JP3200587B2 - Gas treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas processing method in which a coating film formed on a surface of an object to be processed, for example, a semiconductor wafer is gelled by being processed in an ammonia gas atmosphere.

[0002]

2. Description of the Related Art As a method for forming an interlayer insulating film of a semiconductor device, there are a CVD method, a thermal oxidation method, and the like, and another method called a sol-gel method. This method can be performed, for example, using TEOS (tetraethoxysilane; Si (C
A coating solution in which a colloid of 2 H5 O) 4) is dispersed in an organic solvent such as an ethyl alcohol solution is applied to the surface of a semiconductor wafer (hereinafter simply referred to as a wafer), and the coating film is gelled and dried to form silicon oxide. This is a technique for obtaining a film, which is described in JP-A-8-162450 and JP-A-8-59362.

FIG. 6 schematically shows a state of modification of a coating film in this method. First, when a coating liquid is applied to a wafer, TEOS particles or colloid 100 is dissolved in solvent 2.
6 (see FIG. 6 (a)), and then TEOS undergoes polycondensation and hydrolysis to gel the coating film, forming a network structure of TEOS 300 (FIG. 6 (b)). )reference). Then, in order to remove water in the coating solution, the solvent in the coating film is changed to another solvent 4 such as acetone.
00 (see FIG. 6C), and then dried to obtain a silicon oxide coating film.

[0004] After a coating solution is applied to a wafer, the coating film is gelled by, for example, being left overnight, but it is necessary to rapidly perform a gelling process for mass production. Heating the wafer may be considered as one of the techniques for this purpose. In this case, the evaporation of the solvent in the coating film becomes active.
We are studying gelation at room temperature using gas, for example. The reason for including water vapor in the ammonia gas is as follows. That is, when the ammonia gas containing water adheres to the coating film, a part thereof becomes NH3 + H2O →
It is ionized like NH4 + + OH-. In other words, a hydroxyl group is formed in the presence of water, indicating alkalinity. Alkali contributes to gelation because it is a catalyst that promotes polycondensation. For this reason, it is necessary to include water vapor. It can be expected that the number of OH groups is expected to increase as the water content increases and the state becomes closer to saturation, and that the gelation speed increases.

FIG. 7 shows an apparatus used for performing gelation using ammonia gas containing water vapor in a state close to saturation. This apparatus 1 includes a mounting table 1 for a wafer W.
1, a sealable processing container 10 comprising a seal member 12 and a lid 13, a tank 21 for storing a commercially available ammonia water (NH4 OH) (ammonia concentration: 30% by weight at room temperature) 20, and an ammonia water 20 in the tank 21. A bubbling gas supply pipe 22 for introducing ammonia gas thereinto for bubbling, an exhaust port 23 for exhausting a processing gas generated by bubbling, and a gas inlet port 14 provided in the exhaust port 23 and the mounting table 11. And a pipe 25 for communicating with each other.

Since the saturated concentration of ammonia in aqueous ammonia at room temperature is approximately 33% by weight, when ammonia gas is bubbled at room temperature using ammonia water as it is, ammonia gas is first absorbed into the aqueous ammonia. Even if gas is not generated or a gas is generated, a desired flow rate cannot be obtained, and it takes time to gel. Then, when the ammonia concentration in the ammonia water becomes approximately 33% by weight, ammonia gas containing water vapor close to saturation is generated as the processing gas. The generated processing gas is introduced into the processing container 10 via a pipe 25, and is exhausted through an exhaust path 15 opened to a lid 13 of the processing container 10.

[0007]

However, as described above, since commercially available ammonia water is used as it is,
If the replenishment of the ammonia water 20 in the tank 21 is performed during the continuous processing of the wafer, the concentration of the ammonia water 20 temporarily drops and the ammonia gas is absorbed. Therefore, a desired flow rate cannot be obtained even if ammonia gas is not generated or generated, and gelation is not completed, so that a predetermined film thickness and film quality may not be obtained. In order to prevent this, it is possible to interrupt the gelling process immediately before replenishing the ammonia water and restart the gelling process after the process gas is generated again, but this reduces the operation rate of the device and reduces the throughput. Will decrease.

The present invention has been made under such circumstances, and an object of the present invention is to perform a stable treatment in performing a gelation treatment of a coating film using an ammonia gas. It is an object of the present invention to provide a gas processing method capable of performing a uniform processing between them.

