JP2017011102A - Cleaning method of deposition apparatus of silicon carbide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method of a deposition apparatus of a silicon carbide film capable of selectively removing a SiC deposit formed on a TaC coat coating a member and such in a chamber while protecting the TaC coat.SOLUTION: The cleaning method of a deposition apparatus of a silicon carbide film includes: a first step of introducing a hydrogen halide gas into a chamber; and a second step of introducing an oxygen gas into the chamber after the first step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for cleaning a silicon carbide film forming apparatus for forming a thin film of silicon carbide (hereinafter also referred to as “SiC”). More specifically, the present invention relates to a cleaning method useful for removing SiC deposits deposited in a chamber of a silicon carbide film forming apparatus used for power semiconductor applications and the like.

  SiC has a wider band gap than silicon, high dielectric strength, high thermal conductivity, and the like, so that IGBT (Insulated Gate Bipolar Transistors) and SBD (Shot Key B Diode): It is used as a semiconductor element material for power devices such as Schottky barrier diodes).

  For the production of these SiC power devices, a substrate (hereinafter also referred to as “SiC epitaxial wafer”) obtained by epitaxially growing a SiC thin film on a SiC single crystal substrate using a film forming apparatus capable of epitaxial growth is used.

  A film forming apparatus capable of epitaxially growing a SiC thin film normally uses a method in which a susceptor is induction-heated to about 1400 to 1600 ° C. using a high-frequency power source, a SiC substrate is placed on the susceptor, and a source gas is introduced.

  During SiC epitaxial growth in such a film forming apparatus, SiC is deposited not only on the SiC substrate but also on members in the chamber, such as heat shield plates and sealing (top plate), chamber inner wall surface, source gas introduction nozzle, susceptor outer peripheral portion, etc. Things are generated. These SiC deposits become a generation source of particles flying in the chamber, and also drop on the SiC substrate or the SiC epitaxial film during epitaxial growth and cause lattice defects. Therefore, it is necessary to remove the SiC deposit when a certain amount is deposited.

  Examples of the technology for removing the SiC deposit in the chamber include a method in which a member in the chamber is taken out and physically peeled off, a method in which the member is replaced with a new one, or a removal by gas cleaning.

  Patent Document 1 describes a method of removing a SiC deposit by converting a fluorine-containing gas and an oxygen-containing gas into plasma.

Patent Document 2 describes a method of removing SiC deposits by circulating chlorine trifluoride (ClF ₃ ) while heating a susceptor.

JP 2013-46020 A JP 2012-28385 A

  However, in the cleaning method of Patent Document 1, when the susceptor is coated with tantalum carbide (TaC), the TaC protective layer is damaged by the plasma activated active species (for example, F radicals), and the SiC deposit and The problem of poor cleaning selectivity remains.

Also in the cleaning method of Patent Document 2, as in Patent Document 1, when the susceptor is coated with TaC, the active species generated from ClF ₃ are damaged by TaC, and the cleaning selectivity with the SiC deposit is poor. The problem remains.

  Accordingly, in the current situation, it is unavoidable to take out the members in the chamber as described above and physically peel off the SiC deposits or replace them with new ones.

  For this reason, there is a need for a method capable of selectively removing SiC deposits by gas cleaning while protecting the TaC coat in the SiC epitaxial wafer manufacturing apparatus.

  The present invention has been made in view of the above circumstances, and SiC deposits formed thereon can be selectively removed by gas cleaning while protecting the TaC coat coated on the members and the like in the chamber. An object of the present invention is to provide a cleaning method for a silicon carbide film forming apparatus capable of manufacturing an epitaxial wafer.

  As a result of intensive studies to solve the above problems, the present inventors first introduced hydrogen halide gas, then introduced oxygen gas to perform cleaning, while protecting the TaC coat. The inventors have found that the SiC deposit formed thereon can be selectively removed, and have arrived at the present invention. It has also been found that according to this method, the SiC deposit formed thereon can be selectively removed while protecting the SiC coating coated on the members in the chamber.

