CN217438339U - Isolation valve for crystal pulling furnace and crystal pulling furnace - Google Patents

Abstract

The embodiment of the utility model discloses an isolation valve and crystal pulling furnace for crystal pulling furnace, the isolation valve sets up between the main furnace room and the auxiliary furnace room of crystal pulling furnace, the isolation valve includes: a valve seat formed with a passage for communicating the main furnace chamber and the sub-furnace chamber; a valve cover for closing the passage; a gas supply for supplying a protective gas to an inner surface of the valve cover that faces the main furnace chamber when the valve cover closes the passage.

Description

Isolation valve for crystal pulling furnace and crystal pulling furnace

Technical Field

The utility model relates to a monocrystalline silicon production field especially relates to an isolating valve and crystal pulling furnace for crystal pulling furnace.

Background

For the production of single crystal silicon, the czochralski method is mainly used at present. Crystal pulling furnaces suitable for the czochralski method generally comprise: a main furnace chamber in which a quartz crucible for containing polycrystalline silicon and a heater for heating to melt the polycrystalline silicon are disposed, and into which a protective gas such as argon is introduced during the crystal pulling process to exhaust the internal air from oxidation and provide a desired furnace pressure; the auxiliary furnace chamber can be used for accommodating the grown single crystal silicon rod; and an isolation valve arranged between the main furnace chamber and the auxiliary furnace chamber so as to realize different working environments of the main furnace chamber and the auxiliary furnace chamber, such as different furnace pressures between the main furnace chamber and the auxiliary furnace chamber.

For crystal pulling processes, there is a need to open and close the valve cover of the isolation valve, for example, during secondary seed addition, slag extraction, seed crystal replacement, and the like.

The polycrystalline silicon chemically reacts with the quartz crucible containing the polycrystalline silicon during melting, thereby generating silicon oxide. The silicon oxide flows mainly along with the protective gas introduced into the main furnace chamber and is discharged to the outside of the crystal pulling furnace along with the protective gas through the exhaust port. However, when the valve cover of the isolation valve is opened and closed, a certain pressure difference is generated between the main furnace chamber and the auxiliary furnace chamber, and the pressure difference can cause the gas near the isolation valve cover to generate turbulence, so that silicon oxide is contacted with the inner surface of the valve cover to be attached to the inner surface and continuously gathers to form sheet-shaped or granular aggregates, the aggregates are easy to fall into silicon melt, on one hand, thermal shock can be generated, the crystal loses single crystal characteristics (generally called broken lines), and the production failure is caused, on the other hand, impurities are introduced into the crystal to generate defects, and the quality of the single crystal is greatly influenced.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problem, embodiments of the present invention desirably provide an isolation valve for a crystal pulling furnace and a crystal pulling furnace, which can avoid the contact between the gas containing silicon oxide and the inner surface of the valve cover when the turbulent gas is generated due to the pressure difference between the main furnace chamber and the auxiliary furnace chamber during the process of opening and closing the valve cover of the isolation valve, thereby avoiding the generation of aggregates, and avoiding the aggregates from falling into the silicon melt.

The technical scheme of the utility model is realized like this:

in a first aspect, an embodiment of the present invention provides an isolation valve for a crystal pulling furnace, the isolation valve is disposed between a main furnace chamber and an auxiliary furnace chamber of the crystal pulling furnace, the isolation valve includes:

a valve seat formed with a passage for communicating the main furnace chamber and the sub-furnace chamber;

a valve cover for closing the passage;

a gas supply for supplying a protective gas to an inner surface of the valve cover that faces the main furnace chamber when the valve cover closes the passage.

In a second aspect, embodiments of the present invention provide a crystal pulling furnace comprising an isolation valve according to the first aspect.

