CN111779817A - Base rotating device and reaction chamber - Google Patents

Abstract

The base rotating device and reaction chamber provided by the present invention include a rotating shaft, a fixed base and a sealing structure, wherein the rotating shaft has an air inlet channel, the fixed base has a cavity, and one side of the fixed base is provided with an opening , the rotating shaft extends into the fixed base from the opening, and the fixed base is also provided with a through hole, which is used to transport gas to the air inlet channel, and the sealing structure is arranged in the fixed base and sleeved on the rotating shaft , and the sealing structure is a magnetic fluid sealing structure, and the magnetic fluid sealing structure is used to seal the connection between the through hole and the air intake passage. The present invention abandons the oil-liquid seal in the prior art, and adopts the magnetic fluid seal to avoid sliding friction between the rotating shaft and the sealing structure, thereby avoiding the wear of the rotating shaft caused by long-term friction. Therefore, the contamination of the chamber caused by oil leakage is avoided, and the cleanliness of the process environment is guaranteed.

Description

Base rotating device and reaction chamber

technical field

The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a base rotating device and a reaction chamber.

Background technique

At present, a variety of semiconductor devices are equipped with a rotating spindle with a variable-speed rotation structure. At the same time, it is required that the medium at one end of the shaft and the medium at the other end are isolated from each other and do not interfere with each other while ensuring the rotation. According to different process requirements, it is necessary to ensure that the medium pressure at the shaft end is stable and constant. If it is a harmful medium, the medium must also achieve zero leakage.

FIG. 1 is a schematic structural diagram of a gas sealing device for low-speed rotation of a main shaft provided in the prior art. As shown in FIG. 1 , the gas sealing device includes a main shaft 3 and a bearing 2 connected to it, the bearing is fixed on the vent bearing seat 1 , the bearing 2 is sealedly connected with the main shaft 3 , and the inner ring end face of the bearing 2 is sealed and connected along the inner surface of the bearing 2 . The annular sealing ring 4 in the circular direction, the ventilation bearing seat 1 is correspondingly provided with an annular grease groove 7, the annular grease groove 7 is filled with high-density grease, and the annular sealing ring 4 penetrates into the grease and Driven by the driving device, the annular sealing ring 4 of the bearing 2 is rotated in the annular grease groove 7. At the same time, the ventilation bearing 2 is directly provided with a bottom ventilation hole 5, and the main shaft 3 is provided with a main shaft ventilation hole 8. The vent hole 5 communicates with the main shaft vent hole 8 to pass the medium into the chamber. This technology uses oil seal to completely block the gas in the rotating anti-leakage chamber 6 and cannot leak out, which ensures the gas tightness, so it can solve the gas sealing problem of the low-speed rotation of the main shaft to a certain extent.

However, there are at least the following problems in the above technology:

First, the method of sealing the main shaft with oil will have an impact on the environment in the chamber. During each filling and maintenance process, oil will inevitably be leaked into the chamber, which will cause irreversible adverse effects on the micro-environment in the long run;

Second, after the spindle rotates for a long time, the bearing part will be seriously worn, and the later replacement requires the overall disassembly and assembly of the spindle, which is quite time-consuming and labor-intensive.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a base rotating device and a reaction chamber which can avoid oil leakage and wear on the main shaft.

In order to solve the above problems, the present invention provides a base rotating device, which includes:

a rotating shaft with an air intake passage in the rotating shaft;

a fixed base, the fixed base has a cavity, one side of the fixed base is provided with an opening, the rotating shaft extends into the fixed base from the opening, and the fixed base is also provided with There are through holes, and the through holes are used to deliver gas to the intake passage;

a sealing structure, which is arranged in the fixed base and sleeved on the rotating shaft;

The sealing structure is a magnetic fluid sealing structure, and the magnetic fluid sealing structure is used to seal the connection between the through hole and the intake passage.

Optionally, the magnetic fluid sealing structure includes:

an annular permanent magnet, the annular permanent magnet is sleeved on the rotating shaft;

The annular magnetic conductor includes magnetic conductive parts respectively arranged on both sides of the annular permanent magnet in the axial direction, the magnetic conductive parts are sleeved on the rotating shaft, and the magnetic conductive part is connected to the rotating shaft. There is a gap between them, and the gap is filled with magnetic fluid.

Optionally, the magnetic fluid sealing structure includes:

an annular permanent magnet, the annular permanent magnet is sleeved on the rotating shaft;

An annular magnetic conductor, the inner annular surface of the annular magnetic conductor has an annular groove in the circumferential direction, the annular magnetic conductor is sleeved on the annular permanent magnet through the annular groove, and the annular groove is connected to the annular permanent magnet There is a gap therebetween, and the gap is filled with magnetic fluid.

