JPH0264089A - Method and device for measuring diameter of single crystal-lifting device - Google Patents

Abstract

PURPOSE:To enable to accurately measure the real diameter of a single crystal by carrying out the correction of a measured visual field with a preliminarily measured transfer distance when the diameter of the single crystal is measured with a TV camera. CONSTITUTION:The passage of a seed crystal 1 is detected with a seed sensor 3 while the seed crystal 1 is moved down toward a melted liquid 2. It is detected with a seed crystal melted liquid contact-detecting sensor 4 that the seed crystal 1 contacts with the melted liquid 2 and a transfer distance L between the seed sensor 3 and the melted liquid 2 is measured with a single crystal transfer length-measuring member 5. The seed crystal 1 is lifted to form the single crystal and the diameter of the single crystal is measured with a diameter- measuring TV camera 6 at a distance L1 with the contacting point of the seed crystal 1 on the surface of the melted liquid 2. The real distance L1' is determined from the standard distance L between the seed sensor 3 and the surface of the melted liquid 2, the standard distance L1 between a contacting point of the melted liquid 2 with the seed crystal 1 on the surface thereof and the TV camera 6 and an angle theta between the L line and the L1 line. When the imaged visual field dimension of the TV camera 6 in the time of L1 is A, the real imaged visual field A' is determined with a function F(L1), thereby measuring the real diameter dimension of the single crystal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a single crystal pulling device for producing a single crystal by pulling a seed crystal from a melt, and in particular to a single crystal pulling device that produces a single crystal by pulling a seed crystal from a melt. The present invention relates to a method and apparatus for measuring.

[Conventional technology]

The conventional method is explained with reference to the drawings.
As shown in the figure, the seed crystal 1 is lowered toward the melt 2, and during the descent of the seed crystal 1, the passage of the seed crystal is detected by the seed sensor 3, and the seed crystal 1 detects that the seed crystal 1 has contacted the melt 2. The crystal movement length measurement unit 5 calculates the movement distance between the seed sensor 3 and the liquid surface of the melt 2 based on the detection signal of the seed sensor 3 and the detection signal of the contact detection sensor 4, which is detected by the melt contact detection sensor 4. A single crystal is generated by pulling up the seed crystal 1, and the diameter of the single crystal is
The distance L between the contact point of the seed crystal 1 and the surface of the melt 2 is measured by the TV camera 6 for measuring the diameter.

[Problem to be solved by the invention]

However, in the conventional method described above, the dimensions measured with respect to the sampling line for measuring the diameter as shown in Figure 3 were measurements on the outside of the ring formed between the grown single crystal and the melt 2. However, the actual dimensions of a single crystal are relative, and the field of view imaged at this time does not have a 1:1 ratio with the imaged field, so there is a problem that it is often inaccurate. there were.

[Means to solve the problem]

In order to solve the above-mentioned problems, the method of the present invention lowers the seed crystal 1 toward the melt 2 as shown in the first and second figures, and detects the passing of the seed crystal 1 by the seed sensor 3 during the descent of the seed crystal 1. The seed crystal melt contact detection sensor 4 detects that the seed crystal 1 has come into contact with the melt 2, and the seed sensor 3 The movement distance L' between the surface of the melt 2 and the liquid surface of the melt 2 is measured by the single crystal movement length measurement unit 5, and the movement distance L' between the seed crystal I
The diameter of the single crystal is measured by the diameter measurement TV camera 6 at a distance L+ from the contact point of the seed crystal 1 on the surface of the melt 2, and the diameter of the single crystal is measured by the seed sensor 3.
The standard distance between the surface of the melt 2 and the liquid surface of the melt 2 is L, and the standard distance between the contact point of the liquid surface of the melt 2 with the seed crystal 1 and the TV left camera is L.
,, Determine the actual distance L,' by setting the angle between the L line and the L line as θ, and when the imaging field of view dimension of the TV left camera is A when L, the actual distance is calculated using the function F (L1). This method is characterized by determining the imaging field of view A' and measuring the actual diameter of the single crystal.

