JP2941079B2 - Film forming apparatus with sediment recovery device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus by a CVD method using a metal fluoride as a raw material capable of obtaining a film or a plate of an extremely high-purity metal or a compound thereof. The present invention relates to a method of cleaning deposits in an apparatus by using a fluorine gas (hereinafter, abbreviated as F ₂ gas) or a ClF ₃ gas, further collecting a fluoride gas obtained by the above reaction, and using the gas again as a source gas.

[0002]

2. Description of the Related Art Conventionally, fluorides such as tungsten (W), molybdenum (Mo), rhenium (Re), and iridium (Ir) are reduced and thermally decomposed by a CVD method to obtain a metal or a compound film or metal. Method for obtaining plate-like body (JP-A-59-12376)
No. 5) is extremely useful as a method for obtaining a high-purity metal film, and is widely used for producing conductive wires such as ICs and for producing corrosion-resistant and abrasion-resistant materials.

[0003] A method of producing carbides and nitrides by reacting with gases such as hydrocarbons and nitrides is also known (JP-A-61-84375, JP-A-61-157681, etc.).
However, in order to remove the metal or its compound deposited at a place other than the intended place from the CVD apparatus, the apparatus must be disassembled, which is a problem in terms of production efficiency. Also, even with the above metals, Re, Ir and the like are particularly expensive, and it is not economical to dispose them as they are.

[0004]

[Means for Solving the Problems] In view of such problems, the present inventors have conducted intensive studies and as a result, have found that a metal or a compound thereof deposited in a CVD apparatus is again subjected to F ₂ gas or ClF ₃ gas.
The device was converted into fluoride by contact with a gas, collected in a container by a cooling device, and then used again as a raw material gas.

That is, the present invention relates to a film forming apparatus for forming a metal or a compound thereof by a CVD method using a metal fluoride as a raw material, comprising a raw material gas supply apparatus, a CVD apparatus, and an exhaust gas abatement apparatus, and further comprising a pipe connected to the CVD apparatus. The present invention provides a film forming apparatus provided with a deposit recovery device, which is provided with a cleaning gas supply device and a fluoride recovery supply device having the following.

FIG. 1 shows an example of a conceptual diagram of the apparatus of the present invention. First, as a raw material gas used in the apparatus of the present invention,
WF _6, MoF _6, a ReF _6, IRF ₆ and the like, hydrogen to the gas, hydrocarbons, ammonia, adding an amine compound or the like, C and mixed
Heating is performed in a VD apparatus to deposit a metal or a carbide or nitride film or plate corresponding to the fluoride.

As the CVD system, there are a heating system such as a resistance heating system, a high-frequency induction heating system, and an infrared lamp heating system. There are a hot plate system and a core system for the above-mentioned heating systems, respectively. Can be used in the present invention as long as they are completely closed systems.

In the above device, besides the intended place,
Films and powders accumulate in various places and pipes in the equipment, and to remove them, the equipment must be dismantled and cleaning performed, which not only interrupts the operation, but also Is difficult to completely remove, which may cause impurity contamination. In addition, expensive metals such as Re and Ir can be discarded as they are and the utilization rate of metals will be low.
This is a major cause of increased manufacturing costs.

In the present invention, a metal or a compound thereof adhering to these devices is cleaned by a cleaning gas such as F ₂ gas or ClF ₃ gas without disassembling the device, and further, the fluorine obtained by the cleaning process is removed. By cooling the compound, it is separated from other gas and condensed, and this gas is used again as a source gas for CVD.

Accordingly, the raw material supply apparatus of the present invention is mixed, the flow control device for supplying said the _{WF 6, MoF 6, ReF 6} , IrF 6 gas such as a pooled cylinder with the gas, and the gas It comprises a cylinder of hydrogen or a hydrocarbon such as methane, ethane, propane or benzene or a nitrogen compound such as ammonia or dimethylamine, and a flow control device for supplying this gas. These gases may be mixed in the piping before being introduced into the CVD equipment, or may be separated separately in some cases.
It is introduced into the D apparatus and mixed in the apparatus.

[0011] These mixed gases are heated in a CVD apparatus, and a film or a plate of a metal such as W, Mo, Re, Ir or a carbide or nitride thereof is formed according to each reaction. At this time, a film or a powder of the metal, its carbide, nitride, or the like is deposited on the inside of the CVD apparatus or on the subsequent piping depending on the temperature and atmosphere of the portion.

Exhaust gas that has exited the CVD apparatus is absorbed by the exhaust gas abatement apparatus, such as fluoride and chloride, and the other gases are exhausted. The exhaust gas abatement system absorbs, by passing through a solution layer of an oxide or hydroxide of an alkali metal or an alkaline earth metal such as sodium, potassium, calcium, magnesium and / or a packed layer of a solid material.
Be fixed.

If necessary, if an absorbent such as activated carbon or zeolite is provided after the layer, trace amounts of fluoride and chloride passing through the layer can be completely removed in some cases.

