JP2003213429A - Cvd apparatus, and cvd film depositing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CVD apparatus capable of depositing a uniform ceramic film over the entire surface of a base material by correctly and rapidly moving the supporting position of the base material without interrupting a CVD reaction, and a CVD film depositing method by the CVD apparatus. <P>SOLUTION: This CVD apparatus comprises a rotary shaft 4 installed in a CVD reaction vessel, a base material supporting member 1 to support the base material 2 with at least three supporting blades 3 radially and circumferentially provided around the rotary shaft 4, and a movable supporter 5 disposed at the concentric position on the outer side of the base material supporting member 1, and the movable supporter 5 has an end part 6 of the size larger than the thickness of the base material supporting member on a tip thereof, and has an arm-shaped supporting tool 7 which is provided in an expandable, rotatable and vertically movable manner. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a CVD method (Chemical Vapor Deposition method) to, for example, SiC, B ₄ C or Si ₃ N on a substrate surface such as a graphite material or a carbon fiber reinforced carbon composite material.
_{The present invention} relates to a CVD apparatus suitable for forming a ceramic coating such as ₄ and a method for forming a ceramic coating by the CVD apparatus.

[0002]

2. Description of the Related Art For example, a graphite substrate is made of Si by a CVD method.
The SiC-coated graphite material with the C coating has a high-purity S on the surface.
Since the iC film is deposited, it has excellent non-contamination properties, and has high thermal shock resistance against rapid heat and rapid cooling, and is chemically stable and highly corrosion resistant, so it can be used as a susceptor and liner for various heat treatments in semiconductor manufacturing. It is useful as a member requiring heat resistance, such as a tube, a process tube, a wafer boat, and a member for pulling a single crystal.

The formation of the SiC coating by the CVD method uses, for example, hydrogen gas as a carrier gas, CH ₃ SiCl ₃ and (CH ₃ ) ₃ SiC containing Si atoms and C atoms in one molecule.
l, CH ₃ method for reducing thermal decomposition of organic silicon compound, such as SiHCl ₂ in a gas phase or a method of SiC is vapor deposited by a method of vapor-phase reaction of carbon compounds such as SiCl ₄ silicon compounds such as and CH _4, Done in.

However, in the conventional film formation by the CVD method, the substrate to be processed is placed on the upper part of the rotating shaft in the CVD reaction container via the substrate supporting member, and the raw material gas is subjected to the CVD reaction while rotating. However, since the raw material gas does not enter the portion where the substrate to be treated comes into contact with the substrate supporting member, the SiC coating is not formed. Therefore, when forming a SiC film on the entire surface of the base material, it is necessary to interrupt the CVD reaction midway to change the contact position between the base material to be processed and the base material supporting member, resulting in an inefficient film forming process. There is a drawback of being inefficient.

In view of this, in Japanese Patent Laid-Open No. 58-125608, a step of alternately forming a step of forming a SiC film on the surface of a graphite plate and a step of changing the holding position of the graphite plate in the furnace is performed.
A method for forming a C film and a quartz cover having a graphite plate support rod on the upper surface were installed, and a flange supporting a part of the quartz plate was provided at a position concentric with the quartz cover in a furnace having a gas introduction tube opened. A SiC film forming apparatus has been proposed in which a rotating cylinder provided is rotatably installed vertically and vertically. However, this method and apparatus have a low efficiency of forming a SiC film because the CVD reaction is interrupted once and replaced with a hydrogen gas atmosphere when the holding position of the graphite plate is changed. There is a problem in that the crystal properties of the SiC particles are slightly changed, so that the SiC particles tend to form a layer and cause inter-film separation.

Further, Japanese Patent Laid-Open No. 8-100265 discloses a CVD apparatus in which a support member for supporting a substrate to be processed is provided in a CVD reaction furnace, wherein the support member is intermittent and minute. A CVD apparatus characterized by having a shock mechanism for applying a shock, and a method of applying a minute shock to perform coating while sequentially displacing a contact portion between a substrate to be treated and a supporting member.
A method of forming a VD coating is disclosed. However, changing the support position by applying intermittent micro shocks is not only difficult to change the support position accurately, but also difficult to apply when the shape of the substrate to be treated is complicated or large. There's a problem.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above problems and, for example, a ceramic film such as SiC or Si ₃ N ₄ is formed on a substrate surface such as a graphite material or a carbon fiber reinforced carbon composite material by a CVD method. A CVD apparatus capable of forming a uniform ceramic coating on the entire surface of a base material by precisely moving the supporting position of the base material to be processed without interrupting the CVD reaction when forming the It is an object to provide a method for forming a used ceramic coating.