The embodiment of the utility model provides an isolation valve and crystal pulling furnace for crystal pulling furnace, in the in-process of the operation of opening and closing is carried out to the valve gap of isolation valve, even gas near the valve gap can be because of the pressure differential between main furnace room and the auxiliary furnace room takes place the turbulence, because protective gas has been supplied to the internal surface of valve gap, perhaps can make near internal surface exist protective gas all the time, consequently, the gas that contains the silicon oxide in the main furnace room can not contact this internal surface, then the silicon oxide can not contact this internal surface yet, avoided forming the aggregate of silicon oxide on this internal surface from this, and also can not have the aggregate to drop in the silicon melt in the main furnace room through the passageway of disk seat.

Drawings

FIG. 1 is a schematic view of a crystal pulling furnace to which an isolation valve according to an embodiment of the present invention is applied;

fig. 2 is a schematic diagram of an isolation valve according to an embodiment of the present invention;

fig. 3 is a schematic view of a gas supply device according to an embodiment of the present invention;

fig. 4 is a schematic view of a valve cover capable of articulation according to an embodiment of the present invention;

fig. 5 is a schematic view of a nozzle according to an embodiment of the present invention;

fig. 6 is a schematic view of an isolation valve according to another embodiment of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring initially to fig. 1, embodiments of the present invention provide an isolation valve 10 for a crystal pulling furnace 1, the isolation valve 10 being disposed between a main furnace chamber 20 and a sub-furnace chamber 30 of the crystal pulling furnace 1, and more particularly to fig. 2, the isolation valve 10 may include:

a valve seat 11, the valve seat 11 forming a passage 11T for communicating the main furnace chamber 20 and the sub-furnace chamber 30;

a valve cover 12, wherein the valve cover 12 is used for closing the channel 11T;

as the gas supply means 13 schematically shown by a dot-filled part in fig. 2, the gas supply means 13 is for supplying the protective gas P schematically shown by a dotted arrow to the inner surface 12S of the valve cover 12 facing the main furnace chamber 20 when the valve cover 12 closes the passage 11T, and the gas supply means 13 is exemplarily shown to be provided on the inner surface 12S of the valve cover 12 in fig. 2, but the present invention is not limited thereto, and the gas supply means 13 may be provided in any manner as long as the protective gas P can be supplied to the inner surface 12S of the valve cover 12.

In this way, in the process of performing the operation of opening and closing the valve cover 12 of the isolation valve 10, even if the gas in the vicinity of the valve cover 12 is turbulent due to the pressure difference between the main furnace chamber 20 and the sub-furnace chamber 30, since the protective gas P is supplied to the inner surface 12S of the valve cover 12 or the protective gas P is always present in the vicinity of the inner surface 12S, the gas containing silicon oxide in the main furnace chamber 20 does not contact the inner surface 12S, and the silicon oxide does not contact the inner surface 12S, thereby preventing the formation of the aggregate of silicon oxide on the inner surface 12S and the aggregate from falling into the silicon melt in the main furnace chamber 20 through the passage 11T of the valve seat 11.

In a preferred embodiment of the present invention, referring to fig. 3, the gas supply device 13 may include:

a gas source 131 for storing compressed protective gas P;

a spray head 132 for spraying a compressed protective gas P to the inner surface 12S of the valve cover 12;

a conduit 133 for communicating the gas source 131 with the showerhead 132.

As previously mentioned, only the turbulence caused during the opening and closing of the valve cover 12 brings the silicon oxide into contact with the inner surface 12S of the valve cover 12, so in the preferred embodiment of the present invention, still referring to fig. 3, the gas supply device 13 may further include an on-off valve 134 provided on the conduit 133, the on-off valve 134 being opened only when the valve cover 12 is switched from a closed state closing the passage 11T to an open state opening the passage 11T and from the open state to the closed state. Thus, the silicon oxide can be sufficiently prevented from contacting the inner surface 12S of the valve cover 12, and the amount of the protective gas P to be used can be reduced, thereby reducing the cost.

