WO2020078147A1

WO2020078147A1 - Chamber sealing assembly and growth furnace

Info

Publication number: WO2020078147A1
Application number: PCT/CN2019/105409
Authority: WO
Inventors: 冯祥雷
Original assignee: 北京北方华创微电子装备有限公司
Priority date: 2018-10-16
Filing date: 2019-09-11
Publication date: 2020-04-23
Also published as: JP2021534071A; CN111058093A; JP7126027B2; CN111058093B

Abstract

The present invention provides a chamber sealing assembly and a growth furnace. The chamber sealing assembly is arranged between a furnace flange and a reaction chamber, and comprises: a seal spacer ring and seal rings respectively disposed at two axial sides of the seal spacer ring, wherein a first air extraction channel is provided in the seal spacer ring, and the first air extraction channel is in communication with the inside of the seal spacer ring; and a second air extraction channel is provided in the furnace flange, and the second extraction channel is connected to the first air extraction channel and an air extraction device, respectively. The chamber sealing assembly provided by the present invention can prevent air from leaking into a reaction chamber, and improve the efficiency of disassembly and maintenance of the chamber, while avoiding the risk of damaging the reaction chamber.

Description

Chamber sealing assembly and growth furnace

Technical field

The invention relates to the field of semiconductor manufacturing, in particular, to a chamber sealing assembly and a growth furnace.

Background technique

Silicon carbide (SiC) single crystal has excellent semiconductor physical properties such as high thermal conductivity, high breakdown voltage, high carrier mobility, and high chemical stability. It can be made into high frequency, high frequency, and high radiation conditions High-power electronic devices and optoelectronic devices have huge application value in the fields of national defense, high technology, industrial production, power supply, substation, etc., and are regarded as the third generation of wide band gap semiconductor materials with great development prospects.

The growth of silicon carbide single crystal materials requires special process equipment. The process equipment mainly includes growth furnace components, heating components, gas components and control components, among which the growth furnace components are one of the key structures. Figure 1 is a schematic diagram of the structure of the growth furnace. Referring to FIG. 1, the growth furnace includes a reaction chamber 1, an upper chamber 2 and a lower chamber 3, and the upper chamber 2 and the lower chamber 3 are sleeved on the reaction chamber 1 from the upper and lower ends of the reaction chamber 1 respectively . Moreover, a sealing assembly (not shown in the figure) is provided between the upper chamber 2 and the reaction chamber 1 and between the lower chamber 3 and the reaction chamber 1 to form a sealed chamber inside the reaction chamber 1. According to the current SiC growth process requirements, the closed cavity needs to maintain a high vacuum level.

Existing sealing assemblies usually include two sealing rings spaced apart from each other. This will have the following problems in practical applications, namely: during installation, air will be sealed between the two sealing rings. After the evacuation of the reaction chamber 1 is completed, the vacuum inside the chamber is high due to the two seals The pressure in the space between the rings (because of the air) is very different from the pressure in the chamber. Inevitably, even if a small amount of air enclosed in the space leaks into the chamber, it may cause pressure in the chamber. The increase in the rate of rise affects the development of the crystal growth process. At the same time, because the pressure in the compartment is lower than the outside atmospheric pressure, the compartment is in a negative pressure state, which makes it difficult to remove the furnace flange when performing cavity disassembly maintenance, thereby posing a risk of damaging the reaction chamber.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the prior art, and proposes a chamber sealing assembly and a growth furnace, which can not only prevent air from leaking into the reaction chamber, but also improve the efficiency of chamber disassembly and maintenance To avoid the risk of damaging the reaction chamber.

In order to achieve the object of the present invention, a chamber sealing assembly is provided, which is disposed between the furnace flange and the reaction chamber, and includes:

It includes a sealing spacer ring and sealing rings respectively provided on both axial sides of the sealing spacer ring; wherein, a first suction channel is provided in the sealing spacer ring, and the first suction channel and the seal The inner side of the spacer ring communicates; and, a second extraction channel is provided in the furnace flange, and the second extraction channel is respectively connected to the first extraction channel and the extraction device.

Optionally, the first suction channel includes a plurality of suction holes uniformly distributed along the circumferential direction of the sealing spacer ring, and each of the suction holes penetrates the sealing spacer ring.

Optionally, an annular groove is formed on the inner peripheral wall of the sealing spacer ring, and the inner end of each suction hole is located in the annular groove.