[0009]

According to the first aspect of the present invention, there is provided a method of forming a coating film on a surface of a workpiece to which a coating solution in which particles or colloids of a starting material of a film forming component are dispersed in a solvent is coated. In the method for gelling particles or colloids with ammonia gas, the step of carrying the object to be processed into a processing vessel, and the first step in which ammonia water having a concentration of ammonia lower than a saturation concentration is stored A first processing step of bubbling the inside of the container with ammonia gas to generate ammonia gas containing water vapor and supplying the ammonia gas into the processing container, and an ammonia water having a concentration of ammonia lower than the saturation concentration is performed. Ammonia gas containing water vapor is generated by bubbling the inside of the stored second container with ammonia gas, and the ammonia gas is treated in a processing container. A step of exhausting not via, then, by switching the gas flow path to the processing vessel from said first container into the gas flow path to the processing vessel from said second vessel,
It is characterized by including a second processing step of supplying ammonia gas generated from a second container into the processing container, and thereafter, a step of replenishing the first container with the ammonia water.

Since the concentration of ammonia water is lower than the saturation concentration, even if ammonia water is replenished, even if the ammonia gas is bubbled, the ammonia water is absorbed into the ammonia water for a while, so that the ammonia gas containing water vapor is stable. It takes time to occur. According to the present invention, when replenishing the first container with ammonia water,
Since ammonia gas is generated from the second container,
The supply of ammonia gas containing water vapor is not interrupted, so that stable processing can be performed. Further, the conductance of the flow path when gas flows from the first container via the processing container, the conductance of the flow path when gas flows from the first container through the first exhaust path, the processing container from the second container When the flow path is switched, the conductance of the flow path when the gas flows through the second container and the conductance of the flow path when the gas flows from the second container through the second exhaust path are made uniform. Therefore, fluctuations in the flow rate and pressure can be suppressed, so that more stable processing can be performed.

[0011]

FIG. 1 is a plan view schematically showing the entire structure of an example of a coating film forming apparatus used for carrying out the method of the present invention. Reference numeral 31 denotes an input / output port for a wafer as a substrate. The transfer arm 32 takes out the wafer W from the cassette C placed on the cassette stage CS and transfers it to the main arm 33. On one side of a conveyance path (guide rail) 34 of the main arm 33, a coating unit 4, an aging unit 6 to which the gas processing method of this embodiment is applied, and a solvent replacement unit 5 are arranged in this order. I have. Processing units U1 to U4 are also arranged on the other side of the transport path 34. For these processing units U1 to U4, a hydrophobic treatment, a cooling treatment, and a coating film are applied to the substrate before the application liquid is applied to the substrate. A unit for performing a heat treatment (bake treatment) after the formation is assigned to each.

The operation of the embodiment using this coating film forming apparatus will be described. FIG. 2 schematically shows the flow of the coating film forming process in order. The unprocessed wafer W taken out of the cassette C of the cassette stage CS by the main arm 33 is stored in the coating unit 4. Then, the coating liquid T is dropped onto the surface of the wafer W in a state where the inside of the coating unit 4 is filled with the vapor of the solvent (FIG. 2).
(A)). The coating solution used here is obtained by dispersing colloids or particles of TEOS, which is a metal alkoxide, in a solvent containing, for example, ethylene glycol and ethyl alcohol, which are organic solvents, and further, water and a small amount of hydrochloric acid. Because ethylene glycol has a low vapor pressure,
Even if the ethyl alcohol volatilizes, it remains as a solvent in the film,
Has the role of suppressing film loss.

Subsequently, the wafer W is rotated at a high speed while the inside of the coating unit 4 is filled with the solvent vapor, and the coating liquid in which the TEOS sol is dispersed in the solvent is spread on the wafer surface to form the coating film F. (See FIG. 2B).

Next, the wafer W is mounted on the mounting table 61 of the aging unit 6 and sealed by the lid 63. Then, a treatment gas for promoting gelation of the coating film is introduced into the aging unit 6 at room temperature to gel the coating film (see FIG. 2C). The processing gas is an ammonia gas containing water vapor.