Further, the value of the gap ranges from 0.05mm to 0.2mm.

Further, at least the part of the rotating shaft corresponding to the magnetic fluid sealing structure is made of magnetically conductive material, and the fixed base is made of non-magnetically conductive material.

Further, the base rotating device also includes:

A bearing for fixing the rotating shaft in the fixed base.

Further, the inner diameter of the annular magnet conducting body is smaller than the inner diameter of the annular permanent magnet.

Further, the inner diameter of the annular magnet conducting body is larger than the inner diameter of the annular permanent magnet.

Further, the magnetic fluid is a colloidal liquid.

As another aspect of the present invention, the present invention also provides a reaction chamber, comprising a susceptor and a susceptor rotating device for driving the susceptor to rotate, wherein the susceptor rotating device is provided by the present invention Any of the described base rotating devices.

The present invention has the following beneficial effects:

The base rotating device provided by the present invention includes a rotating shaft, a fixed base and a sealing structure, wherein the rotating shaft has an air inlet channel, the fixed base has a cavity, one side of the fixed base is provided with an opening, and the rotating shaft is free from The opening extends into the fixed base, and the fixed base is also provided with a through hole, which is used for conveying gas to the air inlet channel. The sealing structure is set in the fixed base and sleeved on the rotating shaft, and the sealing structure is The structure is a magnetic fluid sealing structure, and the magnetic fluid sealing structure is used to seal the connection between the through hole and the air intake passage. The invention abandons the oil-liquid seal in the prior art, and adopts the magnetic fluid seal to avoid sliding friction between the rotating shaft and the sealing structure, thereby avoiding the wear of the rotating shaft caused by long-term friction. Therefore, the contamination of the chamber caused by oil leakage is avoided, and the cleanliness of the process environment is guaranteed.

The reaction chamber provided by the present invention adopts the base rotating device provided by the present invention, which can avoid sliding friction between the rotating shaft and the sealing structure, thereby avoiding the wear of the rotating shaft caused by long-term friction. There is no oil, thus avoiding the contamination of the chamber caused by oil leakage and ensuring the cleanliness of the process environment.

Description of drawings

1 is a schematic structural diagram of a gas sealing device for low-speed rotation of a main shaft provided in the prior art;

2 is a schematic structural diagram of a base rotating device according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of another base rotating device according to an embodiment of the present invention.

in:

1-vent bearing seat; 2-bearing; 3-spindle; 4-ring sealing ring; 5-venting hole at the bottom;

6-Rotary leak-proof air chamber; 7-Circular grease groove; 8-Spindle ventilation hole; 10-Rotating shaft; 11-Inlet channel; 12-Fixed base; 13-Through hole; 14-Annular permanent magnet ; 15 - ring magnet conductor;

16-bearing; 17-sleeve; 18-clearance.

Detailed ways

In order for those skilled in the art to better understand the technical solutions of the present invention, the susceptor rotation device and the reaction chamber provided by the present invention are described in detail below with reference to the accompanying drawings.

FIG. 2 is a schematic structural diagram of a base rotating device according to an embodiment of the present invention. As shown in FIG. 2 , the base rotating device provided by the embodiment of the present invention includes a rotating shaft 10, a fixed base 12 and a sealing structure, wherein the rotating shaft 10 has an air inlet channel 11, and the fixed base 12 has a cavity, One side of the fixed base 12 is provided with an opening, and the rotating shaft 10 extends into the fixed base 12 from the opening. The sealing structure is disposed in the fixed base 12 and sleeved on the rotating shaft 10 , and the sealing structure is a magnetic fluid sealing structure, and the magnetic fluid sealing structure is used to seal the connection between the through hole 13 and the air intake passage 11 .

The invention abandons the oil-liquid seal in the prior art, and adopts the magnetic fluid seal to avoid sliding friction between the rotating shaft and the sealing structure, thereby avoiding the wear of the rotating shaft caused by long-term friction. Therefore, the contamination of the chamber caused by oil leakage is avoided, and the cleanliness of the process environment is guaranteed.

Wherein, one end of the rotating shaft 10 maintains a certain gap with the fixed base 12 to avoid friction between the rotating shaft 10 and the fixed base 12 during the rotation process.

The present invention does not limit the specific position of the through hole 13, which can be provided on the surface of the fixing base 12 adjacent to the opening, as long as the air intake pipeline and the air intake passage 11 can be communicated. In order to make the air intake of the air intake channel 11 more stable, preferably, it is provided on the surface of the fixed base 12 opposite to the opening, so that the through hole 13 faces the air intake channel 11 on the rotating shaft 10 .