Moreover, in order to solve the same problem, the device of the present invention has the following advantages:
As shown in the second diagram, a lifting means 7 that lowers the seed crystal 1 into the melt 2 and pulls it up from the melt 2, a seed sensor 3 that detects the passage of the seed crystal 1 during its descent, seed crystal 1
a seed crystal melt contact detection sensor 4 that detects when the seed crystal contacts the melt 2; and a crystal that measures the moving distance L' between the seed sensor 3 and the liquid surface of the melt 2 based on the detection signals of the sensors 3 and 4. A diameter measurement unit that measures the diameter of the single crystal produced by pulling up the seed crystal 1 from the melt 2 at the distance L1 between the movement length measurement unit 5 and the contact point of the seed crystal 1 on the surface of the melt 2. The standard distance between the TV camera 6, the seed sensor 3, and the surface of the melt 2 is L, and the standard distance between the contact point between the surface of the melt 2 and the seed crystal l and the TV left camera is L.

A calculation means for calculating the actual distance US by taking the L line and the angle θ formed by the line, and a calculation means for calculating the actual distance US by using the function F(L,) when the imaging field of view of the TV left camera is A when L is This configuration includes a correction means for determining the field of view A' and determining the actual diameter of the single crystal.

[For production]

With such a method and apparatus, when the diameter is measured by the TV left camera, the measurement field of view is corrected using the travel path ML' obtained previously.

That is, the diameter measurement TV camera 6 detects the melt 2 and the seed crystal 1 on the liquid surface.
The diameter of the single crystal is measured at a distance #L 1 from the contact point. It is assumed that the standard distance and Ll are mechanically determined by the angle θ formed by the two (see FIG. 2). Since the actual distance L' moved is determined by the crystal movement length measuring section 5, if θ is fixed, the actual distance L' of the seed crystal 1 on the surface of the melt 2
The distance L, / between the contact point and the TV camera 6 can be determined.

Now, when the imaging field of view of the TV camera 6 at the time of L is A, if L, / is found, the actual imaging field of view A' can be calculated using the function F(Lt) (a function that depends on t, ). Since this can be determined, the actual diameter of the single crystal can be measured correctly.

〔Example〕

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is an explanatory diagram showing the configuration of an apparatus for carrying out the method of the present invention.

In Fig. 1, 1 is a seed crystal, and 7 is a melt 2 of this seed crystal l.
3 is a seed sensor that detects the passing of the seed crystal 1 during its descent; 4 is a sensor that detects that the seed crystal 1 has come into contact with the melt 2; This is a seed crystal melt contact detection sensor.

5 is the seed sensor 3 based on the detection code of the sensors 3 and 4 above.
and a crystal movement length measurement encoder 6 that measures the moving distance L' of the liquid surface of the melt 2, and 6 indicates the diameter of the single crystal produced by pulling up the seed crystal l from the melt 2. There is a camera on the left side of the TV for measuring the diameter at a distance L from the contact point of the crystal l.

In the device of the present invention, in such a configuration, the standard distance between the seed sensor 3 and the liquid surface of the melt 2 is L, and the seed crystal l on the liquid surface of the melt 2.
Let L be the standard distance between the contact point and the TV camera 6.
A calculation means (not shown) that calculates the actual distance L,1 by setting the angle θ between the L line and the L1 line, and a function F(L1
) is provided with a correction means (not shown) for determining the actual imaging field of view A' and determining the actual linear dimension of the single crystal.

At the time when the diameter is measured by the TV camera 6, the measurement field of view is corrected using the previously determined moving distance L'.

That is, the TV left camera for diameter measurement is the seed crystal l on the melt 2 liquid surface.
The distance between the point of contact and the diameter of the single crystal is measured.

It is assumed that the standard distance and Ll are mechanically determined by the angle θ formed by the two (see FIG. 2). Since the actual distance L' moved is determined by the crystal movement length measurement unit 5, if θ is fixed, the distance ML between the actual contact point of the seed crystal l on the surface of the melt 2 and the TV camera 6 is ML, ' can be found.