Next, in the solvent replacement unit 5, solvent replacement of the gelled coating film is performed using ethyl alcohol, HMDS (hexamethyldisilane) and heptane (see FIG. 2 (d)). Thereby, the water in the coating film is replaced with ethyl alcohol. Further, the hydroxyl groups in the coating film are removed by HMDS. Further, the solvent in the coating film is replaced with heptane. The reason for using heptane is to reduce the force applied to the porous structure, that is, the network structure of TEOS by using a solvent having a small surface tension so that the structure does not collapse. Then the wafer W
Is baked in a baking unit for one minute, for example. Thus, an interlayer insulating film made of a silicon oxide film is formed on the surface of wafer W.

FIG. 3 is a schematic view of an example of the aging unit 6. As shown in FIG. 3, the aging unit 6 includes a mounting table 61 on which the wafer W is mounted and a mounting table 6.
A lid 63 which is closely attached to the peripheral portion of the first container 1 via a sealing member 62 to form a processing container 60 together with the mounting table 61;
And an exhaust passage 65 opening at the center of the exhaust passage. A plurality or slit-shaped gas inlets 64 are opened along the outer periphery of the wafer W mounted on the mounting table 61. The aging unit 6 includes a driving source 66.
For example, three elevating pins 67 for raising and lowering the wafer W between the mounting table 61 and a position above the mounting table 61 are provided.

The gas inlet 64 is connected to the processing gas supply pipe 81. The supply pipe 81 is branched on the way, and is connected to the first gas generation source 71 and the second gas generation source 72 via open / close valves V1 and V2, respectively. First
The gas generation source 71 and the second gas generation source 72 have the same configuration, and the ammonia in the tanks 74a and 74b for storing commercially available ammonia water (NH4 OH) (ammonia concentration: 30% by weight at room temperature) 73 Bubbling gas supply pipe 75 for introducing ammonia gas into water 73 for bubbling, exhaust port 76 for exhausting processing gas generated by bubbling, and constant temperature for keeping the temperature of ammonia water 73 at a predetermined temperature, for example, room temperature Means 77 are provided. The tanks 74a and 74b correspond to the first container and the second container in the claims, respectively.

The constant temperature means 77 is not particularly limited. For example, as shown schematically in FIG. 3, the constant temperature means 77 may be constituted by surrounding a tank 74 with a pipe 78 serving as a water circulation path. In this case, the pipe 78 is connected to a water circulating device (not shown) so that temperature-regulated water at normal temperature is constantly circulated. Thereby, the temperature of the ammonia water 73 stored in the tank 74 is always kept at the normal temperature. The processing gas supply pipe 81 is connected between the first gas generation source 71 and the valve V1 and between the second gas generation source 72 and the valve V2 to bypass passages 82 and 83 following the exhaust passage, respectively, to open / close valves V3 and V3. V
4 and branch off.

Next, the operation of the aging unit 6 having the above configuration will be described. First and second gas generating sources 7
Ammonia water in 1,72 is maintained at normal temperature by circulation of temperature control water. Now, bubbling of the ammonia gas is performed in the first gas generation source 71, and the ammonia water 73 of the first gas generation source 71 has already reached the saturated concentration of ammonia (about 33% by weight). It is assumed that a processing gas composed of ammonia gas (which is considered to be close to saturation) is generated and exhausted through the valve V3. At this time, the opening / closing valve V2 on the second gas generation source 72 side is closed.

Then, the wafer W is carried into the processing vessel 60 from the coating unit 4 and the processing is performed for a predetermined time. At this time, the opening / closing valve V1 on the first gas generation source 71 side is opened and the valve V3 on the exhaust side is closed, and the processing gas is supplied from the first gas generation source 71 into the processing chamber 60 (first processing gas).
Processing step).

When the amount of ammonia water in the first gas generation source 71 decreases and is supplemented with ammonia water, the second gas generation source 72 also starts bubbling ammonia gas at a predetermined timing in advance. The ammonia water 73 reaches the saturated concentration of ammonia, and the ammonia gas containing water vapor is generated. At that time, on the second gas generation source 72 side, the on-off valve V2 is kept closed, and the valve V4 to the exhaust side is opened to directly exhaust the generated gas from the second gas generation source 72 via the bypass passage 83. Escape to the road (preliminary exhaust process).

In this state, the supply of the processing gas from the first gas generation source 71 to the processing vessel 60 is stopped by closing the open valve V1 on the first gas generation source 71 side.
The closed valve V2 on the second gas generation source 72 side is opened to supply the processing gas from the second gas generation source 72 to the processing container 60. At that time, at the same time when the valves V1 and V2 are switched,
The closed valve V3 on the first gas generation source 71 side is opened to allow the gas generated by the first gas generation source 71 to escape to the exhaust path, and the second gas generation source 72 side Is closed (second processing step).