[0008]

A CVD apparatus according to the present invention for achieving the above object comprises a rotary shaft 4 installed in a CVD reaction container, and three or more support blades 3 centering on the rotary shaft 4. The base material supporting member 1 that supports the base material 2 to be processed that is radially provided and the movable supporting member 5 that is arranged at a concentric position outside the base material supporting member 1 have the movable supporting member 5 at the tip. Having an end portion 6 having a shape larger than the thickness of the base material supporting member 1,
A structural feature is that the arm-shaped support jig 7 that is expandable / contractible and rotatable or vertically movable is provided.

Further, in the CVD film forming method using this apparatus, the substrate 2 to be processed is placed on the substrate supporting member 1 in the CVD reaction container.
In the process of forming a coating on the surface of the substrate by the CVD reaction while being placed on the rotary shaft 4 while rotating the rotary shaft 4, the rotary shaft 4 is temporarily stopped during the CVD reaction, and the movable support 5 is immediately moved.
Is operated to extend the arm-shaped support jig 7, insert the end portion 6 between the support blades 3 of the base material support member 1, and lift the substrate 2 to be processed by the end portion 6 of the arm-shaped support jig 7. The support blades 3 to separate them from the base material supporting member 1 and then to slightly rotate the rotary shaft 4 to shift the positions of the support blades 3, and then lower the base material 2 to be processed onto the base material supporting member 1 and then to an arm-shaped support jig. The constitutional feature is that 7 is retracted to move the support position of the substrate 2 to be processed on the substrate supporting member 1 and the rotary shaft 4 is operated and rotated.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described with reference to a graphite material containing SiC.
An example of forming a film will be described with reference to the drawings.
FIG. 1 is a perspective view showing a state in which a disk-shaped substrate 2 to be treated is placed on a substrate supporting member 1 installed in a CVD reaction container. The base material support member 1 is composed of three or more support blades 3 provided around the upper shaft of the rotary shaft 4 in order to stably support the base material 2 to be processed. ) Is shown as an example.

In FIG. 1, CVD heated to a predetermined temperature
While rotating the substrate support member 1 by rotating the rotating shaft 4 in the reaction container to rotate the substrate 2 to be treated placed on the substrate support member 1 at the same speed, A raw material gas of a compound or a silicon compound and a carbon compound is supplied together with hydrogen gas to cause a CVD reaction to form a SiC film on the surface of the substrate 2 to be treated.

In this case, the substrate 2 to be treated is the substrate supporting member 1.
Since it is supported by the supporting blades 3, the raw material gas cannot penetrate into the portion of the substrate 2 to be processed which is in contact with the supporting blades 3, and therefore the SiC coating cannot be formed.

The CVD apparatus of the present invention is capable of changing the position where the substrate 2 to be treated and the supporting blades 3 are in contact with each other without interrupting the CVD reaction, and the CVD reaction is continued while the CVD reaction is continued. By moving the supporting position of the treated substrate 2, it is possible to efficiently form the SiC coating on the entire surface of the substrate.

FIG. 2 is a cross-sectional view illustrating the CVD apparatus of the present invention, in which the movable supporting member 5 is arranged outside the base material supporting member 1, that is, outside the supporting blades 3, at concentric positions. The movable support 5 has an arm-like shape, and the tip of the movable support 5 has an end 6 having a shape larger than the thickness of the support blades 3 of the base material supporting member 1, and the arm-like support jig 7 is extendable. hand,
And it is installed so that it can rotate or move up and down. Note that FIG. 2 shows the arm-shaped support jig 7 in a retracted state.

In the movable supporting member 5, the arm-shaped supporting jig 7 is immediately extended after the rotary shaft 4 is stopped, and the end portions 6 are inserted between the supporting blades 3 to rotate the arm-shaped supporting jig 7. Alternatively, the end portion 6 lifts up the substrate 2 to be lifted to separate it from the substrate supporting member 1 and then the rotary shaft 4 is slightly rotated to shift the position, and then the arm-shaped supporting jig 7 is rotated or lowered again. Thus, the end portion 6 lowers the substrate 2 to be processed to the original position, and the contact position between the support blade 3 and the substrate 2 to be processed is moved. In order to smoothly perform this position change, the shape of the end portion 6 is preferably an elliptical plate.

