JP7359720B2 - Measuring jig and measuring method - Google Patents

Description

The present invention relates to a measuring jig and a measuring method for measuring the gap between the outer surface of a cylindrical quartz crucible with a bottom and the inner surface of a cylindrical graphite crucible with a bottom.

The Czochralski method (hereinafter referred to as "CZ method") is known as a method for producing single crystals. In particular, the CZ method is widely used industrially for many silicon single crystals that are used as materials for semiconductor electronic components. In the CZ method, after melting polycrystalline silicon etc. filled in a quartz crucible with a heater, a seed crystal is immersed on the surface of this silicon melt, and the seed crystal is immersed in the silicon melt while rotating the quartz crucible. This is a method of growing a single crystal with the same crystal orientation as the seed crystal by pulling the crystal upward.

FIG. 4 is a conceptual diagram schematically showing a pulling device used when pulling a single crystal by the above-mentioned CZ method. As shown in FIG. 4, the single crystal pulling apparatus 10 includes a pulling chamber 12, a crucible 13 provided in the pulling chamber 12, a heater 14 disposed around the crucible 13, and rotates and raises and lowers the crucible 13. A crucible holding shaft 15 and its rotation/elevating mechanism (not shown), a seed chuck 17 that holds a silicon seed crystal 16, a wire 18 that pulls up the seed chuck 17, and a winding mechanism that rotates or winds up the wire 18. (not shown). Further, a heat insulating material 19 is arranged around the outside of the heater 14 . Silicon single crystal 20 is pulled up from silicon melt 11 as a raw material by wire 18 .

FIG. 5 shows a crucible 13 placed within the single crystal pulling apparatus 10. As shown in FIG. 5, the crucible 13 includes a bottomed cylindrical quartz crucible 13A that accommodates a raw material melt, and a bottomed cylindrical graphite crucible 13B (referred to as a "carbon susceptor") that accommodates the quartz crucible 13A inside. (for example, Patent Documents 1 and 2).

Japanese Patent Application Publication No. 2010-42968 Japanese Patent Application Publication No. 2014-73925

The quartz crucible 13A is manufactured to a size that can be accommodated inside the graphite crucible 13B, but due to manufacturing errors, the quartz crucible 13A must be manufactured so that the outer surface of the quartz crucible 13A and the inner surface of the graphite crucible 13B are in complete contact with each other. It is difficult. As a result of extensive investigation by the present inventor, it has been found that depending on the location where the outer surface of the quartz crucible 13A and the inner surface of the graphite crucible 13B come into contact, the gap 30 formed when the quartz crucible 13A is installed inside the graphite crucible 13B It has been found that if the quartz crucible 13A becomes unstable and shakes within the graphite crucible 13B, there is a risk of damage when the quartz crucible 13A is installed inside the graphite crucible 13B. In addition, not only does the silicon melt shake and cause surface vibration that makes it difficult to pull the silicon single crystal, but the quartz crucible 13A becomes eccentric when pulling the silicon single crystal, making it impossible to uniformly supply heat to the silicon ingot. It was found that this also leads to quality deterioration of silicon ingots.

To solve the above problems, it is possible to create a crucible 13 with good stability by selecting and combining quartz crucibles 13A and graphite crucibles 13B that are compatible with each other. However, in the past, the only way to find a compatible combination of the quartz crucible 13A and graphite crucible 13B was through trial and error, which was not only extremely inefficient, but also did not necessarily result in a favorable combination.

In addition, contrary to modifying the shape of the outer surface of the quartz crucible 13A to match the shape of the inner surface of the graphite crucible 13B or producing each crucible so as to eliminate the gap 30, it is possible to It is also conceivable to intentionally provide a gap 30 between the crucible 13B and the inner surface of the crucible 13B.

However, in any of the above cases, it is necessary to obtain the distance between the gaps 30, but when the quartz crucible 13A is installed inside the graphite crucible 13B, it is impossible to observe the gaps 30 from the outside. There was a problem in that it was not possible to actually measure the distance of the gap 30 between the outer surface of graphite crucible 13A and the inner surface of graphite crucible 13B.