Thereafter, the first gas generating source 71 is replenished with ammonia water, and ammonia gas containing water vapor is generated from the ammonia water that has reached the saturated concentration of ammonia by bubbling of the ammonia gas. On the other hand, when the amount of ammonia water in the second gas generation source 72 decreases, and the amount of ammonia water is replenished, bubbling is performed in the first gas generation source 71 and the supply source of the processing gas is similarly set. From the second gas generation source 72 to the first gas generation source 7 again.
Switch to 1.

Here, when replenishing the first gas generating source 71 with aqueous ammonia, the second gas generating source 72 starts bubbling at the time when the first gas generating source 71 is replenished with aqueous ammonia. The timing is such that ammonia gas containing water vapor is generated in the second gas generation source 72. Such timing, the first
The timing of replenishing the ammonia water of the second gas generation sources 71 and 72 may be determined by an operator, or a water level sensor is provided for each of the gas generation sources 71 and 72, and the level of the ammonia water is determined by the sensors. The timing may be automatically detected and an appropriate timing may be determined.

The opening / closing valves V1, V2, V3, V4 may be manually switched by an operator, or a control device for controlling their switching may be provided to automatically switch at a predetermined timing. You may do so.

FIG. 4 is a schematic view of an example of a gas flow path in the aging unit 6 having the configuration shown in FIG. 3. In this example, a common gas supply source 70 supplies first and second gas generation sources 71 and 72. Is supplied with ammonia gas. As shown in FIG. 4, a conductance adjusting section P1 is provided between the valve V1 and a branch point of the processing gas supply pipe 81.
Is provided. This conductance adjustment unit P1
The purpose is to adjust the conductance from the first gas generation source 71 to the processing container 60 and the conductance from the second gas generation source 72 to the processing container 60 to be uniform. The gas flow resistance is configured to be adjustable. The conductance is adjusted so that the flow rate when the gas flows from the first gas generation source 71 and the flow rate when the gas flows from the second gas generation source 72 are the same, for example, by the flow meter 80 provided in the gas supply pipe 81. It is adjusted to be performed. Note that the conductance adjusting unit may be provided between the valve V2 and the branch point instead of the above-described position, or may be provided at both.

A conductance adjustment is also performed on a first bypass path (first exhaust path) 82 from the first gas generating source 71 to the exhaust path 65 directly via the valve V3 without passing through the processing vessel 60. A part P2 is provided. The conductance of the conductance adjustment unit P2 is changed from the first gas generation source 71 to the exhaust passage 65 via the exhaust side valve V3, the conductance adjustment unit P2, and the first bypass passage 82.
And the conductance of the entire gas flow path from the first gas generation source 71 to the processing vessel side valve V1 and the processing vessel 60.
Are set so that the conductance of the entire gas flow path that reaches the exhaust path 65 via the air passage becomes equal.

Further, from the second gas generation source 72 to the processing vessel 6
A conductance adjuster P3 is also provided in a second bypass path (second exhaust path) 83 that directly reaches the exhaust path 65 via the valve V4 without passing through the zero. The conductance of the conductance adjusting unit P3 is determined by the conductance of the entire gas flow path from the second gas generation source 72 to the exhaust path 65 via the exhaust side valve V4 and the second bypass path 83, and the second gas From the source 72 to the processing vessel side valve V
The conductance is set to be equal to the conductance of the entire gas flow path that reaches the exhaust path 65 via the processing container 2 and the processing container 60.

If the conductance of the gas flow path is adjusted in this manner, for example, a gas is flowed from the first gas generation source 71 to the bypass path 82, and the wafer is loaded into the processing vessel 60, and When the gas flow path is switched to the side 60 and when the supply source of the processing gas to the processing container 60 is switched between the first gas generation source 71 and the second gas generation source 72, Fluctuations in the flow rate and the pressure in the processing vessel 60 are suppressed. For example, if it is now switched from the first gas generation source 71 to the second gas generation source 72, the flow of gas from the first gas generation source 71 to the processing vessel 60 is stopped, and the second gas generation source 72 is stopped. From the bypass 83
Is switched to the valve V2 side. However, since the conductance of each flow path is uniform as described above, the pressure and flow rate of the gas flowing into the processing vessel 60 are:
Some variability may occur with the switching of the valves, but hardly. This means that the processing gas supply source is switched from the second gas generation source 72 to the first gas generation source 71.
The same applies when returning to.