[0014] Next, the cylinder is a deposit which is Cleaning emissions ing gas supply device for supplying a gas for cleaning, this device is also for storing the F ₂ gas and ClF ₃ gas, which is also the cleaning gas and the material gas supplying device And a flow control device.

The piping from the cleaning gas supply device is connected to the CVD device, whereby the cleaning gas is inserted into the piping leading to the CVD device or the exhaust gas abatement device, and the cleaning process is performed.

In order to perform the cleaning process, it is necessary to heat any of the deposits to a temperature of 100 to 400 ° C. In the CVD apparatus, a heating device equipped with a temperature control device is naturally required for performing the CVD, and the temperature may be set to the above-described temperature when cleaning is performed by the heating device. In addition, it is preferable to provide a heating device also in the pipe leading to the exhaust gas abatement apparatus in consideration of the case where the deposits are attached.

Since the CVD apparatus and the piping to be heated come into contact with the raw material gas and the cleaning gas of the CVD while being heated, it is preferable to use a corrosion-resistant material such as Ni or Monel.

In the CVD apparatus, each of the above-mentioned metals is converted into a fluoride by a cleaning gas and introduced into a fluoride recovery and supply device. In the fluoride collection and supply device, the introduced fluoride gas is cooled and agglomerated by a refrigerant, and stored in a cylinder. In this case, the gas is once coagulated and solidified in the trap by the trap, and once the atmosphere gas is exhausted, the gas is coagulated and stored again in the storage cylinder.
Temperature in the trap, if the WF ₆ 0 ° C. or less, MoF _6,
In the case of ReF ₆ and IrF ₆ , cooling to 0 ° C. is sufficient.

Next, the case where the deposit is carbide or nitride is used. In this case, carbon fluoride, carbon fluoride,
Since nitrogen fluoride is also generated, it is necessary to separate the carbon fluoride or nitrogen fluoride from the fluoride of each metal. However, since carbon fluoride and nitrogen fluoride have a lower boiling point than the above-mentioned metal fluorides, only metal fluorides can be trapped by cooling at a temperature of about 0 to -30 ° C. The subsequent operation is the same as the case where only the metal fluoride is aggregated. In addition, the fluorocarbon and nitrogen fluoride that have passed through the trap are removed by the exhaust gas removal device.

The fluoride thus stored is supplied with a fluoride gas by the same device as the source gas supply device, and other hydrogen, hydrocarbons, nitride gases, etc. are supplied from the source gas supply device. A desired film or plate can be formed by mixing with a gas.

By using the apparatus of the present invention as described above, unnecessary deposits deposited in a pipe connected to a CVD apparatus or an exhaust gas abatement apparatus can be cleaned, and the obtained fluoride can be removed. Since it can be used again as a source gas, the CVD operation can be performed extremely economically and efficiently.

[0022]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 WF ₆ was used as a source gas, and hydrogen gas was
₆ : H ₂ (molar ratio) = 1: 7
Introduced into the device.

The CVD apparatus is a 50 mmφ × 300 mm L nickel tube furnace equipped with a heater with a temperature controller, and a 30 × 30 × 2 mm Ni substrate is placed at the center of the furnace.
The total flow rate was 1.2 L / min, the furnace temperature was set at 450 ° C, and the pressure was 76
The reaction was carried out at 0 Torr for 3 hours to obtain a 30 × 30 × 0.6 mm W plate.

When the plate-like body was taken out, the inside of the tubular furnace was observed, and it was found that a film-like substance or a powdery substance had accumulated on the surface. The plate was taken out, the tube furnace was closed again, the chamber was evacuated, the inside of the system was replaced with nitrogen gas, and the system was evacuated.
min) as a mixed gas, and a cleaning treatment was performed at 250 ° C.

The gas subjected to the cleaning treatment was introduced into a fluoride recovery apparatus, and WF ₆ was coagulated and solidified by a trap filled with a refrigerant at -20 ° C. Next, after the atmosphere gas was evacuated, the storage cylinder was similarly cooled to -70 ° C,
Conversely, by heating the trap layer to 20 ° C., it was aggregated in the storage cylinder. WF ₆ obtained at this time, was 280g.

The exhaust gas that has passed through the film forming process or the exhaust gas that has exited the trap after the cleaning process has an inner diameter of 400 mm and a height of 90 mm.
The reactor was introduced into an exhaust gas abatement system having a fixed bed reactor of 0 mm and an adsorbent packed bed having an inner diameter of 50 mm and a height of 50 mm at the subsequent stage. The fixed-bed reactor was filled with 75 kg of soda lime, and 200 g of activated carbon as an adsorbent.

The halogen gas and the halogenated gas were absorbed and fixed by the treatment in the above-mentioned apparatus, and were subjected to the detoxification treatment. Example 2 MoF ₆ was used as a source gas, and hydrogen gas was used as the source gas.
F ₆ : H ₂ (molar ratio) = 1: 7
Introduced into the device.

The CVD apparatus is the same as in the first embodiment. The reaction was carried out at a pressure of 760 Torr for 3 hours at a total flow rate of 1.2 L / min, a furnace temperature of 550 ° C., and a 30 × 30 × 0.6 mm Mo plate was obtained.