The present invention was made to solve the above problem, and a cylindrical quartz crucible with a bottom for growing a silicon single crystal ingot by the CZ method is placed inside a cylindrical graphite crucible with a bottom. An object of the present invention is to provide a measuring jig that can easily measure the gap between the outer surface of a quartz crucible and the inner surface of a graphite crucible.

The present invention has been made to achieve the above object, and in order to grow a silicon single crystal ingot by the CZ method, a cylindrical quartz crucible with a bottom is placed inside a cylindrical graphite crucible with a bottom. A measuring jig for measuring the gap interval between the outer surface of the bottomed cylindrical quartz crucible and the bottomed cylindrical inner surface of the graphite crucible, the longitudinal section including the central axis of the graphite crucible. The present invention provides a measurement jig including a gap plate having a cross-sectional shape in which a cross-sectional shape of the inner surface of the graphite crucible is formed in a region including at least the bottom.

According to such a measuring jig, it becomes possible to easily measure the gap between the outer surface of the quartz crucible and the inner surface of the graphite crucible.

At this time, the measurement jig may include a plurality of gap plates, each of which is connected in a cross-like manner at a position corresponding to the central axis of the graphite crucible.

This makes it possible to more easily, stably, and accurately measure the interval between gaps.

At this time, the gap plate may be a measurement jig on which a scale indicating the diameter of the quartz crucible is formed.

This makes it possible to easily measure the gap interval with high positional accuracy.

At this time, when a bottomed cylindrical quartz crucible is placed inside a bottomed cylindrical graphite crucible in order to grow a silicon single crystal ingot by the CZ method, the outer surface of the bottomed cylindrical quartz crucible and A measuring method for measuring the gap between the bottomed cylindrical graphite crucible and the inner surface thereof, using the above-mentioned measuring jig, the cross-sectional shape part of the gap plate is placed on the outer surface of the bottom of the quartz crucible. A conical taper gauge is inserted into the gap between the cross-sectional portion of the gap plate and the outer surface of the quartz crucible, and the conical surface of the conical taper gauge is connected to the cross-sectional portion of the gap plate and the quartz crucible. It is possible to provide a measuring method for measuring the interval of the gap from the contact position between the conical surface of the conical taper gauge, the cross-sectional portion of the gap plate, and the outer surface of the quartz crucible. .

Thereby, the gap between the outer surface of the quartz crucible and the inner surface of the graphite crucible can be easily and accurately measured.

At this time, the measurement method may be such that the opening of the cylindrical quartz crucible with a bottom is placed downward, and the interval between the gaps is measured with the outer surface of the bottom of the quartz crucible facing upward.

Thereby, the distance between the gaps can be easily measured more simply, stably, and safely.

As described above, according to the measuring jig of the present invention, it becomes possible to easily measure the gap between the outer surface of a quartz crucible and the inner surface of a graphite crucible. Further, in the measuring method of the present invention, by performing measurement using the measuring jig of the present invention, it becomes possible to easily measure the gap between the outer surface of the quartz crucible and the inner surface of the graphite crucible.

1 shows a side view and a top view of a measurement jig according to the present invention. A specific example of the measurement jig according to the present invention will be shown. An example of a taper gauge is shown. A conceptual diagram schematically showing a pulling device is shown. The state when a quartz crucible is installed in a graphite crucible is shown.

Hereinafter, the present invention will be explained in detail, but the present invention is not limited thereto.

As mentioned above, when a bottomed cylindrical quartz crucible is placed inside a bottomed cylindrical graphite crucible in order to grow a silicon single crystal ingot by the CZ method, the outer surface of the quartz crucible and the inner surface of the graphite crucible There is a need for a measuring jig and measuring method that can easily measure the gap between the two.

