JP2010070797A - SiC COATED CARBON MEMBER, AND MANUFACTURING METHOD THEREOF - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a SiC coated carbon member in which members with a SiC coating film being formed thereon in advance can be firmly joined with each other, and a uniform SiC coating layer is formed in an internal space (a hollow part), and a manufacturing method thereof. <P>SOLUTION: In the SiC coated carbon member 1, a plurality of carbon base bodies 2a, 3a with a SiC coating film being formed at least on its surface are joined with each other, and a joined layer of a carbon base body 2 with a carbon base body 3 is constituted of SiC coating films 2b, 3b consisting of each single layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an SiC-coated carbon member and an SiC-coated carbon member manufacturing method, and more particularly to an SiC-coated carbon member obtained by bonding a plurality of SiC-coated carbon substrates and an SiC-coated carbon member manufacturing method.

  In order to supply high-quality products in semiconductor manufacturing, it is important to avoid contamination due to impurity metals and particles. That is, the contamination by the impurity metal or the like is a factor that causes a decrease in the yield of semiconductor products such as generation of crystal defects in the wafer, abnormal crystal growth, change in resistance value, change in breakdown voltage, and the like.

Semiconductors such as wafer boats, boat tables, furnace core tubes, susceptors, and trays used in heat treatment processes for silicon wafers, etc. to avoid contamination as described above, and to ensure improved yield and stable operation of semiconductor products. Conventionally, jigs for heat treatment use quartz glass (SiO ₂ with relatively few particles). ) Materials, silicon carbide (SiC) materials, silicon-silicon carbide (Si-SiC) composite materials, carbon (C) materials, and other ceramic members are used.

Further, a silicon carbide-coated ceramic in which silicon carbide (SiC) is coated on a base made of a silicon carbide (SiC) material, a silicon-silicon carbide (Si-SiC) composite material, a carbon (C) material, a silicon (Si) material, or the like. Made parts are used.
These silicon carbide coated ceramic members coated with silicon carbide (SiC) can be used stably even at a high temperature of 1200 ° C. or higher, and have excellent corrosion resistance against hydrofluoric acid and mixed acids, and also have excellent durability. It has the advantage of being

For this reason, in the case of a semiconductor heat treatment jig used in a high temperature region, the silicon carbide-coated ceramic member is mainly used although the cost is higher than that of a quartz glass material.
In particular, an SiC-coated carbon member in which silicon carbide (SiC) is coated on a carbon (C) substrate is easy to precisely process the carbon substrate. Therefore, as shown in Patent Document 1, a complicated shape such as a susceptor is used. Widely used for members and the like.

Incidentally, as shown in FIG. 4, the susceptor 20 shown in Patent Document 1 is composed of a carbon base, an upper member 21 on which the wafer W is placed, and a carbon base similar to the upper member 21. The lower member 22 is formed with a hollow portion (internal space portion) 23 between the upper members 21. In addition, an opening 22 a communicating with the hollow portion (internal space portion) 23 is formed on the lower surface of the lower member 22.
Further, the upper member 21 and the lower member 22 are covered with a SiC film over the entire surface including the inner surface of the hollow portion 23. The coating of the SiC film is formed by a CVD method or the like. In the figure, reference numeral 24 is a gas supply pipe, and 25 is a gas outlet. H is a heater.
Japanese Patent No. 2628394

In the susceptor shown in Patent Document 1, the upper member and the lower member are joined, and the entire outer surface and the inner surface of the hollow portion are covered with a SiC film by a CVD method or the like.
However, after assembling the upper member and the lower member, it has been difficult to uniformly and completely cover the inner surface of the hollow portion with the SiC film by a CVD method or the like. That is, it is difficult to uniformly distribute the film forming gas for forming the SiC film in the hollow portion (internal space portion), and in particular, when the shape of the hollow portion (internal space portion) is complicated, It was difficult to coat the membrane uniformly and completely.

  As a method for solving this, a method of forming a SiC coating film in advance and bonding the members on which the SiC coating film is formed is also conceivable, but a bonding layer different from the SiC coating film is formed at the joint, There is a possibility that a new technical problem such as peeling occurs in the bonding layer portion.