Optionally, the diameter of the suction hole is a quarter of the axial thickness of the sealing spacer.

Optionally, the number of the suction holes is 12-36.

Optionally, the inner end of the suction hole is located at an intermediate position of the axial thickness of the sealing spacer.

Optionally, an end of the second extraction channel away from the first extraction channel is located on the outer peripheral wall of the furnace flange.

Optionally, it also includes an upper gasket ring and a lower gasket ring, and the sealing ring and the sealing spacer ring are disposed between the upper gasket ring and the lower gasket ring.

As another technical solution, the present invention also provides a growth furnace, including a reaction chamber, an upper chamber and a lower chamber, the upper chamber and the lower chamber are sleeved on the upper and lower ends of the reaction chamber, respectively ; And, the upper chamber and the lower chamber both include a flange end cover, a furnace flange, and a furnace body that are sequentially stacked from bottom to top; wherein, the inner peripheral wall of the furnace flange and the reaction chamber Has an annular gap between the outer peripheral walls;

A chamber seal assembly is provided in the annular gap, and the chamber seal assembly adopts the above chamber seal assembly provided by the present invention.

Optionally, the air extraction device includes a vacuum joint, an air extraction pipeline and an air extraction pump, wherein,

The vacuum joint is connected to the second end of the second suction channel;

The suction line is respectively connected to the suction pump and the vacuum joint.

The invention has the following beneficial effects:

The chamber sealing assembly provided by the invention is provided with a first extraction channel in the sealing spacer ring and a second extraction channel in the furnace flange, which can be sequentially passed through the second extraction using an extraction device The channel and the first suction channel extract the air in the space between the sealing spacer and the reaction chamber, so that the air in the space can be prevented from leaking into the reaction chamber, ensuring the pressure rise rate requirements of the chamber; , When disassembling and maintaining the chamber, the above-mentioned interval can be communicated with the atmosphere by means of the second exhaust channel and the first exhaust channel, so that the negative pressure state in the interval can be released, and the furnace flange can be disassembled, so that Improve the efficiency of disassembly and maintenance of the chamber to avoid the risk of damage to the reaction chamber.

The growth furnace provided by the present invention, by adopting the above chamber sealing assembly provided by the present invention, can not only prevent air from leaking into the reaction chamber, but also can improve the efficiency of chamber disassembly and maintenance and avoid the risk of damage to the reaction chamber .

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the structure of the growth furnace;

2 is a partial cross-sectional view of a growth furnace used in an embodiment of the present invention;

Figure 3 is an enlarged view of the area I in Figure 2;

FIG. 4 is a structural diagram of a sealing spacer used in an embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the chamber sealing assembly and the growth furnace provided by the present invention will be described in detail below with reference to the drawings.

Please refer to FIG. 2, which is a partial cross-sectional view of a growth furnace used in an embodiment of the present invention. The growth furnace includes a reaction chamber 10, an upper chamber and a lower chamber. The upper chamber and the lower chamber are sleeved on the reaction chamber 10 from the upper and lower ends of the reaction chamber 10, respectively. FIG. 2 only shows a partial cross-sectional view of the upper furnace and its sealing structure with the reaction chamber 10. Since the sealing structure between the lower furnace chamber and the reaction chamber 10 is similar to the sealing structure of the upper furnace chamber and the reaction chamber 10, this embodiment only takes the sealing structure of the furnace chamber and the reaction chamber 10 as an example.

In this embodiment, the upper furnace includes an upper end cover 13, an upper furnace body 12 and a furnace flange 11 arranged in this order from top to bottom, wherein the furnace flange 11 is sleeved on the reaction chamber 10 and the furnace flange The space between 11 and the reaction chamber 10 is surrounded by a chamber seal assembly 14 for sealing the furnace flange 11 and the reaction chamber 10.

2 and FIG. 3 together, the chamber seal assembly provided in this embodiment includes a sealing spacer ring 144 and sealing rings 143 respectively disposed on both axial sides of the sealing spacer ring 144. The sealing spacer ring 144 serves to separate and support the sealing ring 143.