  The present invention employs the following means in order to solve the above problems.

(1) A cleaning method for a silicon carbide film forming apparatus, comprising: a first step of introducing hydrogen halide gas into a chamber; and a second step of introducing oxygen gas into the chamber after the first step.
(2) The method for cleaning a silicon carbide film deposition apparatus according to (1), wherein the hydrogen halide gas is a gas selected from the group consisting of HBr and HCl.
(3) The silicon carbide according to any one of (1) and (2), wherein the gas introduced in at least one of the first step and the second step is diluted with an inert gas A cleaning method for a film forming apparatus.
(4) The silicon carbide film forming apparatus according to any one of (1) to (3), wherein the first step and the second step are performed in a temperature range of 550 to 650 ° C. Cleaning method.

  According to the cleaning method of the silicon carbide film forming apparatus of the present invention, the SiC deposit formed thereon can be selectively removed by gas cleaning while protecting the TaC coat coated on the member or the like in the chamber. It is possible to provide a cleaning method for a silicon carbide film forming apparatus capable of manufacturing a SiC epitaxial wafer.

It is a cross-sectional schematic diagram which shows an example of the film-forming apparatus of the silicon carbide film | membrane which is the object of the cleaning method of this invention.

  Hereinafter, a configuration of a cleaning method of a silicon carbide film forming apparatus to which the present invention is applied will be described with reference to the drawings. In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. . In addition, the materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited thereto, and can be implemented with appropriate modifications within the scope of the effects of the present invention. .

  A cleaning method for a silicon carbide film deposition apparatus according to an embodiment of the present invention includes a first step of introducing hydrogen halide gas into a chamber, and a second step of introducing oxygen gas into the chamber after the first step. And a process.

  FIG. 1 is a schematic cross-sectional view showing a CVD apparatus capable of producing a silicon carbide epitaxial wafer as an example of a silicon carbide film forming apparatus that is a target of the cleaning method of the present invention.

  Any apparatus that forms a silicon carbide thin film in a dry process is an object of the cleaning method of the present invention. That is, when a silicon carbide thin film is formed on a target material such as a substrate, SiC deposits are also formed on members other than the target material in the chamber (reaction vessel) and the inner wall of the chamber. In the cleaning method of the present invention, this SiC deposit can be removed.

A silicon carbide film forming apparatus which is a target of the cleaning method of the present invention is, for example, a CVD apparatus 100 as shown in FIG.
This CVD apparatus 100 is a silicon carbide epitaxial wafer manufacturing apparatus capable of forming an epitaxial layer on the wafer surface while introducing a source gas into the chamber 1. The CVD apparatus 100 includes a plurality of mounting units 2b on which a wafer is mounted, and a reaction space between the susceptor 2 and the susceptor 2 in which the plurality of mounting units 2b are arranged in the circumferential direction. 4, and a ceiling (plate) 3 that is disposed above the susceptor 2 so as to prevent deposits from the vapor phase from adhering to the lower surface of the ceiling 3. And a shielding plate 10 disposed close to the lower surface.
The source gas may be, for example, one containing monosilane (SiH ₄ ) as the Si source and propane (C ₃ H ₈ ) as the C source, and further containing hydrogen (H ₂ ) as the carrier gas. Can be used.

  The CVD apparatus 100 shown in FIG. 1 is further arranged on the lower surface side of the susceptor 2 and the upper surface side of the ceiling, and heating means 6 and 7 for heating the wafer placed on the placement portion 2b, and the center of the upper surface of the ceiling 3 And a gas introduction pipe 5 having a gas introduction port for introducing a raw material gas into the reaction space 4 from the section. The gas introduction pipe 5 introduces the source gas discharged from the gas introduction port from the inside to the outside of the reaction space 4.

  The heating means 6 and 7 are, for example, induction coils that heat by high-frequency induction heating, heat the sealing 3, heat the shielding plate 10 by radiant heat from the heated ceiling 3, and heat the wafer by radiant heat from the shielding plate 10. Can be heated.