Therefore, it is difficult for the inventor of the present application to form a SiC film uniformly and completely by a CVD method or the like after assembling the carbon base. Especially, when the shape of the internal space is complicated, the SiC film is made uniform. And based on the knowledge that it would be more difficult to form completely, we conducted diligent research on the premise that a plurality of carbon bases on which a SiC coating film was previously formed were bonded.
That is, the inventor of the present application has earnestly studied a method for joining members having SiC coating films formed in advance, and has come up with a SiC-coated carbon member and a method for producing a SiC-coated carbon member that can suppress separation at the joined portion. Thus, the present invention has been completed.

  As described above, the present invention is capable of firmly joining the members on which the SiC coating film is formed in advance, and the SiC-coated carbon member in which a uniform SiC coating layer is formed in the internal space (hollow portion), and It aims at providing the manufacturing method of a SiC covering carbon member.

  An SiC-coated carbon member according to the present invention, which has been made to solve the above-described problems, is an SiC-coated carbon member obtained by bonding a plurality of carbon substrates each having a SiC coating film formed on at least a surface thereof. The bonding layer of the carbon base is characterized by being composed of a single-layer SiC coating film.

  Thus, the SiC covering carbon members concerning this invention are joined by the SiC coating film which consists of a single layer. That is, a new bonding layer different from the SiC coating film covering the carbon member is newly formed, and the SiC coating carbon members are not bonded to each other by this bonding layer, but are bonded by the SiC coating film. Moreover, peeling between SiC-coated carbon members can be suppressed.

Here, in the SiC coating film of the bonding layer for bonding the carbon substrate, the average particle diameter of the SiC coating film in the vicinity of the bonding surface away from the carbon substrate is SiC near the interface between the carbon substrate and the SiC coating film. It is desirable that it is larger than the average particle diameter of the coating film.
Thus, by making the SiC coating film having a small particle size in the vicinity of the interface between the carbon substrate and the SiC coating film, the thermal stress strain generated at the interface between the carbon substrate and the SiC coating film is easily dispersed, Since it can suppress that the flatness of a joint surface is impaired in joining temperature, it is advantageous in obtaining a stronger SiC coating-film joined body.
Further, the particle size of the large SiC coating film in the vicinity of the bonding surface reduces the SiC crystal grain boundaries having low bonding stability in the vicinity of the bonding surface, and increases the bonding of strong and chemically stable SiC crystal particles. This effect is the same when the particle diameter increases stepwise or continuously from the vicinity of the interface between the carbon substrate and the SiC coating film to the vicinity of the bonding surface of the SiC coating film.

Further, the bonding layer of the carbon substrate and the carbon substrate is composed of a single layer SiC coating film, and a single layer SiC coating film is formed on the surface exposed to the outside of the carbon substrate, It is desirable that the SiC coating film formed on the surface exposed to the outside and the bonding layer are formed of the same layer.
As described above, the SiC coating film formed on the surface exposed to the outside and the bonding layer are formed of the same layer, so that the interface between the bonding layer and the SiC coating film on the surface exposed to the outside is formed. Since there is no distortion in the part and a physically strong bond is obtained, it is possible to suppress physical damage to the SiC coating film from the boundary between the bonding layer and the surface exposed to the outside in a high-temperature thermal cycle. The durability can be further improved.

Further, the bonding layer between the carbon substrate and the carbon substrate is composed of a single-layer SiC coating film, and a single layer of the SiC coating film is formed on the surface exposed to the outside of the carbon substrate. At the same time, it is desirable that a plurality of SiC coating films be formed on at least a part of the exposed surface.
The surface exposed to the outside, for example, when used as a semiconductor heat treatment jig, is exposed to various metal elements or acidic or basic gas species, whether intentionally or unintentionally, to form a metal silicide. And chemical damage such as generation of silicon-containing gas by acid and base or erosion combined with them.
On the other hand, if a plurality of SiC coating films are formed on at least a part of the surface exposed to the outside, the progress of the chemical damage is diffused between the layers of the plurality of SiC coating films. Since the occurrence of so-called stress corrosion cracking is suppressed, the durability of the SiC-coated carbon bonded by the SiC coating film according to the present invention can be further enhanced.

