JP2000239093A - Method and apparatus for detecting deflection of single crystal ingot in semiconductor single crystal puller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for detecting the deflection of a single crystal ingot, always monitoring the deflection of the ingot, capable of automatically detecting the deflection when it occurred and capable of building a system with an inexpensive two-dimensional CCD camera available at stores or the like. SOLUTION: This apparatus 2 for detecting the deflection of a single crystal ingot 3 in a single crystal puller 1 using the CZ method consists of the following two components: (1) a two-dimensional CCD camera 201 which photographs a monitoring area beforehand set for detecting the deflection at a defined position containing one or both of a single crystal ingot 3 in a crucible 101 and a semiconductor melt surface 107 in its vicinity, and (2) an image processor 202 which converts a photographing image photographed with the CCD camera into a black-and-white binary image, counts the number of picture elements of white pixels and/or black ones in a monitoring area of the converted binary image and detects the deflection of the single crystal ingot by the change of the number of counted white pixels or black ones.

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 detecting a deflection of a single crystal ingot in a semiconductor single crystal pulling apparatus by the CZ (Czochralski) method.

[0002]

2. Description of the Related Art As a semiconductor single crystal manufacturing apparatus, a single crystal pulling apparatus utilizing the CZ method is known. In this method, for example, in the case of a silicon semiconductor, for example, rod-shaped polycrystalline silicon crushed into small pieces is put into a quartz glass crucible and melted, and becomes a crystal growth nucleus on the silicon melt surface. A single crystal is grown from the tip of the seed crystal by hanging the seed crystal (seed) with a wire, immersing the wire, and pulling up the seed crystal while slowly rotating it. In such a single crystal pulling apparatus utilizing the CZ method, the growing single crystal ingot is pulled while being slowly rotated while being suspended at the tip of the wire. The ingot may run out.

[0003] When the ingot is deflected, the crystal is bent or displaced, which causes defective products. In addition, when the run-out increases, the swinging ingot comes into contact with the quartz glass crucible to damage the crucible, and the silicon melt in the crucible may leak out, or the ingot may fall. In addition, reduction in yield, loss of production time due to re-melting (melt back) and re-pulling,
Causes energy loss such as electric power. in this way,
The deflection of the ingot during pulling of a single crystal is an important issue not only in crystal quality and yield but also in terms of safety.

The following are conceivable causes of the shake. (1) When the rotation speed of the ingot during pulling is inappropriate and resonates with the single crystal pulling system. (2) When the seed mounting part is eccentric. (3) When the pulling wire is plastically deformed. (4) When the center of rotation of the lifting wire is misaligned (5) When there is a misalignment between the lifting wire and the center of rotation of the crucible (6) The evacuation of the vacuum pump deteriorates and the inertness in the vacuum chamber is reduced. When the flow of gas (argon gas) changes and the lifting wire starts to swing

[0005] Of the above causes, (1) can only be solved by changing the number of revolutions. In the case of (4), (5), and (6),
If pulling of a single crystal has already started, it cannot be corrected. Therefore, there is no other choice but to reduce the rotational speed to reduce the run-out. (2) In the case of (3), the isolation valve (partition valve) between the chamber in which the crucible is housed and the lifting chamber above the chamber is closed,
The operation can be continued by returning the pulling chamber to the atmospheric pressure and adjusting or replacing the wire. However, since (2) and (3) are mostly known before the start of crystal pulling, (1)
(4), (5) and (6) are mostly.

[0006] As a conventional method of detecting the shake of an ingot, the simplest method employs a method in which an operator visually monitors the state of the ingot. With this method, if you confirm that the ingot has run out,
The operator has taken measures such as changing the rotation speed of the ingot to eliminate the deflection of the ingot and to prevent the bending and dislocation of the ingot. If dislocations or the like are unavoidably generated, the raised ingot is re-pulled by re-melting (melt back).

Further, Japanese Patent Application Laid-Open No. 63-170296 discloses that
Using a one-dimensional CCD camera in which pixels are arranged in a line, a high-luminance band-like ring (meniscus) generated at the contact boundary between the ingot and the silicon melt surface is photographed, and the high luminance at the left and right edges of the ingot body is photographed. A method of automatically detecting ingot run-out from a change in the distance between sets is shown.