  As materials for the susceptor 2 and the sealing 3, carbon materials having excellent heat resistance and good thermal conductivity, for example, those made of graphite can be used as materials suitable for high-frequency induction heating. In order to prevent generation of particles or the like, a material whose surface is coated with SiC, TaC or the like can be preferably used. Further, as the susceptor 2 and the sealing 3, one made of silicon carbide can be used.

  Although the sealing 3 can be supported by various methods, in the CVD apparatus 100 shown in FIG. 1, a protrusion provided at the center of the lower surface so as to be located inside the opening 10 b of the shielding plate 10. The support member 13 fixed to the gas introduction pipe 5 is supported via the portion 12. The protrusion 12 makes it difficult for gas to flow from the inner peripheral side of the shielding plate 10 to the ceiling 3.

  The plurality of placement portions 2b accommodated in an accommodation portion (not shown) formed in the susceptor 2 are arranged side by side in the circumferential direction so as to surround the central portion of the disc-shaped susceptor 2. A revolution rotating shaft 2 a is attached to the center of the lower surface of the susceptor 2. The revolving rotary shaft 2 a is arranged immediately below the gas introduction pipe 5. A rotating shaft (not shown) for rotation is attached to each mounting portion 2b. With this configuration, the SiC single crystal wafer is revolved by the susceptor 2 with the gas introduction tube 5 as the central axis, and the SiC single crystal wafer itself is rotated with the mounting portion 2b with the center of the SiC single crystal wafer as the axis. It has become.

  As the material of the mounting portion 2b, a carbon material having excellent heat resistance and good thermal conductivity, for example, a material made of graphite can be used as a material suitable for high frequency induction heating, and particles such as particles from the carbon material can be used. In order to prevent the occurrence, a material whose surface is coated with SiC, TaC or the like can be suitably used. Moreover, as the mounting part 2b, what consists of silicon carbide can also be used.

  The shielding plate 10 can prevent dust particles (graphite) from the lower surface of, for example, the graphite ceiling 3 from falling on the wafer, and reduce the surface density of defects starting from the sealing material piece. . When the shielding plate 10 is provided, the film is dropped from the lower surface of the ceiling by simply performing a simple maintenance operation such as replacing the shielding plate without performing a troublesome cleaning operation such as removing deposits accumulated on the lower surface of the ceiling. It is possible to reduce downfall of SiC deposits and the like entering the inside.

When the material piece of the shielding plate 10 falls on the wafer, a defect starting from the material piece of the shielding plate is formed. In order to suppress the defect, dust generation at a higher temperature than the material of the sealing 3 or in the chamber It is preferably made of a material that hardly causes sublimation due to the interaction with the gas. For this reason, as the shielding plate 10, it is preferable to use one made of SiC, one in which the surface of a graphite substrate is coated with SiC, TaC or the like, or one in which a pyrolytic carbon film is coated. When the shielding plate 10 is made of SiC, or when at least the surface of the lower surface is coated with SiC, the adhesion of the SiC deposit is high, and the amount of the SiC deposit falling from the shielding plate 10 can be reduced. .
The shielding plate 10 is configured to be detachably attached to the chamber, and the shielding plate 10 shown in FIG. 1 is placed on the support portion 11 provided on the inner wall 1a of the chamber 1 at the outer peripheral portion 10a. Yes.

  A cleaning method for a silicon carbide film deposition apparatus according to the present invention includes a first step of introducing a hydrogen halide gas into a chamber of a silicon carbide film deposition apparatus, and an oxygen gas introduced into the chamber after the first step. And a second step.

(First step)
As the hydrogen halide gas introduced in the first step, a gas selected from the group consisting of HBr and HCl can be preferably used.

  It is preferable to use a hydrogen halide gas having a purity of 99.999% or more. For example, when the impurity (for example, moisture) in the hydrogen halide gas is 10 ppm by volume or more, the metal member may be corroded, which is not preferable.

  The flow rate of the hydrogen halide gas is not particularly limited, but can be set to, for example, 10 to 5000 cc / min.