  In addition, a method for producing a SiC-coated carbon member according to the present invention, which has been made to solve the above-described problems, includes a processing step of forming a carbon substrate into a predetermined size and shape, and a coating of SiC on the carbon substrate after the processing step. A step of forming a film, and at least two or more carbon bases on which the SiC coating film is formed are combined, and a high temperature treatment is performed to form a SiC coating film composed of a single layer on the combined portion; And a step of bonding the carbon substrates together.

In this way, the carbon bases on which the SiC coating film is formed in advance are put together, and a SiC coating film made of a single layer is formed on the mating portion by high-temperature treatment. And since carbon base | substrates are joined by the SiC coating film which consists of this single layer, peeling of SiC covering carbon members can be suppressed.
That is, a new bonding layer different from the SiC coating film covering the carbon member is newly formed, and the SiC coating carbon members are not bonded to each other by this bonding layer, but are bonded by the SiC coating film. Moreover, peeling between SiC-coated carbon members can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the SiC coating | coated carbon member and SiC coating | coated carbon in which the member in which the SiC coating film was formed beforehand can be joined firmly, and the uniform SiC coating layer was formed in internal space (hollow part) A member manufacturing method can be obtained.

  An embodiment of the present invention will be described with reference to FIGS. 1 and 2, taking as an example an introduction gas heating plate for heating a gas introduced into a reaction furnace, which is used in the semiconductor manufacturing field. 1 is a front view of the introduction gas heating plate, and FIG. 2 is a cross-sectional view taken along the line II in FIG.

The introduced gas heating plate 1 is obtained by joining a member 2 made of a carbon base 2a in which a groove 2c is formed and a member 3 made of a carbon base 3a in which a groove 3c is formed.
An SiC coating film 2b is formed on the surface of the carbon substrate 2a in the member 2. An SiC coating film 3b is formed on the surface of the carbon substrate 3a in the member 3. The grooves 2c and the grooves 3c of the carbon bases 2a and 3a on which the SiC coating films 2b and 3b are formed are joined so that one flow path (internal space portion) 4 is formed.

Specifically, first, a carbon material is processed, and the carbon bases 2a and 3a are processed into predetermined dimensions and shapes. At this time, grooves 2c and 3c are formed in the carbon bases 2a and 3a.
Thereafter, SiC coating films 2b and 3b are formed on the carbon substrates 2a and 3a, respectively. In order to form this SiC coating film, it can be formed by a known method such as a CVD method.

For example, it can be formed by introducing methyltrichlorosilane ((CH ₃ ) S: Cl ₃ ) diluted to a concentration of 10% with hydrogen gas at a pressure of 200 torr and holding at 1350 ° C. for 2 hours.
The thickness of the SiC coating film formed under these conditions was 30 μm, and the average particle diameter of SiC was 7 μm.

Further, after forming the SiC coating film, the members 2 and 3 are accommodated in a heat treatment furnace (not shown) while the bonding surfaces 2d and 3d of the carbon substrates 2a and 3a are in physical contact with each other, and 1 torr or less. And heat treatment at 1650 ° C. or higher.
By this heat treatment, the SiC coating film on the bonding surface is repeatedly vaporized and recrystallized, and after a predetermined time (for example, 15 hours), a single SiC coating film layer is formed by PVD (physical vapor deposition). Formed as.

Since the introduction gas heating plate 1 is configured as described above, the outer surfaces of the members 2 and 3 and the inner surface of the flow path 4 are completely covered with a uniform SiC coating film. ing.
In addition, since the members 2 and 3 are joined by the SiC coating film made of a single layer, they can be joined firmly, and the separation of the SiC-coated carbon members can be suppressed.

Here, when joining the members 2 and 3 described above, it is preferable to introduce a gas species containing Si such as SiCl ₄ into the heat treatment furnace. This is because when the Si gas phase contains a large amount of Si component, the activation enthalpy when the SiC coating film is vaporized is reduced, and the vaporization reaction of the SiC coating film surface layer having a very low vapor pressure is promoted. This is preferable because the frequency of vaporization and recrystallization of the SiC coating film increases and the time required for bonding is shortened.

  Moreover, it is preferable to introduce a small amount of a gas species containing a C component such as propane simultaneously with the gas species containing the Si component. When the gap between the bonding surface 2d and the bonding surface 3d is large, the introduction of a gas species containing a C component causes the formation of an SiC coating film by CVD (chemical vapor deposition), and the PVD fills the gap. This is preferable because it shortens the time to the time.