When the plate was taken out, the inside of the tubular furnace was observed. As a result, it was found that a film or a powder had accumulated on the surface. The plate was taken out, the tubular furnace was sealed again, evacuated, the system was replaced with nitrogen gas, and evacuated.ClF ₃ gas (400 cc / min) and nitrogen gas (1.6 L / mi
n) was introduced as a mixed gas, and a cleaning treatment was performed at 300 ° C.

The gas subjected to the cleaning treatment was introduced into a fluoride recovery apparatus, and MoF ₆ was coagulated and solidified by a trap filled with a 0 ° C. refrigerant. Next, after the atmosphere gas was evacuated, the storage cylinder was similarly cooled to -70 ° C,
Conversely, the trap layer was heated to 50 ° C. to cause aggregation in the storage cylinder. MoF ₆ obtained at this time was 180 g.

Exhaust gas that passed through the film forming process or exhaust gas that exited the trap after the cleaning process was harmed in the same manner as in Example 1. Example 3 ReF ₆ was used as a raw material gas, and hydrogen gas was used for this gas.
F ₆ : H ₂ (molar ratio) = 1: 7
Introduced into the device.

The CVD apparatus is the same as the first embodiment except that a graphite substrate is used. The total flow rate was set at 1 L / min, the furnace temperature was set at 500 ° C, and the reaction was performed at a pressure of 20 Torr for 3 hours.
A 30 × 0.3 mm Re plate was obtained.

When the plate-like body was taken out, the inside of the tubular furnace was observed, and it was found that a film-like substance or a powdery substance had accumulated on the surface. The plate was taken out, the tube furnace was closed again, the chamber was evacuated, the inside of the system was replaced with nitrogen gas, and the system was evacuated.
min) as a mixed gas, and a cleaning treatment was performed at 300 ° C.

The gas subjected to the cleaning treatment was introduced into a fluoride recovery apparatus, and ReF ₆ was coagulated and solidified by a trap filled with a 0 ° C. refrigerant. Next, after the atmosphere gas was evacuated, the storage cylinder was similarly cooled to -70 ° C, and the trap layer was heated to 70 ° C to condense the storage cylinder. ReF ₆ obtained at this time was 220 g.

Exhaust gas that had passed through the film-forming step or exhaust gas that had exited the trap after the cleaning process was removed in the same manner as in Example 1. Example 4 WF ₆ was used as a raw material gas, and benzene and hydrogen were added to this gas, and the molar ratio was WF ₆ : benzene: hydrogen =
The mixture was mixed at a ratio of 2: 1: 30, and introduced into a CVD apparatus.

The CVD apparatus is the same as in the first embodiment. The total flow rate was set to 2.5L / min, the furnace temperature was set to 500 ° C,
The reaction was performed for 3 hours to obtain a 0.6 mm WC film on the nickel substrate.

When the substrate was taken out, the inside of the tubular furnace was observed. As a result, it was found that a film or a powder had accumulated on the surface. The plate was taken out, the tubular furnace was sealed again, evacuated, and the system was replaced with nitrogen gas and evacuated.Then, fluorine gas (400 cc / min) and nitrogen gas (1.6 L / mi
n) was introduced as a mixed gas, and a cleaning treatment was performed at 300 ° C.

The clean hardening treatment gas is introduced into the fluoride recovery system, aggregating the WF ₆ by a trap filled with 0 ℃ coolant to solidify. Next, after the atmosphere gas was evacuated, the storage cylinder was similarly cooled to -70 ° C,
Conversely, by heating the trap layer to 70 ° C., it was aggregated in the storage cylinder. WF ₆ obtained at this time, was 280g.

Exhaust gas that had passed through the film forming process or exhaust gas that had exited the trap after the cleaning process was removed in the same manner as in Example 1.

[0041]

By using the device of the present invention, C
Unnecessary deposits deposited in the pipes connected to the VD device and the exhaust gas abatement device can be cleaned, and the obtained fluoride can be used again as a raw material gas, so that it is extremely economical and efficient. It can perform the operation of CVD.

[Brief description of the drawings]

FIG. 1 shows a conceptual diagram of an example of a film forming apparatus provided with a deposit collecting apparatus of the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Isamu Mouri 5253 Oki Ube, Oji, Ube City, Yamaguchi Prefecture Inside Ube Laboratory, Central Glass Co., Ltd. (56) References JP-A-62-20875 (JP, A) (58) Surveyed field (Int.Cl. ⁶ , DB name) C23C 16/00-16/58 B01J 19/00-19/32 H01L 21/205

Claims (1)

(57) [Claims] An apparatus for forming a film of a metal or a compound thereof by a CVD method using a metal fluoride as a raw material, comprising a raw material gas supply device, a CVD device, and an exhaust gas abatement device, and further comprising a pipe connected to the CVD device. A film forming apparatus provided with a deposit recovery device, comprising a gas supply device and a fluoride recovery supply device.