  When introducing the hydrogen halide gas, it may be diluted with an inert gas such as argon, helium, or nitrogen. For example, it can be diluted to 10 to 50% by volume. The total flow rates of the hydrogen halide gas and the inert gas when diluted with an inert gas are not particularly limited, but can be set to 10 to 5000 ccm, for example.

  The first step is preferably performed in a temperature range of 550 to 650 ° C, and more preferably performed in a temperature range of 570 to 620 ° C. It is preferable to carry out at a temperature of 650 ° C. or lower because damage to the SiC coat or TaC coat can be avoided even when the SiC coating or TaC coat is coated on the member in the chamber or the chamber wall surface. Further, it is preferable to carry out at a temperature of 550 ° C. or higher because a significant decrease in the cleaning reaction rate of the SiC deposits deposited on the members in the chamber and the chamber wall surface can be avoided.

  The gas introduction time in the first step is preferably determined based on the total growth time of the silicon carbide film (the total growth time of the silicon carbide film). This is because the total growth time of the silicon carbide film and the deposition amount of the SiC deposit are in a proportional relationship. For example, when a SiC epitaxial wafer having a SiC epitaxial layer on a SiC single crystal substrate is manufactured, the total growth time of the SiC epitaxial film and the deposition amount of the SiC deposit are in a proportional relationship.

(Second step)
The oxygen gas introduced in the second step is preferably used with a purity of 99.999% or more. For example, when the impurity (for example, moisture) in the oxygen gas is 10 ppm by volume or more, the metal member may be corroded, which is not preferable.

  The flow rate of oxygen gas is not particularly limited, but can be set to, for example, 10 to 5000 ccm.

  When introducing the oxygen gas, it may be diluted with an inert gas such as argon, helium, or nitrogen. For example, it can be diluted to 10 to 50% by volume. The total flow rates of the oxygen gas and the inert gas when diluted with oxygen gas are not particularly limited, but can be set to 10 to 5000 ccm, for example.

  The second step is preferably performed in a temperature range of 550 to 650 ° C, and more preferably performed in a temperature range of 570 to 620 ° C. It is preferable to carry out at a temperature of 650 ° C. or lower because damage to the SiC coat or TaC coat can be avoided even when the SiC coat or TaC coat is coated on the chamber member or the chamber wall surface. Further, it is preferable to carry out at a temperature of 550 ° C. or higher because a significant decrease in the cleaning reaction rate of the SiC deposits deposited on the members in the chamber and the chamber wall surface can be avoided.

  The gas introduction time in the second step is preferably determined based on the total growth time of the silicon carbide film. This is because the total growth time of the silicon carbide film and the deposition amount of the SiC deposit are in a proportional relationship.

  When HBr is used as the hydrogen halide gas, the reaction for removing the SiC deposit by the HBr gas and oxygen gas is considered as shown in the following formulas (1) and (2).

SiC + 4HBr → SiBr ₄ ↑ + C + 2H ₂ ↑ (1)
C + O ₂ → CO ₂ ↑ (2)

On the other hand, the TaC coat covering the chamber member and the chamber wall surface has the property that even if HBr gas supply and subsequent oxygen gas supply are performed, it is more difficult to react than SiC deposits due to the difference in surface condition. The conditions for removing the deposits do not cause substantial damage.
Further, the SiC coat covering the chamber member and the chamber wall surface is the same SiC as the SiC deposit. However, under the condition for removing the SiC deposit due to the difference in the surface state such as the crystal orientation plane, the (1) and Since the rate of reaction as in (2) is very small compared to SiC deposits, there is no substantial damage.

The end point of cleaning can be determined by measuring the SiBr ₄ concentration and the CO ₂ concentration in the in-chamber cleaning exhaust gas.

When HCl is used as the hydrogen halide gas, the reaction for removing the SiC deposit by HCl gas and oxygen gas is considered as in the following formulas (3) and (4).
SiC + 4HCl → SiCl ₄ ↑ + C + 2H ₂ ↑ (3)
C + O ₂ → CO ₂ ↑ (4)

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which can exhibit the effect of this invention, it can change suitably and can implement.

