circuit for detecting the swing width of the signal. These laser drive control unit 12c, laser light emitting element 12a, laser light receiving element 12
The laser transmission type sensor 12 is constituted by b.

Reference numeral 14 in the figure denotes a data collection / analysis unit constituted by a personal computer or the like, which collects and records swing width data of the dummy ingot 7 detected by the laser transmission type sensor 12. At the same time, predetermined shake characteristics of the ingot are analyzed based on the collected shake width data. Reference numeral 15 denotes a display unit composed of a printer, a monitor, and the like, which outputs and displays the shake characteristics of the ingot generated by the data collection / analysis unit 14 in a predetermined method and format.

FIGS. 3 and 4 show a detailed structure of the dummy ingot 7 suspended from the seed wire 2. FIG. 3 is a longitudinal sectional view of the dummy ingot, and FIG. 4 is a sectional view taken along line AA in FIG. Dummy ingot 7 in the illustrated example
Represents the entire dummy ingot 7 as a plurality of small blocks 7
1 to 7n, and these small blocks 71 to 7
n are connected by a screw portion 21 and assembled. As a material of this dummy ingot 7,
It is desirable to use aluminum which is close to silicon in specific gravity, excellent in workability and strength, and not so expensive.
In addition, aluminum has a smaller specific gravity than silicon, so it is smaller than the actual silicon ingot.However, the shape and weight of the aluminum are made as same as those of the actually manufactured silicon ingot as much as possible, and the surface is anodized to prevent corrosion. It is desirable to do. Furthermore, in order to ensure safety and enable one-person work,
It is desirable to divide one block into 10 kg or less.

As described above, by forming the dummy ingot 7 into an assembling system including the small blocks 71 to 7n, the silicon ingot in each of the actual single crystal pulling steps (neck step, crown step, body step and tail step) can be obtained. A dummy ingot having substantially the same shape and weight can be easily formed, and the runout characteristics can be measured in a state very close to a silicon ingot actually manufactured.

The two small holes 22 formed in the outer peripheral surfaces of the small blocks 71 to 7n are holes into which a handle 23 for turning and screwing the small blocks during assembly is inserted. It is more desirable to attach a dummy neck portion 24 and a dummy seed crystal portion 25 to the crown portion formed by the uppermost small block 71.

Next, a description will be given of an ingot shake measuring operation in the above apparatus. First, prior to the start of the measurement, the laser mounting jig 13 to which the laser light emitting element 12a and the laser light receiving element 12b are mounted is placed on the top surface of the heat insulating material 13 of the crucible portion 8 and set in a fixed position. The input / output terminals of the light emitting element 12a and the laser light receiving element 12b are connected to the laser drive control unit 12c.

On the other hand, by combining the small blocks 71 to 7n of the dummy ingot 7 shown in FIG. 7 and combining them, a dummy ingot having the same shape as the ingot in the pulling-up step for the purpose of measurement is created. For example,
When it is desired to measure the run-out characteristics of the body process during the pulling-up process, the small block 71 constituting the crown portion and some of the small blocks 72 to 7n-1 constituting the body portion are connected as shown in FIG. A dummy ingot 7 having the same shape as the ingot in the actual body process is created.

After the dummy ingot 7 thus prepared is attached to the seed chuck 6 at the tip of the seed wire 2 and suspended, the wire pulling mechanism 1b of the pull head 1 is driven to wind the seed wire 2. Then, the dummy ingot 7 is lowered and lowered, and as shown in FIG.
It is set so as to be located between a and the laser light receiving element 12b.

Next, by operating the feed screw mechanisms 13d and 13e while looking at the scales 13f and 13g, and adjusting the positions of the laser light emitting element 12a and the laser light receiving element 12b in the direction of the arrow, the outer periphery of the dummy ingot 7 is It is set so as to block a part of the light L, for example, about half.
Note that, in order to easily perform this positioning, it is preferable that the width of the laser beam L in plan view be 10 mm or more. With such a laser beam width, an error in the set position of about 2 to 3 mm does not affect the measurement.