Next, a method for forming a SiC film by this CVD apparatus will be described. 3 is a plan view of the cross-sectional view of the CVD apparatus shown in FIG. 2 installed in the CVD reaction container as seen from above, and the movable support tool 5 shows a state in which the arm-shaped support jig 7 is retracted. ing. In addition, although the case where the number of the movable supports 5 is two is illustrated in FIG. 3, it is preferable that the number is three or more in order to stably lift or lower the substrate 2 to be processed.

In this state, the rotary shaft is rotated, and while the substrate 2 to be processed is rotated, a CVD reaction is performed under a predetermined condition to form an SiC film having a desired thickness, and then the supply of the raw material gas is continued. As it is, the rotating shaft 4 is temporarily stopped without interrupting the CVD reaction, and the arm-shaped supporting jig is immediately extended to insert the end portion 6 between the supporting blades 3. That is, FIG. 4 shows a sectional view of the state where the end portion 6 is inserted in the state of FIG.

In FIG. 4, for example, the shape of the end portion 6 is elliptical, and the end of the elliptical shape end portion 6 has an arm-shaped support jig 7.
When the arm-shaped support jig 7 is gently rotated and then rotated, for example, by 180 degrees, the thickness of the support blade 3 becomes larger than that of the support blade 3 as shown in FIG. , Can be separated from the support blade 3.

Next, when the rotary shaft 4 is slightly rotated in this state and rotated by an appropriate angle, for example, in the range of 20 to 70 degrees, the position of the support blade 3 shifts as shown in the plan view of FIG. The contact position for supporting the substrate 2 to be treated can be changed. In this state, if the arm-shaped support jig 7 is rotated and returned to the original state, the substrate 2 to be treated can be seated on the support blade 3 at a contact position different from that before, as shown in FIG. Therefore, the support position can be moved. Next, the arm-shaped support jig 7 is retracted and returned to the state shown in FIG.

Then, by immediately actuating and rotating the rotary shaft 4, the supporting position at which the substrate 2 to be treated comes into contact with the supporting blades 3 of the substrate supporting member 1 is moved, and the raw material gas can penetrate until then. The SiC coating can be formed also on the contact portion where the SiC coating was not formed.

Since a series of these operations can be carried out in an extremely short time, it becomes possible to move or change the supporting position of the substrate to be treated without interrupting the CVD reaction, and to efficiently and efficiently
The SiC coating can be efficiently and uniformly formed on the entire surface of the substrate to be treated. The operation of moving the support position is 1
2 in 1 SiC coating formation process
By performing it more than once, it is possible to form a more uniform SiC film.

[0022]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples.

Example 1 The CVD apparatus shown in FIG. 2 was installed in a CVD reaction vessel,
Cylindrical high-purity graphite material (φ200 × 10t × 100L) was placed as a base material on a base material support member in which four support blades were provided in a cross shape around a rotating shaft, and the air in the system was exhausted. After 1400
The system was heated to a temperature of ° C and hydrogen gas was introduced to replace the system with a hydrogen gas atmosphere. Then, methyltrichlorosilane (CH ₃ SiCl ₃ ) was used as a source gas, and hydrogen gas was used as a carrier gas, and the concentration of methyltrichlorosilane in the mixed gas of methyltrichlorosilane / hydrogen was 7.5 Vol%.
And a SiC coating was formed on the surface of the graphite substrate. In addition,
As the CVD reaction conditions, after performing the CVD reaction for 1 hour under the above conditions, the rotating shaft is stopped, the arm-shaped supporting jig is extended, and the elliptical end portions are inserted between the supporting blades, and the graphite base is formed by the end portions. The material was lifted up, and then the graphite base material was lowered by the rear end portion of which the rotation axis was turned by 30 degrees to be seated on the base material support member. Immediately thereafter, the arm-shaped support jig was retracted and the rotary shaft was rotated. Further, after 1 hour, the same operation was performed to carry out a CVD reaction for a total of 3 hours, and during that time, the supporting position was moved twice every hour, and the SiC film was formed by changing to 3 supporting positions.