[Example 1]
As an object to which the cleaning method of the present invention is applied, an SiC epitaxial wafer manufacturing apparatus manufactured by AIXTRON was used. This SiC epitaxial wafer manufacturing apparatus generally has a configuration as shown in FIG. In this SiC epitaxial wafer manufacturing apparatus, the shielding plate has its surface coated with a SiC coat (silicon carbide film), and the susceptor and mounting portion have their surfaces coated with a TaC coat (tantalum carbide film). Things were used. The surface roughness of both the surface coated with the SiC coat and the surface coated with the TaC coat was Ra ≦ 4 μm in terms of arithmetic average roughness (Ra).

A SiC single crystal wafer was placed on the mounting portion, and after evacuation, hydrogen gas was introduced to adjust the reduced pressure atmosphere to 200 mbar. Thereafter, the temperature was raised to 1570 ° C., growth was performed at a growth rate of 5 μm / h for 1 hour, and a SiC epitaxial film having a thickness of 5 μm was formed on a SiC single crystal wafer to produce a SiC epitaxial wafer.
Hydrogen was used as the carrier gas, and a mixed gas of SiH ₄ and C ₃ H ₈ was used as the source gas.

  Next, the produced epitaxial wafer was taken out and the inside of the chamber was cleaned by the cleaning method of the present invention. As cleaning conditions, the temperature in the chamber was adjusted to 620 ° C., and HBr gas was allowed to flow through the chamber at 2000 ccm for 1 hour, and then switched to oxygen gas and allowed to flow at 2000 ccm for 1 hour.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). The measured results are shown in Table 1.

As shown in Table 1, after cleaning, the arithmetic average roughness (Ra) of the SiC coat surface was 3.5 μm, and the atomic number concentration ratio was Si: C = 50: 50.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the SiC coating surface is 3.5 μm, which is the same as that before the SiC epitaxial film is formed, and the atomic number concentration ratio is Si: C = 50: 50. Met. This result shows that the SiC deposit deposited on the surface of the SiC coat could be removed. In addition, the SiC deposits can be removed without damaging the SiC coating.
Although the SiC deposit and the SiC coat are SiC, as described in Patent Document 1, it is considered that only the SiC deposit can be selectively removed due to a difference in the surface state or the like. That is, it is considered that the SiC deposit is rich in unevenness and has a large number of holes, whereas the SiC coat is a smooth and dense film.

Further, as shown in Table 1, after cleaning, the arithmetic average roughness (Ra) of the TaC coat surface was 3.5 μm, and the atomic number concentration ratio was Ta: C = 50: 50.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface is 3.5 μm, which is about the same as before the SiC epitaxial film is formed, and the atomic number concentration ratio is Ta: C = 50: 50. Met. This result shows that only the SiC deposit deposited on the TaC coat surface could be removed. That is, it shows that the SiC deposit could be removed without damaging the TaC coat.

[Example 2]
In Example 2, the same process as in Example 1 was performed except that the cleaning conditions in Example 1 were changed as follows. That is, the temperature in the chamber is adjusted to 620 ° C., first, HBr gas is allowed to flow in the chamber at 1000 ccm and He gas at 2000 ccm for 1 hour, and then the He gas flow is stopped, and the HBr gas is changed to oxygen gas 1000 ccm. For 1 hour.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). Table 2 shows the measurement results.

As shown in Table 2, after cleaning, the arithmetic average roughness (Ra) of the SiC coat surface was 3.5 μm, and the atomic number concentration ratio was Si: C = 50: 50.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the SiC coating surface is 3.5 μm, which is the same as that before the SiC epitaxial film is formed, and the atomic number concentration ratio is Si: C = 50: 50. Met. This result shows that the SiC deposit deposited on the surface of the SiC coat could be removed.