Further, as shown in FIG. 3, in the SiC coating films 2b and 3b of the bonding layer for bonding the carbon substrates 2 and 3, the particles 2e of the SiC coating film in the vicinity of the bonding surface apart from the carbon substrates 2 and 3 are used. The average particle size of 3e is desirably larger than the average particle size of the SiC coating film particles 2f and 3f in the vicinity of the interface between the carbon substrates 2 and 3 and the SiC coating film. By making the heat treatment temperature in the step of forming the SiC coating films 2b and 3b on the members 2 and 3 lower than the heat treatment temperature in the joining step of the members 2 and 3, as shown in FIG. However, the SiC particle size of the SiC coating films 2b and 3b can be increased on the bonding surfaces 2d and 3d.
Thus, by making the SiC coating film having a small particle size in the vicinity of the interface between the carbon substrate and the SiC coating film, the thermal stress strain generated at the interface between the carbon substrate and the SiC coating film is easily dispersed, Since it can suppress that the flatness of a joint surface is impaired in joining temperature, it is advantageous in obtaining a stronger SiC coating-film joined body.
Further, the particle size of the large SiC coating film in the vicinity of the bonding surface reduces the SiC crystal grain boundaries having low bonding stability in the vicinity of the bonding surface, and increases the bonding of strong and chemically stable SiC crystal particles. This effect is the same when the particle diameter increases stepwise or continuously from the vicinity of the interface between the carbon substrate and the SiC coating film to the vicinity of the bonding surface of the SiC coating film.

Specifically, the heat treatment temperature for forming the SiC coating film on the members 2 and 3 is 1350 ° C., and the SiC coating film having an average SiC particle size of 7 μm is formed.
When the heat treatment temperature in the subsequent joining process of the members 2 and 3 is 1800 ° C. and is held under a condition of 0.1 torr for 8 hours, particles of the SiC coating film in the vicinity of the joining surface apart from the carbon substrates 2a and 3a The average particle diameters of 2e and 3e are 30 μm, and the average particle diameters of the SiC coating film particles 2f and 3f in the vicinity of the interface between the carbon substrates 2a and 3a and the SiC coating films 2b and 3b can be 7 μm. .

Further, after completion of the bonding, the portions corresponding to the bonding surfaces 2d and 3d are masked, and a SiC coating film is newly formed in addition to the bonding portion, so that the SiC coating film other than the bonding portion may have a plurality of layers. . That is, the bonding surfaces 2d and 3d of the carbon substrate 2a and the carbon substrate 3a are composed of a single layer of the SiC coating films 2b and 3b, and are further formed on at least a part of the surface exposed to the outside (outer surfaces of the members 2 and 3). A plurality of SiC coating films may be formed.
Thus, when a plurality of layers of the SiC coating film is formed on at least a part of the surface exposed to the outside (outer surfaces of the members 2 and 3), stress corrosion cracking can be suppressed. preferable.
Of course, a plurality of layers of SiC coating films may be formed in the entire region of the surface exposed to the outside (the outer surfaces of the members 2 and 3).

  As described above, a single SiC coating layer is formed on all surfaces including the internal space of the SiC-coated carbon member, and a single layer of SiC coating film is also formed at the junction. It is possible to obtain a coated carbon member that can withstand various heat cycles.

Example 1
Grooves 2a and 3a are formed in the carbon bases 2 and 3 and processed into a predetermined shape, followed by high-purity treatment with chlorine gas, and introduction of 1300 ° C. and 300 torr (CH ₃ ) SiCl ₃ by a chemical vapor deposition method. Then, a SiC coating film was formed on the surface, and members 2 and 3 were formed.
A uniform SiC coating film having a thickness of 30 μm was formed on the surfaces of the members 2 and 3 at this time.
The average particle diameter of this SiC coating film was 7 μm.

Thereafter, the bonded surfaces of the members 2 and 3 were brought into physical contact with each other and heat-treated at 1800 ° C. and 0.1 torr for 13 hours to obtain the SiC-coated carbon member 1 shown in FIG.
A uniform SiC coating film having a thickness of 30 μm was formed on the surfaces of the members 2 and 3 at this time, and a uniform SiC coating film having a thickness of 65 μm was formed as the bonding layer.
The average particle size of the SiC coating film was 7 μm, and the average particle size of the SiC coating film of the bonding layer was 20 μm.