As described above, the dummy ingot 7,
After the laser light emitting element 12a and the laser light receiving element 12b are set at predetermined positions, the seed wire 2 is rotated at a predetermined speed (5 to 25r) by a wire rotating mechanism including a servo driver 3, a servo motor 4, and a rotary encoder 5.
pm) to start measuring the runout characteristics of the ingot.

When the seed wire 2 rotates and the dummy ingot 7 suspended at the tip of the seed wire 2 starts rotating, if the wire axis of the seed wire 2 and the rotation axis of the crucible portion 8 match, Dummy ingot 7 Crucible part 8
It rotates in accordance with the axis of the rotation axis and does not swing in the horizontal direction. Therefore, the laser light L by the dummy ingot 7
Is always constant, and the amount of light received by the laser light receiving element 12b does not change.

On the other hand, when the wire axis of the seed wire 2 does not coincide with the rotation axis of the crucible part 8, the dummy ingot 7 is moved around the rotation axis of the crucible part 8 according to the amount of displacement. It rotates, and the amount of laser light L received by the laser light receiving element 12b changes. This change in the amount of received light is proportional to the amount of shake of the dummy ingot 7, and the amount of shake of the dummy ingot 7, that is, the amount of displacement of the axis of the seed wire 2 can be detected from the change in the amount of received light.

The light receiving signal indicating the amount of shake of the dummy ingot 7 received by the laser light receiving element 12b is sent to the data collecting / analyzing unit 14 composed of a personal computer or the like via the laser drive control unit 12c. Are sequentially sampled and collected and recorded as the swing width data.

The data collection / analysis section 14 uses the collected swing width data of the dummy ingot 7 to determine, for example, the relationship between the time and the deviation from the reference value (center position) as shown in FIG. And a seed wire 2 sent via the servo driver 3
As shown in FIG. 6, a graph showing a change in the rotation time of each rotation of the seed wire as shown in FIG. 6, or a rotation of the seed wire as shown in FIG. A graph or the like showing the change in the rotation time of is created.

The graph data generated by the data collection / analysis unit 14 is sent to the display unit 15 and printed by a printer or displayed on a monitor screen. By looking at the printed characteristic graph and the characteristic graph displayed on the monitor screen, the measurer can numerically accurately determine the amount of deviation between the rotation axis of the seed wire 2 and the rotation axis of the crucible portion 8. You can know. Therefore, accurate centering of the seed wire 2 can be realized, and a high-quality single crystal can be manufactured.

In the above description, the dummy ingot 7
Has been described in the case of assembling into the same shape as the actual ingot in the body process, and measuring the runout characteristics in the body process. However, as shown in FIG. The characteristics can be measured. Further, as shown in FIG. 8 (b), by assembling in the same shape as the Dale process, the deflection characteristics in the tail process can be measured, and each process accompanying the growth of the single crystal can be performed. Can be measured.

In the above-mentioned embodiment, the dummy ingot 7 of the assembling type as shown in FIG. 3 is used. However, without using the assembling type, for example, as shown in FIGS. 9 (a) to 9 (c). First, a dedicated dummy ingot 7 having the same shape as the ingot shape in each of the crown process, the body process, and the tail process is individually prepared, and the runout characteristic is measured using the dedicated dummy ingot for each process. It is also possible to do so.

The material of the dummy ingot 7 is not limited to aluminum, but may be silicon itself. If the specific gravity is close to that of silicon, another material such as synthetic resin may be used. It can be used.

[0034]

As described above, according to the method and apparatus of the present invention, the deflection width of the ingot can be accurately measured by numerical values, so that the deviation of the rotation axis of the seed wire can be accurately and objectively measured. Can be determined. Therefore, the center of the seed wire can be accurately adjusted, and a high-quality ingot can be manufactured.

