JP2559235B2 - Quartz crucible for silicon single crystal pulling equipment - Google Patents

Description

The present invention relates to a quartz crucible for a silicon single crystal pulling apparatus.

[Conventional technology]

Conventionally, the quartz crucible 1 has been used by being housed in a carbon crucible 2 having a bottomed cylindrical shape as shown in FIG. 4 in order to prevent deformation due to softening during melting of silicon. Similarly, it is provided in a bottomed cylindrical shape, and the silicon polycrystal 3 is charged prior to the melting of silicon according to its volume.

[Problems to be solved by the invention]

However, according to the conventional quartz crucible 1, the charge amount of the silicon polycrystal is different depending on the charging method, and there is a certain limit, and the melting amount (the melting completion line is shown by a chain double-dashed line in FIG. 4). .) Is as small as about half the internal volume of the quartz crucible 1 and the charge amount, that is, the melting amount is increased, the quartz crucible 1 and the carbon crucible 2
There is a problem that the size of the hot zone must be increased.

Therefore, the present invention is to provide a quartz crucible for a silicon single crystal pulling apparatus capable of easily increasing the charge amount of silicon polycrystal without increasing the inner volume of the crucible body.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a flange at least at a position opposite to the peripheral edge of the opening of the crucible body, and provides the flange of the crucible body with a truncated conical cylindrical cover ring at its lower end. The fitting flange is separably connected, and a plurality of slits are provided in the upper part of the fitting flange so as to be separated in the circumferential direction.

[Work]

According to the above means, the volume of the crucible body with respect to the silicon polycrystal is increased by the inner volume of the cover ring. Further, the inert gas supplied into the crucible body is smoothly discharged through the slit. Further, since the crucible body is transported through the flange or the cover ring, it is not necessary to previously install the crucible in the single crystal pulling apparatus when the polysilicon is loaded.

As the material of the cover ring, carbon, silicon carbide, silicon nitride, quartz and the like are used, but carbon and silicon carbide are particularly preferable because they are stable even when heated.

Also, by coating the surface of the cover ring with silicon carbide or silicon nitride, it becomes possible to reduce the inclusion of impurities and extend the life of the cover ring itself.

In this case, the coating layer should be at least 5 by CVD method.
It is preferable that the thickness is not less than μm and the substantial air permeability is 0.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 10 is a crucible main body made of quartz housed in a carbon crucible 11, and at positions opposite to each other on the periphery of the opening,
Like the main body, a flange 12 made of quartz is provided by welding or the like.

On the flange 12 of the crucible body 10, a cover ring 13 having a truncated conical cylindrical shape and made of graphite whose surface is coated with silicon carbide is separated by a fitting flange 14 having a U-shaped cross section integrally provided at the lower end thereof. Connected possible. The fitting flanges 14 are provided at positions facing each other in the circumferential direction, like the flange 12 of the crucible body 10. And
The cover ring 13 above the fitting flange 14 is provided with a plurality of circumferential slits 15 at appropriate intervals in the circumferential direction.

In order to charge the polycrystalline silicon into the quartz crucible having the above structure, the cover ring 13 is attached to the flange 12 of the crucible body 10 placed outside the pulling device by the fitting flange 14 as shown in FIG. Connect and then silicon polycrystal
Cover 16 with cover ring 13 and fill.

The quartz crucible in which the silicon polycrystal has been charged is housed in the carbon crucible 11 in the pulling apparatus by an operator or an appropriate carrying device, and when the silicon polycrystal is completely melted by heating, as shown in FIG. The position indicated by the chain double-dashed line is the melt surface.

Then, the argon gas supplied into the crucible body 10 is smoothly discharged through the slit 15 of the cover ring 13 together with the silicon monoxide gas generated from the melt surface.

Further, unlike the crucible body 10, the cover ring 13 does not melt and is used repeatedly.

In the above embodiment, the flange 12 of the crucible body 10 and the fitting flange 14 of the cover ring 13 are provided at two circumferentially opposite positions, but the present invention is not limited to this and three or four circumferential locations are provided. It may be provided at a location or the like.

Further, the flange 12 of the crucible body 10 has a U-shaped cross section,
The fitting flange 14 of the cover ring 13 fitted with this may be plate-shaped.

Further, although the cover ring 13 is formed by coating graphite with silicon carbide, the base material of silicon carbide may be coated with silicon carbide.

〔The invention's effect〕

As described above, according to the present invention, since the volume of the crucible body with respect to the silicon polycrystal is increased by the amount of the inner volume of the cover ring, the charge amount of the silicon polycrystal can be changed without changing the crucible body to the one having a large inner volume. It can be easily increased (30% increase from the conventional method).

Further, since the exhaust gas of the inert gas supplied into the crucible main body is smoothly carried out through the slit, the discharge of the silicon monoxide gas becomes good and the pulling rate of non-defective products can be improved (5% increase from the conventional product). it can.

Furthermore, since the crucible body is transported through the flange or the cover ring, it is easy to carry,
The silicon polycrystal can be loaded outside the pulling device,
This is particularly convenient when the charge amount is large.

Furthermore, since the flange is provided around the opening of the crucible body, it is possible to prevent sagging of the opening during heating.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
The figure shows a vertical cross-section of a quartz crucible loaded with polycrystal silicon.
2 (a) and 2 (b) are a longitudinal sectional view and a plan view of the crucible body, respectively, and FIGS. 3 (a) and 3 (b) are a longitudinal sectional view, a plan view and an example of a cover ring, respectively. It is a longitudinal cross-sectional view of a conventional quartz crucible. 10 …… Crucible body, 12 …… Flange 13 …… Cover ring, 14 …… Mating flange 15 …… Slit, 16 …… Silicon poly

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayoshi Funayama, 378 Oguni-machi, Oguni-machi, Nishiokitama-gun, Yamagata Prefecture Inside the Oguni Factory of Toshiba Ceramics Co., Ltd. (72) Ryuichi Tsuji 378 Oguni-machi, Oguni-cho, Nishiokitama-gun, Yamagata Prefecture Address Toshiba Ceramics Co., Ltd. Oguni Manufacturing Co., Ltd. (56) Reference JP-A-60-141696 (JP, A) JP-A-53-46473 (JP, A) Actual development: Sho-62-108295 (JP, U)

Claims (3)

(57) [Claims] 1. A crucible main body is provided with a flange at least at a position opposite to each other, and a frusto-conical cylindrical cover ring is attached to the flange of the crucible main body by a fitting flange provided at a lower end thereof. A quartz crucible for a silicon single crystal pulling apparatus, wherein the quartz crucible is connected and a plurality of slits are provided at an upper portion of the fitting flange so as to be separated from each other in a circumferential direction. 2. The quartz crucible for a silicon single crystal pulling apparatus according to claim 1, wherein the surface of the cover ring is coated with silicon carbide. 3. The quartz crucible for a silicon single crystal pulling apparatus according to claim 1, wherein the surface of the cover ring is coated with silicon nitride.