According to the above-described embodiment, the second processing step is performed simultaneously with the first processing step of supplying the ammonia gas containing water vapor from the first gas generating source 71 into the processing container 60 to process the wafer W. When the gas generating source 72 also performs a preliminary exhausting step of generating ammonia gas containing water vapor and escaping the ammonia gas directly into the exhaust path 65 via the bypass path 83, and replenishing the first gas generating source 71 with ammonia water Processing container 60
From the first gas generation source 71 to the second
To process the wafer W by switching to the gas generation source 72 of FIG.
Is performed, the supply of the processing gas is not interrupted when the ammonia water is replenished.

According to the above-described embodiment, since the ammonia water 73 in the first and second gas generating sources 71 and 72 is always kept at the normal temperature by the temperature control water, the temperature accompanying the vaporization and absorption of ammonia is increased. Changes can be suppressed, fluctuations in the amount of generated steam can be eliminated, and the process can be stabilized. In particular, in the case of aqueous ammonia, even a slight change in temperature greatly changes the saturation concentration, so it is conceivable that the amount of gas generated may fluctuate due to temperature disturbance or the like, but according to the present embodiment, the flow rate of ammonia gas is stable. I do.

Further, when the ammonia gas is introduced after the wafer is loaded into the processing container 60, the valves V1 and V3 are switched because the conductance between the bypass path 82 and the gas flow path on the processing container 60 is uniform. At this time, the ammonia gas is introduced at a predetermined pressure and flow rate from the beginning, and the pressure and flow rate of the ammonia gas hardly change even when the first and second gas generation sources 71 and 72 are switched. Can be stably performed, and as a result, a change in the film thickness and film quality of the coating film is suppressed, and uniform processing is performed between wafers. In addition, since the ammonia water can be replenished without interrupting the process, the operation of the apparatus does not have to be stopped each time the ammonia water is replenished, and a decrease in throughput can be prevented.

In the above, the present invention can be modified in various ways. For example, the constant temperature means 77 surrounds the tank 74 of the first gas generating source 71 and the second gas generating source 72 with a resistance heater or the like. By using a throw-in type heater, the ammonia water 73 in the tank 74 may be maintained at room temperature, or the valves V1 and V2 may be replaced by a single three-way valve.

In the present invention, as shown in FIG. 5, a single gas generating source 79 for generating an ammonia gas saturated with water vapor may be connected to the processing vessel 60. The gas generation source 79 is the first gas generation source 71 shown in FIG.
Alternatively, it may be configured similarly to the second gas generation source 72. In this example, an opening / closing valve V is provided in the middle of a processing gas supply pipe 81 that connects and connects the gas generation source 79 and the processing container 60.
5 are provided. A bypass 84 is provided between the valve V5 and the gas generating source 79 in a branched manner. The bypass 84 is connected to the on-off valve V6 and the conductance adjusting section P.
4 and connected to the exhaust path 65. The conductance of the flow path passing through the processing vessel 60 and the conductance of the flow path passing through the bypass path 84 are equalized by the conductance adjusting unit P4.

According to the example shown in FIG. 5, after the ammonia water is replenished, a preliminary exhaust step of directly escaping to the exhaust path 65 via the bypass 84 until the concentration of the ammonia water is stabilized at a predetermined concentration is performed. When the flow path is switched to the processing container 60 side, the conductance of the flow path before and after the switching is uniform, so that the ammonia gas can be supplied into the processing container 60 at a predetermined flow rate from the beginning, and therefore, a stable gel is obtained. Or processing can be performed. Stable valve V
5 and V6 are switched to an open state and a closed state, respectively, to supply the ammonia gas saturated with water vapor into the processing container 60 to perform the processing step of processing the wafer W. Gas can be introduced. Further, by controlling the temperature of the ammonia water of the gas generating source 79 and the conductance of the gas flow path, the processing temperature, the flow rate of the processing gas, and the pressure in the processing chamber 60 can be kept constant. As a result, variations in film quality between wafers can be suppressed.

The object to be processed is not limited to a wafer, but may be a glass substrate for a liquid crystal display. Further, the present invention is not limited to the case where the gelation treatment is performed with ammonia gas, and the processing gas is exhausted from the bypass path, and after the object to be processed is loaded into the processing vessel, the processing vessel side from the bypass path. The present invention can be applied to a device for introducing a processing gas by switching a flow path during the process.