[0008]

However, the above-described conventional shake detection method has the following problems. That is, since it takes several tens of hours to pull up a single crystal, in the case of visual monitoring, it is inevitable to perform patrol monitoring with a fixed time interval, and the occurrence of ingot swing and the monitoring timing did not match. In such a case, the worker will be left unaware of this, and in the meantime, bending and dislocation of the crystal will occur, causing a decrease in yield, a loss of production time due to re-melting and re-pulling, and an energy loss such as electric power. Will be.

In the case of visual monitoring, the burden on the operator increases, and the judgment criteria by the operator vary, making it difficult to standardize. In order to solve such a problem, it is necessary to be able to continuously monitor without manual operation and to automatically detect and notify when an ingot shakes.

On the other hand, in the case of the detection method disclosed in Japanese Patent Application Laid-Open No. 63-170296, it is necessary to take an image such that the right and left meniscus portions of the body of the ingot are simultaneously included in one screen. A dedicated one-dimensional CCD camera in which a large number of pixels are arranged in a line in the left-right direction so that the entire body portion and the silicon melt surface outside thereof can be photographed at a time is required, and the apparatus becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and constantly monitors the vibration of an ingot.
If a run-out occurs, it can be automatically detected,
It is an object of the present invention to provide a method and an apparatus for detecting a shake of a single crystal ingot, which can construct a system using a commercially available inexpensive two-dimensional CCD camera or the like.

[0012]

In order to achieve the above object, the present invention provides a method for detecting run-out in a crucible at a predetermined position including at least one of a single crystal ingot and a semiconductor melt surface in the vicinity thereof. After setting a monitoring area for shake detection in advance, shooting the monitoring area by an imaging unit, and converting a captured image of the monitoring area into a black and white binary image,
Using the converted binary image, count the number of one or both of white pixels and black pixels in the monitoring area,
The shake of the single crystal ingot is detected from the change in the counted number of white pixels or black pixels. Preferably, a two-dimensional CCD camera is used as the imaging means.

With this configuration, the ingot shake can be automatically detected from a change in the number of white pixels or black pixels in the monitoring area. For this reason, visual monitoring by the operator can be eliminated. In addition, shake detection can be performed using a commercially available inexpensive two-dimensional CCD camera.

Further, the shake detecting apparatus according to the present invention includes a monitoring area for detecting shake set in advance at a predetermined position including at least one of the single crystal ingot in the crucible and the semiconductor melt surface in the vicinity thereof. An imaging unit that captures an image, and convert the captured image captured by the imaging unit into a black and white binary image, and determine the number of one or both of white pixels and black pixels in the monitoring area in the converted binary image. And an image processing device for counting the change in the number of white pixels or black pixels and detecting the shake of the single crystal ingot. Preferably, a two-dimensional CCD camera is used as the imaging means.

With such a configuration, it is possible to obtain a single crystal ingot shake detecting device capable of automatically detecting the shake of the ingot from the change in the number of white pixels or black pixels in the monitoring area. Further, since a commercially available inexpensive two-dimensional CCD camera can be used as the imaging means, the cost of the apparatus can be reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a CZ type silicon single crystal pulling apparatus provided with an ingot deflection detecting apparatus according to the present invention, and FIG. 2 is a diagram showing a circuit example of the image processing apparatus in FIG.

In FIG. 1, 1 is a CZ type silicon single crystal pulling apparatus (hereinafter abbreviated as "single crystal pulling apparatus"), and 2 is a single crystal ingot shake detecting apparatus according to the present invention (hereinafter, "shake detecting apparatus"). 3 is an ingot of a silicon single crystal grown from a seed crystal.

The single crystal pulling apparatus 1 comprises a crucible 1 made of quartz glass heated by a graphite heater (not shown) or the like.
01 is surrounded by a vacuum container 102. At the upper end of the neck of the vacuum vessel 102, a crystal rotating / elevating mechanism 1 composed of a motor, a hoisting drum, etc.
03 is installed. A seed crystal (not shown) serving as a nucleus for crystal growth is suspended by being held by a seed chuck or the like at the tip of a stainless steel or tungsten wire 104 connected to the crystal rotating / elevating mechanism 103. The crystal rotating / elevating mechanism 103 is configured to freely rotate / elevate.