For switching the valve cover 12 between the above-mentioned open state and closed state, in a preferred embodiment of the present invention, the valve cover 12 may be hinged to the valve seat 11, for example, referring to fig. 4, the valve cover 12 may be configured to be rotatable about a pivot 14, and the pivot 14 may be fixed to the valve seat 11. Thus, the valve cover 12 can be switched between the open state and the closed state by rotating the pivot 14, and the operation is simple and easy.

In a preferred embodiment of the present invention, the spray head 132 shown in fig. 3 may be fixed to the inner surface 12S of the valve cover 12. In this way, movement of the spray head 132 with the valve cap 12 may be accomplished during opening and closing of the valve cap 12, without requiring additional means for moving the spray head 132 to ensure that the spray head 132 sprays the protective gas P onto the interior surface 12S.

In the aforementioned case, in order to enable the protective gas to be sprayed in an easy manner to the entire inner surface 12S, in a preferred embodiment of the present invention, referring to fig. 5, the spray head 132 may be annular and have a series of exhaust ports 132O uniformly distributed along the circumferential direction of the spray head 132. In fig. 5, only the exhaust port 132O on the radially inner side of the annular head 132 is shown, but it is understood that the exhaust port 132O may be formed on the radially outer side of the head 132 in the case where the diameter of the head 132 is small compared to the size of the cap 12.

In the foregoing case, preferably, referring to fig. 6, when the valve cover 12 is in the closed state, the outer periphery of the spray head 132 may abut against the inner wall of the passage 11T, and the series of exhaust ports 132O may be provided radially inside the spray head 132.

In the foregoing case, still referring to fig. 6, the showerhead 132 may have an annular cavity 132C in communication with the series of exhaust ports 132O and at least one inlet port 132I in communication with the cavity 132C. In the case where the showerhead 132 has the annular cavity 132C, the above-described exhaust port 132O and intake port 132I can be obtained by a simple drilling operation, facilitating the manufacture of the showerhead 132.

Preferably, the protective gas P may be argon.

Referring back to fig. 1, the embodiment of the present invention also provides a crystal pulling furnace 1, wherein the crystal pulling furnace 1 may include an isolation valve 10 according to the previous embodiments of the present invention.

It should be noted that: the embodiment of the utility model provides an between the technical scheme who records, under the condition of conflict, can make up wantonly.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. An isolation valve for a crystal pulling furnace, the isolation valve disposed between a main furnace chamber and a sub-furnace chamber of the crystal pulling furnace, the isolation valve comprising:

a valve seat formed with a passage for communicating the main furnace chamber and the sub-furnace chamber;

a valve cover for closing the passage;

a gas supply for supplying a protective gas to an inner surface of the valve cover that faces the main furnace chamber when the valve cover closes the passage.

2. The isolation valve of claim 1, wherein the gas supply means comprises:

a source for storing a compressed protective gas;

a spray head for spraying a compressed protective gas onto an inner surface of the valve cover;

and the pipeline is used for communicating the gas source with the spray head.

3. The isolation valve of claim 2, wherein the gas supply further comprises an on-off valve disposed on the conduit, the on-off valve opening only when the valve cover switches from a closed state closing the passage to an open state opening the passage and from the open state to the closed state.

4. The isolation valve of claim 3, wherein the valve cover is hinged to the valve seat.

5. The isolation valve of claim 3, wherein the spray head is secured to an inner surface of the valve cover.

6. The isolation valve of claim 5, wherein the spray head is annular and has a series of vents evenly distributed along a circumference of the spray head.

7. The isolation valve of claim 6, wherein the outer periphery of the spray head abuts an inner wall of the passage when the valve cover is in the closed state, and the series of exhaust ports are disposed radially inward of the spray head.

8. An isolation valve as claimed in claim 6 or 7, wherein the spray head has an annular cavity in communication with the series of exhaust ports and at least one inlet port in communication with the cavity.

9. The isolation valve of claim 1, wherein the protective gas is argon.

10. A crystal pulling furnace comprising an isolation valve as claimed in any one of claims 1 to 9.

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