[0037]

As described above, according to the present invention, when performing gelation of a coating film using ammonia gas,
Stable processing can be performed, and uniform processing can be performed between the objects to be processed.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an entire configuration of an example of a coating film forming apparatus used for carrying out a method of the present invention.

FIG. 2 is an explanatory diagram illustrating a flow of a coating film forming process using the coating film forming apparatus.

FIG. 3 is a schematic view of an example of an aging unit in the coating film forming apparatus.

FIG. 4 is a schematic view of an example of a gas flow path in the aging unit shown in FIG.

FIG. 5 is a schematic view of another example of the gas flow path in the aging unit.

FIG. 6 is an explanatory diagram showing a state of denaturation of a coating film in a sol-gel method.

FIG. 7 is a schematic view of a conventional aging unit.

[Explanation of symbols]

 W wafer 4 coating unit 5 solvent replacement unit 6 aging unit 60 processing container 61 mounting table 62 seal member 63 lid 64 gas introduction port 65 exhaust path 66 drive source 67 elevating pins V1, V2, V3, V4, V5, V6 open / close valve 71 , 72, 79 Gas generating source 73 Ammonia water 74 Tank 75 Bubbling gas supply pipe 76 Exhaust port 77 Constant temperature means 78 Piping 81 Processing gas supply pipe 82, 83, 84 Bypass path P1, P2, P3, P4 Conductance adjuster

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasunari Katayama 2655 Tsukudaga, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Inside the Kumamoto Office of Tokyo Electron Kyushu Co., Ltd. 2655 Hisadaki Tokyo Electron Kyushu Co., Ltd. Kumamoto Office (72) Inventor Yoji Mizutani 5-6-6 Akasaka, Minato-ku, Tokyo Tokyo Electron Co., Ltd. (58) Fields surveyed (Int. Cl. ⁷ , (DB name) H01L 21/31 H01L 21/316 H01L 21/768

Claims (3)

(57) [Claims] An object to which a coating liquid in which particles or colloids of a starting material of a film forming component are dispersed in a solvent is applied on the surface thereof is gelled with ammonia gas in the coating film. Carrying out the object to be processed into a processing container, and then bubbling the first container in which ammonia water having a concentration of ammonia lower than the saturation concentration is stored with ammonia gas to remove water. A first processing step of generating ammonia gas containing steam and supplying the ammonia gas into the processing container; and an ammonia gas containing ammonia water having a concentration of ammonia lower than the saturation concentration is stored in the second container. Bubbling to generate ammonia gas containing water vapor,
Exhausting the ammonia gas without passing through the processing container; and thereafter, switching a gas flow path from the first container to the processing container to a gas flow path from the second container to the processing container. A second processing step of supplying ammonia gas generated from the second vessel into the processing vessel, and thereafter, a step of replenishing the ammonia water in the first vessel. Method. 2. An object to be coated on which a coating liquid in which particles or colloid of a film forming component starting material are dispersed in a solvent is coated on the surface, the particles or colloid in the coating film is gelled with ammonia gas. In the method, ammonia gas is bubbled in a first container in which ammonia water having a concentration of ammonia lower than a saturation concentration is stored to generate ammonia gas containing water vapor,
Exhausting the ammonia gas through a first exhaust path without passing through the processing container; loading the object to be processed into the processing container; and setting a flow path of the ammonia gas generated from the first container. A first processing step of switching from the first exhaust path to the processing vessel side and supplying ammonia gas into the processing vessel; and, while the first processing step is being performed, the ammonia concentration is increased to the saturation concentration. Ammonia gas containing water vapor is generated by bubbling the inside of the second container in which the lower ammonia water is stored with ammonia gas, and the ammonia gas is exhausted through the second exhaust passage without passing through the processing container. And then switching the gas flow path from the first container to the processing container to the gas flow path from the second container to the processing container and closing the second exhaust path, And supplying ammonia gas generated from the second container into the processing container.
A gas treatment method comprising the steps of: (a) refilling the first container with the ammonia water. 3. The conductance of the flow path when gas flows from the first container via the processing container, the conductance of the flow path when gas flows from the first container through the first exhaust path, and the second conductance. The conductance of the flow path when gas flows from the container via the processing container, and the conductance of the flow path when gas flows from the second container through the second exhaust path are made uniform. 3. The gas processing method according to 2.