(Comparative Example 1)
In the same manner as in Example 1, members 2 and 3 on which the SiC coating film was formed were formed. Thereafter, the bonding surfaces were brought into physical contact with each other in the same manner as in Example 1 except that bonding was performed by forming a CVD-SiC coating film by introducing 1300 ° C. and 300 torr (CH ₃ ) SiCl ₃ . A SiC-coated carbon was obtained.

(Comparative Example 2)
After the grooves 2a and 3a are formed on the carbon substrate and processed into a predetermined shape, the members 2 and 3 are bonded using a carbon paste and subjected to high-purity treatment by a known method, and 1300 ° C., 300 torr (CH ₃ ). SiCl ₃ was introduced to form a SiC coating film on the surface to obtain SiC coated carbon of Comparative Example 2.

The SiC-coated carbon members of the examples and comparative examples were cut, the state of the SiC coating film formed on the gas flow path 4 was confirmed, and the temperature was raised from 500 ° C. to 1000 ° C. in 2 minutes by lamp heating, and 2 minutes The joining state of the joining surfaces 2d and 3d when the thermal cycle for cooling at 500 was repeated 500 times was confirmed. The results are shown in Table 1.
In Table 1, “◯” means “good”, “Δ” means partial defect, and “x” means fracture or partial non-film formation.

  In the above embodiment, the introduction gas heating plate has been described as an example. However, the present invention is not limited to this, and the wafer boat, the boat table, the furnace core tube, the tray, as the susceptor first described in the conventional example, are not limited thereto. It can be used for various semiconductor heat treatment jigs.

FIG. 1 is a front view of an introduction gas heating plate which is an example of a SiC-coated carbon member according to the present invention. 2 is a cross-sectional view taken along the line II in FIG. FIG. 3 is a schematic diagram showing the state of SiC particles on the bonded surface of the SiC-coated carbon member. FIG. 4 is a cross-sectional view of a susceptor showing an example in which a SiC-coated carbon member is used.

Explanation of symbols

1 Introducing gas heating plate (SiC coated carbon member)
2 Member 2a Carbon substrate 2b SiC coating film 2c Groove 2d Bonding surface 2e SiC coating film particle 2f near the bonding surface away from the carbon substrate 2f SiC coating film particle 3 near the interface between the carbon substrate and the SiC coating film Member 3a Carbon substrate 3b SiC coating film 3c Groove 3d Bonding surface 3e SiC coating film particle 3f near the bonding surface away from the carbon substrate 3f SiC coating film particle 4 near the interface between the carbon substrate and the SiC coating film Road

Claims (5)

A SiC-coated carbon member obtained by bonding a plurality of carbon substrates having a SiC coating film formed on at least a surface thereof,
A SiC-coated carbon member, wherein the bonding layer between the carbon substrate and the carbon substrate is composed of a single-layer SiC coating film. In the SiC coating film of the bonding layer for bonding the carbon substrate,
The average particle diameter of the SiC coating film in the vicinity of the bonding surface away from the carbon substrate is larger than the average particle diameter of the SiC coating film in the vicinity of the interface between the carbon substrate and the SiC coating film. 2. The SiC-coated carbon member according to 1. A bonding layer between the carbon substrate and the carbon substrate is composed of a single layer SiC coating film, and a single layer SiC coating film is formed on a surface exposed to the outside of the carbon substrate;
3. The SiC-coated carbon member according to claim 1, wherein the SiC coating film formed on the surface exposed to the outside and the bonding layer are formed of the same layer. 4.   A bonding layer between the carbon substrate and the carbon substrate is composed of a single layer SiC coating film, and a single layer SiC coating film is formed on a surface exposed to the outside of the carbon substrate; 4. The SiC-coated carbon member according to claim 1, wherein a plurality of SiC coating films are formed on at least a part of the exposed surface. 5. A processing step of forming the carbon substrate into a predetermined size and shape;
Forming a SiC coating film on the carbon substrate that has undergone the processing step;
A step of joining at least two or more carbon substrates on which the SiC coating film is formed, forming a SiC coating film made of a single layer on the mating portion by high-temperature treatment, and bonding the carbon substrates together And a method for producing a SiC-coated carbon member.

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