The magnetic fluid sealing structure adopted in the present invention will be described in detail below with reference to the accompanying drawings.

As a specific implementation of a magnetic fluid sealing structure, FIG. 2 is a schematic structural diagram of a base rotating device provided in an embodiment of the present invention. As shown in FIG. 2, in this embodiment, the magnetic fluid sealing structure includes: a ring-shaped permanent magnet 14 and a ring-shaped magnetic conductor 15, wherein the ring-shaped permanent magnet 14 is sleeved on the rotating shaft 10, and the ring-shaped magnetic conductor 15 comprises a The magnetic conductive parts on both sides of the annular permanent magnet 14 in the axial direction are sleeved on the rotating shaft 10 , and there is a gap 18 between the magnetic conductive part and the rotating shaft 10 , and the gap 18 is filled with magnetic fluid. That is, in this embodiment, the sealing position is provided in the gap 18 between the magnetic conductive portion of the annular magnetic conductive body 15 and the rotating shaft 10 .

The inner diameter of the annular magnet conducting body 15 is smaller than the inner diameter of the annular permanent magnet 14 , and there is a gap between the inner wall of the annular permanent magnet 14 and the rotating shaft 10 .

As another specific implementation of the magnetic fluid sealing structure, FIG. 3 is a schematic structural diagram of another base rotating device provided in an embodiment of the present invention. As shown in FIG. 3 , in this embodiment, the magnetic fluid sealing structure includes: an annular permanent magnet 14 and an annular magnetic conductor 15 , wherein the annular permanent magnet 14 is sleeved on the rotating shaft 10 , and the inner annular surface of the annular magnetic conductor 15 There is an annular groove in the circumferential direction of the ring, the annular magnet 15 is sleeved on the annular permanent magnet 14 through the annular groove, there is a gap 18 between the annular groove and the annular permanent magnet 14, and the gap 18 is filled with magnetic fluid. That is, in the present embodiment, the sealing position is provided in the gap 18 between the annular groove of the annular magnetic conductor 15 and the annular permanent magnet 14 .

The inner diameter of the annular magnet conducting body 15 is larger than the inner diameter of the annular permanent magnet 14 .

Optionally, the annular permanent magnet 14 is fixed on the rotating shaft 10 and rotates together with the rotating shaft 10 .

Wherein, at least the part of the rotating shaft 10 corresponding to the magnetic fluid sealing structure is made of magnetic conductive material, so as to form a magnetic circuit with the annular permanent magnet 14 and the annular magnetic conductive body 15 .

The fixed base 12 is made of non-magnetic conductive material to avoid affecting the magnetic circuit formed by the annular permanent magnet 14 , the rotating shaft 10 and the annular magnetic conductive body 15 .

It should be noted that the present invention provides two specific embodiments of the sealing structure, but the present invention is not limited to these. The magnetic circuit, under the action of the magnetic field generated by the annular permanent magnet 14, concentrates the magnetic fluid filled in the gap between the sealing portion of the rotating shaft 10 and the annular magnetic conductor 15 to form an O-ring, thereby achieving the The gap at the connection between the intake pipe and the intake passage 11 is blocked to achieve the purpose of sealing. Therefore, as long as the sealing is realized by using the principle of the present invention, it belongs to the protection scope of the present invention.

Under ideal conditions, the magnetic fluid sealing structure provided by the embodiment of the present invention can withstand a pressure difference of 0.15-0.2 atmospheres, and the bearing capacity of the entire area is the total bearing pressure of the sealing ring. According to the technical requirements, the standard design pressure of the magnetic fluid sealing structure is greater than two atmospheres, which is absolutely safe in sealing.

The base rotating device provided by the present invention adopts the magnetic fluid sealing structure, which will not affect the chamber environment, is maintenance-free and maintenance-free for a relatively long time, and has excellent reliability. In addition, the space between the rotary shaft 10 and the magnetic fluid sealing structure is filled with magnetic fluid, so the mechanical wear on the rotary shaft 10 is almost reduced to zero, and the rotational noise of the rotary shaft 10 is also reduced while ensuring the chamber process environment. Moreover, the service life of the rotating shaft 10 is greatly improved, from low speed to high speed, from low pressure to high pressure, and from room temperature to high temperature, all of which can meet the requirements of various rotating shaft 10 processes.

In this embodiment, the through hole 13 is used to pass the medium required by the process, such as nitrogen gas. After the nitrogen gas flows into the through hole 13, it will flow to the required process part through the air inlet channel 11 in the rotating shaft 10. Due to the magnetic fluid seal Structure, the nitrogen gas introduced can be output at the output end at a constant pressure, and will not leak at the leak point.