Now, when the size of the imaging field of view of the TV camera 6 at 110 o'clock is A, if 1.1 is found, the actual imaging field of view A' can be found using the function F(L1) (a function that depends on L). The actual diameter of the single crystal will be measured correctly.

FIG. 3 shows an example of a screen imaged by the TV camera 6. As shown in FIG. According to the present invention, the relationship between the imaged screen and the imaged object can be corrected to a ratio of 1:1 using the method described above. Further, by measuring the dimensions B1°B2 of only the ring and subtracting B+ and Bg from the ring outer measurement value α, the actual diameter of the single crystal can be accurately determined.

〔Effect of the invention〕

As described above, according to the present invention, the single crystal pulling device that generates a single crystal by pulling the seed crystal l above the liquid surface of the melt 2 can be operated automatically (unmanned) without human intervention, and can be reproduced. Not only can a single crystal with a certain diameter be grown, but also the absolute dimensions of the single crystal can be accurately measured.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of an apparatus for carrying out the method of the present invention, FIG. 2 is an explanatory diagram of the method of the present invention, and FIG. 3 is a diagram showing an example of an image taken by a TV camera according to the present invention. It is. 1... Seed crystal, 2... Melt, 3...
... Seed sensor, 4 ... Seed crystal melt contact detection sensor, 5 ... Crystal movement length measuring section (encoder), 6 ... TV left camera for diameter measurement 7...
...Elevating means. Answer 1 figure

Claims (2)

[Claims] (1) The seed crystal 1 is lowered toward the melt 2, and the seed sensor 3 detects the passage of the seed crystal 1 during the descent of the seed crystal 1, and the seed crystal 1 detects that the seed crystal 1 has come into contact with the melt 2. The moving distance L between the seed sensor 3 and the liquid surface of the melt 2 is determined by the detection signal of the seed sensor 3 and the detection signal of the contact detection sensor 4, which are detected by the melt contact detection sensor 4.
' is measured by the single crystal movement length measurement unit 5, a single crystal is generated by pulling up the seed crystal 1, and the diameter of the single crystal is determined by the distance L_1 from the contact point of the seed crystal 1 on the surface of the melt 2. Measured by the measurement TV camera 6, the standard distance between the seed sensor 3 and the liquid surface of the melt 2 is L, and the standard distance between the contact point of the liquid surface of the melt 2 with the seed crystal 1 and the TV camera 6. L_
1. Determine the actual distance L_1' by setting the angle between the L line and the L_1 line as θ, and calculate the TV camera 6 when L_1.
1. A method for measuring the diameter of a single crystal pulling apparatus, characterized in that when the imaging field of view size A is , the actual diameter of the single crystal is measured by determining the actual imaging field of view A' using a function F(L_1). (2) A lifting means 7 that lowers the seed crystal 1 into the melt 2 and pulls it up from the melt 2, a seed sensor 3 that detects passage of the seed crystal 1 during its descent, and a seed crystal 1 a seed crystal melt contact detection sensor 4 that detects when the seed crystal contacts the melt 2; and a crystal that measures the moving distance L' between the seed sensor 3 and the liquid surface of the melt 2 based on the detection signals of the sensors 3 and 4. For diameter measurement, which measures the diameter of the single crystal produced by pulling up the seed crystal 1 from the melt 2 at the distance L_1 between the moving length measurement unit 5 and the contact point of the seed crystal 1 on the surface of the melt 2. The standard distance between the TV camera 6, the seed sensor 3 and the liquid surface of the melt 2 is L, the standard distance between the contact point between the melt 2 liquid surface and the seed crystal 1 and the TV camera 6 is L_1, and the L line and L_1 A calculation means for determining the actual distance L_1' by setting the angle θ between the lines, and L_
1, when the imaging field of view of the TV camera 6 is A, the actual imaging field of view A' is determined by the function F(L_1), and the single crystal pulling device comprises a correction means for determining the actual diameter of the single crystal. Diameter measuring device.