The crucible 101 is installed on a crucible rotating / elevating mechanism 105, and is configured to freely rotate / elevate the entire crucible. Vacuum vessel 102
A viewing window 106 made of transparent quartz glass is provided on the shoulder of the camera, and a two-dimensional CCD camera 201, which will be described later, is installed toward the inside of the crucible 101 in this window portion. Reference numeral 107 denotes a melt surface of the silicon melted in the crucible 101.

The shake detecting device 2 includes a two-dimensional CCD camera 201 for photographing the inside of the crucible 101 from the viewing window 106, an image processing device 202 for detecting the shake of the ingot 3 when the single crystal is pulled up by image processing, and a monitor television 20.
3. It comprises a buzzer 204 and an indicator light 205 as alarm means.

The image processing device 202 includes a two-dimensional CCD camera (imaging means) 201 as shown in FIG.
To convert the image taken by the camera into a black and white binary image 2
A value image conversion unit 206, a black pixel counting unit 207 that counts the number of black pixels in a preset monitoring area in the converted binary image, and the counted number of black pixels is preset. A shake determination unit 2 that determines that a shake has occurred in the ingot 3 when it deviates from a pixel number range serving as a comparison reference.
08 and a signal output unit 209 that outputs a detection signal indicating the occurrence of a shake in accordance with the determination result of the shake determination unit 208. The image processing apparatus 202 may be configured as software on a program using a personal computer or the like, or may be configured as a dedicated hardware circuit.

First, before describing the details of the shake detecting operation by the shake detecting apparatus 2 of the present invention, the single crystal pulling operation of the single crystal pulling apparatus 1 will be briefly described.

The rod-shaped polycrystalline silicon as a raw material is put into a crucible 101 crushed in a block shape and melted by heating with a graphite heater (not shown).
The seed crystal is held at the tip of the wire 104 by a seed chuck (not shown) or the like, and is suspended in the crucible 101.

In this state, when the production of a silicon single crystal is started, the wire 10 is moved by the crystal rotating / elevating mechanism 103.
4 is lowered downward, the tip of the seed crystal suspended from the tip of the wire 104 is immersed in the silicon melt surface 107 in the crucible 101, and the crystal rotating / elevating mechanism 103 and the crucible rotating / elevating mechanism 105 Is started, the seed crystal and the crucible 101 are slowly pulled toward the opposite direction at a predetermined speed, and the pulling is started. As a result, the seed step is started, and the growth of the single crystal starts from the tip of the seed crystal.

At the point when the single crystal has grown to some extent from the tip of the seed crystal, the process shifts to a neck step in order to eliminate dislocation of the single crystal, and pulls up while narrowing down the diameter of the growing crystal. Then, after raising the predetermined distance with a small diameter,
The process shifts to a body process for stably growing a large-diameter single crystal as a product, and the large-diameter grown ingot 3 is slowly pulled up. The runout detection device 2 of the present invention constantly monitors the runout of the ingot when pulling a single crystal in such a single crystal manufacturing process, and automatically detects and issues an alarm when runout occurs in the ingot. It was done.

Next, the operation of the shake detecting device 2 will be described with reference to FIGS. FIG. 3 is an explanatory view of a monitoring area for monitoring ingot shake, FIG.
FIG. 3 is a diagram showing an example of a black and white binary image of an ingot and a silicon melt surface in a monitoring area.

At the time of the above-mentioned single crystal pulling operation, a two-dimensional CCD camera 201 captures an image of a predetermined area in the crucible including a monitoring area 4 (see FIG. 3) for monitoring the run-out which is set in advance from the viewing window 106. , And sends the photographed image to the image processing device 202. In the case of this embodiment, the monitoring area 4 is set at a position where the right edge of the ingot 3 and the silicon melt surface 107 near the right edge simultaneously enter the same screen.

The binary image converter 20 of the image processing device 202
6 converts the captured image signal sent from the two-dimensional CCD camera 201 into a digital signal, and then converts it into a monochrome binary image at a predetermined threshold level (threshold). The captured image converted to the black and white binary image is sent to the monitor TV 203 and displayed on the screen,
It is sent to the black pixel counting unit 207.