Example 2 An SiC film was formed by the same method as in Example 1 except that a disc-shaped high-purity graphite material having a diameter of 200 × 5 t was used as the substrate.

Comparative Example 1 A SiC film was formed by the same method as in Example 1 except that the supporting position of the base material was not moved.

Comparative Example 2 A SiC film was formed by the same method as in Example 2 except that the supporting position of the base material was not moved.

The S produced by the CVD method thus produced
Regarding the SiC-coated graphite material on which the iC coating is formed, the state of formation of the SiC coating on the base material supporting portion and the cut cross section are SEM.
The film thickness of the SiC coating was measured by observation, and the results are shown in Table 1.

[0028]

[Table 1]

In Examples 1 and 2, SiC is also used for the base material supporting portion.
A film is formed, and its film thickness is sufficient as compared with the film thickness other than that of the supporting portion.
It can be seen that a coating is formed. On the other hand, in Comparative Examples 1 and 2, since the CVD reaction was performed without moving the supporting position, the SiC coating was not formed on the base material supporting portion, and the graphite material was exposed at that portion. Therefore, the strength characteristics and the corrosion resistance are reduced.

[0030]

As described above, according to the CVD apparatus and the CVD film forming method of the present invention, the supporting position of the substrate to be treated can be moved accurately and promptly without interrupting the CVD reaction, and the efficiency can be improved efficiently. It is possible to uniformly form a ceramic film on the entire surface of the base material. Therefore, it is extremely useful as a manufacturing apparatus and a manufacturing method for a member having heat resistance required, for example, various heat-treating members in semiconductor manufacturing, in which a ceramic film is formed on the entire surface of a substrate such as a graphite material by the CVD method.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a disk-shaped substrate to be processed is placed on a substrate supporting member installed in a CVD reaction container.

FIG. 2 is a sectional view schematically illustrating a CVD apparatus of the present invention.

FIG. 3 is a plan view of the cross-sectional view of FIG. 2 as seen from above.

FIG. 4 is a cross-sectional view schematically showing a state in which an end portion is inserted between the support blades in FIG.

FIG. 5 is a cross-sectional view that schematically shows a state in which the substrate to be processed is lifted and separated from the support blade.

FIG. 6 is a plan view schematically showing a state in which the support blades are displaced and the contact position for supporting the substrate to be processed is moved.

FIG. 7 is a cross-sectional view that schematically shows a state in which the substrate to be treated is moved to a contact position with the support blade and then seated on the support blade.

[Explanation of symbols]

1 Base material support member 2 Base material 3 support blades 4 rotation axes 5 Movable support 6 edge 7 Arm-shaped support jig

Claims (3)

[Claims] 1. A rotary shaft 4 installed in a CVD reaction vessel.
And a base material supporting member 1 for supporting a base material 2 to be processed having three or more supporting blades 3 arranged radially around a rotary shaft 4, and the base material supporting member 1 is arranged outside the base material supporting member 1 at concentric positions. It is composed of a movable supporting member 5, and the movable supporting member 5 has a base material supporting member 1 at its tip.
A CVD apparatus comprising an arm-shaped support jig 7 having an end portion 6 having a shape larger than the thickness of the arm support member, the arm-shaped support jig 7 being expandable and contractable and rotatable or vertically movable. 2. The CVD apparatus according to claim 1, wherein the end portion 6 of the movable support 5 is an elliptical plate. 3. A substrate 2 to be processed is placed on a substrate supporting member 1 in a CVD reaction vessel, and a CV is rotated while rotating a rotating shaft 4.
In the process of forming a film on the surface of the base material by the D reaction, the rotary shaft 4 is temporarily stopped during the CVD reaction, and immediately the movable support tool 5 is operated to extend the arm-shaped support jig 7 to extend the base material support member. Insert the end portion 6 between the supporting blades 3 of 1,
The base material 2 to be processed is lifted by the end portion 6 of the arm-shaped support jig 7 to be separated from the base material support member 1, and then the rotary shaft 4 is slightly rotated to shift the position of the support blades 3. The material 2 is lowered onto the base material support member 1, and then the arm-shaped support jig 7 is retracted to move the support position of the base material 2 to be processed on the base material support member 1 and the rotary shaft 4 is operated and rotated. A CVD film forming method characterized by the above.