However, when the chamber seal assembly is installed, air is sealed in the space between the seal ring 144 and between the two seal rings 143. After the interior of the reaction chamber 10 is evacuated, the inside of the chamber The degree of vacuum is high, because the pressure in the space between the sealing rings 143 on both sides differs greatly from the pressure in the chamber, inevitably, even a small amount of air enclosed in the space between the two sealing rings 143 leaks into In the cavity, the pressure rise rate of the cavity may also be increased, affecting the development of the crystal growth process. At the same time, because the pressure in the above-mentioned interval is lower than the outside atmospheric pressure, the interval is in a negative pressure state, which makes it difficult to remove the furnace flange during cavity removal maintenance, and there is a risk of damaging the reaction chamber.

In order to solve the above problem, in this embodiment, a first exhaust channel 1441 is provided in the sealing spacer 144, and the first exhaust channel 1441 communicates with the inside of the sealing spacer 144, specifically, the first exhaust channel The first and second ends of 1441 are located on the inner and outer peripheral walls of the seal spacer 144, respectively. In addition, a second exhaust channel 111 is provided in the furnace flange 11, and the first end of the second exhaust channel 111 is connected to the second end of the first exhaust channel 1441; the second end of the second exhaust channel 111 The end is used to connect with a suction device (not shown).

After the installation of the chamber seal assembly is completed, the air in the space inside the seal spacer 144 can be extracted through the second air extraction channel 111 and the first air extraction channel 1441 in sequence by the air extraction device, so that the air in the space can be avoided It leaks into the interior of the reaction chamber 10, ensuring the pressure rise rate of the chamber; at the same time, when the chamber is disassembled and maintained, the above-mentioned interval can be adjusted with the help of the second extraction channel 111 and the first extraction channel 1441. The atmospheric environment is connected, so that the negative pressure state in the interval can be released, the disassembly of the furnace flange 11 is facilitated, and the efficiency of disassembly and maintenance of the chamber can be improved, and the existing risk of damaging the reaction chamber can be avoided.

In this embodiment, as shown in FIG. 4, the first suction channel 1441 includes a plurality of suction holes uniformly distributed along the circumferential direction of the seal spacer 144, and each suction hole penetrates through the seal spacer 144. Optionally, each suction hole is a straight through hole provided along the radial direction of the sealing spacer 144. Through a plurality of suction holes uniformly distributed along the circumferential direction of the seal spacer 144, the air in the space inside the seal spacer 144 can be evenly extracted, thereby ensuring that the air can be completely Withdrawing, the sealing ring 143 can be prevented from being deformed by uniform extraction.

In this embodiment, optionally, an annular groove 1442 is formed on the inner peripheral wall of the sealing spacer 144, and the inner end of each suction hole 1441 is located in the annular groove 1442. With the help of the annular groove 1442, it is more advantageous to completely extract the air between the two sealing rings 143.

Optionally, the diameter of the suction hole is a quarter of the axial thickness of the sealing spacer 144. For example, if the axial thickness of the sealing spacer ring 144 is 4 mm, the diameter of the suction hole is 1 mm. If the axial thickness of the sealing spacer ring 144 is 8 mm, the diameter of the suction hole is 2 mm. In this way, the pumping rate can be increased while ensuring the strength of the sealing spacer 144.

Optionally, the number of suction holes is 12 to 36. In this way, the pumping rate can be increased while ensuring the strength of the seal spacer 144.

Optionally, the inner end of the suction hole is located at a middle position of the axial thickness of the sealing spacer ring 144, which is beneficial to enable the air to be completely drawn out.

In this embodiment, as shown in FIG. 2, the second exhaust channel 111 is located on the outer peripheral wall of the furnace flange 11 away from the first exhaust channel 1441 so as to facilitate the installation of the vacuum joint 15 for connecting the exhaust device.

In this embodiment, the chamber sealing assembly further includes an upper gasket ring 141 and a lower gasket ring 142, wherein the sealing ring 143 and the sealing spacer ring 144 are disposed between the upper gasket ring 141 and the lower gasket ring 142. The upper gasket ring 141 and the lower gasket ring 142 are used to fix the two sealing rings 143 immobile.

In this embodiment, the upper end of the upper backing ring 141 is in contact with the upper furnace body 12; the lower end of the lower backing ring 142 is in contact with the lower end cover (not shown). Moreover, the upper furnace body 12, the furnace flange 11 and the lower end cover are fixed together by screws, and by tightening the screws, the upper furnace body 12 and the lower end cover compress the two sealing rings 143 along the axial direction of the reaction chamber 10 , So that the sealing ring 143 expands and deforms in the radial direction of the reaction chamber 10, so that the gap between the furnace flange 11 and the reaction chamber 10 is sealed.