The black pixel counting unit 207 counts the number m (corresponding to the area of the ingot 3) of black pixels existing in the monitoring area 4 from the sent black and white binary image, and determines shake. To the unit 208. The shake determination unit 208 monitors whether or not the counted number m of pixels is out of a preset range of the number of pixels serving as a comparison reference, and determines that a shake has occurred in the ingot 3 when the number of pixels is out of the comparison reference value. judge.

That is, as shown in FIG. 3, the monitoring area 4 is set at a position where the right edge of the ingot 3 and the silicon melt surface 107 near the right edge simultaneously enter the same screen. ing. Therefore, the black-and-white binary image of the monitoring area 4 appears as an image as shown in FIGS.

When the ingot 3 which is pulled up as the crystal grows does not shake, the number of black pixels (the area of the ingot 3) in the monitoring area 4 is small because the ingot 3 does not swing right and left. It remains almost constant and does not change. Meanwhile, ingot 3 being raised
When the shake occurs, the ingot 3 shakes right and left, so that the number m of the black pixels in the monitoring area 4 (ingot 3
4 (a) to 4 (c) changes according to the swing of the ingot 3 as illustrated in FIGS. Moreover,
The degree of this change is proportional to the magnitude of the swing of the ingot 3.

Accordingly, in the present invention, the lower limit L and the upper limit H of the number of black pixels corresponding to the allowable shake range of the ingot 3 are set in advance in the shake determination unit 208 as comparison reference values. The shake determining unit 208 compares the number m of black pixels sent from the black pixel counting unit 207 with the lower limit L and the upper limit H. When the number m of black pixels is between the lower limit L and the upper limit H (L ≦ m ≦ H), the ingot 3
It is determined that no shake has occurred. When the value is smaller than the lower limit L (m <L) or larger than the upper limit H (H <m), it is determined that the ingot 3 has run out, and the determination result is output to the signal output unit. Send to 209.

The signal output unit 209 outputs a detection signal in accordance with the determination result sent from the shake determination unit 208, and when the ingot 3 shakes, for example, sounds the buzzer 204 or turns on the indicator lamp 205. Turns on or emits an alarm to notify the worker. If necessary, the detection signal is sent to a pulling control device (not shown) of the single crystal pulling device 1 and the like, and the operation of the crystal rotating / elevating mechanism 103 or the crucible rotating / elevating mechanism 105 is automatically controlled.

As a measure for preventing a shake when the shake of the ingot 3 is detected, for example, an operator manually operates the crystal rotating / elevating mechanism 103 to cause the ingot 3 to move.
The number of rotations of the ingot 3 is reduced by about 10 rpm from a predetermined number of rotations, or the crystal rotating / elevating mechanism 103 is automatically operated by the above-described pulling control device or the like.
It is sufficient to perform processing such as reducing the rotation speed of about 10 rpm. The automatic operation is particularly effective in the case of a work environment in which the worker does not immediately come.

If the detection signal of the shake detecting device 2 is used, the following application is also possible. That is, in the single crystal pulling, when the crystal changes from a single crystal to a polycrystal during the pulling, and the pulling is performed again, re-melting (melt back) is performed in which the pulled ingot 3 is melted again. . When performing the meltback manually, the state of the meltback can be seen by the operator directly, but when performing the meltback automatically, it is necessary to determine whether or not the meltback is complete. Is difficult.

In such a case, the completion of the meltback can be easily known by detecting the melt bulk using the detection signal of the shake detecting device 2 of the present invention. That is, in the shake detection device 2 of the present invention, the ingot during the meltback is converted to black and displayed, and when the ingot is completely melted, the black portion changes to the same white as the silicon melt surface 107 and the entire screen becomes white. Therefore, by monitoring whether or not the black pixel count value m of the black pixel counting unit 207 has become 0, the completion of the meltback can be automatically known. Further, it is also possible to send the meltback completion signal thus obtained to the pulling control device of the single crystal pulling apparatus 1 to automatically restart the single crystal repulling.

As described above, in the case of the shake detecting device 2 according to the above-described embodiment, the shake of the ingot 3 can be automatically detected. The occurrence timing and the monitoring timing do not coincide with each other, and the operator can immediately take a shake prevention measure. Therefore, it is possible to prevent the occurrence of bending and dislocation of the crystal beforehand, and it is also possible to avoid a decrease in yield, a loss of manufacturing time due to re-melting and re-pulling, and an energy loss such as electric power.