In this embodiment, the magnetic fluid is a colloidal liquid. As a magnetic fluid for sealing, it has the advantages of good stability, no condensation, no precipitation, no decomposition, high saturation magnetization, and high initial permeability.

It should be noted that, with regard to the structure of the annular magnetic conductor 15, an annular groove may be provided on the inner peripheral wall of the annular magnetic conductor 15, and the annular magnetic conductor 15 may also be two independent components, each independent component is One magnetic conductive part and two magnetic conductive parts are respectively arranged on both sides of the annular permanent magnet 14 .

In this embodiment, the base rotating device further includes a bearing 16 , which is disposed in the fixed base 12 and sleeved on the rotating shaft 10 . It supports the rotation of the rotating shaft 10 and reduces the friction coefficient.

Preferably, the number of bearings 16 is plural. At this time, the rotary shaft sealing device further includes a sleeve 17 , the sleeve 17 is arranged between any two adjacent bearings 16 , and the sleeve 17 is arranged between the bearing 16 and the annular magnetic conductor 15 . The sleeve 17 is used to maintain a certain distance between the two adjacent bearings 16 or the bearing 16 and the annular magnetic conductor 15 . The length of the sleeve 17 is comprehensively determined according to the size of the fixed base 12 , the length and number of the bearings 16 , the length of the annular magnet conducting body 15 , and the like.

In addition, in this embodiment, the rotating shaft 10 and the fixed base 12 , the annular permanent magnet 14 , the annular magnetic conductor 15 , the bearing 16 , the sleeve 17 and the like are provided separately. Of course, in practical applications, they can also be integrally formed.

As another aspect of the present invention, the present invention also provides a reaction chamber, including a base and a base rotating device for driving the base to rotate, wherein the base rotating device is the base provided in the embodiment of the present invention Rotary device.

In the reaction chamber provided by the present invention, by using the base rotating device provided by the present invention, sliding friction between the rotating shaft and the sealing structure can be avoided, thereby avoiding the wear of the rotating shaft caused by long-term friction. There is no oil in it, so as to avoid the contamination of the chamber caused by oil leakage and ensure the cleanliness of the process environment.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (10)

1. a base rotating device, is characterized in that, comprises: a rotating shaft with an air intake passage in the rotating shaft; a fixed base, the fixed base has a cavity, one side of the fixed base is provided with an opening, the rotating shaft extends into the fixed base from the opening, and the fixed base is also provided with There are through holes, and the through holes are used to deliver gas to the intake passage; a sealing structure, which is arranged in the fixed base and sleeved on the rotating shaft; The sealing structure is a magnetic fluid sealing structure, and the magnetic fluid sealing structure is used to seal the connection between the through hole and the intake passage. 2. The base rotating device according to claim 1, wherein the magnetic fluid sealing structure comprises: an annular permanent magnet, the annular permanent magnet is sleeved on the rotating shaft; The annular magnetic conductor includes magnetic conductive parts respectively arranged on both sides of the annular permanent magnet in the axial direction, the magnetic conductive parts are sleeved on the rotating shaft, and the magnetic conductive part is connected to the rotating shaft. There is a gap between them, and the gap is filled with magnetic fluid. 3. The base rotating device according to claim 1, wherein the magnetic fluid sealing structure comprises: an annular permanent magnet, the annular permanent magnet is sleeved on the rotating shaft; An annular magnetic conductor, the inner annular surface of the annular magnetic conductor has an annular groove in the circumferential direction, the annular magnetic conductor is sleeved on the annular permanent magnet through the annular groove, and the annular groove is connected to the annular permanent magnet There is a gap therebetween, and the gap is filled with magnetic fluid. 4 . The base rotating device according to claim 2 or 3 , wherein the value of the gap ranges from 0.05 mm to 0.2 mm. 5 . 5. The base rotating device according to any one of claims 1-3, wherein at least the part of the rotating shaft corresponding to the magnetic fluid sealing structure is made of magnetically conductive material, and the fixed The base is made of non-magnetic material. 6. The rotary shaft sealing device of the base rotating device according to any one of claims 1-3, wherein the base rotating device further comprises: A bearing for fixing the rotating shaft in the fixed base. 7 . The base rotating device according to claim 2 , wherein the inner diameter of the annular magnet conducting body is smaller than the inner diameter of the annular permanent magnet. 8 . 8 . The base rotating device according to claim 3 , wherein the inner diameter of the annular magnet conducting body is larger than the inner diameter of the annular permanent magnet. 9 . 9 . The base rotating device according to claim 2 or 3 , wherein the magnetic fluid is a colloidal liquid. 10 . 10. A reaction chamber comprising a base and a base rotating device for driving the base to rotate, wherein the base rotating device comprises the base according to any one of claims 1-9 Rotary device.

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