Further, by using an assembling type dummy ingot in which the whole is divided into a plurality of small blocks and combining these small blocks, a dummy ingot having the same shape as each step of an actually manufactured ingot can be easily formed. Since the ingot can be made, it is possible to individually measure the runout characteristics in each step accompanying the growth of the ingot. For this reason, the runout width can be controlled in any process, and an ingot with more stable quality can be manufactured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main structure of an embodiment of an ingot deflection measuring apparatus according to the present invention.

FIG. 2 is a plan view of the embodiment.

FIG. 3 is a longitudinal sectional view of a dummy ingot.

FIG. 4 is a sectional view taken along line AA in FIG.

FIG. 5: Time and reference value of seed wire (center position)
6 is a graph showing a relationship with a deviation amount from the graph.

FIG. 6 is a graph showing a change in rotation time for each rotation of a seed wire.

FIG. 7 is a graph showing a change in rotation time for each angle during one rotation of a seed wire.

FIG. 8A is an explanatory diagram of a method of measuring a shake characteristic in a crown process, and FIG. 8B is an explanatory diagram of a method of measuring a shake characteristic in a tail process.

FIG. 9 shows another example of the structure of the dummy ingot, and FIG.
Is a diagram showing an example of a dummy ingot dedicated to the crown process,
(B) is a figure which shows the example of the dummy ingot only for a body process, (c) is a figure which shows the example of the dummy ingot only for a tail process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pull head part 2 Seed wire 3 Servo driver 4 Servo motor 5 Rotary encoder 6 Seed chuck 7 Dummy ingot 71-7n Small block 8 Crucible part 12 Laser transmission sensor 12a Laser light emitting element 12b Laser light receiving element 12c Laser drive control part 13 Laser Mounting jig 14 Data collection / analysis unit 14 Display unit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Akio Ima 378 Oguni-machi, Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Toshiba Ceramics Co., Ltd. Toshiba Ceramics Co., Ltd. Oguni Works F-term (reference) 2F065 AA21 CC17 FF02 FF17 FF65 GG06 HH15 PP01 SS11 TT02 4G077 AA02 BA04 EG14 EH00 HA12 PF15

Claims (5)

[Claims] 1. A method for measuring the runout of an ingot for a CZ semiconductor single crystal pulling apparatus, wherein a seed wire connected to a pull head is pulled up at a predetermined speed while rotating at a predetermined rotation speed. A dummy ingot having substantially the same shape and the same weight as an actually manufactured ingot is suspended from the tip of the seed wire, and the seed wire is moved by a wire rotating mechanism of a pull head of a CZ type semiconductor single crystal pulling apparatus. A method for measuring the runout of an ingot, comprising detecting a horizontal runout of a rotating dummy ingot while rotating at a predetermined speed, and obtaining a runout characteristic of the ingot from the obtained runout of the dummy ingot. 2. The method according to claim 1, wherein the dummy ingot is assembled into a plurality of small blocks, and the dummy ingot is formed into a plurality of small blocks. 2. The method according to claim 1, wherein the small blocks are combined. 3. An ingot deflection measuring apparatus for a CZ type semiconductor single crystal pulling apparatus, wherein a seed wire connected to a pull head portion is pulled up at a predetermined speed while rotating at a predetermined rotation speed. A dummy ingot having substantially the same shape and the same weight as an actual ingot for hanging at the tip of the seed wire; and a shake detecting means installed in the crucible portion and detecting a horizontal swing width of the dummy ingot. Position adjusting means for adjusting the position of the shake detecting means; collecting the shake width data of the dummy ingot detected by the shake detecting means; and generating a predetermined shake characteristic of the ingot from the collected shake width data. A data collection / analysis means, and a method and a method for determining a swing characteristic of the ingot obtained by the data collection / analysis means. In deflection measuring device of the ingot being characterized in that a display means for outputting. 4. The dummy ingot is of an assembling type in which the whole is divided into a plurality of small blocks, and is adapted to the ingot shape in each of a neck process, a crown process, a body process, and a tail process of an actually manufactured ingot. 4. The apparatus according to claim 3, wherein the small blocks are combined. 5. The ingot shake measuring device according to claim 3, wherein said shake detecting means comprises a laser transmission type sensor.