As an image pickup means, Japanese Patent Laid-Open No. 63-1
A dedicated one-dimensional CCD camera in which many pixels are arranged in a line in the left-right direction as used in the detection method of No. 70296 is not required, and a commercially available inexpensive two-dimensional CCD camera can be used. Therefore, the manufacturing cost of the device can be reduced.

In the above description, the case where the portion of the ingot 3 is converted to black and the portion of the silicon melt surface 107 is converted to white is taken as an example. Even if the portion of the silicon melt surface 107 is binary-converted to white and black, the ingot can be detected in the same manner as described above, except that the black and white are reversed. Further, although the case where the monitoring area 4 is set at the right edge (see FIG. 3) of the ingot 3 is taken as an example, the same detection can be made even if the monitoring area 4 is set at the opposite left edge.

The viewing window 10 of the single crystal pulling apparatus 1
If the two-dimensional CCD camera 201 installed at 6 is detachable, and the entire shake detection device 2 including the monitor television 203 is mounted on a movable carriage or the like to be a portable device, the shake detection device is not provided. It can be shared with other single crystal pulling devices. Further, the shake detecting device 2 of the present invention is provided with a silicon melt surface 1 at the time of pulling a single crystal.
It is also possible to apply the present invention to digitization of fluctuation of 07, detection of fluctuation of the liquid surface of various liquids, and the like.

In the above-described embodiment, the number of pixels in the black portion (the ingot 3 portion) in the monitoring area 4 is counted. However, as shown in FIG. 5, the white portion (the silicon melt surface 107) is counted. Alternatively, the number of pixels of the (portion) may be counted.

The location of the monitoring area 4 photographed by the two-dimensional CCD camera 201 is determined by the left edge of the ingot 3 as shown in FIG. 6A or the front of the ingot 3 as shown in FIG. It is good also as a center lower part.

As shown in FIG. 7, not only the ingot 3 and the silicon melt surface 107, but also a part of the furnace fixed object (for example, radiation shield) 5 near the ingot 3 and the silicon melt surface 107 are simultaneously photographed. The number of pixels for the white portion and the black portion may be counted.

As shown in FIGS. 8 (a) and 8 (b), a white portion (silicon melt surface 107) is provided in the monitoring area 4.
Alternatively, an image in which only the black portion (3 ingots) is photographed and only the white portion is captured (FIG. 8A)
In the case of, the number of black pixels appearing due to the shake of the ingot 3 is counted, and an image in which only the black portion is captured (FIG. 8B)
In the case of, the number of white pixels appearing due to the shake of the ingot 3 may be counted.

Further, as shown in FIGS. 9A and 9B, the average value of the change in the number of pixels in the white portion or the black portion is calculated, and when the average value exceeds a specified variation, The determination may be made as occurrence of ingot shake. That is, assuming that the number of pixels in the white portion in FIG. 9A is j and the number of pixels in the white portion in FIG. 9B is k, {(j + k) / 2−j} or {(j + k) / 2
It is determined whether or not the ingot sways based on the value of −k｝. In the case of this method, ingot 3
It is possible to detect the run-out even if the diameter of the is changed. Further, according to this method, the shake can be detected not only at the straight body portion of the ingot 3 but also at the shoulder opening and the tail portion of the ingot 3.

As shown in FIGS. 10 (a) and 10 (b), two two-dimensional CCD cameras 201 are prepared. One of the two cameras has a right edge of the ingot 3 and the other has a left edge of the ingot 3. The edge is photographed and the left and right monitoring areas 4
, The number of pixels in each white portion or black portion is counted, and the positions of the monitoring areas 4 are adjusted so that the number of pixels of the ingot 3 is equal to each other when the ingot 3 does not shake. When the difference exceeds the reference value, it may be determined that a shake has occurred. In the case of this method, as in the case of FIGS. 9A and 9B described above, even if the diameter of the ingot 3 changes during the lifting, it is possible to detect the run-out. In addition, the shake can be detected not only at the straight body portion of the ingot 3 but also at the shoulder opening and the tail portion of the ingot 3.