Further, as shown in Table 2, after cleaning, the arithmetic average roughness (Ra) of the TaC coat surface was 3.5 μm, and the atomic number concentration ratio was Ta: C = 50: 50.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface is 3.5 μm, which is about the same as before the SiC epitaxial film is formed, and the atomic number concentration ratio is Ta: C = 50: 50. Met. This result shows that only the SiC deposit deposited on the TaC coat surface could be removed. That is, it shows that the SiC deposit could be removed without damaging the TaC coat.

Example 3
In Example 3, the same steps as in Example 1 were performed except that the cleaning conditions in Example 1 were changed as follows. That is, the temperature in the chamber is adjusted to 620 ° C., first, HBr gas is allowed to flow through the chamber at 1000 ccm for 1 hour, and then the HBr gas is switched to oxygen gas 1000 ccm and He gas is switched to 2000 ccm for 1 hour. It was.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). Table 3 shows the measurement results.

As shown in Table 3, after cleaning, the arithmetic average roughness (Ra) of the SiC coat surface was 3.5 μm, and the atomic number concentration ratio was Si: C = 50: 50.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the SiC coating surface is 3.5 μm, which is the same as that before the SiC epitaxial film is formed, and the atomic number concentration ratio is Si: C = 50: 50. Met. This result shows that the SiC deposit deposited on the surface of the SiC coat could be removed.

Further, as shown in Table 3, after cleaning, the arithmetic mean roughness (Ra) of the TaC coat surface was 3.5 μm, and the atomic number concentration ratio was Ta: C = 50: 50.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface is 3.5 μm, which is about the same as before the SiC epitaxial film is formed, and the atomic number concentration ratio is Ta: C = 50: 50. Met. This result shows that only the SiC deposit deposited on the TaC coat surface could be removed. That is, it shows that the SiC deposit could be removed without damaging the TaC coat.

[Comparative Example 1]
In Comparative Example 1, the same steps as in Example 1 were performed except that the cleaning conditions in Example 1 were changed as follows. That is, the temperature in the chamber was adjusted to 620 ° C., and HBr gas was circulated in the chamber at 2000 ccm for 1 hour. Thereafter, no oxygen gas was circulated.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). Table 4 shows the measurement results.

As shown in Table 4, after cleaning, the arithmetic average roughness (Ra) of the SiC coat surface was 7.5 μm, and the atomic number concentration ratio was Si: C = 2: 98.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the SiC coat surface was 7.5 μm, and the atomic number concentration ratio was Si: C = 2: 98. This result indicates that among the SiC deposits deposited on the surface of the SiC coat, Si could be sufficiently removed, but C could not be removed.
It was found that Si could be sufficiently removed but C could not be removed only by cleaning with HBr gas.

Further, as shown in Table 4, after cleaning, the arithmetic average roughness (Ra) of the TaC coat surface was 7.5 μm, and the atomic number concentration ratio was Si: Ta: C = 4: 3: 93. It was.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface was 7.5 μm, and the atomic number concentration ratio was Si: Ta: C = 4: 3: 93. This result shows that among the SiC deposits deposited on the TaC coat surface, Si could be removed sufficiently, but C could not be removed.
It was found that Si could be sufficiently removed but C could not be removed only by cleaning with HBr gas.

[Comparative Example 2]
In Comparative Example 2, the same process as in Example 1 was performed except that the cleaning conditions in Example 1 were changed as follows. That is, the temperature in the chamber was adjusted to 620 ° C., HBr gas was not circulated, and oxygen gas was circulated in the chamber at 2000 ccm for 1 hour.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). Table 5 shows the measurement results.

As shown in Table 5, after cleaning, the arithmetic average roughness (Ra) of the surface of the SiC coating was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the surface of the SiC coating was 8 μm, unchanged from that before cleaning, and the atomic number concentration ratio was Si: C = 50: 50. This result indicates that the SiC deposit deposited on the surface of the SiC coat could not be removed.
It has been found that SiC deposits cannot be removed only by cleaning with oxygen gas.