As a result of intensive studies on the above-mentioned problems, the present inventors found that when a bottomed cylindrical quartz crucible is placed inside a bottomed cylindrical graphite crucible in order to grow a silicon single crystal ingot by the CZ method. A measuring jig for measuring the gap between the outer surface of the bottomed cylindrical quartz crucible and the bottomed cylindrical inner surface of the graphite crucible, the measuring jig being a measuring jig for measuring a gap interval between the outer surface of the bottomed cylindrical quartz crucible and the inner surface of the bottomed cylindrical graphite crucible, Among them, the distance between the gap between the outer surface of the quartz crucible and the inner surface of the graphite crucible can be easily determined by a measuring jig including a gap plate having a cross-sectional shape formed with a cross-sectional shape of the inner surface of the graphite crucible in a region including at least the bottom. The present invention was completed based on the discovery that the method can be measured.

This will be explained below with reference to the drawings.

(Measurement jig)
FIG. 1A shows a side view of a measuring jig 1 according to the present invention, and FIG. 1B shows a top view. A measuring jig 1 according to the present invention includes a gap plate 3 having a cross-sectional shape portion 2 in which a cross-sectional shape of the inner surface of the graphite crucible is formed in a region including at least the bottom of a longitudinal section including the central axis of the graphite crucible. It is. It is also effective to form a scale 4 on the gap plate 3 to indicate the diameter of the quartz crucible 13A. With such a gap plate 3, it becomes possible to easily measure the gap interval with high positional accuracy.

The material of the gap plate 3 is not particularly limited. If a highly rigid metal material is used, the thickness of the gap plate 3 can be reduced. It is preferable to use a resin material because there is less risk of metal contamination of the crucible. Moreover, since the gap plate 3 can be made from a lightweight resin material, the workability of the measurement becomes easier. Furthermore, resin materials are advantageous in terms of cost. For example, it is also preferable to use materials such as fluororesins such as Teflon (registered trademark) and polyacetal resins such as Duracon (registered trademark).

The gap plate 3 may be manufactured, for example, by cutting out a material in accordance with the cross-sectional shape of the inner surface of the graphite crucible 13B, or may be manufactured using a so-called 3D printer (layered manufacturing). When producing a gap plate, it is necessary to obtain the cross-sectional shape of the inner surface of the graphite crucible 13B in advance. At this time, it is preferable to obtain the shape data of the inner surface of the graphite crucible 13B using a three-dimensional shape measuring machine because the cross-sectional shape data can also be easily obtained. Then, based on the acquired cross-sectional shape data, the gap plate 3 can be easily manufactured by additive manufacturing. Alternatively, the gap plate 3 can be manufactured by a method of taking a mold of the inner surface of the graphite crucible 13B and forming the cross-sectional shape portion 2 of the gap plate 3 to match the mold.

FIG. 2 shows a specific example of the measuring jig 1 according to the present invention. The measurement jig shown in FIG. 2 is a measurement jig used for a quartz crucible with a diameter of 32 inches (approximately 800 mm), which is made by cutting out a Teflon (registered trademark) plate with a thickness of 3 mm. As shown in FIG. 2, it is preferable that a plurality of gap plates 3 are produced and connected in a cross-like manner so as to be orthogonal to each other at a position corresponding to the central axis of the graphite crucible in each gap plate. In the example of FIG. 2, two gap plates are connected orthogonally. In this way, it can be stably placed on the outer surface of the bottom of the quartz crucible 13A, and even when a large quartz crucible is to be measured, one person can accurately measure it. Although FIG. 2 shows an example using two gap plates, it is of course possible to use three or more gap plates connected. The larger the number of gap plates, the more accurately and easily the gap can be evaluated over the entire crucible.

(Measuring method)
A method of measuring the gap between the outer surface of a cylindrical quartz crucible with a bottom and the inner surface of a cylindrical graphite crucible with a bottom using the measurement jig 1 as described above will be described below.