It should be noted that, in this embodiment, there are two sealing rings 143, but the present invention is not limited to this. In practical applications, there may be one or more than three sealing rings 143. In this case, the structure and number of seal spacers can be adaptively improved as long as the seal ring can be fixed.

As another technical solution, an embodiment of the present invention further provides a growth furnace, which includes a reaction chamber, an upper chamber bore, and a lower chamber bore, and the upper chamber bore and the lower chamber bore are respectively sleeved on the upper end and the lower end of the reaction chamber; Moreover, the upper chamber and the lower chamber both include a flange end cover, a furnace flange and a furnace body stacked in this order from the bottom to the top; wherein, the inner peripheral wall of the furnace flange and the outer peripheral wall of the reaction chamber have a ring shape Gap; a chamber seal assembly is provided in the annular gap for sealing the furnace flange and the reaction chamber. The chamber sealing assembly adopts the above chamber sealing assembly provided by the embodiment of the present invention.

In this embodiment, the growth furnace includes a vacuum joint, an exhaust pipe, and an exhaust pump, wherein the vacuum joint is connected to the second end of the second exhaust passage; the exhaust pipe is connected to the exhaust pump and the vacuum joint, respectively.

The growth furnace provided by the embodiment of the present invention, by using the above chamber sealing assembly provided by the embodiment of the present invention, can not only prevent air from leaking into the reaction chamber, but also improve the efficiency of disassembly and maintenance of the chamber and avoid existing damage reactions Cavity risk.

It can be understood that the above embodiments are merely exemplary embodiments adopted for explaining the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various variations and improvements can be made without departing from the spirit and essence of the present invention, and these variations and improvements are also regarded as the protection scope of the present invention.

Claims

A chamber sealing assembly is provided around the furnace flange and the reaction chamber. It is characterized by comprising a sealing spacer ring and sealing rings respectively provided on both axial sides of the sealing spacer ring; A first extraction channel is provided in the sealing spacer ring, and the first extraction channel communicates with the inner side of the sealing spacer ring; and, a second extraction channel is provided in the furnace flange, the first The two suction channels are respectively connected to the first suction channel and the suction device.
The chamber sealing assembly according to claim 1, wherein the first suction channel includes a plurality of suction holes uniformly distributed along the circumferential direction of the sealing spacer, each of the suction holes passing through In the sealing spacer ring.
The chamber seal assembly according to claim 2, wherein an annular groove is formed on the inner peripheral wall of the sealing spacer ring, and the inner end of each of the air suction holes is located in the annular groove.
The chamber sealing assembly according to claim 2, wherein the diameter of the suction hole is a quarter of the axial thickness of the sealing spacer ring.
The chamber sealing assembly according to claim 2, wherein the number of the suction holes is 12-36.
The chamber seal assembly according to claim 2, wherein the inner end of the suction hole is located at an intermediate position of the axial thickness of the seal spacer.
The chamber sealing assembly according to claim 1, wherein an end of the second exhaust passage away from the first exhaust passage is located on the outer peripheral wall of the furnace flange.
The chamber sealing assembly according to any one of claims 1-7, further comprising an upper gasket ring and a lower gasket ring, and the sealing ring and the sealing spacer ring are disposed on the upper gasket ring and Between the lower backing ring.
A growth furnace includes a reaction chamber, an upper chamber and a lower chamber, the upper chamber and the lower chamber are sleeved on the upper and lower ends of the reaction chamber; and, the upper chamber and the lower chamber Each cavity includes a flange end cover, a furnace flange and a furnace body stacked in this order from bottom to top; wherein, there is an annular gap between the inner peripheral wall of the furnace flange and the outer peripheral wall of the reaction cavity;

It is characterized in that a chamber seal assembly is provided in the annular gap, and the chamber seal assembly adopts the chamber seal assembly according to any one of claims 1-8.
The growth furnace according to claim 9, characterized in that the gas extraction device comprises a vacuum joint, a gas extraction pipeline and an gas extraction pump, wherein,

The vacuum joint is connected to the second end of the second suction channel;

The suction line is respectively connected to the suction pump and the vacuum joint.