Further, as shown in Table 5, after cleaning, the arithmetic average roughness (Ra) of the TaC coat surface was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface was 8 μm, unchanged from that before cleaning, and the atomic number concentration ratio was Si: C = 50: 50, unchanged from that before cleaning. It was. This result indicates that the SiC deposit deposited on the surface of the SiC coat could not be removed.
It has been found that SiC deposits cannot be removed only by cleaning with oxygen gas.

[Comparative Example 3]
In Comparative Example 3, the same process as in Example 1 was performed except that the cleaning conditions in Example 1 were changed as follows. That is, the temperature in the chamber was adjusted to 280 ° C., and F ₂ gas was allowed to flow through the chamber at 1000 ccm and He gas at 4000 ccm for 1 hour.

  After cleaning, the shielding plate and the mounting portion are removed, and the SiC coating portion on the shielding plate surface and the TaC coating portion of the mounting portion are measured using a surface roughness meter and an energy dispersive X-ray spectrometer (EDX). Table 6 shows the measurement results.

As shown in Table 6, after cleaning, the arithmetic average roughness (Ra) of the surface of the SiC coating was 3.5 μm, and the atomic number concentration ratio was Si: C = 50: 50.
Before the formation of the SiC epitaxial film, the arithmetic average roughness (Ra) of the SiC coat surface was 4 μm or less, but by the formation of the SiC epitaxial film (before cleaning), the arithmetic average roughness (Ra) of the SiC coat surface Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits were deposited on the surface of the SiC coat after the SiC epitaxial film was formed (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the SiC coating surface is 3.5 μm, which is the same as that before the SiC epitaxial film is formed, and the atomic number concentration ratio is Si: C = 50: 50. Met. This result shows that the SiC deposit deposited on the surface of the SiC coat could be removed.

On the other hand, as shown in Table 6, after cleaning, the arithmetic average roughness (Ra) of the TaC coat surface was 5 μm, and the atomic number concentration ratio was C: F = 82: 18.
The arithmetic average roughness (Ra) of the TaC coat surface was 4 μm or less before the SiC epitaxial film was formed, but after the SiC epitaxial film was formed (before cleaning), the arithmetic average roughness (Ra) of the TaC coat surface was Was 8 μm, and the atomic number concentration ratio was Si: C = 50: 50. This is because SiC deposits are deposited on the surface of the TaC coat by forming the SiC epitaxial film (before cleaning). After cleaning under the above conditions, the arithmetic average roughness (Ra) of the TaC coat surface was 5 μm, and the atomic number concentration ratio was C: F = 82: 18. This result indicates that the SiC deposit can be removed, but the TaC coat is damaged.
Cleaning with F ₂ gas has been found to damage the TaC coat, although SiC deposits can be removed.

  In the above embodiment, the effect of the present invention has been described by taking the member coated with TaC and the member coated with SiC as an example, but while protecting the surface of the member coated with other materials, The formed SiC deposit can also be removed.

DESCRIPTION OF SYMBOLS 1 Chamber 1a Inner wall 2 Susceptor 2b Mounting part 3 Sealing (top plate)
4 reaction space 5 gas introduction pipe 6, 7 induction coil (heating means)
DESCRIPTION OF SYMBOLS 10 Shielding board 10a Outer peripheral part 11 Support part 100 CVD apparatus (Epitaxial wafer manufacturing apparatus, film-forming apparatus of silicon carbide film)

Claims (4)

A first step of introducing hydrogen halide gas into the chamber;
A second step of introducing oxygen gas into the chamber after the first step;
Cleaning method for silicon carbide film deposition apparatus having   2. The method for cleaning a silicon carbide film forming apparatus according to claim 1, wherein the hydrogen halide gas is a gas selected from the group consisting of HBr and HCl.   3. The silicon carbide film forming apparatus according to claim 1, wherein a gas introduced in at least one of the first step and the second step is diluted with an inert gas. 4. Cleaning method.   4. The method for cleaning a silicon carbide film forming apparatus according to claim 1, wherein the first step and the second step are performed in a temperature range of 550 to 650 ° C. 5.

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