The cross-sectional shape portion 2 of the gap plate 3 of the measurement jig 1 has a shape that reflects the cross-sectional shape of the inner surface of the graphite crucible 13B, so if the outer surface of the quartz crucible 13A and the inner surface of the graphite crucible 13B do not match, the gap By applying the cross-sectional portion 2 of the plate 3 to the outer surface of the bottom of the quartz crucible 13A, a gap is created between the cross-sectional portion 2 of the measurement jig 1 and the bottom of the quartz crucible 13A. By measuring the interval between these gaps, it is possible to measure the interval between the gaps. At this time, insert a conical taper gauge as shown in FIG. The gap interval can be measured from the contact position between the surface and the cross-sectional shape portion 2 of the gap plate 3 and the outer surface of the quartz crucible 13A. With such a measurement method, the gap between the outer surface of the bottomed cylindrical quartz crucible 13A and the inner surface of the bottomed cylindrical graphite crucible 13B can be measured extremely easily and accurately without requiring any skill. be able to.

Furthermore, when measuring the gap as described above, it is preferable to measure the gap interval with the opening of the bottomed cylindrical quartz crucible facing down and the outer surface of the bottom of the quartz crucible facing upward. . In this way, even if the crucible is particularly large, measurements can be performed more simply, stably, and safely.

According to the measuring jig and the measuring method using the same according to the present invention, it is possible to measure the outer surface of a quartz crucible and the inner surface of a graphite crucible in a pulling device used for pulling a single crystal by the CZ method, which has not been able to be measured so far. It has become possible to measure the gap between the two very easily and accurately. In particular, when a gap is intentionally formed between the outer surface of a quartz crucible and the inner surface of a graphite crucible, the measurement jig according to the present invention can be used to easily and accurately measure the desired gap. A combination of a quartz crucible and a graphite crucible can be obtained.

Note that the present invention is not limited to the above embodiments. The above-mentioned embodiments are illustrative, and any embodiment that has substantially the same configuration as the technical idea stated in the claims of the present invention and has similar effects is the present invention. covered within the technical scope of.

1...Measuring jig, 2...Cross-sectional shape part, 3...Gap plate, 4...Scale,
10... Single crystal pulling device, 11... Silicon melt, 12... Pulling chamber,
13... Crucible, 13A... Quartz crucible, 13B... Graphite crucible, 14... Heater,
15... Crucible holding shaft, 16... Seed crystal, 17... Seed chuck,
18...Wire, 19...Insulating material, 20...Silicon single crystal, 30...Gap.

Claims (5)

The outer surface of the bottomed cylindrical quartz crucible and the bottomed cylindrical quartz crucible when the bottomed cylindrical quartz crucible is placed inside a bottomed cylindrical graphite crucible for growing a silicon single crystal ingot by the CZ method. A measuring jig for measuring the gap between the inner surface and the inner surface of a cylindrical graphite crucible,
A measurement jig comprising: a gap plate having a cross-sectional shape formed in a cross-sectional shape of an inner surface of the graphite crucible in a region including at least a bottom portion of a vertical cross-section including a central axis of the graphite crucible. 2. The measurement jig according to claim 1, comprising a plurality of gap plates, each of which is connected in a crosswise manner at a position corresponding to a central axis of the graphite crucible. 3. The measurement jig according to claim 1, wherein the gap plate has a scale formed thereon to indicate a diameter of the quartz crucible. The outer surface of the bottomed cylindrical quartz crucible and the bottomed cylindrical quartz crucible when the bottomed cylindrical quartz crucible is placed inside a bottomed cylindrical graphite crucible for growing a silicon single crystal ingot by the CZ method. A measurement method for measuring the gap between the inner surface and the inner surface of a cylindrical graphite crucible,
Using the measurement jig according to any one of claims 1 to 3,
The cross-sectional portion of the gap plate is applied to the outer surface of the bottom of the quartz crucible, and a conical taper gauge is inserted into the gap between the cross-sectional portion of the gap plate and the outer surface of the quartz crucible. contact position of the conical surface of the conical taper gauge with the cross-sectional portion of the gap plate and the outer surface of the quartz crucible, A measuring method characterized by measuring the interval between the gaps. 5. The measuring method according to claim 4, wherein the distance between the gaps is measured with the opening of the cylindrical quartz crucible facing downward and the outer surface of the bottom of the quartz crucible facing upward.

Images