[0047]

As described above, according to the shake detecting method and apparatus of the present invention, the following excellent effects can be obtained. (1) It is possible to constantly monitor and automatically detect the runout of an ingot in a single crystal pulling process of a semiconductor single crystal apparatus using the CZ method, and furthermore, it is possible to quantify the runout, thereby performing the work. It is possible to eliminate a phenomenon in which the criterion varies depending on the user. (2) Visual monitoring is not required, and labor saving is possible.

(3) By detecting the occurrence of the ingot run-out, manual or automatic intervention can be performed in a timely manner, and it is possible to prevent the occurrence of bending or dislocation of the crystal to thereby lower the crystal quality and yield, and In addition, loss of production time due to re-melting and re-pulling, and energy loss such as electric power can be prevented. (4) By detecting the occurrence of ingot runout,
Manual or automatic intervention is possible at the right time,
It is possible to prevent the ingot from coming into contact with the swaying crucible, damage the crucible, leaking out of the silicon melt therein, or dropping the ingot, thereby improving the safety of operation. (5) Only a part of the ingot, such as the right edge and the left edge of the ingot, needs to be two-dimensionally photographed.
It becomes possible to use a CD camera. Therefore, the manufacturing cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a CZ type silicon single crystal pulling apparatus provided with a single crystal ingot deflection detecting apparatus according to the present invention.

FIG. 2 is a diagram illustrating a circuit example of the image processing device in FIG. 1;

FIG. 3 is an explanatory diagram of a monitoring area for shake detection.

4 (a) to 4 (c) are diagrams showing examples of black and white binary images of an ingot and a silicon melt surface in a monitoring area.

FIG. 5 is a diagram illustrating a second setting example of a monitoring area and a shake determination method.

6A is a diagram illustrating a third setting example of a monitoring area and a shake determination method, and FIG. 6B is a diagram illustrating a fourth setting example of a monitoring area and a shake determination method.

FIG. 7 is a diagram illustrating a fifth setting example of a monitoring area and a shake determination method.

8A is a diagram illustrating a sixth setting example of a monitoring area and a shake determination method, and FIG. 8B is a diagram illustrating a seventh setting example of a monitoring area and a shake determination method.

FIGS. 9A and 9B are diagrams illustrating an eighth setting example of a monitoring area and a shake determination method.

FIGS. 10A and 10B are diagrams illustrating a ninth setting example of a monitoring area and a shake determination method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 CZ type silicon single crystal pulling device 2 Runout detector 3 Single crystal ingot 4 Monitoring area 5 Furnace fixed object 101 Crucible 102 Vacuum container 103 Crystal rotating / elevating mechanism 104 Wire 105 Crucible rotating / elevating mechanism 106 Viewing window 107 Silicon melt Surface 201 Two-dimensional CCD camera (imaging means) 202 Image processing device 203 Monitor television 204 Buzzer 205 Indicator light 206 Binary image conversion unit 207 Black pixel counting unit 208 Shake determination unit 209 Signal output unit

Claims (4)

[Claims] 1. A method for detecting deflection of a single crystal ingot in a semiconductor single crystal pulling apparatus utilizing a CZ method, comprising: a predetermined method including one or both of a single crystal ingot in a crucible and a semiconductor melt surface in the vicinity thereof. A monitoring area for shake detection is set in advance at a position, and the monitoring area is photographed by an imaging unit. A photographed image of the monitoring area is converted into a black-and-white binary image, and the converted binary image is used. Counting the number of one or both of the white pixels and the black pixels in the monitoring area, and detecting a shake of the single crystal ingot from a change in the counted number of white pixels or black pixels. Crystal ingot runout detection method. 2. The method according to claim 1, wherein said imaging means is a two-dimensional CCD camera. 3. A device for detecting deflection of a single crystal ingot in a semiconductor single crystal pulling device utilizing a CZ method, wherein the predetermined position includes one or both of a single crystal ingot in a crucible and a semiconductor melt surface in the vicinity thereof. Imaging means for photographing a monitoring area for shake detection which is set in advance at a position; converting an image photographed by the imaging means into a black-and-white binary image; An image processing device that counts the number of one or both of the pixels and black pixels, and detects a shake of the single crystal ingot from a change in the counted number of white or black pixels. Detector for single crystal ingot. 4. The apparatus according to claim 3, wherein said imaging means is a two-dimensional CCD camera.